Frontiers of Silica Research 2019 April 23-24 (lunch-to-lunch)

Organized by Chalmers University of Technology

and Nouryon (formerly AkzoNobel PPC)

Venue: Lecture hall KE in Chemistry building (Kemigården 4)

Chalmers University of Technology, Gothenburg, Sweden

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Welcome to Frontiers of Silica Research 2019

A silica symposium organized by Chalmers University of Technology and Nouryon, held April

23-24, 2019 (lunch-to-lunch), with focus on recent and future research within the field of silica

chemistry.

The venue is lecture hall KE in Chemical and Biological Engineering building, Chalmers

University of Technology, Gothenburg, Sweden.

The purpose of the symposium is for researchers from academia, as well as from industry, to

meet and discuss the field of silica. We hope that by this initiative, the field will nourish and

grow.

Warm regards,

The organizing committee

Krister Holmberg, Aleksandar Matic, Magnus Nydén and Michael Persson

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Content Program ................................................................................................................................................... 4

Abstracts – Oral presentations ................................................................................................................. 6

Abstracts – Posters ................................................................................................................................ 20

List of participants ................................................................................................................................. 35

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Program

Tuesday April 23, 2019

12:00-12:50 Registration and lunch

13:00-15:15 Session 1, chairman: Maria Abrahamsson, Chalmers University of

Technology

13:00-13:10 Welcome, Maria Abrahamsson, Chalmers University of Technology,

Lars Andersson, Nouryon

13:10-13:45 Bioinspired silica formation

Nico Sommerdijk, Eindhoven University of Technology, Eindhoven,

the Netherlands

13:45-14:20 The marine silicon cycle: The production and fate of the four cubic

kilometers of opal produced by marine diatoms each year

Mark Brzezinski, University of California, Santa Barbara CA, USA

14:20-14:40 Investigations into the mechanism of diatom biosilicification under in

vitro conditions

Sai Prakash Maddala, Eindhoven University of Technology,

Eindhoven, the Netherlands

14:40-15:15 Zeolites as catalysts for emission control applications

Hanna Härelind, Chalmers University of Technology, Göteborg,

Sweden

15:15-15:45 Coffee break

15:45-17:15 Session 2, chairman Krister Holmberg, Chalmers

15:45-16:20 Understanding surface hydration and dissolution of silica and silicates

at the nanoscale

Brad Chmelka, University of California, Santa Barbara CA, USA

16:20-16:55 Hybrid nano-composites based on silica nanoparticles for the

consolidation of earthen masonry

Piero Baglioni, CSGI and University of Florence, Sesto Fiorentino, Italy

16:55-17:15 Growth and functionalization of particle based mesoporous silica films

and their usage in catalysis

Emma Björk, Linköping University, Linköping, Sweden

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17:15-17:45 Brief oral presentations of the posters

17:45-18:45 Poster session

19:00 Symposium dinner

Wednesday 24 April, 2019

09:00-10:30 Session 3, chairman: Michael Persson, Nouryon and Chalmers

09:00-09:35 Influence of the protein corona on in vitro targetability and

biodistribution of mesoporous silica nanoparticles

Mika Lindén, Ulm University, Germany

09:35-10.10 Safety assessment of engineered nanomaterials: focus on

inflammatory effects of metals/metal oxides

Bengt Fadeel, Karolinska Institutet, Stockholm, Sweden

10:10-10:30 Functionalized silica particles showing clouding behavior provide

controllable phase inversion in Pickering emulsion systems

Sanna Björkegren, Chalmers University of Technology, Göteborg,

Sweden and Nouryon, Bohus, Sweden

10:30-11:00 Coffee break

11:00-12:35 Session 4, chairman: Magnus Nydén, Nouryon

11:00-11:35 Nanoporous silica for energy applications

Anna Martinelli, Chalmers University of Technology, Göteborg,

Sweden

11:35-11:55 Silica nanoparticles to stabilize CO2-foam for efficient CCUS in

challenging reservoirs

Martin Fernö, University of Bergen, Bergen, Norway

11:55-12:30 Synthesis routes for hierarchical structuring of silica from atomic to

meter scale

Anders Palmqvist, Chalmers University of Technology, Göteborg,

Sweden

12:30-12:35 Concluding remarks, Magnus Nydén, Nouryon

12:40 Lunch

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Abstracts – Oral presentations

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The multiscale assembly of hierarchical silica-based materials

Nico A.J.M. Sommerdijk

Laboratory of Materials and interface Chemistry & Center of Multiscale Electron Microscopy Department of

Chemical Engineering and Chemistry

And

Institute of Complex Molecular Systems

Eindhoven University of Technology, Eindhoven, NL

Inspired by the high complexity and functionality achieved in biological systems we pursue the

use of self-assembly and biomimetic mineralization to generate hierarchically structured silica

based materials.1 To control the formation of these structures it is of importance to understand

the interactions between the different building blocks from the nanoscopic to the mesoscopic

level.

In my lecture I will present our strategy to control silica formation at the nanoscopic level to

prepare well defined particles that subsequently can be assembled in to higher hierarchical

structures that ultimately form the basis for materials with predesigned pore structure. We

illustrate how we use various electron microscopy methods to visualize the evolution of

morphology and structure in solution and in the solid state from the (sub)nanometer level up to

the micrometer level.2 We use time resolved cryoelectron microscopy to visualize solution

structures in their native hydrated state3, 4 and 3D FIB/SEM to visualize the internal structure

of the final products. The results of the imaging are compared with computer simulations for a

more comprehensive understanding of the process.

Together these examples will show the power of advanced as a tool to monitor the development

of morphology and structure in hybrid and mesostructured silicas.

References

1. F. Nudelman and N. A. J. M. Sommerdijk, Angewandte Chemie-International Edition, 2012, 51, 6582-

6596.

2. H. Friedrich, P. M. Frederik, G. de With and N. Sommerdijk, Angewandte Chemie-International

Edition, 2010, 49, 7850-7858.

3. C. C. M. C. Carcouet, M. W. P. van de Put, B. Mezari, P. C. M. M. Magusin, J. Laven, P. H. H.

Bomans, H. Friedrich, A. C. C. Esteves, N. A. J. M. Sommerdijk, R. A. T. M. van Benthem and G. de

With, Nano Letters, 2014, 14, 1433-1438.

4. M. W. P. van de Put, J. P. Patterson, P. H. H. Bomans, N. R. Wilson, H. Friedrich, R. A. T. M. van

Benthem, G. de With, R. K. O'Reilly and N. A. J. M. Sommerdijk, Soft Matter, 2015, 11, 1265-1270.

8

The marine silicon cycle: The production and fate of the four

cubic kilometres of opal produced by marine diatoms each year

Mark Brzezinski

Marine Science Institute, University of California, Santa Barbara CA, 93106)

Keywords: diatoms, silicon, biomineralization, biogeochemistry, climate

Diatoms are unicellular photoautorophs that create ornately sculpted cell walls of amorphous

silica. Their ability to control the hierarchical ordering of silica at the nanoscale under benign

environmental conditions holds great potential for diatom-inspired nanomaterials. Diatoms are

also of enormous environmental importance. Ecologically they form the base of the food web

for some of the world’s most productive fisheries. They account for about 20% of

photosynthesis on Earth making their global impact on global net primary production greater

than that of all tropical rain forests. Diatom absolutely require silicon to grow making the

availability of silicon a key factor controlling their ecological and biogeochemical contribution.

In this talk we will explore the diatom need for silicon from a variety of perspectives and scales.

We will review recent advances in our understanding of the biochemistry and molecular basis

of diatom biomineralization. We will then extent this knowledge into the environment to

explore how the feedbacks between diatom silicon demand, ocean circulation and ocean

chemistry set the silicon content of the ocean and the contribution of diatoms to marine

foodwebs and global biogeochemical cycles. A dominant factor is the Southern Ocean silicon

trap around Antarctica. This unique biogeochemical feature retains dissolved silicon in the

waters around Antarctica denying dissolved silicon to diatoms in the low latitude ocean.

Maintenance of the trap and its impact on climate will be reviewed along with the global

consequences of springing the trap as appears to have occurred in the geologic past.

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Investigations Into The Mechanism Of Diatom Biosilicification

Under In Vitro Conditions

Sai Prakash Maddala1*, Paula Vena1, Ernst Van Eck2, Paul Bomans1, Mohammad Soleimani1,

Heiner Friedrich1, Rolf van Benthem1,2 and Nico Sommerdijk1*

1. Department of Chemical Engineering and Chemistry, Eindhoven University of Technology; 2.

Faculty of Science, Radboud University; 3. DSM, Netherlands

*Email: s.p.maddala@tue.nl and n.sommerdijk@tue.nl

Keywords: Silica, biomimetic, diatoms, polyamines, solid-state NMR

Siliceous exoskeletons, frustules, of diatoms are well known for their excellent mechanical and

optical properties. They also possess intricate organization and high degree of silica

crosslinking, whilst requiring only ambient synthesis conditions. Understanding the

mechanisms involved in the morphological control of biosilica could inspire the production of

new functional materials. According to currently accepted models, diatom biosilica formation

broadly takes place in two stages viz., silica accumulation and storage (in the silica deposition

vesicle) and morphology control of silica.1 Diatoms accumulate orthosilicic acid from the

ocean and store it in their silica deposition vesicles. The concentration of silicon in sea water is

around 0.5 mM and it can reach between 100 to 340 mM in marine diatoms.

Here, we present results from our in vitro investigations into biomineralization of silica. We

mimicked the conditions present in the silica deposition vesicle (SDV) of diatoms; high silicic

acid concentration (250 mM), salinity, the presence of polyamines and mildly acidic pH (pH

5.5). Metastable silicic acid solutions were used as the precursor for silica synthesis. The

reaction were carried out using auto-titrator at pH 5.5 in presence of NaCl solutions (337.5

mM). Polyallylamine (PAH) and Polyethylenimine (PEI) were used as polyamine mimics.

Orthosilicic acid consumption during the reaction was monitored using ammonium molybdate

assay. While the presence of polyamines (PAH) did not affect orthosilicic acid consumption

rate in salt solution, 29Si SSNMR analysis revealed that they reduced the crosslinking of silica

from Q4/Q3 ratio of 3.7 (for silica produced without polyamines), to 1.59. 2D HETCOR NMR

results showed that the ammonium group of PAH was strongly correlated with the Q3 silica

species, suggesting that there might be an ionic interaction between the acidic silanol group and

the polyamine. The incorporation of PEI similarly reduced the Q4/Q3 ratio of silica produced

in water from 2.06 to 1.33. DLS and cryo-TEM measurements revealed that the orthosilicic

acid molecules undergo condensation to form 3 to 4 nm particles, which likely combine to form

the gel. In the SDV, the polyamines have been suggested to aid in the accumulation and storage

of silica in condensed pools, the mechanism of which is poorly understood, and our results help

shed some light on the process.

References

1. N. Kroger and N. Poulsen, Annual Rev. Genet., 42, 83-107 (2008).

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Zeolites as catalysts for emission control applications

Hanna Härelind

Applied Chemistry and Competence Centre for Catalysis, Dept. Chemistry and Chemical Engineering,

Chalmers University of Technology, SE-41296 Göteborg, Sweden

Keywords: lean NOx reduction, ammonia-SCR, zeolites, Cu ion-exchange, SSZ-13

In all combustion processes nitrogen oxides, which are harmful to human health (e.g. lung

diseases) and to the environment (e.g. acidification and eutrophication), are formed. During the

past 50 years catalysts have been used in end-of-pipe solutions to convert pollutants to less

harmful products. Selective catalytic reduction of NOx with ammonia dates back to the 1970th

when it was used to reduce nitrogen oxides in oxygen rich pollution streams from e.g. power

plants. More recently, the same technique has been implemented for NOx reduction for mobile

applications, like diesel- and lean-burn engines.

The catalytic system originally used for this purpose was based on vanadia-titania, for which

the NOx conversion is very efficient. As vanadia is volatile and harmful to the environment

other catalytic materials are desired. Zeolites have been extensively studied for this reaction

showing high catalytic activity and selectivity, however, one draw-back with these systems is

their low hydrothermal stability. More recently, small-pore zeolites (CHA-structure with pore

sizes of 3Å) have been studied for these types of reactions showing high activity/selectivity as

well as good hydrothermal stability.

This work presents an overview of selective catalytic reduction of NOx with ammonia,

including some recent results for copper-exchanged small-pore zeolites (Figure 1), which is the

most promising catalytic system for lean NOx reduction for mobile sources at present.

Figure 1. NH3-SCR enhances the introduction of Cu into the small pores of zeolite SSZ-13.

11

Understanding surface hydration and dissolution of silica and

silicates at the nanoscale

Brad Chmelka, Nathan Prisco, Howard Dobbs, and Jacob Israelachvili

Department of Chemical Engineering, University of California, Santa Barbara, U.S.A.

Keywords: surface properties, hydration, dissolution, nuclear magnetic resonance,

surface forces

The surface compositions and structures of silica and silicate particles in aqueous mixtures

strongly influence their reaction properties with respect to hydration, dissolution, and also

crystallization. Such properties and processes have been challenging to characterize and control,

due to the heterogeneous, multicomponent, and non-equilibrium natures of the solid-liquid

mixtures, which are furthermore exacerbated by the poor long-range order and intrinsically

dilute quantities of surface species. Nevertheless, new insights can obtained from powerful

analytical methods, such as solid-state NMR spectroscopy and the Surfaces Forces Apparatus

(SFA), which provide detailed information on the compositions and structures near particle

surfaces at nanoscale dimensions. Specifically, dynamic nuclear polarization (DNP)-enhanced

NMR analyses enable the compositions of adsorbed species or hydration layers on silica and

silicate particle surfaces to be determined for industrially relevant materials and conditions.

SFA analyses yield complementary quantitative understanding of the solution properties near

silica interfaces that influence adsorption properties and the rates of hydration or dissolution.

The resulting insights suggest opportunities for manipulating hydration and dissolution

processes that are important in diverse technological applications, including the development

of mechanical strength in cementious materials, syntheses of heterogeneous catalysts, and

chemical-mechanical polishing of semiconductor surfaces.

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Hybrid nano-composites based on silica nanoparticles for the

consolidation of earthen masonry

Piero Baglioni,, Rachel Camerini, Rodorico Giorgi, David Chelazzi

aCSGI and Department of Chemistry, University of Florence, via della Lastruccia 3-50019,

Sesto Fiorentino, Italy

Abstract

Earth is one of the oldest silicate-based materials of stone heritage, still largely used in

architecture worldwide. Earthen materials are highly susceptible to wind and water erosion,

leading to loss of cohesion and crumbling. Conventional consolidants (alkoxysilanes, synthetic

or natural polymers) lack physico-chemical compatibility or effectiveness, and can promote

degradation. Nano-composites for the surface consolidation of adobe, i.e. unbaked earth bricks

often containing organic fibers and lime, are for the first time proposed. We investigated,

mimicking the setting of portland cement, the formation of calcium silicate hydrate (CSH)

within adobe porosities, owing to the pozzolanic reaction between nanoparticles of silica and

calcium hydroxide, to consolidate a powdery substrate. Different formulations were

characterized by Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD),

scanning and transmission electron microscopy (SEM, TEM), dynamic light scattering (DLS)

and turbidimetry (UV-Vis spectroscopy). A ternary composite made of SiO2 nanoparticles,

Ca(OH)2 nanoparticles, and hydroxypropyl cellulose, dispersed in a (4:1) ethanol:water blend,

was formulated. Each component is compatible with adobe, and plays a role in its consolidation.

The treatment of adobe samples with the composite leads to the in situ formation of CSH,

providing resistance to peeling, abrasion, and wet-dry cycles, with no aesthetic alteration. This

open new perpective in the preservation of one of the largest used material by humankind.

13

Growth and functionalization of particle based mesoporous silica

films and their usage in catalysis

Pei-Hsuan Wu, Peter Mäkie, Magnus Odén and Emma M. Björk

Nanostructured Materials, Dept. of Physics, Chemistry and Biology, Linköping University, 581 83 Linköping,

Sweden

Mesoporous silica, Mesoporous films, Direct growth, Formation, Catalysis

Mesoporous films with easily accessible pores can be used as e.g. catalyst hosts, sensors, or

drug delivery system. We report the formation of particle based mesoporous films consisting

of SBA-15 particles grown directly onto substrates. The cylindrical pores are oriented parallel

to the substrate surface [1], and the film thickness was altered between 80 nm and 750 nm by

adding NH4F to the synthesis solution. However, the NH4F also affects the formation rate of

the materials [2], and the time for adding substrates to the synthesis solution must be optimized

for a successful film growth (Figure 1). It was observed that the substrate must be added during

the formation of the siliceous network. At this time the micelles can interact with the substrate

and act as nucleation sites for the film particles. Various substrate functionalizations were

studied and we conclude that hydrophobic substrates are required for growing films with

densely packed particles. The synthesis method enables homogenous film growth on rough, 3D

substrates, as well as large surfaces (> 75 cm2).

Figure 1. SEM micrographs of films synthesized with two different NH4F concentrations, and an

illustration of the correlation between the substrate addition time and the material formation stage.

The films could be functionalized with sulfonic acid groups using co-condensation of MPTMS

and H2O2. It was observed that the addition time of the functional group is crucial in order to

form the desired film with a large number of functional groups. The films were also

functionalized with a thin carbon layer through exposure to furfuryl alcohol fumes, resulting in

a ~2 Å thick carbon coating of the pore walls. The carbon/silica hybrid films were sulfonated

using H2SO4 and used as a catalyst in the esterification of acetic acid and ethanol. The

conversion of acetic acid after 1 h was ~30 % with the catalyst and ~5 % without. The film

synthesis technique yields films with chemical variability that can be grown on large and 3D

substrates, which is attractive in many applications. As an outlook, one can imagine films grown

on other types of substrates, e.g. titania or flexible polymers.

[1] E.M. Björk, F. Söderlind, and M. Odén J. Colloid Interface Sci. 413 (2014) 1-7

[2] E.M. Björk, P. Mäkie, L. Rogström, et al. J. Colloid Interface Sci. 521 (2018) 183-189

14

Influence of the protein corona on in vitro targetability and

biodistribution of mesoporous silica nanoparticles

Mika Lindén

Inorganic Chemistry II, Ulm University, Albert-Einstein-Allee 11, Ulm 89075, Germany

Keywords: Cellular targeting, protein adsorption, biodistribution, MSNs

Adsorption of serum proteins on nanoparticles occurs instantaneously upon exposure of the

nanoparticles to the biological medium. The extent of protein adsorption and the composition

of the so-called protein corona is believed to largely influence both active targeting outcomes,

and also the biodistribution and blood circulation time of the particles. It is widely assumed that

the protein adsorption has to be minimized in order to both ensure successful active targeting

and a long blood half-life of nanoparticles. Recent studies challenge this view. For example, it

has recently been suggested that the adsorption of clusterin to nanoparticles would be a pre-

requisite for nanoparticle stealth properties.1 The first part of the presentation will focus on the

influence of protein adsorption on the targetability of antibody-functionalized mesoporous

silica nanoparticles (MSNs) to acute myeloid leukemia stem cells in vitro. It is shown that

protein adsorption indeed can enhance the cellular specificity of such particles in vitro, further

giving support for an active, and positive, influence of specific proteins adsorbed onto

nanoparticles when it comes to their bioresponse. Furthermore, the heterogeneity of the protein

corona in terms of particle-particle variations will be discussed based on STORM microscopy

studies using fluorescently labelled proteins. It is shown that the particle-particle variations are

large, and that they evolve with time in a manner which is strongly dependent on the surface

chemistry of the MSNs, adding more details to the complexity when it comes to linking the

composition of the protein corona to the bioresponse of nanoparticles in general. The second

part of the presentation will be focused on the biodistribution of intravenously injected,

PEGylated MSNs as compared to non-PEGylated particles, with special focus on organ

accumulation versus blood residence times of the particles, as studied by 89Zr-PET in mice. The

results highlight the need for a careful, parallel analysis of the concentration of nanoparticles in

the blood before attempting to link nanoparticle concentrations measured using homogenized

organs to “nanoparticle accumulation” in specific organs.

1 S. Schöttler, G. Becker, S. Winzen, T. Steinbach, K. Mohr, K. Landfester, V. Mailänder, F.R. Wurm, Nature

Nanotech. 11 (2016) 372-377.

15

Safety assessment of engineered nanomaterials: focus on

inflammatory effects of metal/metal oxides

Bengt Fadeel

Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm,

Sweden

The increasing production and use of engineered nanomaterials (ENMs) has led to concerns

about their potential adverse effects on human health. Interactions of ENMs with immune cells

are of particular importance as the immune system represents the first line of cellular defense

against foreign intrusion – microorganisms as well as particles. Metal and metal oxide

nanoparticles have been the subject of intensive toxicological investigations in recent years.

However, a detailed understanding of the mechanism(s) of toxicity is still lacking. Systems

biology approaches to elucidate perturbations of genes or proteins are being applied in

nano(eco)toxicological research and may enable the development of predictive models of ENM

toxicity. Our laboratory has been engaged in several European Commission funded nanosafety

projects in recent years including FP7-NANOMMUNE, FP7-MARINA, FP7-NANOREG,

FP7-SUN, and FP7-NANOSOLUTIONS, as well as the national project MISTRA

Environmental Nanosafety, and we have investigated a large number of ENMs including metal

and metal oxide nanoparticles with emphasis on inflammation. In the present lecture some

lessons learned in these nanosafety projects will be discussed. Careful engineering of

nanomaterials is needed to mitigate the potential toxicity of the material while retaining its

useful properties. This is, in essence, the meaning of safe-by-design. I will also discuss recent

studies on silica nanoparticles demonstrating that purposeful surface modification of ultra-small

silica particles can significantly reduce their toxicity.

Further reading:

Fadeel B. Systems biology in nanosafety research. Nanomedicine (Lond). 2015;10(7):1039-41

[editorial].

Fadeel B. Hide and seek: nanomaterial interactions with the immune system. Front Immunol.

2019;10:133.

16

Functionalised silica particles showing clouding behaviour

provide controllable phase inversion in Pickering emulsion

systems

Sanna Björkegren *,**, Kristina Lundahl **, Lars Nordstierna *, Andreas Sundblom ** and

Anders Palmqvist *

* Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96

Göteborg, Sweden, ** Nouryon, SE-445 80 Bohus, Sweden

Keywords: Surface-functionalized silica sol, cloud points, particle-stabilized emulsions

Understanding, and controlling, the phase

behaviour of particle-stabilized (Pickering)

emulsion systems can expand, and facilitate, the

use of these surfactant-free emulsions in

industrial applications. By surface function-

alization with methyl poly(ethylene) glycol

(mPEG) silane we are able to provide silica

particles with clouding behaviour (Figure 1).

By attaching an additional hydrophobic group, such as a propyl silane, to the particle surface,

we find that the heterogeneously modified particles, functionalized with both propyl and mPEG

silanes, become useful as emulsion stabilizers. By exploiting the increasing hydrophobicity

exhibited by PEG-chains at increasing temperature, phase inversion is achieved, where an

inversion from o/w to w/o is observed at elevated temperatures (Figure 2). The phase inversion

temperature (PIT) is affected by the pH and salt concentration, due to interparticle and

intramolecular effects, as well as PEG-silica interactions.

Figure 1. Silica particles functionalized with mPEG silane

display reversible clouding upon increasing temperature.

Figure 2. Pickering emulsions, with butanol as oil phase, stabilized by silica particles functionalized with propyl

and mPEG silane, undergo phase inversion upon increasing the temperature during homogenization. Left:

Conductivity of the emulsion system, as a function of emulsion temperature. When the system is cooled while still

homogenizing, the emulsion switches back to the initial state, o/w, with a hysteresis effect ∆T. Right: Microscope

images of butanol emulsions. Depending on pH, salt concentration and heating conditions, different systems are

obtained.

Stable o/w emulsion

Unstable system, at the

border of inversion

17

Nanoporous silica for energy applications

Anna Martinelli and Szilvia Vavra

Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Gothenburg,

Sweden

Keywords: Nanoporous silica, protic ionic liquids, ionic mobility

The motion of protons decoupled from molecular diffusion is a desired property of materials

for use in e.g. fuel cells. Particularly challenging is the achievement of such a selective motion

in solid-state nanoporous materials. In this scientific context very relevant materials are

crystalline covalent organic frameworks and ordered mesoporous silica, impregnated with a

suitable proton conducting substance.1 In this contribution, we present some recent and

significant progresses that we have done, based on the design of protic ionic liquid (PIL)

structures able to simultaneously self-assemble and assist a selective protonic motion decoupled

from ionic diffusion.2 We demonstrate that a selective proton mobility is achieved upon addition

of imidazole to the PIL, with enhancements observed in long-chained cations and inside alkyl-

functionalized nanopores.3 These dynamical phenomena are discussed in terms of local

structure and inter-molecular interactions, as probed by 2D and variable temperature solid-state 1H NMR spectroscopy, vibrational spectroscopy and wide-angle X-ray (WAXS) scattering

experiments. The effect of pore size is also addressed and discussed.

References

1. H. Xu, S. Tao and D. Jiang. Proton conduction in crystalline and porous covalent organic frameworks, Nature

Materials – Letters 15, 722–727 (2016).

2. N. Yaghini, V. Gómez-González, L.M. Varela and A. Martinelli. Structural origin of the proton mobility in

a protic ionic liquid/imidazole mixture. Insights from computational and experimental results, Phys Chem

Chem Phys 18(33), 23195–23206 (2016).

3. M. N. Garaga, V. Dracopoulos, U. Werner-Zwanziger, J. Zwanziger, M. Maréchal, M. Persson, L.

Nordstierna, A. Martinelli. A long-chain protic ionic liquid inside silica nanopores: enhanced proton mobility

due to efficient self-assembly and decoupled proton transport, Nanoscale 10(26), 12337–12348 (2018) (front

cover).

18

Silica Nanoparticles to Stabilize CO2-foam for Efficient CCUS in

Challenging Reservoirs

Martin Fernø, Øyvind Eide, Tore L. Føyen, Zachary Alcorn and Jarand Gauteplass

Department of Physics and Technology, University of Bergen

Nanoparticles, CO2, CCUS, foam

The Intergovernmental Panel on Climate Change (IPCC) have pointed to carbon capture and

storage (CCS) as an important contributing factor to reduce the amount of CO2 released to the

atmosphere and achieve the 1.5 C goal. Modelling has shown that can CCS be achieved quite

cost effectively, however that relies on policy incentives to be economically and business case

feasible [1]. To reduce the amount of anthropogenic CO2 released to the atmosphere while at

the same time ensuring a sufficient energy supply, using CO2 as a commodity during oil

production could be an important stepping stone toward pure CO2 storage projects. Carbon

capture, utilization and storage (CCUS) could help overcome many of the technical challenges

facing CCS by providing an economic incentive to store CO2. While CO2 has many beneficial

properties for oil recovery, including a low miscibility pressure and relatively high density, one

key challenge during CO2 enhanced oil recovery (EOR) is the low viscosity of CO2. Low

viscosity causes CO2 to bypass large quantities of oil, resulting in an inefficient displacement

in heterogeneous reservoirs. Using foam for mobility control can remedy this problem, however

traditional surfactant-based foam is often unstable in the presence of oil and in challenging

conditions such as high temperature and high salinity. Silica nanoparticles on the other hand

are proving to be more stable in the presence of oil. Silica nanoparticles also has beneficial

properties at high salinity and temperature, though especially divalent ions can cause the

particles to aggregate, a process accelerated by elevated temperature. We show results from

laboratory experiments assessing silica nanoparticle-stabilized foam, retention, potential for

CO2 EOR, and stability in challenging environments. Challenging environments is in this

context pressure of 9 MPa, temperature of 120 °C and total dissolved solids (TDS) up to 25

wt.%, with a high concentration of divalent ions. The results show that silica nanoparticles is a

viable foam stabilizer, with a lower foam generation rate compared with surfactant-based foam

but increased stability. At low pH values the silica nanoparticles were stable in high salinity

brine, however divalent ions at high temperature proved challenging causing the nanoparticles

to aggregate when dissolved in high divalent ion concentration brines over longer periods of

time. The nanoparticles had lower retention values than tested surfactants in sandstone rock

samples, an important parameter for large scale applications of CO2 foam.

[1] T. S. H. de Coninck, A. Revi, M. Babiker, P. Bertoldi, M. Buckeridge, A. Cartwright, W. Dong, J. Ford, S. Fuss, JC.

Hourcade, D. Ley, R. Mechler, P. Newman, A. Revokatova, S. Schultz, L. Steg, “Strengthening and Implementing the

Global Response,” in Global warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C

above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the

global response to the threat of climate change, 2018.

19

Synthesis routes for hierarchical structuring of silica from atomic

to meter scale

Anders E.C. Palmqvist

Chalmers University of Technology, SE-412 96 Gothenburg, Sweden

Keywords colloidal zeolites and mesoporous silica, controlled aggregation, spray coating

Zeolites are atomically defined, microporous (< 2 nm) and crystalline aluminosilicate

frameworks, whose structure results from the synthesis composition and conditions, and

structure directing agent employed. In zeolites, the site occupancy of aluminium atoms within

a specific zeolite framework can be directed by judicious selection of counter cations during

the synthesis of the zeolite. This allows for improvements in properties such as, e.g.

hydrothermal stability of the zeolite needed for certain catalytic applications. To improve the

processability and volumetric efficiency of zeolites it is desirable to prepare relatively small (<

1 µm) and colloidally stable particles. Colloidal zeolites can be formed from highly alkaline

synthesis solutions, in which the alkalinity is mainly provided by tetraalkylammonium

hydroxides rather than alkali metal hydroxides, which tend to cause gelation and loss of

colloidal stability. The synthesis of colloidal zeolites offers great possibilities to influence the

nucleation and growth processes and thereby affect the final particle size of the formed zeolite.

Mesoporous (2-50 nm) silica typically forms by aggregation of silica oligomers under alkaline

or acidic conditions in the presence of surface-active molecules such as block copolymers,

which form supramolecular aggregates acting as templates or structure directing agents during

the formation of mesostructured silica. The formation process is sensitive to the interaction

between silica species and the surface-active molecules, which provides opportunities to affect

the formation rate of the mesostructured particle and thereby their final size. By careful

selection of the silica speciation of the precursor solution used, it is possible to control the final

particle size of the mesostructured particles and to prepare colloidal mesostructured silica

suspensions.

Recently, we found it possible to controllably aggregate colloidal zeolites into macroscopic

(1 - 10 µm) sized mesoporous particles using an emulsion-based method and creating a particle

with a tuneable bimodal porosity from the combination of the micro- and mesopores from the

zeolite and the inter-zeolite space, respectively. In another approach we have developed a spray

coating procedure to coat ordered mesoporous oxides on large surfaces using an airbrush and a

precursor solution consisting of a microemulsion. The method is scalable and can be applied

on meter long and macroscopically structured surfaces. By combining these approaches, it is in

principle possible to achieve structural control of silica from the atomic to the meter scale.

20

Abstracts – Posters

1. Study of parameters affecting spatial location of particles during film forming process

of silica-polymer dispersions – Romain Bordes

2. Regenerated films from silicon dioxide nanoparticles and cellulose dissolved in

lithium hydroxide-urea – Ran Duan

3. Intraparticle Diffusivity of Mesoporous Silica Microspheres using Multiscale Electron

Tomography and Lattice Boltzmann Simulations – Remco Fijneman

4. A silica based nano-mesoporous material, the relation between structure and efficiency

– Farnaz Ghajeri

5. Silane modified colloidal silica as performance enhancer of acrylic elastomeric cool

roof coatings – Peter Greenwood

6. Lighting up the enzyme immobilization – Gerard Masdeu

7. The critical influence of solution equilibria on the formation of colloidal zeolite

particles – Rosas-Arbelaez W. J.

8. Investigations on the co-ion effect of the surface charge and aggregation behavior of

silica nanoparticles – Isabelle Simonsson

9. Aluminum incorporation and characterization of diatom frustule – Mohammad

Soleimani

10. Development and Evaluation of Polyether Ether Ketone (PEEK) Capillary for

Electrospray – Christian Sögaard

11. Remediation of landfill effluent with amorphous silica. – Keitumetse Tsubane

12. Diatoms – silica miracles made by nature – Angela Wulff

13. Improved Biocatalytic Conversion of CO2 to Formaldehyde by Co-immobilization of

Enzymes in Siliceous Mesostructured Cellular Foams – Milene Zezzi do Valle

Gomes

14. Sympatec – The Particle People – Sjors Sluimer

21

1. Study of parameters affecting spatial location of particles

during film forming process of silica-polymer dispersions

Archana Samanta*, Romain Bordes*

*Chalmers University of Technology, Sweden

Particulate based coatings have been used extensively to achieve specific surface properties like

hydrophobicity1, flame retardancy2, self-cleaning3 and others. As the presence of small

proportion of such particulate deposition can alter the bulk properties of materials significantly,

it is therefore important to understand the mechanism of migration of particles affecting their

spatial location during the film formation process4, and especially the interplay between binder

and the surface chemistry of the particles.

One of such particles of interest is colloidal silica which has been used widely for enhancement

of surface area, magnetic and optical properties of the substrates, among others5. Often these

silica particles are used in combination with other polymeric moieties, surfactants or binders

for several specific applications. The spatial arrangement of these particles at the interface or

the surface of the coating significantly influences their properties and control their surface

functionalities. It is therefore important to understand the underlying concepts which govern

the particle mobility and their spatial location on the surface.

In this study an attempt was made to understand the silica and binder particle migration during

the film forming process. Factors governing the mobility and passage of binder and silica

particles were evaluated with respect to particle concentration and drying rate. Effect of silica

surface chemistry, as well as nature of the binder, on the arrangement behaviour was also

explored in detail. It was found that polymer infiltration, particle stratification, peclet number

and the size ratios of play a significant role in determining the surface morphology and spatial

location of constituent particles. A suitable selection of these parameters can help achieve

desired surface functionality by altering the deposition of type of particulates on the top surface.

Hence, this study has the aim to set a fundamental background to the assembly of various

particulate systems for industrial coating applications.

References

1. Fang, J., Wang, H., Wang, X. & Lin, T. Superhydrophobic nanofibre membranes: effects of particulate

coating on hydrophobicity and surface properties. J. Text. Inst. 103, 937–944 (2012).

2. Yan, L., Xu, Z. & Wang, X. Influence of nano-silica on the flame retardancy and smoke suppression

properties of transparent intumescent fire-retardant coatings. Prog. Org. Coat. 112, 319–329 (2017).

3. Zhang, X.-T. et al. Self-Cleaning Particle Coating with Antireflection Properties. Chem. Mater. 17, 696–

700 (2005).

4. Makepeace, D. K. et al. Stratification in binary colloidal polymer films: experiment and simulations. Soft

Matter 13, 6969–6980 (2017).

5. Liz-Marzán, L. M. & Mulvaney, P. The Assembly of Coated Nanocrystals †. J. Phys. Chem. B 107, 7312–

7326 (2003).

22

2. Regenerated films from silicon dioxide nanoparticles and

cellulose dissolved in lithium hydroxide-urea

Ran Duan, Bo Westerlind, Marcus Haeggström* and Magnus Norgren*

RISE Processum, Box 70, SE-891 22 Örnsköldsvik. ran.duan@processum.se

*Mid Sweden University, Holmgatan 10, SE- 851 70, Sundsvall. magnus.norgren@miun.se

Keywords: Silicon dioxide nanoparticles, Dissolved cellulose, Lithium hydroxide, Urea

Plastics are commonly used for short time packaging while most of them take hundreds of years

to degrade. If plastics end up in the nature and interfere with the biological cycle in the

ecosystem, they might cause damages to living organisms. If instead a biodegradable material

is used, there will be less or no damages when disposed in nature. In some applications, plastics

from fossil-based sources might be substitutable with bio-based alternatives such as cellulose,

which is biodegradable and available in large volumes. In order to replace plastics with

cellulose it is sometime required to improve the properties of the cellulose products.

Many modifications of cellulose have been suggested. Some are based on expensive and

harmful chemistry and thereby not sustainable. Here, a low cost, environmental gentle and

facile method to produce cellulose films modified with silicon dioxide nano particles (SiO2NP)

was studied. Cellulose fibres from dissolving pulp with a DP around 200 (based on Mn) were

dissolved in lithium hydroxide/urea/water (4.6/15/80.4 wt%) at -13 °C. Different amount of

SiO2NPs were added to the prepared cellulose solution. The SiO2NPs to cellulose ratio was

varied from 1:2 to 1:20 based on weight. The mixtures were then casted on a plate and washed

till pH neutral before dried at room temperature. Fig. 1 shows how the film appears while wet.

With 10% of additional SiO2NP in the regenerated cellulose film, the strain at break doubled

compared with no addition; from 4% to 8%. Less or more addition of silicon dioxide

nanoparticles than 10% gave lower strain at break. The addition of SiO2NPs had no effect on

tensile strength, see Fig. 2.

Fig. 1. A regenerated film from dissolved

cellulose containing 10% SiO2NPs (to

cellulose weight)

Fig. 2. Specific stress-strain curves of regenerated cellulose films

with SiO2NPs in different ratios.

23

3. Intraparticle Diffusivity of Mesoporous Silica

Microspheres using Multiscale Electron Tomography and

Lattice Boltzmann Simulations Remco Fijneman*, **, Maurits Goudzwaard* Arthur Keizer*, Tobias Gebäck***, Magnus

Palmlöf**, Michael Persson**, Nico Sommerdijk*, Heiner Friedrich*

*Laboratory of Materials and Interface Chemistry, Eindhoven University of Technology, The Netherlands; **Nouryon Pulp and Performance Chemicals AB, Sweden; ***SuMo Biomaterials, VINN Excellence Centre,

Chalmers University of Technology, Sweden

Keywords: intraparticle diffusivity, electron tomography, mesoporous silica, Kromasil

The multiscale pore structure of mesoporous silica microspheres plays an important role on

mass transfer kinetics in liquid chromatography. Nevertheless, the multiscale pore network of

these materials has never been locally quantified before, mostly because characterizing

micrometer sized objects that are structured down to the nanometer scale is anything but a

straightforward task. Here we demonstrate for the first time, by combining low convergence

angle scanning transmission electron microscopy tomography (LC-STEM tomography)1 with

lattice Boltzmann simulations2, quantitative insight on the pore network and determine locally

the tortuosity and intraparticle diffusion coefficient of commercial mesoporous silica

microspheres. Our results, spanning two orders of magnitude between nanostructures and entire

object, are in good agreement with bulk characterization techniques such as nitrogen gas

physisorption and add valuable local information for the study of mass transfer behaviour (in

liquid chromatography or catalysis) on the single microsphere level.

(1) Loos, J.; Sourty, E.; Lu, K.; Freitag, B.; Tang, D.; Wall, D. Nano Lett. 2009, 9 (4), 1704–1708.

(2) Gebäck, T.; Marucci, M.; Boissier, C.; Arnehed, J.; Heintz, A. J. Phys. Chem. B 2015, 119 (16), 5220–

5227.

Figure 3: (a) A slice of a 3D tomographic reconstruction of a 2 m silica microsphere with 10 nm pores after

segmentation. (b) Effective diffusion coefficients in the x,y, and z direction for respectively the center, median and

edge of the segmented reconstruction as determined via lattice Boltzmann simulations. Local tortuosity factors of

the particle structure can be calculated by dividing the intraparticle diffusivity over the particle porosity.

24

4. A silica based nano-mesoporous material, the relation

between structure and efficiency.

Farnaz Ghajeri*,**, Zareh Topalian**, Ling Xie*, Klaus Leifer* and Christer Sjöström**

*Department of Engineering Sciences, Applied Materials Science, Uppsala University **R&D, Svenska

Aerogel AB, Sweden

Keywords (Silica-based, nanoporous, EM methods, filtration material, insulation

material)

A nano-mesoporouse silica-based material called Quartzene® is investigated under Electron

Microscopy (EM) methods. The properties are among others, high porosity (98%), very low

density (0.06-8 g/ml), low thermal conductivity (24 – 26 mW/m·K) and low acoustic

transmission. It is produced as a powder and the chemical properties, in terms of

hydrophilicity/phobicity, can be tailored to fit the application. Due to its properties, it has a

wide range of application areas and currently it is used for liquid and molecular filtration,

insulation, coating and paint applications. Analysis of this novel material is a challenge due to

it being a powder, highly porous, light weight with a wide pore size distribution from a few nm

to micrometre. The EM analysis challenges and current solutions are to be presented as well as

application related analysis results, the relation between the structure and efficiency is to be

discussed.

Figure 1 TEM image of CMS type Quartzene®

Acknowledgements

Svenska Aerogel AB, Strömmavägen 2, SE-80309 Gävle, Sweden

References: F. Ghajeri, Z. Topalian, A. Tasca, S. Hassan, M. Jafri, K. Leifer, P. Norberg, and C.

Sjöström, Curr. Opin. Green Sustain. Chem. 12, 1 (2018). https://doi.org/10.1016/j.cogsc.2018.07.003

25

5. Silane modified colloidal silica as performance enhancer

of acrylic elastomeric cool roof coatings

Peter Greenwood

Nouryon, Bohus Sweden

Abstract

The use of silane modified colloidal silica to improve dirt-pick-up resistance in waterborne

coatings is well established. In our recent study we have seen that it can play a key role to

enhance the over-all performance of acrylic elastomeric cool roof coatings since they need to

stay clean in order to maintain the cool roof performance. We found a dramatic enhancement

of dirt pickup resistance of the fresh coating, both for hydrophobic and hydrophilic dirt and the

effect was long lasting, even after 1000 hours of accelerated weathering in an UV chamber. The

addition of silane modified colloidal silica did not affect the TSR (total solar reflectance) value

in any negative way or did not cause any degradation of the coating film. The tested starting-

point formulations met the requirements as laid out in ASTM D-6083 for elastomeric coatings.

Furthermore we unexpectedly found a strong improvement in mechanical properties like

Young’s modulus, strength and adherence of the coatings without sacrificing coating flexibility

for neither fresh nor aged coatings. Surprisingly the in-can stability of the coating formulations

was also improved, especially at high temperature storage of 50°C, a temperature that easily

can be reached in warehouses in warm countries. A dosage in the range of 8-10 % colloidal

silica product appeared to be an optimal level.

26

6. Lighting up the enzyme immobilization

Gerard Masdeu,* Marcus Wilhelmsson, Björn Åkerman

Dept. Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Göteborg, Sweden

Keywords: Mesoporous silica, enzyme, fluorescence, SBA-15, lipase

The implementation of enzyme catalysis over traditional chemical processes stems from its

higher sustainability and process efficiency.[1] Biocatalyst stability is however largely hindering

the scale-up. To that end, enzyme immobilization offers improved stability in a broader range

of operating conditions, in addition to facile separation from the product and reusability of the

enzyme.

Mesoporous silica particles serve as promising solid supports for enzymes.[2] This material is

tailor-made synthesized as both pore and particle features are tuneable. Large surface area,

narrow pore size distribution, and thermal and mechanical stability are some of its most

attractive characteristics. Its porous structure enables the co-localization of several enzymes

from a cascade reaction in a very short distance if sitting in the same pore. Enhanced enzymatic

activity on the CO2 reduction was observed in our previous work, probably due to substrate

channeling by direct substrate transporting among the enzymes.[3] Still, physical confinement

of the enzyme may cause activity loss, undesired three-dimensional conformation, and mass

transfer limitations. Understanding of the conjugated system becomes thus crucial to overcome

these technical barriers for the industrial applicability of the catalyst.

Fluorescence spectroscopy is a powerful tool to gain insight into the support–enzyme

interaction. In this work, its sensitivity to the local environment of the probe is being used to

measure real-time kinetics on the immobilization of Cy3-labeled lipase into SBA-15 particles.

The complexity of the modeling system lies on quantum yield variation when the probe is inside

the pores, dye self-quenching, bleaching, and light scattering from the particles.

Fluorescence-based confocal microscopy is currently ongoing to elucidate the immobilization

mechanism, distinguishing the preferred binding sites for the enzyme, and the spatial

distribution of the enzyme molecules inside the particle (Figure 1). The distribution will affect

the transport behavior of substrate/product as well as the reaction kinetics.[4]

Figure 4. Spatial distribution of Cy5-labeled lipase in Alexa532-labeled SBA-15 particles imaged by confocal

microscopy. Emission detection of (A) Cy5, (B) Alexa532. (C) Dual-colored imaging. Scale bar: 10 µm.

[1] J. Chapman, A. Ismail, C. Dinu, Catalysts 2018, 8, 238. [2] M. Hartmann, X. Kostrov, Chem. Soc. Rev. 2013,

42, 6277–6289. [3] P. S. Nabavi Zadeh, M. Zezzi Do Valle Gomes, B. Åkerman, A. E. C. Palmqvist, ACS Catal.

2018, 8, 7251–7260. [4] Y. Zhang, J. Ge, Z. Liu, ACS Catal. 2015, 5, 4503–4513.

* Corresponding author: masdeu@chalmers.se

27

7. The critical influence of solution equilibria on the

formation of colloidal zeolite particles

Rosas-Arbelaez W. J.*, Palmqvist A.E.C.*

Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Sweden*

Keywords: colloidal zeolites, solution equilibria, high yield, particle size

The understanding of zeolite formation has been an area of scientific investigations since the

development of the first synthesis methods for their preparation. These studies have focused

mainly on developing new synthesis protocols, growth models and reaction mechanisms, as

well as employing a variety of characterization methods to follow their formation1. With the

advent of synthesis methods for colloidal zeolites from clear solutions at temperatures below

100 °C, observations of the nucleation and growth of zeolites could be monitored in situ.

Different synthesis conditions have been investigated and modelling of the formation of zeolites

have been made possible, focusing on the hydrolysis, nucleation and growth stages2,3. Despite

these efforts, there is still an incomplete understanding of the detailed processes dictating the

nucleation, growth and discontinuation of growth of zeolites in solution. Especially, the

frequently observed termination of zeolite growth before the full conversion of the precursors

is reached has not been addressed to a considerable extent. Typical zeolite formation yields may

range from 30 to 90% and little attention has been devoted to understanding the cause of this

apparent premature termination of growth or how it can be improved.

In this study, as starting point, we synthesized colloidal silicalite-1 particles from a clear

solution with the chemical composition 9 TPAOH: 25 SiO2: 100 EtOH: 480 H2O, obtaining a

colloidal suspension of TPA-silicalite-1 particles. We followed the growth of the particles and

confirmed that they stop growing after about 20 hours having reached an average size of 105 nm

and with a silica conversion yield of 64% in agreement with previous studies4. Based on the

results from our current study, we find that the reason for the incomplete conversion of the

silica to the zeolite is due to a dynamic equilibrium between growth and dissolution of the

zeolite crystals in the solution. Thus, by modifying the chemical composition of the synthesis

solution at this stage, we could shift this equilibrium favoring a further growth of the particles

and achieve full conversion. Moreover, in a series of subsequent syntheses, we systematically

varied the chemical composition of the synthesis solutions at the initial stage and at various

stages during the zeolite formation. This gave us further insight into the effect of the chemical

equilibria on the yield and about the nucleation of the zeolite particles. With this new knowledge,

we were able to simultaneously control the particle size and the yield of the synthesis. We found

that the same principles observed for silicalite-1 also applies to zeolite ZSM-5, surpassing the

values in size and yield obtained in previous studies5. In addition, the chemical composition of

the synthesis solution could be modified to shift the chemical equilibrium favoring

incorporation of more tetrahedrally coordinated aluminum in the MFI framework.

References

1. Cundy C.S., Cox P.A., Microporous Mesoporous Mater. 82, 1-78 (2005).

2. Burkett S.L, Davis M.E., Chem. Mater., 7(5), 920-928 (1995).

3. Yang S., Navrotsky A., Chem. Mater. 16, 3682-3687, (2004).

4. Persson A. E., Schoeman B.J., Sterte J., Otterstedt J.-E., Zeolites, 14(7), 557-567 (1994).

5. Persson A. E., Schoeman B.J., Sterte J., Otterstedt J.-E., Zeolites, 15(7), 611-619 (1995).

28

8. Investigations on the co-ion effect of the surface charge and

aggregation behavior of silica nanoparticles

I. Simonsson*, C. Sögaard*, M. Rambaran**, and Z. Abbas*

*Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, 412 96, Sweden

*Department of Chemistry, University of the West Indies, Mona, St. Andrew, Jamaica

Key words: Silica nanoparticles, surface charge density, co-ion effect, gel-time

Using gel time experiments and potentiometric titrations we have studied the effect of anions

on the charging behavior of commercial amorphous silica nanoparticles, Ludox® TM. While

counterions have been reported to exhibit clear ion specific effects on a wide variety of charged

surfaces, whether co-ions/anions could affect the surface charge and gel times of colloidal silica

has not been established to any great extent. Gel times were determined with the presence of a

large variety of anions (Cl-, NO3-, ClO3-, ClO4-, SO42-) and with the K+ and Na+ cations.

Surface charge densities (SCDs) as a function of pH was derived from titrations using the

corresponding acid (i.e. HCl, HNO3, H2SO4) to the anions investigated (Cl-, NO3-, SO42-)

and the titrations were run from pH 10 to pH 3. The concentrations with respect to cations were

in the range 0.10-0.50 M for our experiments.

Our results could be explained by looking at the mean ionic activity coefficients (γ±) of the

salts studied, which are connected to the degree of ion pairing between the cations and the

anions in water; a low γ± corresponds to more extensive ion pairing. Especially the determined

gel times showed great differences, e.g. 0.50 M NaCl vs. 0.50 M NaSO4: 13 minutes vs. 154

minutes, but also the SCDs revealed a distinct co-ion effect.

Figure 1. Gel-time measurements of TM

silica nanoparticles in the presence of a

variety of salts and cation concentrations.

Figure 2. SCDs obtained

by potentiometric titrations

of TM silica nanoparticles

in the presence of a variety

of salts and with cation

concentrations of 0.10 and

0.20 M.

Figure 1. Gel-time measurements of TM

silica nanoparticles in the presence of a

variety of salts and cation concentrations.

29

9. Aluminum incorporation and characterization of diatom

frustule

Mohammad Soleimani, Sai Maddala, Anat Akiva, Rolf A.T.M. van Benthem, Heiner

Friedrich, and Nico A. J. M. Sommerdijk*

Laboratory of Materials and Interface Chemistry & Centre for Multiscale Electron Microscopy Department of

Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven, the Netherlands

Keywords: Diatoms, Aluminum incorporation, Biomineralization

Diatoms are single-cell algae that construct an amorphous silica exoskeleton, the frustule, which

has a hierarchical pore structure. Diatoms construct the frustule through the biomineralization

of orthosilicic acid. Besides silicon, diatoms also incorporate aluminum into their silica cell

wall, impacting the solubility and dissolution rate of frustule. However, the influence of

aluminum on morphology and chemistry of silica in the frustule is not yet known. Here, we

investigate the effects of aluminium on the biomineralization of silica using, Pinnularia sp and

Thalassiosira pseudonana as model organisms. Investigations into aluminum incorporation

were carried out using series of silicon starved cultures of synchronized cells. The cells are

subsequently fed with of silicon and aluminium precursors at varying Si/Al ratios. Intact

frustules are extracted from the cells and are analyzed by TEM, SEM-EDS, and IR. Preliminary

characterization with SEM_EDX revealed the incorporation of aluminum into valves and girdle

bands of frustules at all Si/Al ratio. SEM Images of Pinnularia sp and Thalassiosira pseudonana

show no abnormality or defect in the frustule in the presence of aluminum. The growth curve

of Pinnularia Sp in the presence of different amounts of aluminum shows that increasing the

concentration of aluminum in the culture, significantly increases the growth rate until day 6.

Fluorescence microscopy shows that frustule formation inside the SDV of Pinnularia sp is

completed after six hours. Further investigations into the influence of aluminum on morphology

at nano scale and distribution of aluminum at different parts of frustule will be made.

Fluorescence microscopy will be employed in order to screen the formation of new formed cell

walls and to affirm the synchronous state of the culture. Solid state 27Al and 29Si NMR

spectroscopy will be utilized throughout the frustule formation to evaluate the coordination

environment of aluminum and crosslinking of silicon.

30

10. Development and Evaluation of Polyether Ether Ketone

(PEEK) Capillary for Electrospray

Christian Sögaard* , Isabelle Simonsson*, Zareen Abbas*

Department of Chemistry and Molecular Biology, University of Gothenburg *

Keywords: Particle Size Measurement, Particle Distribution, ES-SMPS

Abstract: With the development of nanomaterials in the form of nanoparticles the need for

analytical methods to determine particle size distributions is crucial. Typically dynamic light

scattering (DLS) is used for this purpose, but this method is limited by the un-proportional

impact of large particles or aggregates on the size distribution. Electrospray scanning mobility

particle sizer (ES-SMPS) offers an alternative to DLS. In ES-SMPS the particles are separated

depending on their electric mobility and the method is thus not affected by larger particles and

aggregates (1). However, one limiting factor has been the silica capillaries used in the

electrospray. The silica capillaries carry a negative charge at pH above 3 and particles need to

either be neutral of also carry a negative charge if clogging of the capillary is to be prevented

(2). This means that knowledge of the charge behaviour of the particles is required for the silica

capillary to work properly. Furthermore, pH adjustment of the sample might be needed which

risks destabilizing the nanoparticles. We have developed a polyether ether ketone (PEEK)

capillary as a replacement for the silica capillary. The PEEK capillary has a neutral surface

charge at a broad pH range making pH adjustment of the sample unnecessary. Due to this we

have not only shown that the PEEK capillary can be used to produce equally good size

distributions for negatively charged particles (SiO2, Au, and latex) but also precise particle

distributions for positively charged particles (TiO2). Moreover, the PEEK capillaries are 8-9

times cheaper than the silica capillaries. Our results thus strengthen the ES-SMPS method as a

tool for determining size distribution of nanoparticles.

The figure shows a graphical abstract of the results produced with the PEEK capillary in comparison with the silica

capillary(3).

References:

1. Johnson A-CJ, Greenwood P, Hagstrom M, Abbas Z, Wall S. Aggregation of nanosized colloidal silica

in the presence of various alkali cations investigated by the electrospray technique. Langmuir.

2008;24(22):12798-806.

2. Bolt GH. Determination of the Charge Density of Silica Sols. The Journal of Physical Chemistry.

1957;61(9):1166-9.

3. Sögaard C, Simonsson I, Abbas Z. Development and Evaluation of Polyether Ether Ketone (PEEK)

Capillary for Electrospray. ACS Omega. 2019;4(1):1151-6.

31

11. Remediation of landfill effluent with amorphous silica

K. Tsubane, J. Sturve*, M.Persson**

University of Gothenburg, *University of Gothenburg, ** Nouryon

Keywords: effluent, silica, remediation, metals

Over the years, the increase of household, commercial and industrial waste has been

tremendous as economies grow and countries develop. This in turn calls for sustainable

development of waste management strategies and disposal plans. From the disposed waste in

landfills, leachate of chemicals, whose constitution is a mixture of contaminants and stressors,

mainly heavy metals, organic chemicals and ammonia to mention few, is produced. This might

endanger freshwater ecosystems when transported either through percolation or surface run off,

threatening the healthy life of aquatic organisms. From a specialty chemicals producing

company in Sweden, amorphous silicon dioxide (SiO2) is produced as colloidal dispersions

generating a surplus of silica gels that can be recovered from the manufacturing process.

Because of its adsorbent properties, it was suggested that the silica could be used to remove

toxins from landfill effluent. The aim of this study was to determine whether or not amorphous

silicon dioxide can remove toxins from landfill effluent.

To assess the toxicity effects of effluent in freshwater ecosystems, two model systems namely

Daphnia magna and zebra fish (Danio rerio), famously used for environmental monitoring of

pollutants and assessment of embryonic forms development of fish were used respectively.

72hpf and 48hours exposures were done for zebrafish and daphnia exposed to untreated and

diluted effluent from a landfill and to a mixture of metals Cd, Cu, Ni, and Pb. After noting their

effects, same effluent concentrations were mixed with the amorphous SiO2 for remediation and

filtered. The models were again exposed to the filtrate and results recorded. The use of

amorphous SiO2 adsorbed metals that were toxic to the embryos by a magnitude of 65-70%.

The present study presents a significant step in using amorphous SiO2 from recovery process

to remediate effluent polluted freshwater ecosystems.

32

12. Diatoms – silica miracles made by nature

Angela Wulff and Sofie Allert*

Dept of Biological and Environmental Sciences, University of Gothenburg, Box 461, 405 30 Göteborg, Sweden,

*Swedish Algae Factory, Stena Center 1B, 412 92 Göteborg, Sweden

Keywords: Nanopores, photonic, ultraviolet radiation (UVR)

Diatoms are unicellular, microscopic algae present in marine and freshwater habitats but also

in e.g. ice. They are photosynthetic but some can live in the dark, provided with a suitable

carbon source. The cell wall (frustule) is incorporated by silica (SiO2. nH2O), ornamented with

nanopores – each species with a unique pattern. Flux of material takes place through these pores.

More than 100 000 species have evolved over at least 100 million years. Besides being the basis

of the food web, diatoms contribute to ca 20% of the global oxygen production. They are

divided into two different groups based on their shape, centric and pennate. Generally, centric

diatoms are pelagic and pennate diatoms form biofilms.

Protection from UVR may be a reason for the evolution of frustules. Experimental evidence for

harmful effects of UVR is found for many species and conditions, but it is also clear that

diatoms can cope with relatively high UVR intensities. There seems to be a difference between

centric and pennate diatoms. We have observed high UVR tolerance in pennate diatoms despite

that they, in contrast to centrics, contain no or only very small amounts of UVR-absorbing

compounds1,2. To explore the role of the frustules, we carried out optical studies as well as

electromagnetic simulations of simplified geometry models. We suggest that the redistribution

of UVR due to frustules is an important evolutionary cause of the presence and evolution of

frustules in diatoms, by decreasing the rate of UVR-induced degradation of DNA inside the

cells3.

The Swedish Algae Factory is cultivating diatoms and producing pure diatom silica. The ability

of the diatom frustules to protect from UVR can be utilized also to protect humans and sensitive

materials from harmful wavelengths. Many of the UV filters used today in e.g. sunscreen

products are being increasingly questioned due to their harmful impact on health and

environment. Another area where properties of the diatom silica can be utilized is the solar cell

market. The use of solar energy is growing fast and is regarded as one of the most important

sources for future energy. The intrinsic structure of the frustules can enhance the efficiency of

solar panels by improved light absorptions and redistribution of UVR. In addition, the very

precise nano-sized structure of the frustules is designed for uptake and release of gases and

chemicals. This feature is being explored in several applications including skin care, batteries,

sensors and drug delivery.

References 1)Wulff A, et al. 1999. UV radiation effects on microbenthos – a four month field experiment. Aquat Microb Ecol,

19:269-278 2)Wulff A, et al. 2008. UV radiation effects on pigments, photosynthetic efficiency and DNA of a semi-natural

Antarctic marine benthic diatom community. Aquat Biol 3:167-177 3)Aguirre LE, Ouyang L, Elfwing A, Hedblom M, Wulff A, Inganäs O. 2018. Diatom frustules protect DNA from

ultraviolet light. Scientific Reports 8:5138

33

13. Improved Biocatalytic Conversion of CO2 to Formaldehyde by

Co-immobilization of Enzymes in Siliceous Mesostructured

Cellular Foams

Milene Zezzi do Valle Gomes, Pegah S. Nabavi Zadeh, Björn Åkerman and Anders Palmqvist

Department of Chemistry and Chemical Engineering, Chalmers University of Tehnology, SE-412 96,

Gothenburg – Sweden

Keywords: Silica; formate dehydrogenase; formaldehyde dehydrogenase, FRET

The bioconversion of CO2 to formaldehyde requires the use of two enzymes: formate

dehydrogenase (FateDH), that converts CO2 to formate, and formaldehyde dehydrogenase

(FaldDH) which reduces formate to formaldehyde[1]. In a previous study[2] we have shown

that the activity of FaldDH can be improved by the immobilization of this enzyme through

physical adsorption in siliceous mesostructured cellular foams (MCF), which surface was

functionalized with mercaptopropyl groups (MCF-MP).

In this work, a MCF-MP with similar physical properties (pore size: 32.8 nm; window size:

11.3 nm) was used to co-immobilize FateDH and FaldDH. Two methods of immobilization

were used. In the first one the enzymes were mixed together with the MCF-MP for 4 h, whereas

in the second method, initially the FaldDH was mixed with MCF-MP for 2 hours and after that

the FaldDH was added and the immobilization was allowed for more 4 hours. Using the first

method of immobilization no enzyme activity could be observed. This is due to the fact that

FaldDH is a large enzyme (molecular size of 8.6 nm x 8.6 nm x 19 nm) and probably hindered

the access of the smaller FateDH (hydrodynamic radius of 3.5 nm) inside the pores resulting in

a very low immobilization of this enzyme. Using the second method of immobilization the two

enzymes were successfully immobilized in the MCF-MP and the co-immobilization of enzymes

resulted in a specific activity about 4 times higher than for the enzymes free in solution. Förster

resonance energy transfer (FRET) was used to estimate the distance between the FateDH and

FaldDH when immobilized in the MCF-MP. The findings of this work suggested that upon

immobilization in MCF-MP the two enzymes get in close proximity and are adsorbed in an

optimized orientation inside the pores in a way that the active site is more accessible to the

substrate.

The improvement of the catalytic activity of this multi-enzymatic system is an important step

for the development of a sustainable and efficient method for utilizing CO2.

1. Obert, R. and B.C. Dave, Enzymatic conversion of carbon dioxide to methanol: Enhanced methanol

production in silica sol-gel matrices. Journal of the American Chemical Society, 1999. 121(51): p.

12192-12193.

2. Zezzi do Valle Gomes, M. and A.E.C. Palmqvist, Immobilization of formaldehyde dehydrogenase in

tailored siliceous mesostructured cellular foams and evaluation of its activity for conversion of formate

to formaldehyde. Colloids and Surfaces B: Biointerfaces, 2018. 163: p. 41-46.

34

14. Sympatec – The Particle People

Nano-particles

Sympatec develops, manufactures, sells, services and supports an innovative range of best

instruments for particle size and shape analysis in laboratory and process for customers

worldwide.

With continuous inn ovations in the technological fields of laser diffraction, dynamic image

analysis, ultrasonic extinction and photon cross-correlation spectroscopy (PCCS), Sympatec

makes a prominent contribution to the development, production and quality control of most

challenging particulate systems.

Typical applications cover dry powders and granules, fibres, suspensions, emulsions, gels,

sprays and inhalants within a size range from 0.5 nm to 34,000 μm. Modular instruments show

great versatility and can be adapted to the specific task within your laboratory. The proven

measurement technologies are also available for integration into your process. Moreover, all

instruments reliably deliver most accurate, reproducible and comparable results at shortest

measuring times.

Sympatec – The Particle People.

Dr.-Ing. E.h. Stephan Röthele

Managing Director

Sympatec GmbH

System | Partikel | Technik

Am Pulverhaus 1

38678 Clausthal-Zellerfeld

Germany

Phone +49 5323 717 0

Fax +49 5323 717 229

sales@sympatec.com

www.sympatec.com

Media Contact

Dr. Sebastian Röthele

Corporate Marketing Management

Sympatec GmbH

System | Partikel | Technik

Am Pulverhaus 1

38678 Clausthal-Zellerfeld

Germany

Phone +49 5323 717 272

Fax +49 5323 717 229

seroethele@sympatec.com

marketing@sympatec.com

www.sympatec.com

35

List of participants

Aleksandar Matic Chalmers University of

Technology matic@chalmers.se

Anders Palmqvist Chalmers University of

Technology anders.palmqvist@chalmers.se

Anders Törncrona Nouryon anders.toerncrona@nouryon.com

Andreas Sundblom Nouryon Andreas.sundblom@nouryon.com

Angela Wulff University of Gothenburg angela.wulff@bioenv.gu.se

Anna Martinelli Chalmers University of

Technology, anna.martinelli@chalmers.se

Antiope Lotsari Chalmers University of

Technology antiope@chalmers.se

Bengt Fadeel Karolinska Institutet Bengt.Fadeel@ki.se

Björn Elgh Dentsply Sirona bjorn.elgh@dentsplysirona.com

Börje Persson Nouryon borje.s.persson@nouryon.com

Brad Chmelka University of California bradc@ucsb.edu

Catarina Elg Nouryon catarina.elg@nouryon.com

Catarina Petersen Nouryon catarina.petersen@nouryon.com

Charlotte Angel Nouryon charlotte.angel@nouryon.com

Christer Sjöström Svenska Aerogel AB christer.sjostrom@aerogel.se

Christian Sögaard University of Gothenburg christian.sogaard@chem.gu.se

Eiwe Ljungblom TestBed Nano eiwe@projekttillvaxt.se

Emma Björk Linköping University emma.bjork@liu.se

Emma Lundin Nouryon emma.lundin@nouryon.com

Eric Jacquinot Merck Performance Materials eric.jacquinot@merckgroup.com

Erik Nilebäck Chalmers Industriteknik erik.nileback@chalmersindustriteknik.se

Erik Sanne Nouryon erik.sanne@nouryon.com

Farnaz Ghajeri Uppsala University farnaz.ghajeri@aerogel.se

Frida Ryttsén Essity Hygiene & Health AB frida.ryttsen@essity.com

Gerard Masdeu Chalmers University of

Technology masdeu@chalmers.se

Gorgeous Sarah Chinkonono University of Gothenburg gschinkonono@gmail.com

Hampus Lindmark Nouryon Hampus.Lindmark@nouryon.com

Hanna Andersson Nouryon hanna.andersson@nouryon.com

Hanna Härelind Chalmers University of

Technology hanna.harelind@chalmers.se

Harriet Otterholm Swedish Algae Factory harriet@swedishalgaefactory.com

Helene Andersson Moore Essity Hygiene & Health AB helene.andersson.moore@essity.com

Isabelle Simonsson University of Gothenburg isabelle.simonsson@chem.gu.se

Jagoda Podgruszecka Nouryon jagoda.podgruszecka@nouryon.com

Jennie Malker Nouryon jennie.malker@nouryon.com

Jieke Jiang University of Twente j.jiang-1@utwente.nl

Joakim Högblom Nouryon joakim.hogblom@nouryon.com

Johanna Falkenby Nouryon johanna.falkenby@nouryon.com

John Janiak Nouryon john.janiak@gmail.com

Jonny Livrell Nouryon jonny.livrell@nouryon.com

36

Keitumetse Tsubane University of Gothenburg tumetset@hotmail.com

Khalid Elamin Department of Chemistry and

Molecular Biology khalid.elamin@gu.se

Krister Holmberg Chalmers University of

Technology krister.holmberg@chalmers.se

Krzysztof Kolman Nouryon krzysztof.kolman@nouryon.com

Lars Andersson Nouryon lars.andersson@nouryon.com

Magnus Hagström Nouryon magnus.hagstrom@nouryon.com

Magnus Nydén Nouryon magnus.nyden@nouryon.com

Magnus Palmlöf Nouryon magnus.palmlof@akzonobel.com

Maria Abrahamsson Chalmers University of

Technology abmaria@chalmers.se

Mark Brzezinski University of California mark.brzezinski@lifesci.ucsb.edu

Martin Fernö University of Bergen Martin.Ferno@uib.no

Martin Pettersson Nouryon martin.pettersson@nouryon.com

Matilda Garbe Nouryon matilda.garbe@nouryon.com

Mats Hulander Chalmers University of

Technology mats.hulander@chalmers.se

Mats Josefson AstraZeneca mats.josefson@astrazeneca.com

Michael Persson Nouryon michael.persson@nouryon.com

Mika Lindén Ulm University mika.linden@uni-ulm.de

Mikael Widell Nouryon mikael.widell@nouryon.com

Milene Zezzi do Valle

Gomes

Chalmers University of

Technology milene@chalmers.se

Mohammad Hasani Chalmers University of

Technology m.hasani@chalmers.se

Mohammad Soleimani Eindhoven University of

Technology m.soleimani@tue.nl

Nico Sommerdijk Eindhoven University of

Technology N.Sommerdijk@tue.nl

Øyvind Eide University of Bergen oyvind.eide@uib.no

Patrick Wilhelm Nouryon patrick.wilhelm@nouryon.com

Per Jageland Nouryon per.jageland@nouryon.com

Per Restorp Nouryon per.restorp@akzonobel.com

Peter Gidlund Nouryon peter.gidlund@nouryon.com

Peter Greenwood Nouryon peter.greenwood@nouryon.com

Peter Hell Nouryon peter.hell@nouryon,com

Peter Westbye Nouryon peter.westbye@nouryon.com

Piero Baglioni CSGI and University of Florence piero.baglioni@unifi.it

Ran Duan RISE Processum ran.duan@processum.se

Rasmus Olsson Nouryon rasmus.l.olsson@nouryon.com

Remco Fijneman Nouryon/Eindhoven University of

Technology remco.fijneman@nouryon.com

Rickard Frost Chalmers University of

Technology rickard.frost@chalmers.se

Romain Bordes Chalmers University of

Technology bordes@chalmers.se

37

Sai Prakash Maddala Eindhoven University of

Technology s.p.maddala@tue.nl

Sanna Björkegren Nouryon/Chalmers University of

Technology sanna.bjorkegren1@akzonobel.com

Simon Stebbing PQ Corporation simon.stebbing@pqcorp.com

Sjoerd Sluimer Sympatec ssluimer@sympatec.com

Sofie Allert Swedish Algae Factory AB sofie@swedishalgaefactory.com

Szilvia Vavra Chalmers University of

Technology vavra@chalmers.se

Torbjörn Ehrenberger Nouryon torbjorn.ehrenberger@nouryon.com

Walter Rosas Chalmers University of

Technology arbelaez@chalmers.se

Ylva Wildlock Nouryon ylva.wildlock@nouryon.com

Zareen Abbas University of Gothenburg,

Chemistry and Molecular Biology zareen@chem.gu.se