SANS METHOD FOR INVESTIGATION OF

MICELLAR SURFACTANT

SYSTEMS

Summer Student Practice in Joint Institute for Nuclear Research 2012

OUR SUPERVISOR:DR ALDONA RAJEWSKA

FRANK LABORATORY OF NEUTRON PHYSICS

THE AIM OF OUR PROJECT

In our experiment we determined the temperature and concentration influence on the micelle shape of the

nonionic surfactant C10E7 by small-angle neutron scattering method.

C10E7heptaethylene glycol monodecyl ether

C24H50O8

H-(OCH2CH2)7OCH2(CH2)8CH3

WHAT ARE SURFACTANTS?

Surfactants (SURFACE ACTIVE AGENTS) are the chemical compounds which consist of two parts: polar, hydrophilic head (P) and apolar, hydrophobic tail (R).

CLASSIFICATION OF SURFACTANTS

CLASSICAL GEMINI

CLASSICAL SURFACTANTS

IONIC

NONIONIC

ANIONIC

CATIONIC

ZWITTERIONIC

CHARACTERISTIC FEATURES OF SURFACTANTS

Adsorption at various interfaces

CHARACTERISTIC FEATURES OF SURFACTANTS

Micellization

THE CRITICAL MICELLE CONCENTRATION

It is the concentration of surfactants above which micelles form in the bulk phase.

WHAT CAN BE DETERMINED?

¥ Critical micelle concentration

¥ Aggregation number

¥ Shape and size of the micelles

¥ Counterion binding degree

¥ Surface free energy

SHAPES OF MICELLES

THE ROLE OF SURFACTANTS

¥ Cleaning

¥ Emulsifying

¥ Wetting

¥ Dispersing

¥ Foaming

¥ Antifoaming

¥ Solubilizing

APPLICATION OF SURFACTANTS

SANS – SMALL ANGLE NEUTRON SCATTERING

In this method, the beam of neutrons is elastically scattered bya sample. The scattering pattern provides informations about the shape, size and orientation of components of the sample. SANS is used for studying the structure of a material on length scale of 10 to 1000 Å.

IBR-2 PULSED REACTOR YUMO

FROM EXPERIMENTAL DATA TO PDDF

SCATTERING INTENSITIES AND DISTANCE DISTRIBUTION

FUNCTIONS OF GEOMETRICAL BODIES

H-(OCH2CH2)7OCH2(CH2)8CH3

WHAT INFORMATION CAN WE OBTAIN?

¥ Volume fraction, data consistency

¥ Specific surface area, surfactant head group area

¥ General or specific dimensions

¥ Particle volume, molecular weight.

What are the disadvantages?

Nuclear reactors needed

Price

Sometimes long measurement times

ACKNOWLEDGMENT

¥ Aldona Rajewska

¥ Roman Zawodny

¥ Władysław Chmielowski

¥ Stanislav Pakuliak

Thank you for your attention.

BIBLIOGRAPHY

¥ Modern aspects of small angle scattering, ed. by H. Brumberger

¥ Structure and dynamics of strongly interacting colloids and supramolecular aggregates in solutions, ed. by S.H. Chen

¥ Surfactant solutions. New methods of investigation, ed. By R. Zana

¥ Giant Micelles: Properties and Applications (Surfactant Science) by R. Zana

¥ Gemini Surfactants: Synthesis, Interfacial and Solution-Phase Behavior, andApplications (Surfactant Science) by R. Zana

¥ Dynamics of Surfactant Self-Assemblies: Micelles, Microemulsions, Vesicles and Lyotropic Phases (Surfactant Science) by R. Zana

¥ Surfactants in solutions by K. L. Mittal

¥ Micellar solutions and microemulsions:structure, dynamics and statistical thermodynamics by S.H. Chen and Raj Rajagopalan

¥ Physics of complex and supermolecular fluids by Samuel A. Safran, Noel A. Clark

PICTURES USED¥ http://en.wikipedia.org/wiki/File:Micelle.png

¥ http://www.nature.com/nmat/journal/v9/n5/fig_tab/nmat2761_F1.html

¥ http://en.wikipedia.org/wiki/File:Surfactant.jpg

¥ http://www.che.udel.edu/research_groups/wagner/image/research/rod.gif

¥ http://grantscienceworld.com/Phyical%20Science/physical%20science%20pictures/micelle.jpg

¥ http://img.search.com/thumb/c/c6/Phospholipids_aqueous_solution_structures.svg/250px-Phospholipids_aqueous_solution_structures.svg.png

¥ http://image.tutorvista.com/cms/images/44/Types-of-micelles.JPG

¥ http://www.detergentsandsoaps.com/gifs/surface-active.gif

¥ http://2.bp.blogspot.com/-8vkt3iXSi-I/TsqC0iavzHI/AAAAAAAAB4Y/NJ7TQLhh2P8/s1600/eco-friendly-paint.jpg

¥ http://3.bp.blogspot.com/_rGpP2bAbGgA/S-HINhF11bI/AAAAAAAAAnU/6-4rpGWHsCA/s1600/detergents.jpg

¥ http://cdn.mommyish.com/files/2011/11/johnson-and-johnson-baby-shampoo-chemicals.jpg

¥ http://www.monarchbearing.com/images/adhesives.jpg

¥ http://offsetprintinginks.files.wordpress.com/2011/10/offset-printing-inks.jpg

¥ http://www.realbollywood.com/up_images/inks6613.jpg

¥ http://www.epa-herbicides.com/images/1015-Herbicide-sprayingMan.jpg

¥ http://i616.photobucket.com/albums/tt242/faileon/micela.png

¥ http://www.baschem.co.uk/Products/Product/Antifoams/antifoam1.jpg