2nd chair: first oil drilling in 1858 in

Wietze close to Hannover

Mineralogy since 1831 in Hannover

Claus Rüscher

Geopolymer:● handling/hosting hydrides for

storing Hydrogen● ● As green binder1. Project “Jirasit/Thailand”2. Project “Temuujin/Mongolia”3. Project “Tchakoute/Cameroon”4. Project “Debnath/Bangladesh”

Thanks to AvH/DAAD/“Lower saxonia“/DFG

Bonjour Prof. Rüscher,I am preparing the program for our present Geopolymer Camp (July 9-11) and I finished reading the various recent papers (2017-2018) dedicated to Phosphate-based Geopolymer. My intention is to focus on this chemistry in the First session on Tuesday, July 10, morning (at 11:00) titled “Acid-based geopolymers (phosphate/MK-based): chemistry and terminology”. Would you be available and make a presentation on the recent works of your team? …Thank you in advance for your input.Mit freundlichen Grüssen,JD

Thanks to JD!!

1. Mechanical and microstructural properties of metakaolin-based geopolymer cements from sodium waterglass and phosphoric acid solution as hardeners: A comparative study. Tchakouté, H. K., Rüscher, C. H.,Applied Clay Science 140 (2017) 81-87.2. Influence of the molar concentration of phosphoric acid solution on the properties of metakaolin-phosphate-based geopolymer cements.Tchakoute, H. K., Rüscher, C.H., Kamseu, E., Andreola, F., Leonelli, C., Appl. Clay Science 147 (2017) 184-194.3. The influence of gibbsite in kaolin and the formation of berlinite on the properties of metakaolin-phosphate-based geopolymer cements.Tchakoute, H.K., Rüscher, C.H., Kamseu, E., Djobo, J.N.Y., Leonelli, C., Mat. Chem. Phys. 199 (2017) 280-288.4. Influence of gibbsite and quartz in kaolin on the properties of metakaolin-based geopolymer cements. Tchakoute, H. K., Rüscher, C. H., Djobo, J. N. Y., Kenne, B. B. D., Njopwouo, D.,Applied Clay Science 107 (2015) 188–194.

Þ Use of natural raw material, kaolin! => compare „activation“ with phosphoric acid versus NWG (sodium silicate solution) => effect of X M H3PO4 => compare

again (main characterisations: XRD/IR/TG/CS)

4. Tchakoute, H. K., et al., 2015: Influence of gibbsite and quartz in kaolin on the properties of metakaolin-based geopolymer cements. Tchakoute, H. K., et al.,2015:Kaolins from Cameroon: K1, K2, K3

3. The influence of gibbsite in kaolin and the formation of berlinite on the properties of metakaolin-phosphate-based geopolymer cements. Tchakoute, H.K., et al., 2017:Kaolins from Cameroon K2, K3

What sense makes the bulk chemical composition?

K4 (Cameroon)SiO2 41.46Al2O3 31.47Fe2O3 7.65K2O 0.51MgO 1.50Na2O 0.65CaO 0.69SO3 0.15P2O5 0.09MnO 0.06LOI 15.76

∞2 Theta (CuKa)10 20 30 40 50 60 70 80

Cou

nts

0

1000

2000

3000

4000

5000

6000

K3

K1

K2

quartz

gibbsite

∞2 Theta (CuKa)

10 20 30 40 50 60 70 80

Cou

nts

0

500

1000

1500

MK3

gibbsite, 700∞C heated (scaled)

MK1

MK2

quartz

I I I

A

Thermal transformation:

ÞMKhere 700°C, 4h

Temperature (∞C)200 400 600 800

Mas

s lo

ss (%

)

60

70

80

90

100

K3

K2 K1

"gibbsite"

Kaolinite „ideally“:Al2Si2O5(OH)4 => [Al2O3*Si2O4] + 2 H2O

-13.9 wt% expected!

Thermal transformation:

ÞMKhere 700°C, 4h

Wavenumber / cm-1

500 1000 1500 2000 2500 3000 3500 4000

Abs

orba

nce

Uni

ts

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

K1

K2

K3

gibbsite

quartz

Wavenumber / cm-1

500 1000 1500 2000 2500

Abs

orba

nce

Uni

ts

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

MK1

MK3

MK2

quartz

gibbsite, 700∞C heated

1077 cm-11072 cm-1

560 cm-1

MK + NWG => GP (28 days), liq/sol = 0.87 NWG = sodium silicate solution:29 % SiO2, 9% Na2O, 62% H2O

(wt%)

Wavenumber / cm-1

500 1000 1500 2000 2500

Abs

orba

nce

Uni

ts

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

MK1

MK3

MK2

quartz

gibbsite, 700∞C heated

1077 cm-11072 cm-1

560 cm-1

Wavenumber / cm-1

500 1000 1500 2000 2500

Abs

orba

nce

Uni

ts

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

GP1

GP3

GP2

gibbsite, 700∞C heated

1077 cm-11027 cm-1

1021 cm-1

1019 cm-1

1015 cm-1

DOSPM? Eur. J. Mineral, 2010: Silicate-, aluminosilicate and calciumsilicate gels for building materials…

Wavenumber (cm-1)

500 1000 1500 2000 2500 3000 3500 4000

Abs

orba

nce

unit

s

GMK2

GMK3

0.1

0.2

0.3

0.4

0.5

0.6

0.7

3412

1647

1089

931

800

67259

252

546

6

3438

1647

10941157

937

805

66859

252

5467

Wavenumber / cm-1

500 1000 1500 2000 2500

Abs

orba

nce

Uni

ts

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

GP1

GP3

GP2

gibbsite, 700∞C heated

1077 cm-11027 cm-1

1021 cm-1

1019 cm-1

1015 cm-1

Wavenumber / cm-1

500 1000 1500 2000 2500

Abs

orba

nce

Uni

ts

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

MK1

MK3

MK2

quartz

gibbsite, 700∞C heated

1077 cm-11072 cm-1

560 cm-1

MK + 10 M phosporic acid => XX, liq/sol = 0.95, 60°C for 24 h (28 days)

36 MPa

54 MPa

MK + NWG => GP (28 days),

Room temperature!

30 MPa

38 MPa

48 MPa

1089 1094

Consider DOSPM! [PO4] NWGMK1 (22%Qz) 1021MK2 (10%Qz 11%Al2O3): 1089 1019MK3 (8% Qz 28%Al2O3): 1094 1015

Here: γ-, χ-Al2O3 has obviously negative effect on strength, Quartz positive!

[PO4] NWGMK1 (22%Qz) 48 MPaMK2 (10%Qz 11%Al2O3): 54 MPa 38 MPaMK3 (8% Qz 28%Al2O3): 36 MPa 54 MPa

IR spectra of AlPO4 polymorphs (SiSiO4)

MK + 10 M phosporic acid => XX, liq/sol = 0.95, 60°C for 24 h (28 days)

Now, many things could be investigated:

NWG = sodium silicate solution:29 % SiO2, 9% Na2O, 62% H2O

(wt%)

MK + NWG => GP (28 days),liq/sol = 0.87

How much Geopolymer is inside and what type of Geopolymer and how intra- and inter-connected, i.e. with the additions?

1st: Consider γ-, χ-Al2O3, Quartz and unreacted MK

∞2 Theta (CuKa)

10 20 30 40 50 60 70 80

Cou

nts

0

500

1000

1500

MK3

gibbsite, 700∞C heated (scaled)

MK1

MK2

quartz

I I I

A

2 Theta (CuKa)

10 20 30 40 50 60 70 80

Rel

. Int

ensi

ty

0

500

1000

1500

52/48

70/30

60/40

75/25 (%MK/KWG)

45/55

35/65

MK

liq/sol=1.8

liq/sol=0.66

liq/sol=1.2

liq/sol=0.9

2 Theta (CuKa)

10 20 30 40 50 60 70 80

Rel

. Int

ensi

ty

0

200

400

600

800

1000

1200

GP2

gibbsite, 700∞C heated

GP1

quartz

GP3

I I I

A

A

MK + NWG => GP (28 days), liq/sol = 0.87, unreacted MK?

MK + 10 M phosporic acid => XX, liq/sol = 0.95, 60°C for 24 h (28 days)

°2 Theta (CuKa)

10 20 30 40 50 60 70 80

Cou

nts

0

500

1000

1500

MK3

"Al2O3"

MK1

MK2

quartz

II

A

°2 Theta (CuKa)

10 20 30 40 50 60 70 80

Cou

nts

0

500

1000

1500

MK3

"Al2O3"

MK1

MK2

quartz

II

A

∞2 Theta (CuKa)

10 20 30 40 50 60 70 80

Cou

nts

0

100

200

300

400

500

600

GMK2

"Al2O3"

GMK3

quartz

∞2 Theta (CuKa)

10 20 30 40 50 60 70 80

Cou

nts

0

100

200

300

400

500

600

GMK2

"Al2O3"

GMK3

quartz

Unreacted MK subtracted =>Observe: „Main structural unit)

∞2 Theta (CuKa)

10 20 30 40 50 60 70 80

Cou

nts

0

200

400

600

800

1000

1200

GP1-0.3MK1

GP3-0.3MK3

GP2-0.3MK2

NWG [PO4] MK1 (22%Qz) : GP1 48 Mpa MK2 (10%Qz 11%Al2O3): GP2 38 MPa GMK2 / 54 MPa MK3 (8% Qz 28%Al2O3): GP3 36 MPa GMK3 / 36 MPa

Bell ….Kriven, J. Mater. Chem. 18 (2008) 5974: X-Ray pair distribution

analysis …(of „total scattering“ synchrotron data)!

2 Theta

10 20 30 40 50 60 70 80

Inte

nsit

y

0

200

400

600

800

MK2-0.10quartz MK3-0.08quartz Quartz

I IA

A

I

MK + 10 M phosporic acid => XX, liq/sol = 0.95, 60°C for 24 h (28 days)

2 Theta

10 20 30 40 50 60 70 80

Inte

nsit

y

0

100

200

300

400

500

2 Theta

10 20 30 40 50 60 70 80

Inte

nsit

y

0

50

100

150

200

250

300

GMK2-0.10quartz GMK3-0.08quartz

GMK2

GMK3

AB+Q

B+Q

B+Q

B+Q

B+Q

B

B+Q

B+Q

B+Q

B+Q

B+Q

B+Q

B+Q

B BA

B

B

B

B B

B B

A

B

B

BB

BB

B

Wavenumber (cm-1)

800 1000 1200 1400

Abs

orba

nce

unit

s

PS1

PS2PS3

PS4

PS5

PS6

1107

1112

1115

1119

1144

1142

875

879

883

886

890

890

949

958

967

972

981

986

2nd : Consider the effect of [PO4]3- concentration

M14: 875 949 1107 (PS6)M12: 879 967 1112 (PS5)M10: 883 967 1115 (PS4)M08: 886 972 1119 (PS3)M06: 890 961 1142 (PS2)M04: 890 986 1144 (PS1)

MK4 + X M phosporic acid, liq/sol = 0.80, 60°C for 24 h (28 days)

Wavenumber (cm-1)

500 1000 1500 2000 2500

Abso

rban

ce u

nits

466

1076

MK4

A

2 Theta

10 20 30 40 50 60 70 80

Cou

nts

MK4

Q

Q

AH H

QQQ

QQQ

Q

H Q

Q

QQ

K4 (Cameroon)SiO2 41.46Al2O3 31.47Fe2O3 7.65K2O 0.51MgO 1.50Na2O 0.65CaO 0.69SO3 0.15P2O5 0.09MnO 0.06LOI 15.76

Concentration of Phosphoric acid (M)

4 6 8 10 12 14

Com

pres

sive

str

engt

hs (

MP

a)

0

20

40

60

80

100

36 43

82

94

67

GPS1GPS2

GPS3

GPS4

GPS5

GPS6

Wavenumber (cm-1)

500 1000 1500 2000 2500 3000 3500 4000

Abs

orba

nce

unit

s

0.2

0.4

0.6

0.8

1.0

1.2

466

472

467

460

463

GPS1

GPS2

GPS3

GPS4

GPS5

531

530

527

530

525

590

590

592

592

592

799

666

920

925

926

932

931

1082

1083

1085

1088

1095

1646

3420

1.4

GPS6920

672

59251

946

0

1101

1152

10821083

1085

1089

1095/1140

1101/1152 DOSPMGSP6 (14 M)

GSP5 (12 M)

GSP4 (10 M)

GSP3 (8 M)

GSP2 (6 M)

GSP1 (4 M)

2 Theta

10 20 30 40 50 60 70 80

Inte

nsit

y

GPS4

IB

A

Q+B

Q+B

Q

Q

Q Q

Q+B

QQ

Q

Q

Q

Q

Q

Q+B

HH

Q+B

Q+B

GPWG

Q+B

HH

H H

GPS4: MK4 + 10 M phosporic acid, liq/sol = 0.80, 60°C for 24 h (28 days)

GPWG: MK4 + NWG, liq/sol = 0.80, (28 days)

GPWG 64 MPa

GS4 94 MPa

Wavenumber (cm-1)

500 1000 1500 2000 2500 3000 3500 4000

Abs

orba

nce

unit

s

1019

1647

1088

1639

865

799

925

GPS4

GPWG

Here: Not convinced on Q + B, instead the contribution of B is small!

ÞUse of natural raw material, kaolin! Þcompare „activation“ with phosphoric acid

versus NWG (sodium silicate solution) Þ effect of X M H3PO4

If time: Compare Geopolymers based on ● Polysiloxo-polyphosphate ● Polysiloxo● Polysiloxo-sialate

OPC + H2O => CSH-binder!

2 Theta

10 20 30 40 50 60 70 80

Inte

nsit

y

0

100

200

300

400

500

2 Theta

10 20 30 40 50 60 70 80

Inte

nsit

y

0

50

100

150

200

250

300

GMK2-0.10quartz GMK3-0.08quartz

GMK2

GMK3

AB+Q

B+Q

B+Q

B+Q

B+Q

B

B+Q

B+Q

B+Q

B+Q

B+Q

B+Q

B+Q

B BA

B

B

B

B B

B B

A

B

B

BB

BB

B

30-40 MPa

54 MPa

36 MPa

30-40 MPa

120 MPa

Thanks