Synthesis of Organosilicate Gels by Non-Hydrolytic Reactions of
Silicon Acetate

a 2013

Synthesis of Organosilicate Gels by Non-Hydrolytic Reactions of Silicon Acetate

PINKAS, Jiří, Martin KEJÍK, Zdeněk MORAVEC and Craig BARNES

Basic information

Original name

Synthesis of Organosilicate Gels by Non-Hydrolytic Reactions of Silicon Acetate

Authors

PINKAS, Jiří (203 Czech Republic, guarantor, belonging to the institution), Martin KEJÍK (203 Czech Republic, belonging to the institution), Zdeněk MORAVEC (203 Czech Republic, belonging to the institution) and Craig BARNES (840 United States of America)

Edition

XVII International Sol-Gel Conference, Madrid, Spain, 2013

Other information

Language

English

Type of outcome

Konferenční abstrakt

Field of Study

10402 Inorganic and nuclear chemistry

Country of publisher

Spain

Confidentiality degree

není předmětem státního či obchodního tajemství

RIV identification code

RIV/00216224:14740/13:00069404

Organization unit

Central European Institute of Technology

Keywords in English

Organosilicates; Non-Hydrolytic; Sol-Gel; Silicon Acetate

Změněno: 11/10/2013 16:55, prof. RNDr. Jiří Pinkas, Ph.D.

Abstract

V originále

A non-hydrolytic sol-gel synthesis of new mesoporous organosilicate materials containing phenolic and bisphenolic structural motifs was developed. Xerogels are formed in polycondensation reactions of multifunctional phenols, such as hydroquinone, 4,4-dihydroxybiphenyl, bisphenol A, and phloroglucinol with silicon acetate in polar ether solvent. Acetic acid was identified as an elimination reaction byproduct. Xerogels were obtained upon drying in vacuo and the produced materials contain residual acetoxy and phenolic hydroxyl groups allowing for later grafting and surface modification. An impact of employed spacer molecule and reaction conditions on the degree of condensation and xerogel porosity was studied. Condensation degree was established by gravimetric techniques and appears to be independent of reaction temperature but strongly depends on the nature of the spacer molecule. Hydroquinone provided gels with the highest value of 91%. Surface area of xerogels depends both on reaction temperature and the phenol ligand. A higher reaction temperature leads to a larger surface area; phloroglucinol providing gel with up to 790 m2/g of surface. Additionally a study of grafting organic groups on the gel surface by the reactions with alcohols and phenols and anchoring of aluminum species by treating the gels with compounds such as AlR3 and AlX3 was performed. All the prepared xerogels and modified materials were characterized by elemental analyses, solid-state 13C, 27Al, and 29Si NMR, IR spectroscopy, surface area analysis, thermal analysis TG/DSC, and XRD.

Links

ED1.1.00/02.0068, research and development project

Name: CEITEC - central european institute of technology

LH11028, research and development project

Name: Nehydrolytické sol-gelové reakce pro přípravu křemičitanů a fosforečnanů s řízenou porozitou a funkčními skupinami na povrchu (Acronym: NHSGKNOX)

Investor: Ministry of Education, Youth and Sports of the CR

Citovat

PINKAS, Jiří, Martin KEJÍK, Zdeněk MORAVEC and Craig BARNES. Synthesis of Organosilicate Gels by Non-Hydrolytic Reactions of Silicon Acetate. In XVII International Sol-Gel Conference, Madrid, Spain. 2013.

@proceedings{1122962,
   author = {Pinkas, Jiří and Kejík, Martin and Moravec, Zdeněk and Barnes, Craig},
   booktitle = {XVII International Sol-Gel Conference, Madrid, Spain},
   keywords = {Organosilicates; Non-Hydrolytic; Sol-Gel; Silicon Acetate},
   language = {eng},
   title = {Synthesis of Organosilicate Gels by Non-Hydrolytic Reactions of Silicon Acetate},
   year = {2013}
}

TY  - CONF
ID  - 1122962
AU  - Pinkas, Jiří - Kejík, Martin - Moravec, Zdeněk - Barnes, Craig
PY  - 2013
TI  - Synthesis of Organosilicate Gels by Non-Hydrolytic Reactions of Silicon Acetate
KW  - Organosilicates
KW  - Non-Hydrolytic
KW  - Sol-Gel
KW  - Silicon Acetate
N2  - A non-hydrolytic sol-gel synthesis of new mesoporous organosilicate materials containing phenolic and bisphenolic structural motifs was developed. Xerogels are formed in polycondensation reactions of multifunctional phenols, such as hydroquinone, 4,4-dihydroxybiphenyl, bisphenol A, and phloroglucinol with silicon acetate in polar ether solvent. Acetic acid was identified as an elimination reaction byproduct. Xerogels were obtained upon drying in vacuo and the produced materials contain residual acetoxy and phenolic hydroxyl groups allowing for later grafting and surface modification. An impact of employed spacer molecule and reaction conditions on the degree of condensation and xerogel porosity was studied. Condensation degree was established by gravimetric techniques and appears to be independent of reaction temperature but strongly depends on the nature of the spacer molecule. Hydroquinone provided gels with the highest value of 91%. Surface area of xerogels depends both on reaction temperature and the phenol ligand. A higher reaction temperature leads to a larger surface area; phloroglucinol providing gel with up to 790 m2/g of surface. Additionally a study of grafting organic groups on the gel surface by the reactions with alcohols and phenols and anchoring of aluminum species by treating the gels with compounds such as AlR3 and AlX3 was performed. All the prepared xerogels and modified materials were characterized by elemental analyses, solid-state 13C, 27Al, and 29Si NMR, IR spectroscopy, surface area analysis, thermal analysis TG/DSC, and XRD.
ER  -

PINKAS, Jiří, Martin KEJÍK, Zdeněk MORAVEC and Craig BARNES. Synthesis of Organosilicate Gels by Non-Hydrolytic Reactions of Silicon Acetate. In \textit{XVII International Sol-Gel Conference, Madrid, Spain}. 2013.

Detailed Information on Publication Record