a 2013

Porous organosilicates by non-hydrolytic sol-gel routes

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

Basic information

Original name

Porous organosilicates by non-hydrolytic sol-gel routes

Authors

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

Edition

The 246th ACS National Meeting, Indianapolis, Indiana, USA, 2013

Other information

Language

English

Type of outcome

Konferenční abstrakt

Field of Study

10402 Inorganic and nuclear chemistry

Country of publisher

United States of America

Confidentiality degree

není předmětem státního či obchodního tajemství

RIV identification code

RIV/00216224:14740/13:00069407

Organization unit

Central European Institute of Technology

UT WoS

000329618404652

Keywords in English

non-hydrolytic; inorganic-organic; organosilicates
Změněno: 11/10/2013 16:52, prof. RNDr. Jiří Pinkas, Ph.D.

Abstract

V originále

New non-hydrolytic sol-gel reactions providing hybrid organosilicate materials containing various polyphenolic structural motifs were developed. Mesoporous gels are formed in polycondensation reactions of multifunctional phenols, such as hydroquinone, 4,4-dihydroxybiphenyl, bisphenol A, and phloroglucinol with silicon(IV) acetate in polar ether solvent. Acetic acid was identified as a byproduct in elimination reactions. Xerogels were obtained by drying under vacuum. The produced materials contain residual acetoxy and phenolic hydroxyl groups allowing for subsequent grafting and surface modification. An impact of the employed spacer molecules and reaction conditions on the degree of condensation and xerogel porosity was studied. The condensation degree was established by gravimetric techniques and appears to be independent of reaction temperature but strongly depends on the nature of the spacer molecules. Hydroquinone provided gels with the highest value of 91%. The surface area of xerogels depends both on reaction temperature and the nature of polyphenolic ligand. A higher reaction temperature leads to a larger surface area. Phloroglucinol provided a xerogel with 790 m2/g of surface. Additionally a study of grafting of 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 aluminum alkyls AlR3 and aluminum halides 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