@inproceedings{822f860e505a4bf584524d8f852b8f1a,
title = "Silicification and biosilicification: part 2. Silicification at pH 7 in the presence of a cationically charged polymer in solution and immobilized on substrates",
abstract = "Biosilicification is facilitated by proteins and occurs under modest conditions in an aqueous medium (pH 7 and ambient temperature). Silicification at neutral pH in vitro has been shown to occur in the presence of various cationically charged synthetic macromolecules in solution. Here, the synthesis of silica from an aqueous silica precursor in the presence of poly(allylamine hydrochloride) (PAH) and polyacrylic acid (PAA) both in solution and immobilized on substrates is investigated. The results show that the formation of ordered silica structures under these modest conditions was favored for the PAH and the PAH-PAA in solution but neither for PAA in solution nor when the polymers were immobilized as PAH-PAA bilayers on flat substrates. It is possible that the immobilization of the PAH by the electrostatically self-assembly (ESA) technique may allow it to retain its catalytic function, while not allowing it to fulfill its role as a template / structure directing agent. The silica structures were characterized using scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). For the PAH system in solution silica spheres were seen and for PAH-PAA in solution hexagonal silica structures were observed in co-existence with silica spheres. The results presented herein may be helpful in elucidating biosilicification mechanism(s) and should lead to a better understanding of silicification.",
keywords = "biosilicification, silicification, ambient temperature, pH7, neutral pH, poly(allylamine hydrochloride) (PAH), polyacrylic acid (PAA), electrostatically self-assembly (ESA) technique ",
author = "Siddharth Patwardhan and Durstock, {M F} and Clarson, {Stephen J.}",
note = "e-isbn: 9780841219410; Symposium on Synthesis and Properties of Silicones and Silicone-Modified Materials held at the 221st National Meeting of the American-Chemical-Society ; Conference date: 01-04-2001 Through 05-04-2001",
year = "2003",
month = mar,
day = "10",
doi = "10.1021/bk-2003-0838.ch030",
language = "English",
isbn = "0841238049 ",
series = "ACS Symposium series ",
publisher = "American Chemical Society",
pages = "366--374",
editor = "S.J. Clarson and J.J. Fitzgerald and M.J. Owen and D. Smith and M.E. VanDyke",
booktitle = "Synthesis and properties of silicones and silicone-modified materials",
address = "United States",
}