室温干燥得到的疏水性气凝胶粉末的光谱和纹理特性。

Spectral and Texture Properties of Hydrophobic Aerogel Powders Obtained from Room Temperature Drying.

机构信息

Faculty of Chemistry and Pharmacy, Department of Physical Chemistry, University of Sofia St. Kliment Ohridski, 1164 Sofia, Bulgaria.

Bulgarian Academy of Sciences, Institute of General and Inorganic Chemistry, 1113 Sofia, Bulgaria.

出版信息

Molecules. 2021 Mar 23;26(6):1796. doi: 10.3390/molecules26061796.

DOI:10.3390/molecules26061796

PMID:33806761

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8004964/

Abstract

Attenuated Total Reflectance Infrared (ATR-IR) spectroscopy and texture measurements based on nitrogen adsorption-desorption isotherms are combined to characterize silica aerogel granules with different degrees of hydrophobicity. The aerogels were prepared from tetraethoxysilane via a room temperature hydrolysis-gelation process, solvent exchange, hydrophobization, and drying at subcritical conditions. The dependencies between the texture properties, pore architectures, surface fractal dimensions, and degree of hydrophobicity of the samples are extracted from the ATR-IR spectra and the adsorption-desorption isotherms. The IR absorption in the region of the Si-O-Si and Si-OH vibrations is used for a description of the structural and chemical changes in aerogel powders connected with their surface hydrophobization. The Frenkel-Halsey-Hill (FHH) theory is applied to determine the surface fractal dimension of the powder species.

摘要

衰减全反射红外（ATR-IR）光谱和基于氮气吸附-解吸等温线的纹理测量相结合，用于表征具有不同疏水性程度的二氧化硅气凝胶颗粒。气凝胶是通过室温水解-凝胶化过程、溶剂交换、疏水化和亚临界条件下干燥从四乙氧基硅烷制备的。从 ATR-IR 光谱和吸附-解吸等温线中提取了样品的纹理特性、孔结构、表面分形维数和疏水性程度之间的依赖性。在 Si-O-Si 和 Si-OH 振动区域的 IR 吸收用于描述与表面疏水化相关的气凝胶粉末的结构和化学变化。Frenkel-Halsey-Hill（FHH）理论用于确定粉末种类的表面分形维数。