High Nanopore Volume Tetrethoxysilane Based Aerogels Prepared with Addition of N, N-Dimethylformamide at Different Stage of the Sol-Gel Process

Authors

  • Chaoshuai LEI Aerospace Institute of Advanced Materials & Processing Technology https://orcid.org/0000-0002-6975-2273
  • Enshuang ZHANG Aerospace Institute of Advanced Materials & Processing Technology https://orcid.org/0000-0001-7163-0622
  • Hongyan HUANG Aerospace Institute of Advanced Materials & Processing Technology
  • Xuyang JI Aerospace Institute of Advanced Materials & Processing Technology
  • Lijuan HE Aerospace Institute of Advanced Materials & Processing Technology
  • Wenjing LI Aerospace Institute of Advanced Materials & Processing Technology
  • Jieying YANG Aerospace Institute of Advanced Materials & Processing Technology
  • Yingmin ZHAO Aerospace Institute of Advanced Materials & Processing Technology
  • Hao ZHANG Aerospace Institute of Advanced Materials & Processing Technology

DOI:

https://doi.org/10.5755/j02.ms.24912

Keywords:

silica aerogels, sol-gel process, supercritical drying, nanoporous structure, DMF

Abstract

Using tetraethoxysilane (TEOS) as a precursor, silica aerogels were synthesized via the sol-gel polymerization followed by supercritical drying process. During the polymerization period, N, N-dimethylformamide (DMF), acting as a chemical additive for the structure control, was introduced in the hydrolysis step and condensation step, respectively. As a result, the nanopore volumes for the pores smaller than 100 nm were up to 6.0 cm3/g and 5.7 cm3/g for the samples that produced with DMF addition in the hydrolysis step and condensation step, while the value for the sample without DMF was only 4.6 cm3/g. Besides, the sample with DMF addition in the condensation step possessed more uniform pore size distribution while compared with that with DMF addition in the hydrolysis step. DMF can provide a shielding layer around the colloid particles through hydrogen bonds, inhibiting the aggregation of colloid particles and the enlarging of pore sizes.

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Published

2021-08-23

Issue

Section

POLYMERS AND COMPOSITES