INORGANICCHEMICALSINDUSTRY ›› 2011, Vol. 43 ›› Issue (5): 43-.

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Preparation of hydrophobic silica aerogels at ambient pressure

 WANG  Wu, CHEN  Jian, HUANG  Kun   

  1. Department of Materials and Chemical Engineering,Sichuan Univesity of Sciences and Engineering,Zigong 643000,China
  • Published:2011-05-12

Abstract: Silica aerogels were prepared by sol-gel technique at ambient pressure using tetraethyl orthosilicate (TEOS) as silica source,and HF as catalyst.Influences of some factors,such as water,catalyst,and enthanol (EtOH) on,the gelation process were investigated.Structure and properties of silica aerogels were studied by the means of FT-IR,SPM and so on.Results showed:aerogels showed good hydrophobicity after surface modification by trimethylchlorosilane (TMCS).Density of as-prepared aerogels was in range of 200~400 kg/m3 and the contact angle with water was larger than 120°.When n(TEOS)∶n(EtOH)∶n(H2O)∶n(HF)=1∶6∶4∶0.25,the comprehensive performance of aerogels was the best.Gelation time would shorten with the increase of water and hydrofluoric acid dosage and would increase with the increase of ethanol.

Key words: hydrophobic aerogels, silica, ambient pressure drying, surface modification

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