納米纖維素增強SiO2氣凝膠力學性能與微觀結構

《複合材料學報》優先在線發表論文。

摘要：為克服SiO2氣凝膠強度低、易破碎等缺點，通過原位溶膠-凝膠法（sol-gel）製備納米纖維素（Cellulose Nanofibrils, CNF）增強SiO2氣凝膠，並對SiO2氣凝膠的化學結構、微觀形貌和力學、物理性能進行表徵分析，探討了CNF對SiO2氣凝膠力學性能的增強機制。結果表明：CNF獨特的納米級網路結構可增強SiO2顆粒之間的聯結強度；Si—OH（960cm-1）、Si—O—Si（1225 cm-1、1056 cm-1和800 cm-1）等特徵吸收峰的出現表明，CNF與SiO2之間形成穩定的化學鍵聯結；採用不同濃度CNF氣凝膠作為SiO2增強相均可達到力學性能增強的效果，同時仍能保持SiO2氣凝膠本身質輕、高孔隙率、高比表面積等特性；當以CNF質量分數為6wt%的溶液製備氣凝膠時，CNF增強SiO2氣凝膠具有最優的力學性能，壓縮模量和壓縮強度分別為12.43MPa和2.59MPa。

關鍵詞：納米纖維素；SiO2氣凝膠；力學性能；微觀結構

Abstract:In order to eliminate the low mechanical property and brittle character of SiO2aerogel, the cellulose nanofibrils (CNF) were used to reinforce SiO2aerogel throughin-situsol-gel process.The chemical structure, morphology, mechanical and physical properties of SiO2aerogels were characterized and analyzed.The improvement of mechanical propertyand mechanism was investigated of SiO2aerogel reinforced with CNF. The results show that the CNF of unique nano network structure can enhance the bonding strength between SiO2particles. The appearance of Si—OH (960cm-1) and Si—O—Si (1225cm-1, 1056cm-1and 800cm-1) characteristic absorption peaks represent the formation of stable chemical bond between cellulose and SiO2. The CNF with different concentrations all can significantly improve the mechanical property of SiO2aerogel, and still remain SiO2aerogel itself light mass, high porosity and high specific area. When preparing at 6wt% CNF concentration, the SiO2aerogel reinforced with CNF has the best mechanical property; its compressive modulus and strength are 12.43MPa and 2.59MPa, respectively.

Keywords:cellulose; SiO2aerogel; mechanical property; microstructure

作者：付菁菁等，農業部南京農業機械化研究所，南京

通訊作者：王思群，美國田納西大學再生碳中心，美國諾克斯維爾

全文詳見中國知網學術期刊優先數字出版。

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