SiO_(2)气凝胶微球的制备及其在织物隔热涂层中的应用

Preparation of SiO_(2)aerogel microspheres and their application in thermal insulation coatings of fabrics

分别以十二烷基三甲基溴化铵(DTAB)、醋酸为乳化剂和催化剂,在水包油分散液中将甲基三甲氧基硅烷(MTMS)水解为硅醇,随后以司班-80(Span-80)为乳化剂将上述水分散液分散于正己烷中,将氨水作为催化剂催化硅醇缩合,经老化、常压干燥制得SiO_(2)气凝胶微球。探究DTAB、醋酸、氨水、Span-80用量及老化时间对SiO_(2)气凝胶微球形貌、堆积密度和导热性能的影响,测试SiO_(2)气凝胶微球的热稳定性和疏水性,并将其应用于棉织物的隔热涂层整理。结果表明:当DTAB用量为0.10 g、醋酸用量为0.100 mL、氨水用量为1.20 mL、Span-80用量为0.80 g、老化时间为3 h时,制备所得的SiO_(2)气凝胶微球具有介孔结构,形貌规整、大小均匀、黏连较少,热稳定性佳,导热系数为0.0465 W/(m·K),水接触角为142°;SiO_(2)气凝胶微球涂层织物正面加热至40.0℃时,其正反面温差达3.2℃,表现出较好的隔热效果。该研究可为隔热涂层织物的生产和应用提供一定的借鉴。

Methyl trimethoxylsilane(MTMS)was dispersed in water by dodecyl trimethyl ammonium bromide(DTAB)and hydrolyzed by acetic acid,ammonia was than added and the mixture was dispersed into hexane by Span-80,after silyl alcohol condensation and ageing,SiO_(2)aerogel microspheres were prepared by normal pressure drying.The effects of DTAB,acetic acid,ammonia,Span-80 as well as the aging time on the morphology,thermal conductivity and bulk density of SiO_(2)aerogel microspheres were studied,their thermal stability and hydrophobic performance were investigated,and the heat insulation property of the SiO_(2)aerogel microspheres coated fabrics was tested.The results showed that,with 0.10 g of DTAB,0.100 mL of acetic acid,1.20 mL of ammonia and 0.80 g of Span-80,after aging for 3 h,the prepared SiO_(2)aerogel microspheres were mesoporous materials with regular morphology,uniform size,less adhesion and good thermal stability.Their thermal conductivity was 0.0465 W/(m·K),and the water contact angle was 142°.when the heating temperature was 40.0℃,the temperature difference between the front and back of SiO_(2)aerogel microspheres coated fabric reached 3.2℃,indicating its good heat insulation effect.This study can provide some support for the production and application of thermal insulating coating fabrics.