硬脂酸改性纳米氧化铝的工艺

Surface modification process of nano-Al_2O_3 with stearic acid

以硬脂酸为改性剂,对纳米氧化铝表面进行改性,探讨不同溶剂、硬脂酸用量、反应温度、反应时间对改性效果的影响,并采用傅里叶变换红外光谱(FT-IR)、热重分析(TGA)、扫描电镜(SEM)等分析手段对改性前后的纳米氧化铝进行表征。结果表明:硬脂酸改性纳米氧化铝的优化工艺条件为溶剂正丁醇、硬脂酸用量6%、反应温度30℃、反应时间30 min,此时改性后的纳米氧化铝的活化度可达到97.6%,沉降体积降低到2.80 mL·g^(-1),且由亲水转变为疏水。红外光谱表明:硬脂酸成功接枝到了纳米氧化铝表面;热重分析表明硬脂酸在纳米氧化铝表面的接枝率达到7.66%;扫描电镜结果表明改性后的纳米氧化铝的分散性得到了提高。

Surface modification process of nano-alumina using stearic acid as modification was studied.The effects of different solvents,the amount of stearic acid,the reaction temperature and the reaction time on the modification effect were studied.The nano-aluminas before and after modification were characterized by Fourier transform infrared spectoscopy(FT-IR),thermogravimetric analysis(TGA),and scanning electron microscopy(SEM).The optimum modification conditions were that solvent of reaction,the mass faction of stearic acid,reaction temperature and reaction time were n-butanol,6%,30℃,and 30 min,respectively.The activation degree of modified nano-alumina reached 97.6%and its settlement volume in liquid paraffin of 2.80 mL·g-1 could be obtained.The modified nano-alumina was changed from hydrophilic to hydrophobic.FT-IR results indicated that stearic acid was successfully grafted to nano-alumina;TGA analyses showed that grafting rate of stearic acid on the surface of nano-alumina was 7.66%;SEM images showed that the dispersion of modified nano-alumina was improved.