(1. 中南大學(xué) 冶金科學(xué)與工程學(xué)院，長(zhǎng)沙 410083；
2. 中南大學(xué) 化學(xué)化工學(xué)院，長(zhǎng)沙 410083)
摘 要: 基于超細(xì)氫氧化鋁粒度分布曲線(xiàn)和紅外光譜，通過(guò)粒子數(shù)計(jì)算和3 700~3 000 cm−1間紅外光譜分峰擬合，研究了干燥過(guò)程中表面活性劑對(duì)超細(xì)粉體粒度的影響規(guī)律。結(jié)果表明：加入表面活性劑后，干燥后超細(xì)氫氧化鋁粒子總數(shù)的減少不大于6%；而不加表面活性劑時(shí)，粒子總數(shù)減少99.98%；同時(shí)可能是由于粒度小于0.1 μm的粒子易吸附于表面活性劑的原因，干燥過(guò)程中的團(tuán)聚程度較小，而粒徑為0.5~10 μm的粒子團(tuán)聚較明顯。紅外光譜分析結(jié)果表明：加入表面活性劑A和B后，在1 310 cm−1處出現(xiàn)游離O—H特征峰，同時(shí)游離的O—H從32.3%(質(zhì)量分?jǐn)?shù))分別增加至39.88%和35.95%，多分子間締合的O—H特征峰從36.65%分別減少至29.78%和27.79%；這說(shuō)明表面活性劑的加入可以明顯抑制分子間O—H的形成，從而可降低粒子的團(tuán)聚程度。
關(guān)鍵字: 表面活性劑；超細(xì)氫氧化鋁；機(jī)理
ultra-fine Al(OH)3 in drying process
（1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China;
2. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract: The influence of surfactant on the particle size and agglomeration mechanism was studied in term of the particle numbers calculated from particle size distribution and multi-peak fitting of IR spectra. The results show that the particle number reduces less than 6% with addition of surfactant, while that reduces 99.98% without adding surfactant. The coarse particle (0.5−10 μm) is much easier to be agglomerated than the ultra-fine particle(less than 0.1 μm), which maybe due to the easy absorption of surfactant for the ultra-fine particle. The results from IR show that the characteristic peak appears at 1 310 cm−1 accounting for free O—H when surfactant is added, and then free O—H increases from 32.30% (mass fraction) to 39.88% and 35.95%, respectively, and O—H in association molecular reduces from 36.65% to 29.78% and 27.79%, respectively. This shows that the agglomeration is inhibited by reducing the amount of O—H in association molecules with addition of surfactant in the drying process.
Key words: surfactant; ultra-fine Al(OH)3 powder; agglomeration mechanism
