NaOH处理镨黄表面对其粒径的影响研究

Effect of Pretreatment of Sodium Hydroxide Solution on Particle Size of Yellow Pigment

为了解不同浓度Na OH溶液处理镨黄表面对其粒径的影响。配制了不同浓度的Na OH溶液对镨黄进行处理并用无水乙醇淋洗过滤,运用分光光度计,激光粒度仪分别对其滤液和滤渣进行分析;对不同浓度Na OH溶液处理后镨黄进行纯水分散,对照未处理的镨黄,用显微镜和自然沉降实验进行分析。结果:过滤处理后滤液分层,但无水乙醇与Na OH溶液混合物为透明不分层;其中30%Na OH处理的滤液中小颗粒最多,10%Na OH处理的滤液中小颗粒最少;激光粒度仪测量干燥滤渣时,颗粒大小顺序为:原镨黄<10%Na OH镨黄<20%Na OH镨黄<30%Na OH镨黄。200倍的显微镜下观察到纯水中的粒径大小为:原镨黄>10%Na OH处理镨黄>20%Na OH处理镨黄>30%,水中的完全沉降时间和沉淀表面层白色深浅顺序为10%Na OH镨黄<20%Na OH镨黄<30%Na OH镨黄。结果表明:Na OH处理过的镨黄在无水乙醇中的相容性大于水中且阻碍乙醇和水的互溶;浓度高的Na OH溶液处理镨黄,过滤后滤液中小颗粒量越多,滤渣的小颗粒量越少,但滤渣干燥后颗粒的平均粒径越大,而在纯水中的颗粒越小,沉降时间越长,完全沉淀后沉淀表面白色越深。

In order to investigate the effect of retreating yellow pigment with different concentrations of sodium hydroxide solution on particle size. The yellow pigments were pretreated and rinsed with anhydrous alcohol, spectrophotometer and laser granularity analyzer were used to analyze the filtrates and residues;The pretreated yellow pigment dispersions were prepared by adding pure-water, microscope and natural settling experiment were used to analyze and compare pretreated yellow pigment with untreated yellow pigment. The results showed that the filtrate was stratified after filtration treatment, but the mixture of anhydrous alcohol and sodium hydroxide solution was transparent and unstratified. The small particles were the most in the filtrate after pretreatment with 30% sodium hydroxide solution, and were the least in the filtrate after pretreatment with 10% sodium hydroxide solution. The order of size in the dry residue was analyzed by laser granularity analyzer： original yellow pigment yellow pigment pretreated with 10% sodium hydroxide solution yellow pigment pretreated with 20% sodium hydroxide solution yellow pigment pretreated with 30% sodium hydroxide solution. The order of yellow pigment size in pure water was analyzed by microscope（200 times）： original yellow pigment yellow pigment pretreated with 10% sodium hydroxide solution yellow pigment pretreated with 20% sodium hydroxide solution yellow pigment pretreated with 30% sodium hydroxide solution. The order of settling time and color of sediment surface ： yellow pigment pretreated with 30% sodium hydroxide solution yellow pigment pretreated with 20% sodium hydroxide solution yellow pigment pretreated with 10% sodium hydroxide solution. The compatibility of pretreated yellow pigments with anhydrous alcohol was better than with pure-water, and pretreated yellow pigments inhibited the intersolubility of anhydrous alcohol and pure-water;While the yellow pigment was pretreated with high concentrations of sodium hydroxide solution and was rinsed with anhydrous alcohol, the small particles of yellow pigment in the filtrate were more than the residue. The particle size of dry residue was the largest than the others. But the particle size in the pure-water was the smallest than the others, the settling time was the longest and the color of sediment surface was the deepest.