pH值对油酸盐发泡性能影响及泡沫循环利用机理研究

Effect of pH value on foaming properties of oleate and recirculating utilization mechanism of foam

关键词:  pH值  油酸盐  泡沫循环  消泡机理 

Key words:  pH value  oleate  foam circulation  defoaming mechanism

摘要:

油酸盐中含有酸碱敏感性羧酸官能团,因而可实现泡沫的酸碱循环利用。通过Waring-Blender法、酸碱滴定测试、表面与界面张力测试、微观分析等研究手段,分析了pH值变化对油酸盐水溶液性质、油酸盐羧酸官能团电离度以及油酸盐发泡性能的影响。同时,开展了6次泡沫循环实验,并从微观现象解释以及“铺展与架桥”理论对其消泡机理进行了深入分析。研究结果表明,油酸盐中的羧酸官能团通过失去或得到质子来实现活性与非活性之间的可逆转换,从而实现泡沫的循环利用。此外,通过消泡机理分析可以看出,氢离子的侵入可以促进油酸盐泡沫结构中非水溶性油酸的形成,并进入泡沫液膜结构,通过铺展或架桥作用使得液膜破裂,从而达到消泡的作用。 

Abstract:

The acid and alkali circulation utilization of foam can be realize due to the exist of pH-sensitivity carboxyl groups in oleate. With methods of Warning-blender, acid-base titration test, surface tension and interfacial tension test and microscopic analysis, etc., the effects of pH values change on aqueous solution properties of oleate, ionization degree of carboxyl group of oleate, and foaming properties of oleate were analyzed. Meanwhile, six foam circulation experiments have been carried out, and defoaming mechanism was discussed through explanation of microscopic phenomena, spreading and bridging mechanisms. The results show that carboxyl group of oleate can easily lose or receive protons to realize the reversible interconversions between active and inactive, further to realize circulation utilization of foam. Also, the defoaming mechanism analysis suggests that the invasion of hydrogen ions can lead to form water insoluble oleic acid of foam structure of oleate, and into the foam liquid films structure, facilitate liquid films rupture through spreading or bridging action, so as to achieve the effect of defoaming.