摘要
采用共沉淀法制备了3种形态的MgAl双金属氢氧化物颗粒的水分散体系,并以其为乳化剂制备了Pickering乳液.比较了3种颗粒的分散体系及其稳定的Pickering乳液的性质.X射线衍射(XRD)和透射电子显微镜(TEM)表征结果表明,低结晶度的颗粒以形状不规则、结构疏松、表面粗糙的絮状体形式分散于水中,且颗粒尺寸随高速搅拌分散时间的延长而减小;而良好结晶的颗粒以形状规则、结构致密、表面平滑的六角片存在于水中.Zeta电位测试表明,3种颗粒在水中均带正电荷,NaCl可降低颗粒的Zeta电位而使其发生絮凝,但良好结晶颗粒的分散体系在更高NaCl浓度时才出现明显沉淀.分别采用3种双金属氢氧化物颗粒/NaCl水分散体系制备了水包油(O/W)型Pickering乳液,并比较了乳液的稳定性.结果表明,NaCl的引入在一定程度上可提高3类乳液的稳定性;良好结晶颗粒稳定乳液的能力强于低结晶度的颗粒;对于低结晶度颗粒,大颗粒稳定乳液的能力比小颗粒更强.
Three aqueous dispersions of MgAl double hydroxide particles with different forms were prepared by a coprecipitation method.And then Pickering emulsions were prepared from them.The properties of the aqueous particle dispersions and the emulsions were studied.X-ray diffraction（XRD） and transmission electron microscope（TEM） characterizations indicate that the low crystallized particles dispersed in water in the manner of irregular shaped and loose structured particles with rough surfaces,while the well crystallized particles were the compact structured hexagonal platelets with smooth surfaces.Zeta potential measurements show that NaCl reduced the zeta potential of the three particles,resulting in particle flocculation in water.But the well crystallized particle dispersion flocculated in a higher salt concentration.The three double hydroxide particle/NaCl dispersions were used to prepare emulsions containing equal volumes of oil and water,respectively.The stability of the three emulsion systems was further compared.The results show that the stability of all emulsions was improved to some extent by the addition of NaCl.The emulsifying ability of the well crystallized particles appeared to be better than that of the low crystallized particles.For the low crystallized double hydroxides,the larger particles were better emulsion stabilizers than the smaller ones.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2013年第2期386-393,共8页
Chemical Journal of Chinese Universities
基金
国家'八六三'计划项目(批准号:2009AA06Z202)资助
