聚电解质和表面活性剂对铝镁型混合金属氢氧化物正电溶胶稳定性的影响

EFFECTS OF POLYELECTROLYTE AND SURFACTANT ON THE STABILITY OF ALUMINUM-MAGNESIUM MIXED METAL HYDROXIDE POSITIVE SOL

研究了非离子型聚丙烯酰胺（ＰＡＭ）、阴离子型部分水解聚丙烯酰胺（ＰＨＰＡ）、阳离子型聚丙烯酰胺（ＣＰＡＭ）、醋酸乙烯酯—马来酸酐共聚物（ＶＡ－ＭＡ）及阴离子型表面活性剂十二烷基磺酸钠（ＡＳ）和阳离子型表面活性剂十六烷基三甲基溴化胺（ＣＴＡＢ）对铝镁型混合金属氢氧化物（Ａｌ－ＭｇＭＭＨ）正电溶胶稳定性的影响，根据“桥联”作用、静电作用和疏水作用等对其作用机理进行了探讨．

It was studied that nonionic polyacrylamide (PAM),anionic partial hydrolyzed polyacrylamide(PHPA),cationic polyacrylamide(CPAM),vinyl acetatemaleic anhydride copolymer(VAMA)and sodium dodecyl sulfonate(AS),hexadecyltrimethylammonium bromide(CTAB) affected on the stability of aluminummagnesium mixed metal hydroxide(AlMg MMH)positive sol by way of measuring percent transmittance(T) of supernatant liquid.The following results were obtained:(1)With increasing the concentration of anionic polyelectrolytes such as PHPA and VAMA,the AlMg MMH positive sol slightly coagulated first,then flocculated to settle,and finally might obtain stabilization gradually again because the colloidal particles adsorbed more polyelectrolyte to form protective layer.(2)The more the negative charge in polyelectrolyte molecular chain existed,the stronger the flocculation for the sol was.For PAM in which molecular chain there were hardly any negatively charged radicals,the colloidal particles didnt flocculate to settle,only slightly coagulated over a wide range of PAM concentration.(3)With CPAM,AlMg MMH positive sol was not flocculated to settle over a wide range of CPAM concentration,only when the CPAM concentration reached a certain value the characteristic of slightly coagulation might appear.(4)With anionic surfactant AS,AlMg MMH positive sol might be flocculated.But the cationic surfactant CTAB didnt aftect the stability of AlMg MMH positive sol.These results have been explained with electrostatic force,"bridging"and hydrophobic effect.