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坡缕石/聚丙烯酰胺杂化物的合成、性质与絮凝应用

Synthesis, Solution Property and Application of Palygorskite/polyacrylamide Hybrid

【作者】 王猛

【导师】 钱锦文;

【作者基本信息】 浙江大学 , 高分子化学与物理, 2004, 硕士

【摘要】 目前无机-有机杂化物的研究重点主要集中于结构材料、电磁材料和膜材料,本文采用聚合物—粘土法合成了一种水溶性杂化物(絮凝剂)用于废水处理。 对天然矿物坡缕石(palygorskite,PGS)进行酸活化,增加内表面积及活性。酸活化处理的坡缕石(APGS)与氯化乙醇胺(EAC1)反应得到氯化乙醇胺改性破缕石(APGS-EAC1),与高价铈盐Ce4+组成氧化还原非均相引发体系,引发丙烯酰胺单体在坡缕石晶体的纳米孔道间聚合得到了坡缕石/聚丙烯酰胺(PGS/PAM)无机-有机杂化物。采用1H-NMR,FTIR,粘度法和电导法对合成的杂化物进行了结构表征,结果表明杂化物中存在PGS(?)⊕NH3R离子键合作用。实验考察了APGS-EAC1用量、聚合反应时间和单体浓度对杂化物特性粘数的影响,初步探讨了反应动力学。 研究了PGS/PAM的水溶液性质。发现杂化物粘度行为具有聚电解质效应,并且受杂化物特性粘数、改性坡缕石的含量、外加盐(NaCl)浓度和溶液pH值等因素的影响。杂化物电导具有弱电解质的电离行为,电离度与杂化物特性粘数、改性坡缕石含量密切相关。考察了杂化物的SEC谱图与实验中的注射浓度的关系,在较低的注射浓度下呈现不光滑的多峰分布,暗示杂化物的分子可能包含星形结构。 考察了改性坡缕石含量、杂化物特性粘数对其絮凝效果的影响,给出了杂化絮凝剂的絮凝模型。由PGS/PAM杂化絮凝剂分别处理高岭土和氧化铁红两种配制废水,发现杂化絮凝剂的絮凝效果明显优于纯PAM絮凝剂。将杂化絮凝剂用于处理实际废水,效果也非常明显。

【Abstract】 Recently, inorganic-organic polymer hybrids have caught a great deal of attention from many researchers. The addition of inorganic materials, especially inorganic materials with nano-scale, to organic polymer endows these organic materials many unique physical and chemical properties. So inorganic-organic polymer hybrids have been utilized extensively in structural materials, electronic or optical materials, and membrane materials, but only a few efforts have been made on the syntheses of water-soluble polymers and few study has been made on solution properties of those. In this thesis, a water-soluble hybrid, palygorskite-polyacrylamide was synthesized by polymer-clay method, and this hybrid was used as flocculent in water-treatment.First, a natural mineral, palygorskite(PGS) was acid activated by HC1 solution, and then acid activated palygorskite (APGS) reacted with ethanolamine hydrochloride (EACl), and the modified palygorskite (APGS-EACl) was obtained. Acrylamide was initiated by heterogeneous redox initiator system, composed of reductive agent APGS-EACl together with oxidant Ce4+, and polymerization occurred in the inner surface of nano-scale tunnel of PGS crystal. The palygorskite/polyacrylamide (PGS/PAM) hybrid obtained was characterized by H-NMR, FTIR, viscosimetry and specific conductivity method. It can be interpreted in terms of ion bond structure (PGSeeNH3R) in PGS/PAM hybrid. The influence of dosage of APGS-EACl, polymerization time, and monomer concentration on the of the PGS/PAM hybrid was investigated, and it is also found that the of the hybrid increases with increasing reaction time differing from conventional free-radical polymerization.Dilute solution behavior of water-soluble PGS/PAM hybrid have been investigated by specific conductivity method, viscometry, and size exclusion chromatography (SEC). It was found that the polyelectrolyte behavior and specific conductivity of hybrids in deionized water at low concentration region depend strongly on its degree of ionization, which is firmly connected to the content of APGS-EACl and the intrinsic viscosity. The SEC chromatograms of PGS/PAM hybrid not only display the polyelectrolyte behavior but also reveal unregulated peak. All results indicate that PGS/PAM hybrid is a weak polyelectrolyte, i.e., an ionized hybrid, and probably a star-like ionized hybrid in which the PGS particle acts as a core and the chains of PAM act as arms, according to the SEC chromatograms.Flocculating effect of PGS/PAM hybrid was better than that of pure PAM for both 0.25wt% kaolin suspension and 0.5wt% hematite suspension, respectively. Finally, PGS/PAM hybrid flocculent was also applied in treating real waster water. A new flocculating model for PGS/PAM hybrid flocculent was proposed.

  • 【网络出版投稿人】 浙江大学
  • 【网络出版年期】2004年 03期
  • 【分类号】X703
  • 【下载频次】245
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