| Alkaline Ca-bentonite is the first anion exchange bentonite which has been developed in recent years. Because calcium ion in the bentonite layer with activity hydroxide, it make possibility to more organics intercalate into the bentonite layer. Using organic acids which is rich in nature, alkaline Ca-bentonite can be modified by a wide range of organic acid bentonite. Gluconic acid is a polyhydroxy organic acid, and it can modify alkaline Ca-bentonite make a polyhydroxy bentonite which is good hydrophilicity and good compatibility for polyhydroxy polymer or macromolecular.In this work, gluconic acid modified alkaline Ca-bentonite as the starting point, on the one hand, the bentonite modified reaction was carried on under mild conditions so as to maintain the layered structure, and the numbers of hydroxyl of bentonite surface were increased. Gluconic acid modified bentonite which is a good capacity and stability anhydrous material was prepared. On the other hand, let gluconic acid molecule fully enter the bentonite layer and occurre acid-base neutralization reaction with OH" in layer. Due to intense heat of the reaction, the bentonite layers were exfoliated into nano-piece. Then particle exfoliated gluconic acid nano-montmorillonite (P-EGAM) was prepared. As an inorganic/ organic composite nano-materials, gluconic acid nano-montmorillonite can modify the natural polymers or polymerized hydrophilicity macromolecular to a high degree decentralize.In this paper, optimum preparation conditions of gluconic acid modified bentonite anhydrous material and paticle exfoliated gluconic acid montmorillonite were obtained through single-factor experiment. Using IRD, XRD, DSC and SEM, structure of the products were characterized. At the same time, both the properties and application of this two materials were preliminary studied. Results of characterization and application showed that the new anhydrous material remains the layered structure and the layer spacing of alkaline Ca-bentonite. It also indicates that the new anhydrous material has porous and roughness surface, and is good thermostability and regeneration of low temperature. Result of application in normal pressure ethanol vapor dehydration showed, when ethanol concentration in the feed was 95% (mass), production capacity was 0.706 gram product·(gram adsorbent)-1. Results of characterization and application showed that the particle exfoliated gluconic acid montmorillonite was a montmorillonite particle modified by gluconic acid. Its thermostability was similarly to calcium gluconate. Its interior structure and surface were changed apparently. It was a nano-piece which thickness was smaller than 100 nm. The application result in cassava starch modification showed that the P-EGAM could increase the viscosity of P-EGAM/ starch composites, and the optimal proportion of P-EGAM addition is 2.5%. Finally, exfoliated mechanism was preliminary speculated by comprehensive comparison of preparation, characterization and application of the two materials. From data of endothermic enthalpy change of DSC, exfoliated rate of gluconic acid montmorillonite was calculated.Research and development of gluconic acid modified alkaline Ca-bentonite can combine organically with the development of bentonite and cassava starch. It also can broaden the application of bentonite in the field of dehydration of organic solvents and hydrophilic polymer composite material.
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