应用化学 ›› 2010, Vol. 27 ›› Issue (07): 811-816.DOI: 10.3724/SP.J.1095.2010.90595

• 研究论文 • 上一篇    下一篇

类水滑石对低取代度阳离子淀粉的吸附行为

李燕1,侯万国2*   

  1. (1.长治学院化学系 长治;2.山东大学胶体与界面化学教育部重点实验室 济南 250100)
  • 收稿日期:2009-09-04 修回日期:2009-12-31 出版日期:2010-07-10 发布日期:2010-07-10
  • 通讯作者: 侯万国,男,博士,教授; E-mail:wghou@sdu.edu.cn; 研究方向:胶体与界面化学
  • 基金资助:
    国家自然科学基金(50772062)国家重点基础研究发展(九七三)计划(2004CB418504)及山西省高校科技开发(20091038)资助项目

Adsorption of Low-substituted Cationic Starch on Aluminum Magnesium Hydrotalcite Analogue

LI Yan1, HOU Wan-Guo2*   

  1. (1.Department of Chemistry,Changzhi College,Changzhi;
    2.Key Laboratory for Colloid and Interface Chemistry of
    Education Ministry,Shandong University,Jinan 250100)
  • Received:2009-09-04 Revised:2009-12-31 Published:2010-07-10 Online:2010-07-10
  • Contact: WanGuo HOU

摘要:

研究了低取代度阳离子淀粉(CS-L)在Mg-Al类水滑石(HTlc)上的吸附行为。 CS-L可在带结构正电荷的Mg-Al HTlc表面吸附,吸附方程符合Langmuir等温式,300 min左右达吸附平衡,饱和吸附量为33.92 mg/g。 吸附驱动力可能缘自于:CS-L醚键或羟基与HTlc羟基之间形成氢键;熵效应,即吸附所引起的CS的熵减少小于被吸附水释放引起的熵增加。 随着pH值的增加,CS-L和HTlc的Zeta电位均降低,二者静电排斥作用减小,吸附量增加;惰性电解质NaCl和CaCl2的加入可屏蔽HTlc与CS-L之间及CS-L分子内带正电的链段之间的静电排斥力,吸附量增加;pH=9时,带负电的Al八面体多聚体容易吸附在带结构正电荷的HTlc表面进而吸附CS分子,吸附量显著增加;温度升高降低二者氢键作用,吸附量降低。 比较了CS-L与高取代度阳离子淀粉(CS-H)在Mg-Al HTlc上的吸附行为。

关键词: 吸附, 类水滑石化合物, 低取代度, 阳离子淀粉

Abstract:

The adsorption of low-substituted cationic starch(CS-L) on Mg-Al HTlc was investigated. The following results were obtained:CS-L can be adsorbed on the external surface of positively changed Mg-Al HTlc. The adsorption isotherm followed the typical Langmuir equation and the saturated adsorption amount was 33.92 mg/g. The driving force for adsorption was probably due to two effects:(1)hydrogen bonding between the hydroxyl group or ether group of CS-L and the hydroxyl group of HTlc; (2)entropic effect, where the entropic loss for the CS-L adsorption is less then entropic gain for the released solvent molecules. The adsorption amount of CS-L increased with pH, which may be contributed to the decrease of the zeta potentials of CS-L and the HTlc with pH. The adsorption amount of CS-L increased with the addition of NaCl and CaCl2 because inert electrolytes screened the repulsion between HTlc particles and CS-L and the intramolecular repulsion between the cationic groups of the CS-L. At pH=9, the adsorption of CS-L on HTlc increased dramatically with the concentration of AlCl3 since the hydrolysate of Al3+ might play a role as a linkage between CS-L and HTlc, and. The adsorption amount of CS-L decreased with increasing temperature as a result of hydrogen bonding decrease. The adsorption kinetics of CS-L on Mg-Al HTlc showed that the equilibrium time of adsorption was about 300 min. Furthermore, the comparison of adsorption behaviors between CS-L and CS-H on Mg-Al HTlc was also carried out.

Key words: Adsorption, Hydrotalcite-like compounds, Low degree of substitution, Cationic Starch

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