煤的表面电位与表面官能团间的关系  

RELATIONSHIP BETWEEN SURFACE POTENTIAL AND FUNCTIONAL GROUPS OF COALS

作　　者：王宝俊[1] 李敏[1] 赵清艳[1] 秦育红[1] 谢克昌[1] 

机构地区：[1]太原理工大学煤科学与技术教育部和山西省重点实验室,山西太原030024

出　　处：《化工学报》2004年第8期1329-1334,共6页CIESC Journal

基　　金：国家重点基础研究 (No G19990 2 2 10 1);国家自然科学基金 (No 40 3 72 0 73 );山西省自然科学基金 (No 2 0 0 3 10 2 1);太原理工大学青年基金 (No 190 10 0 0 5 7)~~

摘　　要：测定了 5种不同变质程度的典型中国动力煤在不同pH值的水介质中的 ζ电位和用H2 O2 氧化后各煤种ζ电位的变化 ,得到了 ζ电位等电点 pH值 ;用FTIR定量表征了与煤表面电位有关的官能团以及被H2 O2 氧化后的变化 ;通过对模型化合物的ZINDO量子化学理论计算 ,得到了H+ 在煤表面的吸附能、相关化学键的键级、键长和净电荷分布 .综合分析实验和计算的结果 ,确认了在水体系中煤的表面电荷为负电荷 ;煤的 ζ电位等电点随煤化程度的提高有规律地升高 ;与煤表面 ζ电位密切相关的负电性官能团主要是 —OH基团 ;原煤经H2 O2氧化后 ,—OH、 CO 和—COOH等官能团增多 ,煤表面负电性增加 ;H+ 在煤表面发生化学吸附 。The ζ-potentials of five kinds of Chinese typical steam coals with different ranks in aqueous solution with different pH values and the effects of H2O2-oxidation on ζ-potential of the corresponding coals were measured. The pH values at the isoelectric point (IEP) of the coals were determined. The functional groups related to the coal surface potentials and their changes by H2O2-oxidation were quantitatively characterized using FTIR. The adsorption energy of H+ on different coal surface, along with correlated chemical bond length, order, and net charge distribution were obtained by means of ZINDO quantum chemical calculation of model compounds. According to a comprehensive analysis of ζ-potential, FTIR spectra and the results of ZINDO calculation, the following conclusions were reached. Coal surface is negatively charged in aqueous system. IEP rise regularly with increase in coal rank, -OH is the main negative functional group closely related to ζ-potential on coal surface. Chemical adsorption of H+ occurs on coal surface, and the adsorption energy increases with increase in coal rank.

关 键 词：煤 Ζ电位 ZINDO 表面 氧化 等电点 氢离子 

分 类 号：O641.12[理学—物理化学] TQ530[理学—化学]