Surface analysis of cryofixation-vacuum-freeze-dried polyaluminum chloride-humic acid (PACl-HA) flocs

CORC > 生态环境研究中心 > 中国科学院生态环境研究中心 > 环境水质学国家重点实验室

	Surface analysis of cryofixation-vacuum-freeze-dried polyaluminum chloride-humic acid (PACl-HA) flocs
	Wang, Yili; Du, Baiyu; Liu, Jie; Lu, Jia; Shi, Baoyou; Tang, Hongxiao
刊名	JOURNAL OF COLLOID AND INTERFACE SCIENCE
	2007-12-15
卷号	316 期号:2 页码:457-466
关键词	cryofixation-vacuum-freeze-drying polyaluminum chloride (PACl) humic acid floc structure surface fractal analysis
英文摘要	The powder of polyaluminum chloride-humic acid (PACl-HA) flocs was prepared by cryofixation-vacuum-freeze-drying method. The FTIR spectra show that some characteristic functional groups in polyaluminum chloride (PACl), humic acid (HA), and kaolin still existed in the dried floes. X-ray diffractometry (XRD) patterns indicate that these floes are amorphous. Nitrogen adsorption-desorption isotherms were obtained for different samples of the dried PACl-HA floes. The BET specific surface area, BJH cumulative absorbed volume and BJH desorption average pore diameter of them were determined. The peak values of 8.4-11.2 nm (pore diameter) for pore size distribution (PSD) curves indicate that the pores of the dried floes are mostly mesopores. The surface fractal dimensions D(s) and the corresponding fractal scales determined from both SEM images and nitrogen adsorption-desorption data sets reveal the multi-scale surface fractal properties of the dried PACl-HA floes, which exhibited two distinct fractal regimes: a regime of low fractal dimensions (2.07-2.26) at higher scales (23-387 mu), mainly belonging to exterior surface scales, and a higher fractal dimensions (2.24-2.37) at lower scales (0.80-7.81 nm), failing in pore surface scales. Both HA addition and kaolin reduction in dried floc can decrease the irregularity and roughness of external surface. However, for the irregularity and roughness of pore surface, the addition of HA or kaolin in dried floc can increase them. Furthermore, some difference was found between the pore surface fractal dimensions D(s) calculated from nitrogen adsorption and desorption data. The pore surface D(s) values calculated through thermodynamic model were much greater than three. (C) 2007 Elsevier Inc. All rights reserved.
WOS记录号	WOS:000250987500029
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/22599]
专题	生态环境研究中心_环境水质学国家重点实验室
推荐引用方式 GB/T 7714	Wang, Yili,Du, Baiyu,Liu, Jie,et al. Surface analysis of cryofixation-vacuum-freeze-dried polyaluminum chloride-humic acid (PACl-HA) flocs[J]. JOURNAL OF COLLOID AND INTERFACE SCIENCE,2007,316(2):457-466.
APA	Wang, Yili,Du, Baiyu,Liu, Jie,Lu, Jia,Shi, Baoyou,&Tang, Hongxiao.(2007).Surface analysis of cryofixation-vacuum-freeze-dried polyaluminum chloride-humic acid (PACl-HA) flocs.JOURNAL OF COLLOID AND INTERFACE SCIENCE,316(2),457-466.
MLA	Wang, Yili,et al."Surface analysis of cryofixation-vacuum-freeze-dried polyaluminum chloride-humic acid (PACl-HA) flocs".JOURNAL OF COLLOID AND INTERFACE SCIENCE 316.2(2007):457-466.