Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 4

年份

2022 1

2021 1

2014 1

2007 1

关键词

检索范围：

排序：展示方式：

Effects of polyethylenimine on the dispersibility of hollow silica nanoparticles

WEN Lixiong, WANG Qing, ZHENG Tianyuan, CHEN Jianfeng

《化学科学与工程前沿（英文）》 2007年第1卷第3期页码 277-282 doi: 10.1007/s11705-007-0050-4

摘要： In this study, two different methods were applied to disperse hollow silica nanoparticles (HSNP); one employed polyethylenimine (PEI) as the dispersant during the synthesis processes for preparing HSNP, while the other added PEI into suspensions of the prepared HSNP and used milling treatment to achieve the desired dispersion. It was found that adding PEI during the synthesis process of HSNP had no noticeable improvement in the dispersion, while adding PEI into suspensions of the prepared HSNP and utilizing milling treatment resulted in remarkable dispersion improvement. Therefore, the latter was chosen as the method in dispersing HSNP suspensions. The adsorption of PEI on the surface of HSNP and the stability of the aqueous suspensions was investigated. The results indicated that the adsorption of PEI on the surface of HSNP would increase the repulsive energy among particles, hence reducing the agglomeration of HSNP and improving the stability of the aqueous suspensions. The change of HSNP’s ζ potential after adding PEI and the relationship between the adsorbed amount of PEI and pH were also investigated.

关键词： dispersion improvement different prepared HSNP relationship agglomeration

HTML PDF 收藏

Effective and selective adsorption of uranyl ions by porous polyethylenimine-functionalized carboxylated

Juan Shen, Fang Cao, Siqi Liu, Congjun Wang, Rigui Chen, Ke Chen

《化学科学与工程前沿（英文）》 2022年第16卷第3期页码 408-419 doi: 10.1007/s11705-021-2054-x

摘要： Composite materials have elicited much interest because of their superior performance in the removal of toxic and radioactive uranyl ions from aqueous solutions. With polyethyleneimine as a functional group, carboxylated chitosan as a matrix, and oxidizing activated carbon as a nanofiller, this study synthesized a novel environment-friendly polyethylenimine-functionalized carboxylated chitosan/oxidized activated charcoal (PCO) biocomposite with a unique three-dimensional porous structure. PCO was synthesized through an easy chemical cross-linking method. Detailed characterization certified the formation of the unique three-dimensional porous structure. The obtained PCO was used to remove uranyl ions from an aqueous solution, demonstrating the maximum adsorption capacity of 450 mg·g . The adsorption capacity of PCO decreased by less than 7.51% after five adsorption-desorption cycles. PCO exhibited good adsorption selectivity ( = 3.45 × 10 mL·g ) for uranyl ions. The adsorption mechanism of PCO was also discussed. The material showed good potential for application in the treatment of wastewater containing uranyl ions.

关键词： polyethylenimine carboxylated chitosan activated charcoal uranyl ion adsorption

HTML PDF 收藏

Removal of clofibric acid from aqueous solution by polyethylenimine-modified chitosan beads

Yao NIE,Shubo DENG,Bin WANG,Jun HUANG,Gang YU

《环境科学与工程前沿（英文）》 2014年第8卷第5期页码 675-682 doi: 10.1007/s11783-013-0622-0

摘要： Polyethylenimine (PEI)-modified chitosan was prepared and used to remove clofibric acid (CA) from aqueous solution. PEI was chemically grafted on the porous chitosan through a crosslinking reaction, and the effects of PEI concentration and reaction time in the preparation on the adsorption of clofibric acid were optimized. Scanning electron microscopy (SEM) showed that PEI macromolecules were uniformly grafted on the porous chitosan, and the analysis of pore size distribution indicated that more mesopores were formed due to the crosslinking of PEI molecules in the macropores of chitosan. The PEI-modified chitosan had fast adsorption for CA within the initial 5 h, while this adsorbent exhibited an adsorption capacity of 349 mg·g for CA at pH 5.0 according to the Langmuir fitting, higher than 213 mg·g on the porous chitosan. The CA adsorption on the PEI-modified chitosan was pH-dependent, and the maximum adsorption was achieved at pH 4.0. Based on the surface charge analysis and comparison of different pharmaceuticals adsorption, electrostatic interaction dominated the sorption of CA on the PEI-modified chitosan. The PEI-modified chitosan has a potential application for the removal of some anionic micropollutants from water or wastewater.

关键词： clofibric acid PEI-modified chitosan adsorption capacity adsorption mechanism electrostatic interaction

HTML PDF 收藏

Adsorption performance and physicochemical mechanism of MnO

Xiaoyan Deng, Luxing Wang, Qihui Xiu, Ying Wang, Hong Han, Dongmei Dai, Yongji Xu, Hongtao Gao, Xien Liu

《化学科学与工程前沿（英文）》 2021年第15卷第3期页码 538-551 doi: 10.1007/s11705-020-1958-1

摘要： In this work, an adsorbent, which we call MnPT, was prepared by combining MnO , polyethylenimine and tannic acid, and exhibited efficient performance for Cu(II) and Cr(VI) removal from aqueous solution. The oxygen/nitrogen-containing functional groups on the surface of MnPT might increase the enrichment of metal ions by complexation. The maximum adsorption capacities of MnPT for Cu(II) and Cr(VI) were 121.5 and 790.2 mg·g , respectively. The surface complexation formation model was used to elucidate the physicochemical interplay in the process of Cu(II) and Cr(VI) co-adsorption on MnPT. Electrostatic force, solvation action, adsorbate–adsorbate lateral interaction, and complexation were involved in the spontaneous adsorption process. Physical electrostatic action was dominant in the initial stage, whereas chemical action was the driving force leading to adsorption equilibrium. It should be noted that after adsorption on the surface of MnPT, Cr(VI) reacted with some reducing functional groups (hydroxylamine-NH ) and was converted into Cr(III). The adsorption capacity declined by 12% after recycling five times. Understanding the adsorption mechanism might provide a technical basis for the procedural design of heavy metal adsorbents. This MnPT nanocomposite has been proven to be a low-cost, efficient, and promising adsorbent for removing heavy metal ions from wastewater.

关键词： MnO₂-polyethylenimine-tannic acid composite surface complexation formation model Cu(II) Cr(VI) physicochemical mechanism