Optimization of dispersion and suspension-stability for carbon nanotube flow-electrode

doi:10.16085/j.issn.1000-6613.2018-0650

Chemical Industry and Engineering Progress ›› 2019, Vol. 38 ›› Issue (02): 956-963.DOI: 10.16085/j.issn.1000-6613.2018-0650

• Materials science and technology • Previous Articles Next Articles

Optimization of dispersion and suspension-stability for carbon nanotube flow-electrode

Xiaotong ZHAO^1,^2,³(),Shichang XU^1,³(),Dongya MA^1,^2,³,Yue WANG^1,^2,³,Qiaoling WANG^1,^2,³

1. Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
2. State Key Laboratory of Chemical Engineering, Tianjin 300072, China
3. Tianjin Key Laboratory of Membrane Science and Desalination Technology, Tianjin 300072, China

Received:2018-03-29 Revised:2018-11-05 Online:2019-02-05 Published:2019-02-05
Contact: Shichang XU

碳纳米管流动电极分散性和悬浮稳定性的优化

赵晓童^1,^2,³(),徐世昌^1,³(),马冬雅^1,^2,³,王越^1,^2,³,王巧灵^1,^2,³

1. 天津大学化工学院化学工程研究所，天津 300072
2. 化学工程联合国家重点实验室，天津 300072
3. 天津市膜科学与海水淡化技术重点实验室，天津 300072

通讯作者: 徐世昌
作者简介:<named-content content-type="corresp-name">赵晓童</named-content>（1992—），女，硕士研究生，研究方向为电容法脱盐技术。E-mail：<email>zhxt@tju.edu.cn</email>。|徐世昌，副研究员，研究方向为海水淡化膜科学与分离技术。E-mail：<email>xushichang@sina.com</email>。
基金资助:
国家自然科学基金(21576190)

Abstract

Abstract:

The flow-electrode is a suspension system composed of carbon nano-materials, dispersants and deionized water, and its good dispersion and suspension-stability is the key to ensure the high desalination efficiency of the flow-electrode capacitive deionization (FCDI) process. In this paper, the carbon nanotubes (CNT) as the active materials of flow-electrode was modified by sulfonation to improve the materials hydrophilicity, and the specific capacitance, dispersion and suspension stability of flow-electrodes of CNT and CNT-S were investigated. The sodium dodecyl sulfate (SDS) and cetyltrimethyl ammonium bromide (CTAB) were used to examine the effects of dispersants on the performance of flow-electrodes, and the effects of the quality-ratio of dispersants on the performance of flow-electrode were also assessed. The results showed that the CNT-S flow-electrode had a better dispersion and suspension stability than the CNT flow-electrode. In addition, compared with CTAB dispersant, the SDS with identical charge characteristics as CNT-S can enhance the specific capacitance, dispersion and suspension stability of the CNT-S flow-electrode, and the specific capacitance of the CNT-S flow-electrode was 40.04F/g at SDS quality-ratio of 0.6. For the FCDI cell assembled with the CNT-S flow-electrode at 0.6 SDS quality-ratio, the high salt removal efficiency of 51.9% was achieved in 1.0g/L NaCl solution at voltage of 1.2V and the salt removal efficiency of FCDI cell still maintained at 51.6% after 20 regeneration cycles, showing that the CNT-S flow-electrode at 0.6 SDS quality-ratio had excellent recycle stability. These results provided the new evidence to the practical application of FCDI process.

Key words: flow-electrode, sulfonated carbon nanotubes (CNT-S), specific capacitance, dispersion ability, suspension stability

摘要：

流动电极作为一种由碳纳米材料、分散剂和去离子水组成的水性悬浮液体系，其良好的材料分散性和悬浮稳定性是确保流动电极电容法去离子装置（FCDI）脱盐性能的关键。本文以碳纳米管（CNT）为流动电极的活性材料，通过磺化剂实现了CNT材料表面的亲水化改性，重点研究分析了CNT改性前后流动电极的比电容、分散性和悬浮稳定性变化规律；探究了水性分散剂种类[十二烷基硫酸钠（SDS）和十六烷基三甲基溴化铵（CTAB）]和含量对流动电极性能的影响。结果表明，改性后的CNT-S流动电极的分散性和悬浮稳定性明显优于CNT流动电极，其比电容略低但比电容的稳定性较高。与CNT-S具有相同电荷特性的分散剂SDS比CTAB更有助于提高CNT-S流动电极的分散性和悬浮稳定性，当SDS比含量为0.6时，CNT-S流动电极的比电容最大，为40.04F/g。在工作电压为1.2V、SDS比含量为0.6、原料液浓度为1.0g/L（NaCl溶液）时，对FCDI装置的脱盐稳定性测试结果表明：装置的初始盐移除效率为51.9%，经20次循环脱盐后其除盐效率仍可保持在51.6%，证明所制备的流动电极具有很好的循环稳定性，为FCDI技术实用化开发提供了实验依据。

关键词: 流动电极, 磺化碳纳米管（CNT-S）, 比电容, 分散性, 悬浮稳定性

CLC Number:

TB383.1

Xiaotong ZHAO, Shichang XU, Dongya MA, Yue WANG, Qiaoling WANG. Optimization of dispersion and suspension-stability for carbon nanotube flow-electrode[J]. Chemical Industry and Engineering Progress, 2019, 38(02): 956-963.

赵晓童, 徐世昌, 马冬雅, 王越, 王巧灵. 碳纳米管流动电极分散性和悬浮稳定性的优化[J]. 化工进展, 2019, 38(02): 956-963.

Figures/Tables 18

References 19

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型号	尺寸			纯度/%	COOH 含量/％	比表面积/m²·g^-1	密度/g·cm^-3		电导率/S·cm^-1
型号	管外径/nm	管内径/nm	管长/μm	纯度/%	COOH 含量/％	比表面积/m²·g^-1	振实密度	真密度	电导率/S·cm^-1
TNMC3	10~20	5~10	10~30	>98	2.00	>200	0.22	2.1	>100

型号	尺寸			纯度/%	COOH 含量/％	比表面积/m²·g^-1	密度/g·cm^-3		电导率/S·cm^-1
型号	管外径/nm	管内径/nm	管长/μm	纯度/%	COOH 含量/％	比表面积/m²·g^-1	振实密度	真密度	电导率/S·cm^-1
TNMC3	10~20	5~10	10~30	>98	2.00	>200	0.22	2.1	>100

样品	Zeta电位/mV
CNT	-5.447
CNT-S	-18.4

样品	Zeta电位/mV
CNT	-5.447
CNT-S	-18.4

样品	Zeta电压/mV
CNT-S	-18.4
SDS/CNT-S	-22.5
CTAB/CNT-S	10.6

Optimization of dispersion and suspension-stability for carbon nanotube flow-electrode

碳纳米管流动电极分散性和悬浮稳定性的优化

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Figures/Tables 18

References 19

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样品	R _SDS	C _S/F·g^-1
0^#	0.0	19.40
1^#	0.2	22.64
2^#	0.4	30.26
3^#	0.6	40.04
4^#	0.8	37.74
5^#	1.0	31.04

装置	活性材料	负载量/%	分散剂	原料液浓度 /g?L^-1	盐移除效率/%
FCDI^[1]	AC	5	—	1.1	48.8
Single mode FCDI^[17]	AC	5	—	1.0	70
FCDI^[18]	AC	5	—	35.0	20
AFCDI^[19]	AC-N/AC-S	20	—	25.0	8.2
FCDI(本文)	CNT-S	2	SDS	1.0	51.9

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