C6位羧基纤维素制备及其对Cu<sup>2+</sup>吸附性能

李继丰; 闫文静; 方婷; 顾殿宽; 胡超凡; 杜兆芳; 陈巍

doi:10.13801/j.cnki.fhclxb.20210607.004

C6位羧基纤维素制备及其对Cu²⁺吸附性能

doi: 10.13801/j.cnki.fhclxb.20210607.004

安徽农业大学　轻纺工程与艺术学院，合肥 230036

基金项目: 安徽省科技重大专项(16030701089；18030701206)

详细信息

通讯作者:
杜兆芳，博士，教授，博士生导师，研究方向为生物质纤维材料改性及应用　E-mail：dzf@ahau.edu.cn

中图分类号: X505；TQ424
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出版历程
- 收稿日期: 2021-03-31
- 修回日期: 2021-05-19
- 录用日期: 2021-06-02
- 网络出版日期: 2021-06-07
- 刊出日期: 2021-03-01

Preparation of C6 carboxylic cellulose and adsorption for Cu²⁺

College of Light-Textile Engineering and Art, Anhui Agricultural University, Hefei 230036, China

摘要

摘要: 为提高纤维素对金属离子污染物的吸附能力，本实验通过选择性氧化体系制备C6位羧基微晶纤维素(CMCC)，利用现代测试表征技术分析了CMCC的氧化过程和氧化机制，并研究了CMCC对Cu²⁺吸附性能。结果表明，NMR和FTIR测试说明HNO₃/H₃PO₄-NaNO₂氧化体系可将微晶纤维素(MCC)大分子中吡喃葡萄糖环上C6位伯羟基选择性氧化成羧基。氧化反应对MCC表面产生一定程度的刻蚀，制备的CMCC吸湿性高、结晶度低，同时氧化会造成MCC热稳定性降低。Cu²⁺吸附实验显示CMCC吸附行为遵循准二级动力学模型和Langmuir等温线，对Cu²⁺的饱和吸附容量高达165.5 mg/g。吸附热力学分析发现，CMCC对Cu²⁺的吸附方式主要是通过羧基和金属离子化学反应的结合。实验表明该含有活性羧基的功能性纤维素可作为一种高效的吸附剂，广泛应用在金属离子污染物处理领域。
- 羧基微晶纤维素 /
- 选择性氧化 /
- 结晶度 /
- 铜离子 /
- 吸附 /
- 污染物
Abstract: In order to improve the adsorption capacity of cellulose to metal ion pollutants, this study prepared C6 carboxylic microcrystalline cellulose (CMCC) by selective oxidation system. The oxidation process and oxidation mechanism of CMCC were analyzed by using modern test and characterization techniques, and the adsorption capacity of CMCC for Cu²⁺ was studied. The results show that the HNO₃/H₃PO₄-NaNO₂ system selectively oxidized the C6 primary hydroxyl group on the pyranose ring in microcrystalline cellulose (MCC) macromolecule to carboxyl group by NMR and FTIR testing. The oxidation reaction etches the MCC surface to a certain extent, which improves the hygroscopicity of the CMCC, decreases the crystallinity, and reduces the thermal stability of the CMCC. Cu²⁺ adsorption experiments show that the adsorption behavior of CMCC follows the quasi-second-order kinetic model and Langmuir isotherm, and the saturated adsorption capacity of Cu²⁺ is as high as 165.5 mg/g. The adsorption thermodynamic analysis show that the adsorption of Cu²⁺ by CMCC is mainly through the chemical reaction between the carboxyl group and metal ions. The results indicate that the functional cellulose containing carboxyl active group can be used as a highly efficient adsorbent and will be widely used in the field of metal ion pollutant treatment.
- carboxylic microcrystalline cellulose /
- selective oxidation /
- crystallinity /
- copper ions /
- adsorption /
- pollutant

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图 1 微晶纤维素(MCC)和C6位羧基微晶纤维素(CMCC)的固相¹³C CP/MAS NMR谱图

Figure 1. Solid-state ¹³C CP/MAS NMR spectra of microcrystalline cellulose (MCC) and C6 carboxylic microcrystalline cellulose (CMCC)

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图 2 不同氧化时间的MCC的FTIR图谱(A：MCC；B~H：氧化30 min、60 min、90 min、120 min、150 min、180 min和300 min的CMCC)

Figure 2. FTIR spectra of MCC by oxidized with different time (A: MCC; B-H: CMCC with oxidation of 30 min, 60 min, 90 min, 120 min, 150 min, 18 0min and 300 min, respectively)

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图 3 MCC的氧化机制图

Figure 3. Oxidation schematic diagram of MCC

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图 4 MCC氧化前后的微观形貌图像((a) MCC；(b) CMCC氧化30 min；(c) CMCC氧化120 min；(d) CMCC氧化180 min)

Figure 4. Microscopic morphologies before and after MCC oxidation ((a) MCC; (b) CMCC with oxidation time of 30 min; (c) CMCC with oxidation time of 120 min; (d) CMCC with oxidation time of 180 min)

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图 5 不同氧化时间的MCC的XRD图谱(A：MCC；B~H：氧化30 min、60 min、90 min、120 min、150 min、180 min和300 min的CMCC)

Figure 5. XRD patterns of MCC by oxidized with different time (A: MCC; B-H: CMCC with oxidation of 30 min, 60 min, 90 min, 120 min, 150 min, 180 min and 300 min, respectively)

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图 6 MCC和不同氧化时间的CMCC的DTG曲线

Figure 6. DTG curves of MCC and CMCC by oxidized with different time

A—MCC; B-H—CMCC with oxidation of 30 min, 60 min, 90 min, 120 min, 150 min, 180 min and 300 min, respectively

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图 7 溶液pH和电解质NaCl对氧化3 h的CMCC吸附性能的影响

Figure 7. Effect of pH and NaCl on the adsorption properties of CMCC oxidized for 3 h

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图 8 吸附时间对氧化3 h的CMCC吸附性能的影响

Figure 8. Effect of time on the adsorption performance of CMCC oxidized for 3 h

Q_t—Adsorption amout of Cu²⁺ corresponding to adsorption time t

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图 9 氧化3 h的CMCC吸附Cu²⁺的动力学模型拟合曲线：(a) 准一级动力学模型；(b) 准二阶动力学模型

Figure 9. Kinetic fitting curves of adsorption data of Cu²⁺ onto CMCC oxidized for 3 h: (a) Pseudo-first-order kinetic model; (b) Pseudo-second-order kinetic model

Q_e—Amout of Cu²⁺ removed per unit mass of adsorbent

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图 10 不同初始浓度的Cu²⁺对氧化3 h的CMCC吸附性能的影响

Figure 10. Effect of initial concentrations on the adsorption capacities of Cu²⁺ onto CMCC oxidized for 3 h

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图 11 氧化3 h的CMCC对Cu²⁺的等温吸附模型拟合曲线

Figure 11. CMCC oxidized for 3 h isothermal adsorption model for Cu²⁺ fitting curve

C_e—MB concentration at adsorption equilibrium

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图 12 氧化3 h的CMCC吸附Cu²⁺热力学拟合曲线

Figure 12. Thermodynamic fitting curve of adsorption data of Cu²⁺ onto CMCC oxidized for 3 h

K_c—Adsorption equilibrium constant

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表 1 氧化3 h的CMCC吸附Cu²⁺的动力学模型拟合参数

Table 1. Parameters of kinetic adsorption models for Cu²⁺ onto CMCC oxidized for 3 h

Adsorbates	Q_exp/(mg·g⁻¹)	Pseudo-first-order model			Pseudo-second-order model
Adsorbates	Q_exp/(mg·g⁻¹)	Q_1e,cal/(mg·g⁻¹)	k₁/min⁻¹	R²	Q_2e,cal/(mg·g⁻¹)	k₂/(g·mg⁻¹·min⁻¹)	R²
Cu²⁺	162.5	91.2	1.06×10⁻²	0.9755	155.6	9.1×10⁻⁵	0.9967
Notes: k₁, k₂—Pseudo-first-order kinetic and Pseudo-second-order kinetic constants, respectively; Q_e(cal)—Calculation amount of Cu²⁺ removed per unit mass of adsorbent; Q_e_(exp)—Experimental amount of Cu²⁺ removed per unit mass of adsorbent; R²—Correlation coefficient.

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表 2 氧化3 h的CMCC对Cu²⁺的吸附等温拟合结果

Table 2. Isothermal parameters for the adsorption of Cu²⁺ onto CMCC-3

Adsorbates	Langmuir			Freundlich
Adsorbates	Q_m/(mg·g⁻¹)	k_L/(L·mg⁻¹)	R²	k_F/(L·mg⁻¹)	n	R²
Cu²⁺	165.5	0.0074	0.9985	7.8	2.2	0.7903
Notes: Q_m—Langmuir adsorption maximum; k_L—Langmuir coefficient of distribution of the adsorption;k_F—Freundlich coefficient of distribution of the adsorption; n—Heterogeneous coefficient.

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表 3 同类纤维素对Cu²⁺的吸附容量对比

Table 3. Adsorption capacity comparison of similar cellulose adsorbents to Cu²⁺

Adsorbent	Adsorption capacity/(mg·g⁻¹)	References
MCC	15.5	[23]
TEMPO oxidized cellulose	112.0	[24]
Phosphorylated cellulose	114.0	[25]
Carboxymethyl cellulose	115.5	[26]
CMCC	165.5	This work
Note: TEMPO—2,2,6, 6-Tetramethylpiperidine-nitrogen oxide.

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表 4 氧化3 h的CMCC吸附Cu²⁺的热力学参数

Table 4. Values of thermodynamic parameters for the adsorption of Cu²⁺ onto CMCC oxidized for 3 h

T/K	ΔG^o/(kJ·mol⁻¹)	ΔH^o/(kJ·mol⁻¹)	ΔS^o/(J·mol⁻¹·K⁻¹)
303	−2.5	−23	−65.4
308	−1.7
313	−1.4
318	−0.9
323	−0.7
Notes: ΔG^o—Change in Gibbs free energy for the adsorption process; ΔH^o—Change in enthalpy of adsorption; ΔS^o—Entropy change of adsorption process.

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参考文献(30)

[1]	DU Z L, CHEN H A, GUO X Y, et al. Mechanism and industrial application feasibility analysis on microwave-assisted rapid synthesis of amino-carboxyl functionalized cellulose for enhanced heavy metal removal[J]. Chemosphere,2021,268:128833. doi: 10.1016/j.chemosphere.2020.128833
[2]	PEI L J, LIU J J, GU X M, et al. Adsorption kinetic and mechanism of reactive dye on cotton yarns with different wettability in siloxane non-aqueous medium[J]. Journal of the Textile Institute,2019,111(7):925-933.
[3]	PEI X P, GAN L, TONG Z H, et al. Robust cellulose-based composite adsorption membrane for heavy metal removal[J]. Journal of Hazardous Materials,2021,406:115-125.
[4]	王瑞佳, 聂敬恒, 樊源源, 等. 微晶纤维素辅助制备C-TiO₂复合材料及其对Cd²⁺的吸附性能[J]. 复合材料学报, 2020, 37(2):415-421. WANG Ruijia, NIE Jingheng, FAN Yuanyan, et al. Preparation of C-TiO₂ composite with assistance of microcrystalline cellulose and its adsorption properties for Cd²⁺[J]. Acta Materiae Compositae Sinica,2020,37(2):415-421(in Chinese).
[5]	GUO X, XU D, YUAN H M, et al. A novel fluorescent nanocellulosic hydrogel based on carbon dots for efficient adsorption and sensitive sensing in heavy metals[J]. Journal of Materials Chemistry A,2019,7(47):27081-27088. doi: 10.1039/C9TA11502A
[6]	张晓涛, 王喜明. 木质纤维素/纳米蒙脱土复合材料对废水中Cu(II)的吸附及解吸[J]. 复合材料学报, 2015, 32(2):385-394. ZHANG Xiaotao, WANG Ximing. Adsorption and desorption of Cu (II) in wastewater by lignocellulose/ nano-montmorillonite composites[J]. Acta Materiae Compositae Sinica,2015,32(2):385-394(in Chinese).
[7]	SARKAYA K, BAKHSHPOUR M, BENIZLI A. Ag⁺ ions imprinted cryogels for selective removal of silver ions from aqueous solutions[J]. Separation Science and Technology,2019,54(18):2993-3004. doi: 10.1080/01496395.2018.1556300
[8]	SELLAOUI L, SOETAREDJO F, ISMADJI S, et al. Insights on the statistical physics modeling of the adsorption of Cd²⁺ and Pb²⁺ ions on bentonite-chitosan composite in single and binary systems[J]. Chemical Engineering Journal,2018,354:569-576. doi: 10.1016/j.cej.2018.08.073
[9]	TAO J, XIONG J, JIAO C, et al. Hybrid mesoporous silica based on hyperbranch-substrate nanonetwork as highly efcient adsorbent for water treatment[J]. ACS Sustainable Chemistry & Engineering,2016,4(1):60-68.
[10]	SELAMBAKKANNU S, OTHMAN N, BAKAR K, et al. Modification of radiation grafted banana trunk fibers for adsorption of anionic dyes[J]. Fibers and Polymers,2019,20(2):2556-2569.
[11]	VALENCIA L, MONTI S, KUMAR S, et al. Nanocellulose/graphene oxide layered membranes: Elucidating their behaviour during filtration of water and metal ions in real time[J]. Nanoscale,2019,11(46):22413-22422. doi: 10.1039/C9NR07116D
[12]	谢水波, 罗景阳, 刘青, 等. 羟乙基纤维素/海藻酸钠复合膜对六价铀的吸附性能及吸附机制[J]. 复合材料学报, 2015, 32(1):268-275. XIE S B, LUO J Y, LIU Q, et al. Adsorption characteristics and mechanism of hydroxyethyl cellulose/sodium alginate blend films for uranium(Ⅵ)[J]. Acta Materiae Compo-sitae Sinica,2015,32(1):268-275(in Chinese).
[13]	HOU X B, LI Y C, PAN Y F, et al. Controlled release of agrochemicals and heavy metal ion capture dual-functional redox-responsive hydrogel for soil remediation[J]. Chemical Communications,2018,54(97):13714-13717. doi: 10.1039/C8CC07872F
[14]	QIN F M, FANG Z Q, ZHOU J, et al. Efficient removal of Cu²⁺ in water by carboxymethylated cellulose nanofibrils: Performance and mechanism[J]. Biomacromolecules,2019,20(12):4466-4475. doi: 10.1021/acs.biomac.9b01198
[15]	HUANG Z J, HUANG Z Y, FENG L J, et al. Modified cellulose by polyethyleneimine and ethylenediamine with induced Cu(II) and Pb(II) adsorption potentialities[J]. Carbohydrate Polymers,2018,202:470-478. doi: 10.1016/j.carbpol.2018.08.136
[16]	LI Y, XIAO H N, PAN Y F, et al. Study on cellulose microfilaments based composite spheres: Microwave-assisted synthesis, characterization, and application in pollutant removal[J]. Journal of Environmental Management,2018,228:85-92.
[17]	XU Y H, CHEN D D, Du Z F, et al. Structure and properties of silk fibroin grafted carboxylic cotton fabric via amide covalent modification[J]. Carbohydrate Polymers,2017,161:99-108. doi: 10.1016/j.carbpol.2016.12.071
[18]	PISITSAK P, PHAMONPON W, SOONTORNCHATCHAVET P, et al. The use of water hyacinth fibers to develop chitosan-based biocomposites with improved Cu²⁺ removal efficiency[J]. Composites Communications,2019,16:1-4. doi: 10.1016/j.coco.2019.08.003
[19]	ZHANG L L, LU H L, YU J, et al. Synthesis of lignocellulose-based composite hydrogel as a novel biosorbent for Cu²⁺ removal[J]. Cellulose,2018,25(12):7315-7328. doi: 10.1007/s10570-018-2077-8
[20]	ALLOUSS D, ESSAMLALI Y, CHAKIR A, et al. Effective removal of Cu(II) from aqueous solution over graphene oxide encapsulated carboxymethy lcellulose- alginate hydrogel microspheres: Towards real wastewater treatment plants[J]. Cellulose, 2020, 27(7): 7476-7492.
[21]	TIAN C H, SHE J R, WU Y Q, et al. Reusable and cross-linked cellulose nanofibrils aerogel for the removal of heavy metal ions[J]. Polymer Composites,2018,39(12):4442-4451. doi: 10.1002/pc.24536
[22]	MILHOMENS G C, DE ALMEIDA C G, ZANETTE R D S, et al. Biocompatibility and adsorption properties of hydrogels obtained by graft polymerization of acrylic acid on cellulose from rice hulls[J]. Iranian Polymer Journal,2018,27(12):1023-1032. doi: 10.1007/s13726-018-0672-z
[23]	MEHREZ E E N, EMAD K R, SHAIMAA T E, et al. Synthesis, characterization and adsorption properties of microcrystalline cellulose based nanogel for dyes and heavy metals removal[J]. International Journal of Biological Macromolecules, 2018, 113: 248-258.
[24]	SRIVASTAVA S, KARDAM, RAJ K R. Nanotech reinforcement onto cellulosic fibers: Green remediation of toxic metals[J]. International Journal of Green Nanotechnology,2012,4(1):46-53. doi: 10.1080/19430892.2012.654744
[25]	LIU P, BORRALL P F, BOZIC M, et al. Nanocelluloses and their phosphorylated derivatives for selective adsorption of Ag⁺, Cu²⁺and Fe³⁺ from industrial effluents[J]. Journal of Hazardous Materials,2015,294:177-185. doi: 10.1016/j.jhazmat.2015.04.001
[26]	SEHAQUI H, DE LARRAYA U P, LIU P, et al. Enhancing adsorption of heavy metal ions onto biobased nanofibers from waste pulp residues for application in wastewater treatment[J]. Cellulose,2014,21:2831-2844. doi: 10.1007/s10570-014-0310-7
[27]	LIU F L, HUA S, ZHOU L, et al. Development and characterization of chitosan functionalized dialdehyde viscose fiber for adsorption of Au(III) and Pd(II)[J]. International Journal of Biological Macromolecules,2021,173:457-466. doi: 10.1016/j.ijbiomac.2021.01.145
[28]	DU K F, LI S K, ZHAO L S, et al. One-step growth of porous cellulose beads directly on bamboo fibers via oxidation-derived method in aqueous phase and their potential for heavy metal ions adsorption[J]. ACS Sustainable Chemistry & Engineering,2018,6(12):17068-17075.
[29]	LAI W J, LIN S C. Hydroxyethyl cellulose-grafted loofa sponge-based metal affinity adsorbents for protein purification and enzyme immobilization[J]. Process Biochemistry,2018,74:141-147. doi: 10.1016/j.procbio.2018.08.024
[30]	MYERS A L. Thermodynamics of adsorption in porous materials[J]. Aiche Journal, 2002, 48(1): 145-160.