交联羧甲基纤维素的制备及对染料吸附性能的研究

酸催化下,取代度0.82的羧甲基纤维素钠(CMC)经固相加热反应,制备吸附材料交联羧甲基纤维素(CCMC)。研究反应条件对CCMC交联度、交联度对CCMC吸附碱性品红(BF)和亚甲基蓝(MB)性能的影响。结果表明,酸浓度对CCMC交联度影响最大,交联度0.39的CCMC的吸附性能最佳。以交联度0.39的CCMC为吸附剂,研究吸附条件包括固液比、染料初始浓度、pH、吸附时间对CCMC吸附性能的影响。20℃,固液比0.25 g/L条件下,CCMC对BF和MB的饱和吸附量分别为570 mg/g和540 mg/g。     

交联羧甲基纤维素的制备及对染料吸附性能的研究

酸催化下,取代度0.82的羧甲基纤维素钠(CMC)经固相加热反应,制备吸附材料交联羧甲基纤维素(CCMC)。研究反应条件对CCMC交联度、交联度对CCMC吸附碱性品红(BF)和亚甲基蓝(MB)性能的影响。结果表明,酸浓度对CCMC交联度影响最大,交联度0.39的CCMC的吸附性能最佳。以交联度0.39的CCMC为吸附剂,研究吸附条件包括固液比、染料初始浓度、pH、吸附时间对CCMC吸附性能的影响。20℃,固液比0.25 g/L条件下,CCMC对BF和MB的饱和吸附量分别为570 mg/g和540 mg/g。     

羧甲基纤维素-单宁基吸附树脂的制备及性能研究

制备了羧甲基纤维素-单宁基吸附树脂,并研究了吸附树脂对亚甲基蓝的吸附性能。羧甲基纤维素与单宁结合,通过羧甲基纤维素羧基与单宁酚羟基的协同作用,能有效提高吸附树脂对亚甲基蓝的吸附性能,最大吸附容量可达1 300 mg/g。在亚甲基蓝溶液初始质量浓度为1 000 mg/L,吸附剂投加质量浓度为1.5 g/L时,吸附树脂对亚甲基蓝的吸附率可达98%以上,且羧甲基纤维素-单宁基吸附树脂具有较好的重复使用性能。     

五爪金龙吸附阳离子染料的性能研究

以五爪金龙为原料,经粉碎制成不同粒径的粉末吸附剂,探究了五爪金龙吸附亚甲基蓝、罗丹明B、碱性品红的性能。研究发现,五爪金龙吸附亚甲基蓝、罗丹明B、碱性品红最佳粒径为0.3 mm、最佳投加量分别为1.6、2.6、0.8 g,pH均为5、温度为30℃、震荡时间均为40 min。利用准一级、准二级动力学方程模拟五爪金龙吸附亚甲基蓝、罗丹明B和碱性品红的动力学过程,结果表明五爪金龙吸附亚甲基蓝、罗丹明B和碱性品红的过程适合于准二级动力学模型。研究热力学参数发现,五爪金龙吸附亚甲基蓝、碱性品红的过程是一个自发的趋于无序的放热过程,吸附罗丹明B的过程是一个自发的趋于有序的放热过程。     

交联度对交联羧甲基淀粉性能的影响

以玉米淀粉为原料,以环氧氯丙烷为交联剂,制备交联淀粉(CS),以高、中、低三种交联度的CS为原料,以氯乙酸为醚化剂,制备不同取代度的交联羧甲基淀粉(CCMS),分析其理化性能、吸附性能。结果表明,交联度相同时,随着取代度的增大,CCMS的透明度、溶解度和膨胀力均增大,吸附量提高;取代度相同时,CCMS的透明度、溶解度和膨胀力随着交联度的增加而减小,吸附量呈上升趋势可以改善其再生性能。     

玉米淀粉/羧甲基纤维素生物复合凝胶的制备及吸附行为研究

以玉米淀粉与羧甲基纤维素（CMC）为骨架,以丙烯酸（AA）、丙烯酰胺（AM）、2-丙烯酰胺基-2-甲基丙磺酸（AMPS）为单体制备复合凝胶,对复合凝胶材料进行表征。以亚甲基蓝（MB）为吸附质,考察复合凝胶吸附剂对阳离子染料吸附过程的动力学和热力学行为,分析阳离子强度、水体pH值、染料初始质量浓度等对吸附剂吸附性能的影响。结果表明：玉米淀粉-CMC-g-AA-AM-AMPS凝胶是一种表面多孔的吸附材料,其比表面积为24.939 7 m2/g,平均吸附孔径为8.668 2 nm。凝胶对MB的吸附过程与准二级动力学模型和Langmuir模型拟合较好,属于单分子层的化学吸附。阳离子对凝胶吸附MB有明显抑制作用,抑制效果为Al3+>Ca2+>Na+。随着离子强度的增加,抑制作用越明显。在投加量为0.1 g、温度为298 K、pH值为11.0、MB初始质量浓度为2 000 mg/L条件下,吸附剂最大吸附量达到1 938.82 mg/g、去除率为96.94%,能有效去除MB。     

羧甲基纤维素的环氧氯丙烷交联改性研究

采用环氧氯丙烷作为交联剂,对纤维素原料和羧甲基纤维素(CMC)成品进行交联改性,采用两种不同的反应途径制备交联改性的CMC产品,通过对各自产品粘度随温度的变化以及透光度、耐温性的研究,发现先羧甲基化后交联的产品的性能更为优异。     

交联羧甲基淀粉对重金属离子的吸附研究

以木薯淀粉为原料,环氧氯丙烷为交联剂,氯乙酸为醚化剂,制备水不溶的交联羧甲基淀粉(CLCMS);考察了吸附剂用量、溶液pH、吸附时间对交联羧甲基淀粉去除重金属离子效果的影响;采用不同浓度的HCl溶液处理吸附重金属离子后的吸附剂;探讨了该变性淀粉的合成机理以及吸附剂的吸附机理。     

芝麻叶对亚甲基蓝吸附的动力学与热力学研究

以天然芝麻叶为吸附剂,亚甲基蓝(MB)为吸附质,考察芝麻叶吸附亚甲基蓝的动力学、热力学以及溶液pH值、吸附剂投入量、温度等对吸附的影响.采用准一级、准二级、颗粒内扩散吸附动力模型及Langmuir,Freundlich及Dubinin-Radushkevich(D-R)等温模型分别对吸附动力学和吸附等温线进行分析.结果...     

山东某硫铁矿烧渣硫酸浸出液制备铁红工艺研究

为了以山东某硫铁矿烧渣硫酸浸出液制备铁红,采用氨水调节溶液pH值,与碳酸氢铵协同沉淀铁离子,沉淀物焙烧制备铁红。结果表明,浓氨水用量为10 mL,碳酸氢铵用量为2 g时,铁离子沉淀率达到97.18%;沉淀物焙烧时间为1.0 h,焙烧温度为800℃,获得铁红Fe_2O_3含量约98.76%,根据氧化铁颜料标准(GB T 1863—2008),为A级铁红,颜料索引号为颜料红101(77491)。     

In vitro enzymatic degradation kinetics of polymeric blends of crosslinked starch and carboxymethyl cellulose

Hydrophilic blend matrices of crosslinked starch and carboxymethyl cellulose were synthesized and their susceptibilities to enzymatic degradation were assessed by taking α‐amylase as a model enzyme. The polymeric blends were characterized by FT‐IR spectroscopy, differential scanning calorimetry and scanning electron microscopy. The influence of the chemical compositions of the blends, and the pH values and temperatures of the α‐amylase solutions was investigated by studying the swelling and degradation kinetics of the blends. The impact of the concentrations of the enzyme solutions on the degradation profiles was also examined. The blends were found to exhibit a mixed type of degradation mechanism, ie both diffusion and surface erosion. Copyright © 2005 Society of Chemical Industry     

Adsorption kinetics and mechanism of cationic methyl violet and methylene blue dyes onto sepiolite

The use of low-cost and ecofriendly adsorbents was investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. Sepiolite was used as an adsorbent for the removal of methyl violet (MV) and methylene blue (MB) from aqueous solutions. The rate of adsorption was investigated under various parameters such as contact time, stirring speed, ionic strength, pH and temperature for the removal of these dyes. Kinetic study showed that the adsorption of dyes on sepiolite was a gradual process. Quasi-equilibrium reached within 3 h. Adsorption rate increased with the increase in ionic strength, pH and temperature. Pseudo-first-order, the Elvoich equation, pseudo-second-order, mass transfer and intra-particle diffusion models were used to fit the experimental data. The sorption kinetics of MV and MB onto sepiolite was described by the pseudo-second-order kinetic equation. Intra-particle diffusion process was identified as the main mechanism controlling the rate of the dye sorption. The diffusion coefficient, D, was found to increase when the ionic strength, pH and temperature were raised. Thermodynamic activation parameters such as ΔG¹, ΔS¹ and ΔH¹ were also calculated.     

Effect of carboxymethyl cellulose on dissolution kinetics of carboxymethyl cellulose-sodium carbonate two-component tablet

Sodium carbonate and carboxymethyl cellulose powders are compressed into two-component tablets with three mass ratios, 97%:3%, 95%:5% and 93%:7%. The dissolution tests for two-component tablets and reference pure sodium carbonate tablets are carried out at various temperatures. The dissolution process of each tablet is measured by electrical conductivity tracking method and the concentration of dissolved sodium carbonate is quantified with calibrated conductivity-concentration converting equation of sodium carbonate. The quantified dissolution data is fitted with both surface reaction model and diffusion layer model and the results clearly show that surface reaction model is suggested as the appropriate dissolution model for all measured tablets. Therefore, it is determined that carboxymethyl cellulose is a stable element to remain the dissolution mechanism of tablet unchanged. The dissolution rate constant quantified with surface reaction model presents that carboxymethyl cellulose-sodium carbonate two-component tablets obtain significant higher dissolution rate constant than pure sodium carbonate tablet and higher proportion of carboxymethyl cellulose leads to apparent higher dissolution rate constant. The results prove for the usage of carboxymethyl cellulose in most practical applications at a relative low-level, the effect of carboxymethyl cellulose is effective and positive for two-component tablet to enhance the dissolution process and improve dissolution rate constant and this effect is speculated coming from its dynamic physical transforming process in water including dilation and conglutination.     

原花青素在HZ818树脂上的吸附热力学和动力学

通过在不同温度下的静态吸附实验,研究了葡萄籽原花青素在大孔树脂HZ818上的吸附热力学及动力学特性。分别采用Langmuir、Freundlich等温式对不同温度下的等温吸附数据进行拟合,采用Largergren拟一级动力学模型、拟二级动力学模型和颗粒内扩散动力学模型对吸附动力学数据进行分析。结果表明:原花青素在HZ818树脂上的吸附量随着温度的升高而增大,等温吸附数据更符合Langmuir等温吸附方程,吸附焓变大于0,吉布斯自由能变小于0,HZ818树脂对原花青素的吸附过程为自发进行的吸热过程;吸附动力学更符合拟二级动力学模型,过程受主要包括颗粒内扩散在内的多因素共同影响。     

Highly effective adsorption performance of carboxymethyl cellulose microspheres crosslinked with epichlorohydrin

Different sizes of epichlorohydrin‐crosslinked carboxymethyl cellulose (E/CMC) microspheres were successfully prepared by an inverse suspension method. With further modification by monochloroacetic acid (MCA), MCA–E/CMC microspheres were successfully synthesized. The structures and morphologies of these microspheres were analyzed with polarizing microscopy, scanning electron microscopy, ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller analysis, and laser particle ζ‐potential recording. The adsorption properties of the microspheres were investigated with methylene blue (MB) as a model pollutant. The highest adsorption amount of MB (998.2 mg/g) onto MCA–E_0.7/CMC which was the samples which treated with 0.7 mL of C₄H₉OH was obtained. Meanwhile, the effect of the operating parameters, such as the contact time, initial pH of the solution, temperature, and initial dye concentration, on the adsorption amount and MB removal were systematically studied. The results show that pseudo‐second‐order kinetic model provided the best correlation with the experimental data for the adsorption of MB onto the MCA–E_0.7/CMC microspheres. Both the physical and chemical adsorption played the main role in the adsorption process. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44363.     

Adsorption removal of Brilliant green and Safranin-O contaminants from water using a hydrogel based on carboxymethyl cellulose and sodium alginate crosslinked by epichlorohydrin

The current study investigates the adsorption properties of a chemically crosslinked hydrogel based on sodium alginate (NaALG) and carboxymethyl cellulose (CMC). The structural characteristics of the investigated hydrogel are described using information from Fourier Transform–infrared spectra, X-ray diffraction patterns and field emission scanning electron microscopy pictures. The NaALG/epichlorohydrin (ECH)/CMC hydrogel was synthesised under optimised conditions with respect to the swelling percentage. Various reaction parameters were varied to obtain the maximum swelling percentage. The synthesised hydrogel was taken as an adsorbent in the decolorisation of Brilliant green (BG) and Safranin-O (SO) dyes from water. According to the kinetic investigations, the decolorisation equilibrium of SO by NaALG/ECH/CMC was discovered in 4 hours (98.98%), while the removal of BG by NaALG/ECH/CMC took 6 hours (97.7%). Chemical processes were used to describe the decolorisation mechanisms, which significantly supported the pseudo-first-order model. NaALG/ECH/CMC hydrogel absorption was indicated to take place in monolayer adsorption form (Langmuir isotherm). The highest adsorption capacity for BG was discovered to be 864.8 mg g⁻¹ and for SO it was 193.1 mg g⁻¹, by synthesised hydrogel, where “mg” refers to the commercial colourant and not to the pure dye. Therefore, the synthesised hydrogel can be considered as a smart device for the adsorption of dye in water purification tasks.     

Hydrogels of starch/carboxymethyl cellulose crosslinked with sodium trimetaphosphate via reactive extrusion

Hydrogels are materials with advantages in specific applications, such as, retention of food active compounds. This work aims to develop starch (S)/carboxymethyl cellulose (CMC) hydrogels with porous structure, using reactive extrusion to promote crosslinking with sodium trimetaphosphate (STMP). The expansion, porosity, degree of substitution, gel fraction, swelling properties, and FTIR are studied, comparing S, S/CMC, S/STMP, and S/CMC/STMP formulations. Samples containing STMP present the same degree of substitution (0.050 ± 0.001). Higher porosity and percentage of open pores are observed in the mixed hydrogel (S/CMC/STMP). Crosslinking increase the swelling capacity at pH 7, and this property, just like the gel fraction, are sensitive to pH variations. The hydrogel S/CMC present the highest swelling rate compared with the other samples, suggesting strong interaction between components. The reactive extrusion process is efficient to produce starch and starch/CMC hydrogels crosslinked with STMP and the overall results demonstrate the advantages of the mixed hydrogel.