共查询到16条相似文献,搜索用时 517 毫秒
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研究了甲醛、环氧氯丙烷交联壳聚糖树脂(AECTS)对Ni(II)的吸附行为和吸附Ni(II)对树脂结构及性能的影响.用FTIR,WAXD,TGA和DSC对吸附产物进行了结构表征,并深入分析了AECTS与Ni(II)之间的作用机理.结果表明:AECTS主要以配位形式吸附Ni(II);AECTS吸附Ni(II)后,结晶度下降、总体上热稳定性变差;Ni(II)对AECTS的主链分解具有明显的催化功能,而空气气氛中对AECTS在500℃附近的分解表现出火焰缓蚀作用.AECTS对Ni(II)的吸附行为符合Langmuir模型,属于单分子层吸附,所有吸附位对Ni(II)的作用近似相同;与壳聚糖(CTS)比较,造成AECTS对Ni(II)吸附量增大的主要原因是AECTS结晶度下降和孔隙率增加,二者导致在交联处理前Ni(II)难于接近的吸附位点“活性”相对增大,使其更容易与Ni(II)相结合;不同介质对AECTS吸附Ni(II)的影响大小顺序为HCl>CdCl2>MgCl2>NaCl,前两者使吸附量减小,MgCl2使吸附量稍有增加,NaCl对吸附量基本没有影响. 相似文献
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交联壳聚糖树脂与Zn2+的配位作用 总被引:1,自引:1,他引:1
研究了甲醛、环氧氯丙烷交联壳聚糖树脂(Chitosan crosslinked by aldehyde and epichlorohydrin,AECTS)吸附Zn2 后对树脂结构及性能所产生的影响.用FTIR、XRD、TG、DSC和SEM对吸附产物进行了结构表征,并分析了AECTS与Zn2 之间的作用机理.结果表明,Zn2 与AECTS中的氨基发生配位而被吸附;AECTS吸附Zn2 后,结晶度下降、总体上热稳定性变差;Zn2 对AECTS的主链分解具有明显的催化功能;Zn2 的配位使得AECTS的表面形态发生了改变. 相似文献
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交联壳聚糖树脂与Zn2+的配位作用 总被引:2,自引:0,他引:2
研究了甲醛、环氧氯丙烷交联壳聚糖树脂(Chitosan crosslinked by aldehyde and epichlorohydrin,AECTS)吸附Zn2 后对树脂结构及性能所产生的影响.用FTIR、XRD、TG、DsC和SEM对吸附产物进行了结构表征,并深入分析了AECTS与Zn2 之间的作用机理.结果表明,Zn2 与AECTS中的氨基发生配位而被吸附;AECTS吸附Zn2 后,结晶度下降、总体上热稳定性变差:Zn2 对AECTS的主链分解具有明显的催化功能;Zn2 的配位使得AECTS的表面形态发生了改变. 相似文献
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交联壳聚糖树脂吸附Co2+的机理研究 总被引:1,自引:0,他引:1
研究了甲醛、环氧氯丙烷交联壳聚糖 (AECTS) 对Co2 的吸附热力学行为,用FTIR、WXRD对吸附产物进行了结构表征,并研究了溶液中介质种类的不同对Co2 吸附量的影响.结果表明:AECTS主要以配位吸附和物理吸附形式吸附Co2 ;树脂与Co2 配位后,结晶度下降;AECTS对Co2 的吸附行为同时符合Freundlich模型和Langmuir模型;吸附为自发的、放热的熵减小过程;不同介质对树脂吸附Co2 的影响大小顺序为HCl>CdCl2>MgCl2>NaCl,前两者使吸附量减小,后两者使吸附量增加,作用机理相差较大. 相似文献
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交联壳聚糖对Zn2+的吸附性能 总被引:1,自引:0,他引:1
研究了甲醛、环氧氯丙烷交联壳聚糖树脂(AECTS)对Zn 2 的吸附行为,探讨温度、溶液的pH、反应时间、再生次数等因素对吸附性能的影响,并用红外光谱(FTIR)和光电子能谱(XPS)对吸附产物表面的元素结构及其结合能的变化进行表征. 结果表明,AECTS对Zn 2 的吸附导致AECTS结构和性能发生显著变化. FTIR和XPS分析表明,Zn 2 以配位键的形式吸附于AECTS,使AECTS中氨基的伸缩振动、变形振动发生了明显变化,N原子发生化学位移,而AECTS分子链上的羟基没有直接参与配位反应;AECTS对Zn 2 有较强的吸附能力和较快的吸附速率,在30 ℃、Zn 2 初始质量浓度为1 g/L的溶液中,吸附量可达163 mg/g树脂,是壳聚糖饱和吸附量的1.7倍左右;吸附量受pH的影响较大,在pH=5时吸附量最高;AECTS对Zn 2 的吸附行为符合Freundlich等温吸附方程,温度升高吸附量增大,该过程为一吸热过程;AECTS经再生重复使用5次,吸附量基本不变. 相似文献
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利用滴加法合成了球形含Ni2+交联壳聚糖, 并通过胺化引入大量活性氨基, 再经除镍制成对重金属镍离子具有较好吸附能力的新型吸附剂[P-C-CTS(Ni)]. 通过Ni2+吸附容量的测定, IR及XPS分析, 验证了合成技术路线的正确性. 通过研究pH值对吸附量的影响, 初步讨论了无柠檬酸根(Cit)配位体存在时, 吸附剂对Ni(II)的吸附为螯合作用. 通过Cit存在条件下(cNi=cCit=0.852 mmol•L-1), 吸附剂对Ni(II)离子和Cit的吸附量随pH值的变化, 结合相应pH值下金属镍的形态分布, 探讨了其对Ni(II)的吸附机理, 研究认为不仅仅是简单的螯合作用, 其吸附机理和吸附量与溶液中金属离子的存在形式有关, 引入静电吸附原理解释了吸附剂对Ni(II)的吸附现象. 相似文献
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Magnesium, the dominant bivalent cation in natural seawater, exerts a substantial influence on the patterns of ion interactions in this saline medium. Mean activity coefficients of hydrochloric acid in mixtures of this acid with magnesium chloride at four ionic strengths, namelyI=0.1, 0.3809, 0.6729, and 0.8720 mole-kg–1, were obtained from emf measurements of cells without liquid junction at nine temperatures from 5 to 45°C. The three highest ionic strengths correspond to seawater of salinities 20, 35, and 45, respectively. In addition, mixtures of HCl, NaCl, and MgCl2 were studied atI=0.6729, the molal ratio of NaCl to MgCl2 being maintained at 7.202 as in natural seawater. The Harned coefficients 1 2 were found to decrease slowly with increase in temperature. The trace activity coefficient of HCl in solutions of MgCl2 as well as in NaCl MgCl2 mixtures was found to be nearly identical with that measured earlier in synthetic seawater of the same ionic strength but containing NaCl, MgCl2, KCl, and CaCl2. 相似文献
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O. V. Solovtsova T. Yu. Grankina O. K. Krasil’nikova N. V. Serebryakova S. M. Shinkarev A. M. Voloshchuk 《Colloid Journal》2008,70(3):341-348
The structure and adsorption properties (with respect to water vapor and nickel cations) of chitosan samples dehydrated by either lyophilization after precipitation with NaOH or Na2CO3 or drying in air are investigated. IR spectroscopy and X-ray diffraction data testify that the lyophilization causes both changes in the conformation of chitosan macromolecules and a substantial rise in the crystallinity of the polymer to compare with the air dried one. Chitosan structure ordering resultant from the lyophilization noticeably increases its sorption ability with respect to both water vapor and nickel cations. For example, the sorption capacity of the lyophilized chitosan with respect to nickel cations is as high as 4.5 mmol/g and, thus, is threefold higher than that of air-dried chitosan. The comparative analysis of water adsorption isotherms in the region of low degrees of filling indicates that chitosan structure ordering resultant from the lyophilization changes the number and the energy of primary adsorption sites. 相似文献
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S. N. Orlov K. A. Burkov M. Yu. Skripkin 《Russian Journal of Applied Chemistry》2011,84(12):2029-2032
Equilibrium adsorption of copper(II) ions on red mud (alumina industrial wastes) modified by various methods was studied.
The effect exerted by the nature the modifier (NaHSO4, NaCl + HCl, and H2SO4) on the sorption activity of red mud was determined. 相似文献
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The influence exerted by the degree of substitution of sulfoethylated chitosan cross-linked with glutaraldehyde on the sorption of Pd(II) chloride complexes from multicomponent solutions containing Pt(IV), Cu(II), Ni(II), Co(II), Cd(II), and Zn(II) was studied. The sorption of transition metal ions under the conditions of the experiment at pH 0.5–5.0 is virtually fully suppressed. The strongest interfering effect on the Pd(II) sorption is exerted by Pt(IV). Calculation of the selectivity coefficients KPd/Pt shows that the selectivity of the Pd(II) sorption relative to Pt(IV) increases with an increase in the degree of substitution of chitosan from 0.3 to 0.5. Integral kinetic curves of the Pd(II) sorption were obtained, and the dependences were subjected to mathematical processing using the models of diffusion and chemical kinetics. The equilibrium in the palladium(II) chloride solution–sorbent system is attained within 40 min. Pd and Pt are quantitatively desorbed from the sorbent surface under dynamic conditions with 3.5 M HCl solution. 相似文献
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The kinetic and thermodynamic adsorption and adsorption isotherms of Pb(II) and Cu(II) ions onto H2SO4 modified chitosan were studied in a batch adsorption system. The experimental results were fitted using Freundlich, Langmuir and Dubinin–Radushkevich isotherms; the Langmuir isotherm showed the best conformity to the equilibrium data. The pseudo-first order, pseudo-second order and intraparticle diffusion kinetic models were employed to analyze the kinetic data. The adsorption behavior of Pb(II) and Cu(II) was best described by the pseudo-second order model. Thermodynamic parameters such as free energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°) were determined; the adsorption process was found to be both spontaneous and exothermic. No physical damage to the adsorbents was observed after three cycles of adsorption/desorption using EDTA and HCl as eluents. The mechanistic pathway of the Pb(II) and Cu(II) uptake was examined by means of Fourier transform infrared (FTIR) and Energy dispersive X-ray (EDX) spectroscopy. The equilibrium parameter (RL) indicated that chitosan–H2SO4 was favorable for Pb(II) and Cu(II) adsorption. 相似文献