壳聚糖复合微球的制备及其对F-的吸附

以活性炭、氧化铝和硫酸铝为包合物制备了壳聚糖复合微球。通过对吸附时间、温度、包合物吸附剂等相关因素,考察了壳聚糖复合微球对含氟水的处理效果,结果表明Al2(SO4)3-活性炭-壳聚糖复合微球除氟的效果最佳。该复合微球在29．0℃处理8min后,对F^-的吸附率高达99．28％,用稀碱液淋洗可实现对复合微球的再生,脱洗率达93．69％。     

淀粉/二氧化硅微球对水中重金属离子的吸附性能

利用土豆淀粉、玉米淀粉、正硅酸乙酯为原料,氨水为催化剂,通过溶胶-凝胶法制备了淀粉/二氧化硅复合微球,研究了该复合微球对水中铅离子的吸附性能。结果表明,在弱碱性条件下,淀粉/二氧化硅复合微球对水中铅离子表现出良好的吸附性能,其对铅离子的吸附行为符合Langmuir模型和Freundlich模型,对铅离子的饱和吸附量为31.34 mg/g。动力学研究表明,淀粉/二氧化硅复合微球对铅离子的吸附符合拟二级动力学模型,在淀粉/二氧化硅复合微球的活性点上的化学反应为吸附控制步骤。     

聚合电解质负载磷酸钡复合微球对铅的吸附

以卡拉胶(CN)、海藻酸钠(SA)和壳聚糖(CS)为基质包裹磷酸钡合成了CN-SA-CS@Ba P复合微球球形吸附剂,对其形貌特征进行了表征,研究了对含铅废水的净化效果,结果表明,CN-SA-CS@Ba P复合微球在p H为4~6时去除效果最好;随着水溶液中Pb~(2+)初始含量的增加,复合微球对铅的吸附量也随之增加,但是去除效率却逐渐降低;随着接触时间增加,复合微球的吸附量逐渐增大并在180 min左右达到吸附平衡。复合微球对Pb~(2+)的吸附平衡最符合Langmuir等温线模型,最大吸附量可达132.1 mg/g;复合微球对Pb~(2+)具有快的吸附速率,其吸附动力学遵循准2级反应动力学模型,这与其三维网络结构和大量功能性基团有关。     

复合淀粉微球对铜离子的吸附及动力学研究

以复合淀粉微球为载体,研究其对Cu2+的吸附行为,考察了反应时间、pH值、反应温度、Cu2+的初始浓度等因素对吸附量的影响,并研究了吸附行为的动力学模型。结果表明,复合淀粉微球在120 min时可以达到对Cu2+吸附的平衡状态,静态吸附实验发现,在pH=6、温度35℃、Cu2+初始浓度0.10 mol/L时复合淀粉微球对Cu2+的吸附量较高。动力学实验研究表明,吸附行为可能更符合准二级动力学模型。     

MnO_2@海藻酸基炭吸附去除双氯芬酸钠及其再生

通过热裂解法制备了MnO_2@海藻酸炭微球复合吸附剂,并以双氯芬酸钠为代表,考察了溶液pH值、双氯芬酸钠初始质量浓度和吸附剂投加量对吸附性能的影响。通过扫描电子显微镜(SEM)表征了颗粒表面形貌。并以表面富集双氯芬酸的吸附剂为类Fenton体系的催化剂研究了吸附剂的再生效果。结果表明:吸附剂在酸性条件下表现出较好的吸附能力;双氯芬酸钠初始质量浓度越大,平衡吸附量越大;吸附量随着吸附剂投加量的增加而减小;吸附过程符合Langmuir等温吸附模型和准二级动力学模型,从水中吸附DCF是自发的、吸热的,并且在吸附过程中同时起主导作用,吸附过程自发进行并且有效地实现了吸附剂的原位再生和循环使用。     

磁性复合微球处理水中氯仿的应用研究

采用磁性复合微球为吸附载体,将其应用于水体中氯仿的吸附研究,在此过程中以紫外吸光光度法就磁性复合微球粒径、表面性质对吸附性能的影响作了考察,最终选取粒径为1.5μm、表面富含胺基磁性的复合微球为最佳吸附材料。与此同时,利用CODCr法作为评价手段对磁性的复合微球吸附氯仿的处理工艺条件进行了优化,确定每处理质量浓度为74 mg/L的氯仿溶液2 mL需用磁性复合微球约1 mg,最佳吸附时间为4.0 h,磁性复合微球的富集时间为4.0 h,此时对氯仿的吸附效率大于83%。     

磁性壳聚糖/β-环糊精复合微球的制备及其吸附性能

以反相悬浮交联法制备磁性壳聚糖/β-环糊精复合微球。用光学显微镜、红外光谱仪、振动样品磁强计(VSM)对微球进行了表征,并研究其对模型蛋白(木瓜蛋白酶)的吸附行为。结果表明,微球为完整的球形,具有良好的磁响应性。模型蛋白在微球上的吸附关系既可用Langmuir方程描述,又可用计量置换吸附Freundlich方程描述,且更符合Freundlich方程描述;聚丙烯酰胺凝胶电泳(SDS-PAGE)结果表明,吸附的模型蛋白能从磁性粒子表面完整地脱附下来。     

β-环糊精固化单宁复合微球制备及吸附性能研究

以β-环糊精、单宁为单体,环氧氯丙烷为交联剂,反相悬浮交联制备β-环糊精/单宁复合微球。通过红外光谱法、X射线衍射法对微球进行表征,证明单宁成功固定在β-环糊精上。以阳离子染料亚甲基蓝为有机吸附质模型,考察了染料初始溶液pH、初始溶液质量浓度对微球吸附性能的影响。吸附性能实验表明,pH在中性条件下,β-环糊精空腔与单宁酚羟基协同作用,有利于提高微球与亚甲基蓝之间的静电吸附能力,吸附率为80.31%;当亚甲基蓝初始浓度增大至1000 mg/L时,网络中的空隙被填充,吸附位点趋于饱和,吸附量最大达到630.41 mg/g。β-环糊精/单宁复合微球具有较好的重复使用性能,大大提高了2种单体在工业废水吸附领域的应用价值。     

松香基双季铵盐/海藻酸钠复合微球的制备分析

以2%的海藻酸钠和2%的松香基双季铵盐为原料,通过静电吸附制备了松香基双季铵盐/海藻酸钠微球和海藻酸钠微球,采用FTIR确证了复合前后微球的结构;采用SEM对两种微球的微观形貌进行分析,表明松香基双季铵盐/海藻酸钠微球比海藻酸钠微球的孔隙发达宽松;通过对铜离子吸附性能分析,表明松香基双季铵盐/海藻酸钠微球比海藻酸钠微球对铜离子吸附效果优。     

交联β-环糊精-可溶性淀粉复合微球对茉莉香精的吸附性

以可溶性淀粉、β-环糊精(β-CD)为主要原料,采用反相乳液聚合法合成了交联β-CD-可溶性淀粉复合微球,并采用单因素试验法优选出复合微球吸附茉莉香精的最佳工艺条件。研究结果表明:β-CD与淀粉交联形成了复合微球,其球形较规整、分布均匀且表面呈多孔结构;当吸附时间为3 h、吸附温度为50℃和φ(茉莉香精)=30%(相对于茉莉香精和无水乙醇总体积而言)时,复合微球对茉莉香精的吸附率可达到83.85%,并且其缓释性能较好。     

交联壳聚糖磁性微球制备及吸附性能研究

采用超声波辅助化学共沉淀法制备纳米Fe3O4,在此基础上选用乳化交联法,以戊二醛为交联剂,壳聚糖为单体包埋磁性纳米颗粒,合成了微米及纳米尺度上具有高吸附性、介质分离的磁性壳聚糖纳米微球(MCTS),并对复合材料的吸附性能进行了讨论。通过将壳聚糖包裹纳米磁性粒子制备成的磁性壳聚糖微球,具有比表面积大、多孔、易回收、可再生等优点,并且该磁性微球稳定性好、吸附性能强,有效地提高了壳聚糖的应用价值,而对于金属废水处理、药物的分离纯化和天然药物有效成分的富集纯化等意义重大。     

Preparation,characterization, and adsorption properties of chitosan microspheres crosslinked by formaldehyde for copper (II) from aqueous solution

The chitosan microspheres crosslinked by formaldehyde were prepared by spray drying method and used as an adsorbent for copper (II) from aqueous solution. A batch adsorption system was applied to study the adsorption of copper (II) from aqueous solution by chitosan microspheres. The maximum adsorption capacity of the chitosan microspheres for copper (II) was 144.928 mg/g at pH 6.0. Langmuir adsorption model was found to be applicable in interpreting the adsorption process. To elucidate the adsorption mechanism, the chitosan microspheres before and after copper (II) adsorption were further characterized by Fourier transform infrared spectra, zeta potential analysis, and scanning electron microscope. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Fabrication of chitosan microspheres for efficient adsorption of methyl orange

In this article, morphology, structure and size controllable chitosan microspheres with high mechanical strength were synthesized by microfluidic technology combining chemical crosslinking and used as an adsorbent for methyl orange. The synthesized adsorbents were characterized using scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR), and an Energy Dispersive Spectrometer(EDS). The effect of pH revealed that the adsorption process depended on pH and the pH variation of methyl orange solution after adsorption indicated that adsorption capacity was affected through the associated role of chitosan nature and pH variation. Experimental results suggested that the as-prepared chitosan microspheres were controlled within a narrow size distribution(coefficients of variation is 1.81%), whose adsorption capacity reached to 207 mg·g~(-1) and mechanical strength was suitable to resist forces. In addition, the adsorption isotherm was well fitted with the Langmuir model, and the adsorption kinetic was best described by the pseudo-second-order kinetic model.The high performance microfluidic-synthesized chitosan microspheres have promising potentials in the applications of removing dyes from wastewater.     

壳聚糖固化单宁微球的制备及其吸附性能

5 g单宁酸与10 g壳聚糖微球在100 mL pH=7的溶液中反应6 h,再用0.06 mol/L环氧氯丙烷在pH=10,50℃反应4 h制得壳聚糖固化单宁微球,每克壳聚糖微球固载单宁量为0.27 g。采用扫描电镜和红外光谱对微球进行了表征,考察了微球的溶胀性能及对金属离子的吸附性能。研究表明,通过此法制得的壳聚糖固化单宁微球具有表面粗糙,内部疏松多孔的结构。与壳聚糖微球相比,壳聚糖固化单宁微球在溶液中的溶胀性减小,在pH=5及9时,分别减小了63%和50%。对金属离子的吸附容量增大,对Cd2+的吸附容量从0.6 mmol/g提高到2.2 mmol/g,提高了2.66倍。     

Human serum albumin (HSA) adsorption with chitosan microspheres

In this study, chitosan microspheres were prepared and characterized for adsorption of human serum albumin (HSA) as affinity sorbent. The chitosan microspheres were obtained with a “suspension crosslinking technique” in the size range of 30–700 μm by using a crosslinker, i.e., glutaraldehyde. The chitosan microspheres used in HSA adsorption studies were having the average size of 170 ± 81 μm. Adsorption medium pH and the initial HSA concentration in the adsorption medium were changed as 4.0–7.0 and 0.5–2.0 mg HSA/mL, respectively, to investigate the HSA adsorption capacity of chitosan microspheres. Maximum HSA adsorption (i.e., 11.35 mg HSA/g chitosan microspheres) was obtained at pH 5.0 and 1.5 mg HSA/mL of the initial HSA concentration in the adsorption medium was obtained as the saturation value for HSA adsorption. A very common dye ligand, i.e., Cibacron Blue F3GA was attached to the chitosan microspheres to increase the HSA adsorption capacity. Actually, the HSA adsorption capacity was increased up to 15.35 mg HSA/g chitosan microspheres in the case of Cibacron Blue F3GA attached to chitosan microspheres used. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3035–3039, 2002     

Effect of heparin coating on epichlorohydrin cross-linked chitosan microspheres on the adsorption of copper (II) ions

Epichlorohydrin cross-linked chitosan microspheres (CS) and chitosan–heparin polyelectrolyte complex microspheres (CSH) were used in the adsorption of copper (II) ions in aqueous solution. The chitosan microspheres were prepared by the phase inversion method. The use of a cross-linking agent improved the resistance to acidic medium. Polyelectrolyte complex microspheres were prepared by impregnating heparin in cross-linked chitosan microspheres. The microspheres were characterized by IR, TGA and DSC. A study on the effect of the pH on the adsorption of copper (II) ions showed that the optimum pH for both CS and CSH microspheres was 6.0. From a kinetic evaluation, it could be established that the adsorption equilibrium was achieved after 8 h for CS and 25 h for CSH microspheres. The adsorption isotherms were interpreted using Langmuir and Freundlich mathematical models. The results revealed that experimental data of CS was best adjusted by Langmuir model, with maximum capacity of surface saturation equal to 39.31 mg g⁻¹. On the other hand, Langmuir and Freundlich models provided a good fit for adsorption by CSH and the adsorption capacity was 81.04 mg g⁻¹. The interactions between copper (II) ions and both CS and CSH were confirmed by electron paramagnetic resonance spectroscopy, which revealed the formation of a square-planar complex with tetrahedral distortion on the surface of the adsorbents.     

磁性壳聚糖微球的制备及其对2，4-二氯苯酚的吸附

采用反相悬浮聚合法合成了磁性壳聚糖微球,平均粒径不超过5μm。将其用于2,4-二氯苯酚的吸附研究。考察了吸附时间、吸附温度、DCP浓度以及磁性壳聚糖用量等因素对氯酚吸附的影响。结果表明,温度对吸附影响不大,最佳吸附时间为2h时,吸附剂磁性壳聚糖微球用量为1g。对DCP的吸附率在80％以上。在最佳条件下的吸附容量为1．70mg／g。     

Adsorption of methyl orange from aqueous solution by composite magnetic microspheres of chitosan and quaternary ammonium chitosan derivative

Novel composite magnetic microspheres containing chitosan and quaternary ammonium chitosan derivative (CHMMs) were prepared by inverse suspension method, and used for the methyl orange (MO) removal from aqueous solutions. The CHMMs were characterized by a scanning electron microscope, a transmission electron microscope, and Fourier transform infrared spectroscopy, respectively. Compared with the chitosan beads, the incorporation of quaternary ammonium chitosan derivative significantly reduced the particle size. The MO adsorption by CHMMs was investigated by batch adsorption experiments. The adsorption kinetics was conformed to the pseudo second-order kinetics equation. The adsorption isotherm followed the Langmuir model better than the Freundlich model and the calculated maximum MO adsorption capacity was 266.6 mg·g^-1 at 293 K. Thermodynamic studies indicated that the MO adsorption was endothermic in nature with the enthalpy change (ΔH°) of 99.44 kJ·mol^-1. The CHMMs had a stable performance for MO adsorption in the pH range of 4-10, but high ionic strength deteriorated the MO removal due to the shielding of the ion exchange interaction. A 1 mol·L^-1 NaCl solution could be used to regenerate the exhausted CHMMs. The proposed CHMMs can be used as an effective adsorbent for dye removal or recovery from the dye wastewater.     

壳聚糖-琼胶复合微球的制备及其药物释放性能

采用小分子离子交联法制备了pH值敏感的壳聚糖-琼胶复合微球,对壳聚糖-琼胶复合微球的粒径、形貌、pH值敏感性等进行了表征.以茶碱为模型药物研究了壳聚糖-琼胶复合微球的药物释放性能,结果发现一定量琼胶的引入有助于改善壳聚糖微球的药物缓释性能.