Cu2+印迹交联壳聚糖微球的合成及吸附性能

利用分子印迹技术,以壳聚糖(CS)为功能单体,Cu~(2+)为印迹离子,通过稀氨水固化、环氧氯丙烷交联、盐酸洗脱Cu~(2+),制得了Cu~(2+)印迹交联壳聚糖微球(Cu~(2+)-ICM)。采用FTIR、XRD和FESEM对产品进行了表征,并测定了微球的骨架密度、含水量和交联度。结果表明:交联改性可使微球具有多孔结构和良好的结构稳定性,能够很好地降低CS的酸溶性,提高微球对Cu~(2+)的吸附性能。通过正交实验L_9(3~4)得到Cu~(2+)-ICM的最优制备条件为:CS 1.5 g,环氧氯丙烷2.5 mL,80℃下交联3.0 h,制得的微球对Cu~(2+)吸附量为67.80 mg/g。在单组分体系中考察了微球对Cu~(2+)的吸附性能。结果表明:当微球投加量为50 mg,Cu~(2+)初始质量浓度为338.7 mg/L,pH=5.0时,吸附量为72.80 mg/g。     

壳聚糖/纤维素复合微球对Cu2+的吸附

制备壳聚糖/纤维素(CS/CE)和交联壳聚糖/纤维素(ECS/CE)复合微球,用于吸附重金属离子,考察了微球对Cu2+的吸附性能。溶解性测试表明交联反应可提高微球在酸性介质中的化学稳定性。静态吸附表明,CS/CE和ECS/CE均能有效吸附Cu2+,pH 6附近吸附容量最大。吸附等温线与Langmuir和Freundlich模型均吻合,由Lang-muir模型得到的Cu2+饱和吸附容量分别为38.76 mg/g(CS/CE)和34.13 mg/g(ECS/CE)。CS/CE和ECS/CE对Cu2+的吸附初期为内扩散控制,但后期为配合反应控制。FTIR和X-射线光电子能谱(XPS)分析表明,壳聚糖中的N为Cu2+的主要吸附位,发生表面配合吸附。     

交联壳聚糖微球树脂对Cu(Ⅱ)吸附性能研究

采用反相悬浮法,以戊二醛为交联剂,以环己烷为致孔剂制备交联壳聚糖微球树脂(CCMR);通过静态吸附试验研究树脂对Cu(Ⅱ)的吸附行为。利用金相显微镜和比表面积仪对交联壳聚糖微球树脂(CCMR)的表观形貌和比表面积进行表征;通过紫外可见光谱考察了Cu(Ⅱ)初始浓度对吸附性能影响,研究其吸附动力学。结果表明,随着致孔剂用量的增加,交联壳聚糖微球树脂比表面积增大,吸附性能增强,其中添加环己烷100 m L,乙酸乙酯5 m L制备交联壳聚糖微球树脂对浓度为8 mg/m L的Cu(Ⅱ)溶液的平衡吸附容量可达190 mg/g,吸附性能较好,吸附过程符合准二级吸附动力学模型。     

壳聚糖交联微球对水中镍离子的吸附性能

以戊二醛为交联剂,采用反相悬浮法合成了壳聚糖交联微球,研究了该微球对Ni2+的吸附性能及其重复使用性。结果表明,壳聚糖交联微球对Ni2+的吸附条件是25℃时,p H 7.0,在50 m L质量浓度为300 mg/L Ni2+溶液中,投加0.05 g吸附剂,吸附2 h,吸附量为45.65 mg/g。该微球经0.1 mol/L盐酸解吸后可再生,重复使用7次,吸附量仍可达原来的81.9%。微球良好的再生性显著降低了处理成本,提高了处理效果,减少了二次污染。     

功能化壳聚糖磁性微球的制备及其对Cr~(3+)、Ni~(2+)的吸附

以经SiO_2包覆的Fe_3O_4和4-氯苯基异氰酸酯修饰的壳聚糖为原料,六亚甲基双异氰酸酯(HDI)为连接剂,制得功能化Fe_3O_4@Si O_2-壳聚糖磁性微球(磁性微球C),并利用SEM、FTIR对其进行表征,考察了所得磁性微球C对Cr~(3+)和Ni~(2+)的吸附性能。结果表明:磁性微球C的平均粒径为520 nm左右且分散性好。对Cr~(3+)、Ni~(2+)的吸附在60 min内达到平衡,在吸附剂质量为0.2 g,Cr~(3+)浓度为2.5 mmol/L,p H=3.0时,Cr~(3+)的单位吸附量为191.1 mg/g;在Ni~(2+)浓度为0.1 mmol/L,pH=5.0时,Ni~(2+)的单位吸附量为4.725 mg/g。所测等温吸附数据既符合Langmuir模型,也符合Freundlich模型。     

交联壳聚糖多孔微球吸附亮绿的研究

利用液体石蜡作有机分散介质,戊二醛作交联剂,制备了交联壳聚糖多孔微球,采用SEM对壳聚糖微球的形貌、大小进行了表征,研究交联壳聚糖微球对亮绿的吸附性能,探讨交联壳聚糖多孔微球用量、亮绿初始浓度、pH值、吸附时间、吸附温度的影响.结果表明,室温下,交联壳聚糖微球粒径为0.5～1.0 mm,亮绿初始浓度10 mg·L-1,pH=6,振摇30 min时,吸附量达1.22 mg·g-1;CODCr去除率达73%.亮绿初始浓度越大,吸附量越大,吸附速率越大;吸附剂用量越大,平衡吸附量越小,吸附速率越大.交联壳聚糖微球对亮绿具有很高的吸附容量和较快的吸附速率,再生重复使用,其脱色率仍达90%以上.等温吸附较好符合Freundlich方程.     

新型聚胺基微球制备及其吸附蛋白质性质

以反相乳液为模板,通过在聚乙烯亚胺（PEI）水溶液/液体石蜡的W/O乳状液中连续滴加戊二醛的方式,在液滴间聚并过程中,交联剂和PEI在油水界面发生交联反应,制备得到新型的聚胺基交联微球。所得微球表面光滑,球形对称,粒径分布范围0.37～4.29 ?m,平均粒径为 1.44 ?m。微球表面Zeta电位的等电点为10.6,热重分析结果表明交联反应提高了PEI的分解温度。吸附蛋白质的实验结果证明,微球能自脂肪酶、纤维素酶、?-淀粉酶、果胶酶的混合蛋白质溶液中选择性吸附脂肪酶,微球对所检测脂肪酶的最大吸附量为127.8 mg/g。     

纳米四氧化三铁沸石微球吸附废水中铅离子研究

采用纳米Fe_3O_4对人造沸石(NZ)进行改性,研究了吸附剂投加量、废水pH、不同交联剂、离子含量等对改性磁性沸石微球去除废水中Pb~(2+)性能的影响,分析了改性沸石的吸附动力学和吸附等温线。结果表明,在Pb~(2+)溶液pH=3,吸附剂投加量为0.6 g/L条件下,钙交联纳米Fe_3O_4改性沸石微球(Ca-MZS)对溶液中Pb~(2+)的去除率达93.4%,最大吸附量为77.1 mg/g,较NZ的最大吸附量8.02 mg/g有明显提高。Ca-MZS比铁交联纳米Fe_3O_4改性沸石微球(Fe-MZS)的最大吸附量高2.57 mg/g。Ca-MZS对Pb~(2+)的吸附过程符合准2级动力学模型和Freundlich模型。Pb~(2+)溶液分别加入Na~+、K~+时,Ca-MZS对Pb~(2+)去除率分别下降了9.3个、16.1个百分点。     

壳聚糖基吸附剂的合成及其对Cu(Ⅱ)吸附性能研究

以壳聚糖、聚乙烯亚胺(PEI)、环氧氯丙烷(ECH)为原料,掺杂不同含量的钛铁矿粉末,制备了一系列壳聚糖基复合吸附剂,并用FTIR、SEM表征了微球的结构。当钛铁矿粉末掺杂量为0. 05 g时,制得的复合吸附剂微球对Cu(Ⅱ)吸附量可达到1. 20 mmol/g。吸附过程能较好地用Langmuir吸附等温线方程及准二级动力学方程进行拟合,相关系数R~2都在0. 90以上,表明是化学吸附控制。随着体系中NaNO_3浓度的增加,复合吸附剂对Cu(Ⅱ)的吸附量会显著上升,增幅可达55%。     

交联壳聚糖微球的制备及其对不同pH有机染料的吸附性能

本文以壳聚糖为原料,戊二醛为交联剂,采用乳化交联法制备了交联壳聚糖微球。并通过红外光谱仪(FT-IR)、X射线衍射仪(XRD)、扫描电镜(SEM)对壳聚糖和交联壳聚糖微球的结构与形貌进行表征,使用紫外/可见分光光度计测试了甲基橙溶液的吸收波长及吸光度。主要研究了不同p H条件下交联壳聚糖微球对甲基橙溶液的吸附脱色效果。结果表明:交联壳聚糖微球形状规则、表面光滑,其粒径为100μm左右;当甲基橙溶液p H值为3时,吸附速率最快;动力学研究结果表明该吸附过程符合准二级吸附动力学方程模型。     

壳聚糖希夫碱及壳聚糖改性微球的吸附性能研究

以壳聚糖和对二甲氨基苯甲醛为原料合成壳聚糖希夫碱,以壳聚糖希夫碱为底物,采用反相悬浮聚合法,制备壳聚糖希夫碱微球。对二者的吸附性能进行比较研究。结果表明,希夫碱微球的吸附性能优于壳聚糖希夫碱,对四氧化三铁的吸附容量分别为113.179 mg/g和39.279 mg/g,对亚甲基蓝的吸附平衡时间均为150 min,饱和吸附容量随着亚甲基蓝初始质量浓度的增大而增大,且微球的吸附容量大于壳聚糖希夫碱,吸附率不随浓度增大单调递增,而是有一极大值。     

Removal of Cr(VI) from aqueous solution using amino‐modified Fe3O4–SiO2–chitosan magnetic microspheres with high acid resistance and adsorption capacity

A novel, bioadsorbent material of polyethylenimine‐modified magnetic chitosan microspheres enwrapping magnetic silica nanoparticles (Fe₃O₄–SiO₂–CTS‐PEI) was prepared under relatively mild conditions. The characterization results indicated that the adsorbent exhibited high acid resistance and magnetic responsiveness. The Fe₃O₄ loss of the adsorbent was measured as 0.09% after immersion in pH 2.0 water for 24 h, and the saturated magnetization was 11.7 emu/g. The introduction of PEI obviously improved the adsorption capacity of Cr(VI) onto the adsorbent by approximately 2.5 times. The adsorption isotherms and kinetics preferably fit the Langmuir model and the pseudo‐second‐order model. The maximum adsorption capacity was determined as 236.4 mg/g at 25°C, which was much improved compared to other magnetic chitosan materials, and the equilibrium was reached within 60 to 120 min. The obtained thermodynamic parameters revealed the spontaneous and endothermic nature of the adsorption process. Furthermore, the Cr(VI)‐adsorbed adsorbent could be effectively regenerated using a 0.1 mol/L NaOH solution, and the adsorbent showed a good reusability. Due to the properties of good acid resistance, strong magnetic responsiveness, high adsorption capacity, and relatively rapid adsorption rate, the Fe₃O₄–SiO₂–CTS‐PEI microspheres have a potential use in Cr(VI) removal from acidic wastewater. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43078.     

Adsorption of heavy‐metal ions on poly(ethylene imine)‐immobilized poly(methyl methacrylate) microspheres

Poly(methyl methacrylate) (PMMA) microspheres carrying poly(ethylene imine) (PEI) were prepared for the removal of heavy‐metal ions (copper, cadmium, and lead) from aqueous solutions with different amounts of these ions (50–600 mg/L) and different pH values (3.0–7.0). Ester groups in the PMMA structures were converted to imine groups in a reaction with PEI as a metal‐chelating ligand in the presence of NaH. The adsorption of heavy‐metal ions on the unmodified PMMA microspheres was very low [3.6 μmol/g for Cu(II), 4.6 μmol/g for Cd(II), and 4.2 μmol/g for Pb(II)]. PEI immobilization significantly increased the heavy‐metal adsorption [0.224 mmol/g for Cu(II), 0.276 mmol/g for Cd(II), and 0.126 mmol/g for Pb(II)]. The affinity order of adsorption (in moles) was Cd(II) > Cu(II) > Pb(II). The adsorption of heavy‐metal ions increased with increasing pH and reached a plateau value around pH 5.5. Their adsorption behavior was approximately described with the Langmuir equation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 197–205, 2001     

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     

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。     

Removal of copper(II) from an aqueous solution with copper(II)‐imprinted chitosan microspheres

Ion‐imprinted chitosan (CS) microspheres (MIPs) were prepared with Cu(II) as a template and epichlorohydrin as a crosslinker for the selective separation of Cu(II) from aqueous solution. The microspheres showed a higher adsorption capacity and selectivity for the Cu(II) ions than nonimprinted chitosan microspheres (NMIPs) without a template. The results show that the adsorption of Cu(II) on the CS microspheres was affected by the initial pH value, initial Cu(II) concentration, and temperature. The kinetic parameters of the adsorption process indicated that the adsorption followed a second‐order adsorption process. Equilibrium experiments showed very good fits with the Langmuir isotherm equation for the monolayer adsorption process. The maximum sorption capacity calculated from the Langmuir isotherm was 201.66 mg/g for the Cu–MIPs and 189.51 mg/g for the NMIPs; these values were close to the experimental ones. The selectivity coefficients of Cu(II) and other metal ions on the NMIPs indicated a preference for Cu(II). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Zeolite X/chitosan hybrid microspheres and their adsorption properties for Cu(II) ions in aqueous solutions

The preparation of zeolite X/chitosan (CS) hybrid microspheres for efficient removal of Cu(II) ions by an impregnation-gelation-hydrothermal synthesis technique is reported here. Characterizations by various techniques indicate that the microspheres show porous structures and intimate interaction between zeolite and CS. The adsorption experiments are performed to evaluate the adsorption capacity of zeolite X/CS hybrid microspheres and comparisons are made with binderless zeolite X microspheres, pure CS microspheres and mechanical mixed zeolite X/CS microspheres. The effects of Cu(II) solution concentration and the pH are investigated. The results indicate that zeolite X/CS hybrid microspheres with the zeolite content of 60 wt% show the highest adsorption capacity, which is 90 mg/g at the initial Cu(II) concentration of 10 mg/L and 150.4 mg/g at Cu(II) concentration of 500 mg/L. The adsorption capacity increases with increasing initial pH and reaches a maximum at pH 5.5 in the range of 0–6.0. The equilibrium adsorption data are well described by the Langmuir isotherm model, exhibiting a maximum adsorption capacity of 152.0 mg/g, and the kinetic data are well fitted with the pseudo-second-order equation. Complete removal of Cu(II) ions can be obtained even at very low concentrations. The microspheres show high adsorption capacity and efficiency for Cu(II) ions, exhibiting potential practical application in the treatment of water pollution of heavy metal ions.     

Facile preparation of EDTA‐functionalized chitosan magnetic adsorbent for removal of Pb(II)

A novel magnetic adsorbent (EDTA /chitosan/ PMMS) was facilely prepared by reacting chitosan with EDTA anhydride in presence of PEI ‐ coated magnetic microspheres. The as‐synthesized EDTA/ chitosan /PMMS was characterized by XRD, SEM, TGA, FT‐IR , and VSM, and then employed in removal of heavy metals of Pb(II) from aqueous solution. The results of the batch adsorption experiments revealed that the adsorbents had extremely high uptake capacities for Pb(II) in the pH range of 2 to 5.5, and the adsorption kinetics for EDTA/ chitosan /PMMS was consistent with the pseudo – second ‐ order kinetic model. Moreover, its equilibrium data were fitted with the Langmuir isothermal model well, which indicated that the adsorption mechanism was a homogeneous monolayer chemisorptions process. The maximum adsorption capacity of EDTA/ chitosan /PMMS for Pb(II) was found to be 210 mg g ^{? 1} at pH 4 (30 ° C), and further reuse experiments results suggested that EDTA /chitosan/ PMMS could be a potential recyclable magnetic adsorbent in the practical wastewater treatment. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42384.     

改性纤维素微球的制备及其对Pb2＋吸附性能的研究

利用绿色环保的碱／尿素／水溶剂体系直接制备纤维素溶液共混聚乙烯亚胺（PEI）,然后通过高压静电法制备再生纤维素微球,并与戊二醛交联固定化,制备了复合型吸附材料。借助吸附动力学和吸附等温方程研究了改性纤维素微球对Pb2＋的吸附性能,结果表明改性纤维素微球对Pb2＋具有较好的吸附容量达到9．46mg／g,相比空白微球提高50％以上,并且吸附过程符合准二级动力学方程和Freundlich等温方程。     

松香基表面活性剂调控制备NiO纳米微球及其吸附刚果红

通过天然产物松香制备松香基表面活性剂,利用该表面活性剂调控晶体生长制备出多级Ni(OH)2纳米结构,并进一步制备成NiO微球.通过FT-IR、NMR、XRD、SEM、TEM等表征确定了NiO的形貌及结构,通过BET等表征测试确定了其为多级多孔的结构.FT-IR、UV研究表明该多级纳米NiO对刚果红具有极高的吸附能力,其...