羧化改性壳聚糖微球的制备及吸附硝基酚的性能

采用反相悬浮环氧氯丙烷交联、氯乙酸羧甲基化制备交联羧化壳聚糖微球,用红外光谱和扫描电镜对微球进行表征,并用于2,4-二硝基苯酚的吸附研究。考察了吸附时间、溶液pH值、酚的浓度和NaCl等因素对2,4-二硝基苯酚吸附的影响。结果表明,羧化改性交联壳聚糖微球具有较好的耐酸碱性能,对2,4-二硝基苯酚有良好的吸附性能,在pH值为3.6条件下,吸附在瞬间就能达到平衡,吸附量达230 mg.g-1,吸附符合Freundlich等温方程。     

壳聚糖固载环糊精微球的制备及吸附硝基酚

反相悬浮法制备甲醛保护壳聚糖(CTS)微球,环氧氯丙烷为交联剂β-环糊精反应制得壳聚糖固载环糊精微球。产物用红外光谱、扫描电子显微镜和X射线衍射仪进行表征,并用于吸附2,4-二硝基酚研究。考察了吸附时间、溶液pH值、酚浓度和NaCl含量对吸附的影响。实验结果表明,壳聚糖固载环糊精(CTS-CD)微球具有较好的耐酸碱性能,在pH值为3.6条件下,对2,4-二硝基酚的吸附快速达到平衡,吸附量为325mg/g,吸附符合Freundlich等温方程和二级动力学方程。     

壳聚糖Schiff碱的制备及其对金属离子吸附性能研究

文章采用微波辐射技术制备戊二醛交联壳聚糖水杨醛Schiff碱,探究其对铜离子的吸附性能。通过红外光谱仪,热分析仪和扫描电子显微镜对其结构及性能进行一系列表征,同时通过正交实验法考察其反应温度、时间、吸附动力学等影响因素对交联产物吸附性能的影响。扫描电镜分析表明交联改性后壳聚糖的表面明显发生变化,比壳聚糖更加松散,在吸附完成后改性壳聚糖的表面变得严密。由分析热失重可知改性壳聚糖热分解反应是258℃。由吸附动力学曲线可以得出改性壳聚糖对铜离子的吸附符合二级吸附动力学方程。     

胺基化壳聚糖树脂吸附2,4-二氯苯酚

改性制得的胺基化壳聚糖用于对2,4-二氯苯酚吸附的研究中,最佳吸附条件为在30℃、pH为4、吸附时间为1 h,胺化剂用量为0.1 g以及二氯苯酚浓度为0.09 mol/L。通过对Langmuir等温吸附方程及Freundlich等温吸附方程的分析得出吸附更加符合Langmuir等温吸附方程。     

壳聚糖交联微球的制备及其对重金属离子的吸附作用

采用碱解法制备出高脱乙酰度的壳聚糖,再采用戊二醛或环氧氯丙烷对壳聚糖进行交联制得多孔交联微球。结果表明:环氧氯丙烷比戊二醛更适宜作为壳聚糖的交联剂,交联微球对Cu²⁺、Ni²⁺、Cd²⁺的吸附容量受金属离子初始浓度、吸附时间和溶液pH值的影响,其关系为:Cd²⁺>Cu²⁺>Ni²⁺。     

活性炭对水中2,4-二氯酚的吸附研究

以活性炭作为去除水中2,4 二氯酚的吸附剂,考察了振荡时间、水样pH值对吸附效果的影响,采用Langmuir和Freundlich模式对吸附等温线作了线性拟合,结果表明2,4 二氯酚在活性炭上的吸附可用Langmuir和Freundlich较好地描述,吸附呈单分子层形式且易于进行,活性炭对2,4 二氯酚吸附性能良好,吸附剂易于再生。     

交联壳聚糖微球对喹乙醇吸附性能的研究

以壳聚糖为原料,乙酸乙酯为致孔剂,环氧氯丙烷为交联剂,通过交联法制备出改性壳聚糖,考察了交联壳聚糖微球对喹乙醇吸附的影响。结果表明,V(壳聚糖)∶V(乙酸乙酯)∶V(环氧氯丙烷)=30∶1∶1时,制备的交联壳聚糖微球对喹乙醇吸附性能较好;红外光谱表明,环氧氯丙烷与壳聚糖发生反应;扫描电镜分析验证环氧氯丙烷用量对交联壳聚糖微球吸附性能有一定影响;吸附动力学曲线得知交联壳聚糖微球在3 h对喹乙醇吸附达到平衡,有较好的吸附速度;与类似物(喹烯酮和乙酰甲喹)吸附特性比较得知,交联壳聚糖微球对喹乙醇有较好的选择吸附性。     

牛血清白蛋白在交联壳聚糖微球上的吸附研究

采用反相悬浮法,以甲醛为预交联剂,环氧氯丙烷交联制备壳聚糖微球,用红外光谱和扫描电镜对微球进行表征,并用于牛血清白蛋白的吸附研究.考察了吸附时间、溶液pH值、牛血清白蛋白的浓度、温度、氯化钠含量等因素对牛血清白蛋白吸附的影响.结果表明,交联CTS微球不溶于酸和碱,对牛血清白蛋白具有良好的吸附性能,在pH 5.0时,吸附在1.5 h内可达平衡,吸附数据符合Langmuir等温方程.     

改性壳聚糖加碘膜的制备与表征

壳聚糖(CTS)和水杨醛、环氧氯丙烷交联制备壳聚糖衍生物(RS-CTS-E),并制备相应衍生物的凝胶膜,将凝胶膜浸没在一定浓度碘乙醇溶液中,制备改性壳聚糖加碘膜(RS-CTS-E-I2),并对其进行了IR、SEM等表征。碘含量分析表明:改性壳聚糖凝胶膜对单质碘吸附量随碘乙醇溶液浓度增加而增大。碘吸附动力学结果表明其平衡吸附时间为6 h。抑菌性测试结果表明,w(I2)=19.05%时RS-CTS-E-I2膜对金黄色葡萄球菌抑菌环和大肠杆菌抑菌环的抑菌环直径分别为(31±1)mm和(30±1)mm,均为高度敏感。     

α-酮戊二酸修饰壳聚糖微球对牛血清蛋白的吸附

采用反相悬浮法制备交联壳聚糖微球,再与α-酮戊二酸反应生成Schiff碱,NaBH4还原制得改性壳聚糖微球.用FFIR、SEM和XRD对其进行表征,并将之用于牛血清白蛋白的吸附研究,考察了吸附时间,溶液pH值、牛血清白蛋白的浓度.温度、NaCl含量等因素对牛血清白蛋白吸附的影响.结果表明,α-酮戊二酸改性交联壳聚糖微球不溶于酸和碱,对牛血清白蛋白具有良好的吸附性能,在pH=5.0时,吸附在1 h内可达平衡,吸附数据符合Langmuir等温方程和Lagergren二级动力学方程.     

Mechanism of removing chlorophenolic compounds from solution by a water-insoluble cationic starch

The removal of three chlorophenolic compounds from solutions using highly crosslinked cationic starch containing a tertiary amine group was investigated. The three chlorophenolic compounds were 2-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol. The adsorption process predominated over the initial pH = 2∼6 for 2-chlorophenol, and predominated over the initial pH = 2 to 4 range for 2,4-dichlorophenol and 2,4,6-trichlorophenol. The ion-exchange process predominated at initial pH = 12 for 2-chlorophenol, and predominated over the initial pH = 10 to 12 range for 2,4-dichlorophenol and 2,4,6-trichlorophenol. Both processes coexist over the initial pH=8 to 10 range for 2-chlorophenol, and coexist over the initial pH = 6∼8 for 2,4-dichlorophenol and 2,4,6-trichlorophenol. Experimental results indicate that the adsorption process is initially pH-independent, and the ion-exchange process is initially pH-dependent. The adsorption and ion-exchange processes are concentration-dependent and correspond to the Langmuir isothermal adsorption. They are endothermic for 2-chlorophenol and 2,4-chlorophenol, and are exothermic for 2,4,6-chlorophenol. The ion-exchange capacity is larger than the adsorption capacity. Moreover, the order of the amount of three chlorophenolic compounds removed by the cationic starch is 2,4,6-chlorophenol > 2,4-dichlorophenol > 2-chlorophenol.     

交联羧甲基壳聚糖对镁的吸附性能研究

讨论了交联羧甲基壳聚糖对Mg2+的吸附作用,探讨了溶液的pH值、吸附时间、温度等因素对其吸附性能的影响。实验表明,在pH值为4~5时,交联羧甲基壳聚糖对Mg2+的吸附性能很好,吸附率可达95%以上,饱和吸附容量为96.7 mg/g,且具有良好的重复使用性能,在线性范围内方法的相对标准偏差为8.1%。     

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     

阳离子木屑纤维素的制备及其对水中2,4-二氯苯酚的吸附性能

以3-氯-2-羟丙基三甲基氯化铵(CTA)为醚化剂,对木屑纤维素(MC)进行了改性,并对产物进行了表征. 探讨了阳离子木屑纤维素用量、pH值、吸附温度、吸附时间等因素对水溶液中2,4-二氯苯酚(2,4-DCP)静态吸附效果的影响. 结果表明,阳离子木屑纤维素的制备条件为：CTA/MC质量比2.0,反应时间2.0 h,反应温度30℃,NaOH溶液浓度30%(w). 阳离子木屑纤维素对水溶液中2,4-DCP的最佳吸附条件为：pH 8.0,吸附时间90 min,吸附温度25℃. 此条件下,处理100 mL 2,4-DCP溶液(50 mg/L)的吸附率可达88.92%,吸附容量为1.482 mg/g. 木屑纤维素经改性后,对水中2,4-二氯苯酚存在化学吸附.     

Adsorption of Some Platinum Group Metals on Some Complexane Types of Chemically Modified Chitosan

Abstract

A few kinds of complexane types of chemically modified chitosan, i.e., monocarboxymethylated chitosan (MCM-chitosan) and IDA- and DTPA-types of chitosan (IDA- and DTPA-chitosan) were synthesized to examine the adsorption of palladium(II), platinum(IV), and iridium(III) from hydrochloric acid solution as well as the elution of palladium and platinum and compared with those by crosslinked copper(II)-complexed chitosan (crosslinked chitosan). The adsorption of palladium(II) monotonously decreased with increasing hydrochloric acid concentration with all kinds of adsorbents. The adsorption of platinum(IV) also decreased with increasing hydrochloric acid concentration with all kinds of adsorbents except for DTPA-chitosan, with which it decreased in the low concentration region and increased in the high concentration region. The adsorption of iridium(III) also decreased with increasing concentration of hydrochloric acid with all kinds of adsorbents except for IDA-chitosan, but that on DTPA-chitosan was much smaller than other adsorbents. The adsorption on IDA-chitosan increased with increasing hydrochloric acid concentration in its low concentration region, and decreased in the high concentration region, different from other adsorbents. The magnitude of adsorption capacity of each adsorbent for palladium(II) was in the order MCM-chitosan = IDA-chitosan > DTPA-chitosan > crosslinked chitosan, while that for platinum(IV) was in the order, DTPA-chitosan > MCM-chitosan = IDA-chitosan > crosslinked chitosan. The elution of loaded palladium(II) and platinum(IV) with hydrochloric acid solution was much improved by chemical modification, especially that of platinum(IV) which was drastically improved by using IDA- and MCM-chitosan.     

交联壳聚糖对废水中Cu2+的吸附性能

以壳聚糖为原料制备交联壳聚糖吸附剂,并将其用于吸附废水中的Cu2+,考察了交联剂的用量、溶液中Cu2+初始浓度、pH、温度和时间等对交联壳聚糖吸附性能的影响。结果表明,壳聚糖与交联剂的用量比为m(壳聚糖)∶V(甲醛)∶V(戊二醛)=1.5g∶6mL∶4.5mL、溶液pH为6,溶液中Cu2+初始浓度为5mmol/L时吸附效果最佳,且吸附量随着温度升高而增加,吸附表现为吸热过程。     

硅胶负载交联壳聚糖树脂的制备及吸附性能

以壳聚糖、硅胶为主要原料制备了一种硅胶负载交联壳聚糖树脂,采用红外光谱(IR)、X-衍射(XRD)和扫描电镜(SEM)对其进行结构性能表征,并研究了树脂对金、银离子的吸附行为。重点考察了交联剂用量、介质pH值和初始离子浓度等因素对树脂材料吸附率的影响,试验结果表明,该树脂对金银离子的吸附率均大于90%。对于金离子的吸附而言,控制pH值在4,吸附时间90 min时吸附率最高;对于银离子的吸附而言,控制pH值在4~6,吸附时间100 min时吸附率最高。离子初始质量浓度对树脂材料的吸附率影响不大。     

Cu2+ removal from aqueous solution by modified chitosan hydrogels

BACKGROUND: The adsorption of Cu²⁺ from aqueous solution using crosslinked chitosan hydrogels impregnated with Congo Red (CR) by ion‐imprint technology was systematically investigated with particular reference to the effects of contact time, pH, and initial concentration on adsorption. RESULTS: The adsorption capacity of the crosslinked chitosan without impregnation was only 68.68 mg g^?1 for Cu²⁺. However, the adsorption capacity increased from 77.42 (without imprint ion) to 84.54 mg g^?1 (imprint ion content 0.5 mmol) after the chitosan was impregnated with a ratio of 1/12 of CR to chitosan. The as‐prepared adsorbents were found to be pH‐dependent and the process of adsorption agreed well with the Freundlich isotherm. The loaded adsorbents could be regenerated and reused without the appreciable loss of capacity. CONCLUSION: Chitosan hydrogels impregnated with CR showed higher Cu²⁺ adsorption capacities compared with those prepared conventionally without imprint ion, and thus developed a good approach to increase Cu²⁺ adsorption efficiency in the treatment of waste‐water. Copyright © 2012 Society of Chemical Industry