交联羧甲基魔芋葡甘聚糖吸附重金属离子的研究

以异丙醇为分散剂,环氧氯丙烷为交联剂,在碱性介质中由一氯乙酸和魔芋葡甘聚糖(KGM)反应,制备了取代度为0.265和0.550的两种交联羧甲基魔芋葡甘聚糖(CMKGM),并将其用于吸附溶液中Cu2 、Pb2 和Cd2 。结果表明,CMKGM对3种重金属离子的吸附约在20min内达到平衡,与金属离子类型无关,吸附遵从二级动力学方程;pH对吸附量影响较大,适宜范围为5~6;吸附能较好地服从Langmuir等温吸附方程,CMKGM(DS=0.550)吸附Pb2 的最大吸附容量(Qm)为41.7mg/g,Langmuir常数(b)为0.305mg/L,均大于Cu2 和Cd2 相应值;再生后的CMKGM吸附性能好,脱吸附百分率高。     

一种新型交联羧甲基葡甘聚糖微球对Cr(Ⅵ)的吸附性能研究

通过Fe3+交联羧甲基葡甘聚糖制得了一种新型羧甲基葡甘聚糖凝胶球,研究了羧甲基葡甘聚糖铁凝胶球对Cr(Ⅵ)的吸附性能。分别考察了吸附时间、羧甲基葡甘聚糖浓度、FeCl3浓度、pH值、温度、Cr(Ⅵ)浓度和微球粒径对吸附的影响,同时用红外光谱初步表征了羧甲基葡甘聚糖铁凝胶球-Cr(Ⅵ)复合物的结构。结果表明,293K时,微球对Cr(Ⅵ)的吸附反应在12h时达平衡,当羧甲基葡甘聚糖质量分数为1.0%,FeCl3质量分数为1.0%,Cr(Ⅵ)浓度为400mg/L时,吸附量达到0.4385mmol/g。根据不同温度下微球吸附Cr(Ⅵ)的等温线,计算了吸附过程的热力学参数,同时用Freundlich方程对实验数据进行了拟合,发现该方程适用于所研究的吸附体系。该体系为自发放热过程,体系熵减少,降温有利于吸附。     

魔芋葡甘聚糖DEAE阴离子交换介质的制备及表征

以交联的魔芋葡甘聚糖微球(KGM)为基质,制备了DEAE型的阴离子交换层析介质,考察了反应物浓度、温度、时间等反应因素对魔芋葡甘聚糖层析介质离子交换容量的影响,确定最优反应参数.结果表明,层析介质的离子交换容量达到3.42mmol/g,蛋白吸附容量高达126.84mg/mL,蛋白洗脱率为90.42%.     

一种羧甲基葡甘聚糖钛凝胶球的吸附性能

用钛交联羧甲基葡甘聚糖制得羧甲基葡甘聚糖钛凝胶球,研究该凝胶球对十二烷基苯磺酸钠(SDBS)的吸附性能。分别探究了吸附时间、p H值、Ti(SO_4)_2浓度、羧甲基葡甘聚糖(CMKGK)浓度、SDBS浓度及温度对吸附的影响。结果表明:Ti(SO_4)_2浓度为2%、CMKGM浓度为2%时制得的凝胶球吸附效果最佳,吸附反应在8h达到平衡,当SDBS溶液的pH值为4、初始浓度为2 000 mg·L~(-1),温度为298K时,凝胶球对SDBS的吸附量达到493 mg·g~(-1),而且吸附量随着SDBS溶液初始浓度的增大而增大。钛交联羧甲基葡甘聚糖凝胶球对SDBS的吸附符合Freundlich等温方程,升高温度不利于吸附。动力学研究表明此吸附遵从准二级动力学方程。     

羧甲基交联魔芋葡甘聚糖微球的制备与表征

采用交联魔芋葡甘聚糖颗粒(CKGG)合成了羧甲基交联魔芋葡甘聚糖微球(CMCKGG)，讨论了羧甲基化过程中的影响因素．用正交设计的方法确定了具有较好交换容量的CMCKGG制备奈件．当碱用量为CKGG量的20％，氯乙酸钠用量为CKGG量的10倍，温度55℃，反应时间8h时，制得的CMCKGG阳离子交换容量为0．7389mmol／g．红外光谱．光学显微镜和扫描电镜的结果表明，该颗粒为蜂窝状多孔微球，粒度均匀．     

一种磷酸根-羧甲基葡甘聚糖锆凝胶球的吸附性能

用氧氯化锆溶液交联羧甲基葡甘聚糖制得新型吸附材料—羧甲基葡甘聚糖锆凝胶球。探究了凝胶球对磷酸根的吸附性能,考察了羧甲基葡甘聚糖浓度、氧氯化锆浓度、吸附时间、pH值、温度和磷酸根浓度对吸附的影响。结果表明:298K时,凝胶球对磷酸根的吸附9h达平衡,当CMKGM和氧氯化锆浓度均为2.0%,磷酸根初始浓度为600mg·L-1,pH为2.5时,吸附量为186.65mg/g。利用Langmuir方程拟合实验数据,发现该方程适合于所研究的吸附体系。该体系为吸热体系,升温有利于吸附。     

新型交联羧甲基葡甘聚糖凝胶球对尿素的吸附性能

本文用CuSO4溶液处理羧甲基葡甘聚糖制得了一种新型吸附材料—羧甲基葡甘聚糖铜凝胶球,研究了该凝胶球对尿素的吸附性能。分别考察了吸附时间、羧甲基葡甘聚糖浓度、CuSO4浓度、pH值、温度和尿素浓度对吸附的影响,同时用红外光谱初步表征了Cu2+交联羧甲基葡甘聚糖凝胶球-尿素复合物的结构。结果表明:310K时,凝胶球对尿素的吸附反应在9h时达平衡。当羧甲基葡甘聚糖浓度为2%,Cu2+质量分数为2%,尿素浓度为800mg.L-1时,pH值为6.5,吸附量为101.85mg.g-1。根据不同温度下凝胶球吸附尿素的等温线,计算了吸附过程的热力学参数,同时用Freundlich方程对实验数据进行了拟合,发现该方程适用于所研究的吸附体系。该体系为自发放热过程,体系熵减少,降温有利于吸附。     

离子液体和KGM修饰电极上的直接电化学

将血红蛋白固定在用室温离子液体和魔芋葡甘聚糖(KGM)水凝胶修饰的玻碳电极上,其循环伏安扫描显示一对可逆的氧化还原电流峰,克式量电位(-0.38V,vs.SCE)随溶液pH值的增大而负移,呈良好的线性关系,斜率为51 mV/pH,表明在离子液体和KGM共同修饰的电极上包埋在魔芋葡甘聚糖水凝胶中的血红蛋白发生了直接可逆的电子传递反应,并伴随有一质子的迁移过程.此外,还考察了该血红蛋白修饰电极对O2还原反应的电催化性能.     

魔芋葡甘聚糖／SiO2纳米复合物的制备与表征

用纳米SiO2为原料,以魔芋葡甘聚糖(KGM)为基体,采用共混法制得KGM/SiO2纳米复合物。通过傅立叶红外光谱(FTIR)、热重分析(TG)、透射电镜(TEM)等手段对该体系进行了表征。结果表明:由于纳米SiO2粒子的引入,KGM分子FTIR的某些特征峰的波数发生明显变化;纳米SiO2在复合物中的分散性较好;复合材料的热稳定性高于KGM薄膜;此外,复合材料的力学性能有所提高。     

魔芋葡甘聚糖功能材料研究与应用进展

为了更好地开发利用魔芋葡甘聚糖(KGM),本文阐明了KGM独特的结构、优良的理化性质,分析了其结构与性能的关系, 综述了在食品、化工、医药、石油钻探等应用领域中形成的以KGM为基本组成的功能材料研究进展。并对近几年国内外KGM在该领域的研究动向及其应用前景进行了探讨。     

A Review of the Development of Properties and Structures Based on Konjac Glucomannan as Functional Materials

In recent years, konjac glucomannan(KGM) has gained considerable attention due to its non-toxic, harmless, excellent biocompatibility, biodegradability, good water imbibition as well as gel properties. KGM and its derivatives have been widely used in food science, chemical, pharmaceutical, and material areas. In this review, we will focus on the most recent advances in the structures and properties of KGM. We will first describe the influence of different modification methods on the structures and properties of KGM. Then we will review the results obtained with KGM as functional materials in different studies in the fields of hydrogels, aerogels, nanoparticles, membrane materials, microspheres and microcapsule to provide theoretical basis for the further study.     

Molecular Dynamics Simulations of the Interactions between Konjac Glucomannan and Carrageenan

The interactions between konjac glucomannan and carrageenan were studied with the method of molecular dynamics simulation. Part representative structure segments of KGM and two unit structures of κ-carrageenan （Fig. 2） were used as mode, and the force-field was AMBER2. The stability and sites of konjac glucomannan/carrageenan interactions in water were researched at 373 K with the following results： the potential energy （EPOT） of the mixed gel was dropped, while those of single-konjac glucomannan gel and single carrageenan were increased. The surface area （SA） of KGM in the mixed system was decreased to 1002.2A^°^2, and that of carrageenan to 800.9 A^°^2. The variations of two parameters showed that the stability of compound gel konjac glucomannan/carrageenan was improved, which is consistent with the previous studies. The sites of interactions in the mixed gel were the -OH groups on C（2）, C（4） and C（6）, the acetyl group in KGM mannose, and the -OH group on C（6） in carrageenan. The hydrogen bond was formed directly or indirectly by the bridge of waters.     

高取代度魔芋葡甘聚糖醋酸酯的制备及其热塑性和流变性研究

以魔芋葡甘聚糖(KGM)为原料,浓硫酸为催化剂,乙酸酐为改性剂,制备了KGM醋酸酯.研究了反应条件对KGM醋酸酯取代度(DS)的影响,KGM醋酸酯制备的最佳反应条件是乙醇∶水量比5∶5,反应时间2h,反应温度75℃,催化剂浓硫酸的浓度0.1mol/L,KGM与乙酸酐的量比5∶40(g/mL),取代度高达2.93,其分子量与KGM相比,则明显降低.运用傅立叶红外光谱仪(FTIR)、X射线衍射仪(XRD)、扫描电镜(SEM)、热重分析仪(TGA)、示差扫描量热仪(DSC)和旋转流变仪对KGM和高取代度KGM醋酸酯进行了表征.结果表明,KGM醋酸酯的羰基(CO)特征吸收峰较KGM明显增强,其表观形貌大部分为疏松絮状,KGM及其醋酸酯均为非晶态结构.与KGM相比,KGM醋酸酯的热稳定性下降,分解温度(Td)由KGM的261.10℃降低至KGM醋酸酯的204.56℃,KGM醋酸酯出现了明显的玻璃化转变,其玻璃化转变温度(Tg)为128.49℃.KGM醋酸酯是典型的黏弹性材料,其弹性比率占21.27%,其剪切黏度η对温度变化非常敏感,可通过温度的改变来调节KGM醋酸酯的加工流动性.KGM醋酸酯具有较好的热塑性.     

KMnO4引发魔芋粉-丙烯腈的接枝共聚反应

以KMnO4为引发剂进行魔芋粉与丙烯腈的接枝共聚反应。研究了魔芋粉预氧化时间、引发剂浓度、单体浓度、酸度、反应时间、反应温度和反应物加料方式等聚合条件对接枝效率的影响，并对接枝机理作了探讨。     

长链脂肪酸魔芋葡甘聚糖酯的制备及乳化性能研究

采用非均相酰化法制备了四个系列的长链脂肪酸魔芋葡甘聚糖酯（ＫＧＭＥ）．ＤＴＡ图显示了葡甘聚糖酯的晶态结构变化,Ｘ 射线衍射分析表明了不同长度的酰链对葡甘聚糖酯晶态结构的影响．初步研究了葡甘聚糖酯在芳香烃及环烷烃两种水包油（Ｏ／Ｗ）乳液体系中其取代度与乳化力的关系．实验证明在水包油乳液体系中,取代度在某一范围的葡甘聚糖酯显示出较好的乳化能力,且在高盐浓度和酸性情况下,仍给出好的乳化作用．丁香油 水（Ｏ／Ｗ）乳液体系在室温下静置四个星期未发现破乳分离现象     

Study on the Dynamics of Blending of Glucomannan with Carrageenan and Guaran Gum

In order to prove up the interaction between konjac glucomannan (KGM) and other amyloses, by using KGM, guaran gum and carrageenan as materials, their blending in different external conditions was modeled by means of molecular dynamics (MD) method. The result showed that 323 K was a significant turning point for the formation of hydrogen bond, and KGM and guaran gum were just juxtaposed together via intermolecular hydrogen bond; but with the addition of carrageenan, KGM, guaran gum and carrageenan were spirally twisted together, and when their blending proportion is 3:2:9 the combination was the most compact. Moreover, the research result has provided the sequent studies afterwards on amyloses with some references.     

Formation Mechanism and Stability Study of Konjac Glucomannan Helical Structure

The formation mechanism and stability of konjac glucomannan (KGM) helical structure were investigated by molecular dynamic simulation and experimental method. The results indicate that the molecular conformation of KGM is a non-typical helical structure. In detail, helical structure of KGM is mainly sustained by acetyl group, whose size and stability are affected by the molecular polymerization degree of KGM. In vacuum among the non-bonding interactions, electrostatic force is the greatest factor affecting its helical structure, but in water solution, hydrogen bond affects the helical arrangement greatly. To our interest, temperature exhibits a reversible destroying effect to some extent; the helical structure will disappear completely and present a ruleless clew-like arrangement till 341 K. This work suggests that the method of combining molecular dynamic simulation and experiment tools can be effective in the study of KGM helical structure.     

Viscoelastic properties of konjac glucomannan in the presence of salts

Journal of Thermal Analysis and Calorimetry - Viscoelastic properties of konjac glucomannan (KGM) were studied in the entanglement region using steady and small-amplitude oscillatory rheological...     

Synthesis and Properties of IPN Hydrogels Based on Konjac Glucomannan and Poly（acrylic acid）

As a random copolymer of β-(1,4) linked D-mannose and D-glucose, konjac gluco- mannan (KGM) is a naturally occurring water-soluble polysaccharide, and has been paid attention in the field of drug controlled release carriers potentially used in colon1,2. …