交联羧甲基魔芋葡甘聚糖空心微球制备及应用

以魔芋葡甘聚糖(KGM)为壁材,通过羧甲基化并经乳状液化学交联制备球体较为完好的羧甲基魔芋葡甘聚糖(CMKGM)空心微球.通过扫描电镜(SEM)和透射电镜(TEM)对CMKGM空心微球的形貌和粒径进行了表征.结果表明,KGM溶胶浓度为0.5%-1%、乳化剪切速率为8000r/min、环氧氯丙烷(ECH)为5ml时,可以得到粒径均匀、形貌规整、溶胀性能良好的CMKGM空心微球.增大溶液的pH和羧甲基试剂的用量均有利于CMKGM空心微球对水中Cu2+的吸附.     

离子液体介质中纤维素酶降解纤维素的研究进展

以不可再生资源为原料和能源进行的传统加工工业正面临着资源日益枯竭的现实,所以对可再生资源的研究势在必行。在各种可再生资源中,纤维素生物质是唯一可再生的碳资源,具有取之不尽用之不竭的物质基础,被普遍认为将会部分替代或补充不可再生资源。但由于纤维素的超分子结构,传统的工艺很难将其降解转化,离子液体作为一种新型的绿色溶剂,不仅能够很好地溶解纤维素,同时也是纤维素酶解反应的良好溶剂。综述了国内外离子液体对纤维素溶解、再生以及降解的近期研究成果,分析了其中存在的问题,提出了离子液体降解纤维素的发展方向。     

胶原蛋白-葡甘聚糖-软骨素共混膜的结构表征和物理性能研究

用溶液共混法制备了胶原蛋白-葡甘聚糖-软骨素共混膜。并进行了FPIR，XRD，SFM分析及透光率抗张强度、断裂伸长率、吸水率、透汽性、吸附性和渗透性测试。结果表明：共混膜中胶原蛋白、葡甘聚糖及软骨素之间存在着强烈的相互作用和良好的相容性，三者共混明显改善了几种材料及二元共混膜的性能。该共混膜可望用作生物医用材料。     

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。     

Preparation and characterization of novel macroporous cellulose beads regenerated from ionic liquid for fast chromatography

Macroporous cellulose beads (MCB) used as anion exchangers were successfully prepared from cellulose solution in ionic liquid by double emulsification followed by cross-linking and modification with diethylaminoethyl. The pore structure and properties of the MCB were investigated and the results were compared with homogeneous cellulose beads (HCB). The MCB in size of about 71 μm is characterized by two sets of pores, i.e., diffusion pores (10–20 nm) and macropores (800–2000 nm), determined by mercury porosimeter. In addition, the bed permeability and effective porosity for BSA of MCB-packed column are 58% and 25% higher than those of HCB-packed column, respectively. The adsorption properties of MCB were evaluated, and compared with HCB and commercial absorbent (Sepharose 6 Fast Flow, CSFF). It is found that the pore diffusivity of BSA in MCB is over 7.9 times higher than HCB, and 6.7 times higher than CSFF, respectively. While the equilibrium adsorption capacity (q_m) of BSA on MCB is obviously lower than that on HCB and CSFF, the dynamic binding capacity (DBC) on MCB at 10% breakthrough reaches 47.7 mg/mL, higher than HCB (40.3 mg/mL) and CSFF (46.2 mg/mL) at flow rate of 360 cm/h. In addition, the MCB-packed column showed better column efficiency over the HCB packed one. Therefore, we demonstrated that the MCB possessed more advantages than other ones, like HCB and CSFF, and was expected as an ideal material for fast chromatography.     

纤维素/聚硅氧烷离子液体混合气相色谱固定相的制备

纤维素是液相色谱中应用十分广泛的一类固定相,可是由于涂渍性能不佳,纤维素在气相色谱中的应用鲜有报道。本论文首先通过酯化反应合成了脂溶性较好的三醋酸纤维素（CTA）,然后与自制的聚硅氧烷离子液体（PIL-C12-NTf₂）混配,制备了含纤维素的气相色谱固定相（CTA@PIL-C12-NTf₂）,并涂渍了毛细管柱。其柱效为3165 plates/m（110 ℃,萘,k=4.95）。麦氏常数及溶剂化参数模型的测试结果证明,该固定相属中强极性固定相,主要作用力是氢键碱性作用和偶极作用。值得注意的是,引入纤维素可明显改善三取代芳香化合物位置异构体及壬烷（C9）同分异构体的分离选择性。此外,该固定相对正构烷烃、醇、脂肪酸酯及邻苯二甲酸酯等也具有良好的分离选择性。该研究不仅初步展现了纤维素在分离选择性上的特点,而且也为探索纤维素衍生物在气相色谱中的应用提供了一条新的途径。     

Mechanical behavior and wrinkling patterns of phase-separated binary polymer blend film

The wrinkling of phase-separated binary polymer blend film was studied through combining the Monte Carlo (MC) simulation for morphologies with the lattice spring model (LSM) for mechanical properties. The information of morphology and structure obtained by use of MC simulation is input to the LSM composed of a three-dimensional network of springs, which allows us to determine the wrinkling and the mechanical properties of polymer blend film, such as strain, stress, and Young’s modulus. The simulated results show that the wrinkling of phase-separated binary polymer blend film is related not only to the structure of morphology, but also to the disparity in elastic moduli between polymers of blend. Our simulation results provide fundamental insight into the relationship between morphology, wrinkling, and mechanical properties for phase-separated polymer blend films and can yield guidelines for formulating blends with the desired mechanical behavior. The wrinkling results also reveal that the stretching of the phase-separated film can form the micro-template, which has a wide application prospect.     

Preparation, characterization and effect of annealing on performance of cellulose acetate/sulfonated polysulfone and cellulose acetate/epoxy resin blend ultrafiltration membranes

Polymeric membranes based on cellulose acetate (CA)--sulfonated polysulfone blends at three different polymer compositions were prepared by solution blending and phase inversion technique, characterized and subjected to annealing at 70, 80 and 90 °C. The permeate water flux, separation of bovine serum albumin and its flux by the blend membranes before and after thermal treatment, have been compared and discussed. Similarly, CA and epoxy resin (diglycidyl ether of bisphenol-A) were blended in various compositions, in the presence and in the absence of polyethyleneglycol 600 as non-solvent additive, using N,N^′-dimethylformamide as solvent, and used for preparing ultraflltration membranes by phase inversion technique. The polymer blend composition, additive concentration, casting and gelation conditions were optimized. Blend membranes were characterized in terms of compaction, pure water flux, water content and membrane resistance. The effects of polymer blend composition and additive concentration on the above parameters were determined and the results are discussed.     

Preparation and Properties of Chitosan/Konjac Glucomannan Blend Fibers

Chitosan and konjac glucomannan (KGM) blend fibers were prepared by spinning their solution through a viscose‐type spinneret into a coagulating bath containing aqueous sodium hydroxide and ethanol. The structure and properties of the blend fibers were studied with the aids of infrared spectra (IR), scanning electron micrography (SEM) and X‐ray diffraction (XRD). The structure analysis indicated that there were strong interaction and good miscibility between the chitosan and KGM molecule which resulted from intermolecular hydrogen bonds. Mechanical properties and water‐retention properties were measured. Through controlling blend conditions, blend fibers can obtain better mechanical properties than the pure chitosan fiber. The water‐retention values (WRV) of blend fibers increase as the amount of KGM is raised. The fibers treated with alcoholic solution of acetic acid have good antibacterial activity to Staphylococcus aureus.     

Physical properties and phase separation structure of Antheraea pernyi/Bombyx mori silk fibroin blend films

The physical structure and compatibility of solution-cast Antheraea pernyi/Bombyx mori silk fibroin blend films were stuided by differential scanning calorimetry (DSC), thermomechanical (TMA) and thermogravimetric (TGA) analysis, dynamic viscoelastic measurement, infrared spectroscopy, and x-ray diffractometry. The DSC curves of the blend films showed independent endotherms at 280 and 358°C, corresponding to the thermal decomposition of B. mori and A. pernyi silk fibroins with random coil conformation. The intensity was roughly proportionate to the amount of each component in the blend. The thermal behavior corresponding to the conformational transitions induced by heating on A. pernyi and B. mori silk fibroins overlapped in the temperature range 190–230°C. Thermal expansion and contraction properties, as well as weight retention behavior of the blend films were intermediate between the pure components, as shown by the TMA and TGA curves. The onset temperature of the storage modulus curve decreased markedly, approaching that of B. mori silk fibroin film when the amount of this component in the blend increased. The loss modulus curve of the blend films showed two peaks at ca. 190 and 210°C, the former corresponding to B. mori, and the latter to A. pernyi silk fibroin. Infrared spectra of the blends exhibited absorption bands characteristic of the pure components overlapping in the spectral region 2000–400 cm^?1. The x-ray diffraction peaks at 23 and 21.5°, attributed to the crystalline spacings of A. pernyi and B. mori fibroins, respectively, overlapped in the diffraction curves of the blends, while the peak at 11.4°, of A. pernyi, increased as the content of this fibroin in the blend increased. The degree of crystallinity, calculated from the x-ray diffraction curves, diminished as the amount of B. mori silk fibroin decreased. A low degree of compatibility exists between the two fibroins when they are cast from aqueous solution in the experimental conditions adopted in this work. © 1994 John Wiley & Sons, Inc.     

萘环荧光离子液体合成、表征及光谱性能研究

以1-氯甲基萘和N-烷基咪唑为原料,四氢呋喃为溶剂,合成了5个具有荧光的新型离子液体.采用红外光谱(FT-IR)、核磁共振氢谱(1H NMR)、碳谱(13C NMR)等测试技术对产物进行了结构表征.并对其紫外光谱、荧光光谱等光谱性质进行了初步的研究.实验结果表明咪唑离子液体1,2二甲基-4-甲基萘咪唑氯化盐较咪唑离离子...     

基于室温离子液体的有序多孔金膜葡萄糖传感器

将1-丁基-3-甲基咪唑四氟硼酸盐（[BMIm][BF4]）、N,N-二甲基甲酰胺（DMF）与葡萄糖氧化酶（GOD）的混合物修饰于三维有序大孔（3DOM）金膜电极上,构建了一种新型的葡萄糖传感器．固定的GOD在pH7．0的磷酸缓冲液（PBS）中展现出一对可逆性好的氧化还原峰,这归因于GOD的活性中心黄素腺嘌呤二核苷酸（FAD）的直接电化学行为．研究表明,离子液体（IL）、DMF以及3DOM金膜对GOD的直接电化学都起到了重要的作用．3DOM金膜修饰电极作为基底提高了酶的负载量,加速了GOD与电极表面的电子传递;IL的应用增加了固定GOD的电化学活性;DMF与IL、GOD的协同作用更好地保持了GOD的生物活性．固定在电极表面的GOD对葡萄糖显示出良好的催化性能,其检测线性范围为10～125nmol／L,检测限为3．3nmol／L（S／N=3）,酶催化反应的表观米氏常数Km为0．018mmol／L．     

Separation and enzymatic degradation of blend films of poly(L-lactic acid) and cellulose

Blend films of poly(L -lactic acid) (PLLA) and cellulose with various composition was prepared by casting from trifluoroacetic acid solution. One hydroxyl group per each glucose unit was esterified by trifluoroacetic acid. The trifluoroacetyl group was hydrolyzed completely during the degradation. Weight losses for 90/10 and 75/25 PLLA/cellulose blends by proteinaze K were greatly increased compared with pure PLLA sample due to the large depression of the crystallinity of PLLA component, while cellulase was effective only for the degradation of pure cellulose film. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1861–1864, 1998     

Porous Membranes Built Up from Hydrophilic Poly(ionic liquid)s

Porous polymer membranes made via electrostatic complexation are fabricated from a water‐soluble poly(ionic liquid) (PIL) for the first time. The porous structure is formed as a consequence of simultaneous phase separation of the PIL and ionic complexation with an acid, which occurred in a basic solution of a nonsolvent for the PIL. These membranes have a stimuli‐responsive porosity, with open and closed pores in isopropanol and in water, respectively. This property is quantitatively demonstrated in filtration experiments, where water is passing much slower through the membranes than isopropanol.

     

咪唑四氟硼酸盐离子液体中磷钼酸掺杂聚吡咯薄膜修饰电极的制备及其电催化活性

以1-丁基-3-甲基咪唑四氟硼酸盐(BMIMBF4)离子液体作为介质,利用电化学方法在铂电极表面制备了磷钼酸掺杂聚吡咯薄膜;采用扫描电子显微镜观察了所制备的薄膜的形貌,利用热重分析评价了其热稳定性,利用循环伏安法测定了其电化学活性和对甲醇的电催化氧化活性.结果表明,与传统的硫酸溶液相比,以BMI-MBF4离子液体作为反应介质制备的修饰电极的表面形貌更均匀,电化学活性和对甲醇的电催化氧化活性更强.     

Entanglement properties of cellulose and amylose in an ionic liquid

Concentrated solutions of cellulose and amylose were prepared with an ionic liquid 1‐butyl‐3‐methylimidazolium chloride (BmimCl), which was chosen as a good solvent for these polysaccharides. Dynamic viscoelasticity of the concentrated solutions was examined to obtain the molecular weight between entanglements, M_e. The value of M_e in the molten state (M_e,melt), a material constant that reflecting the entanglement properties, was determined for cellulose and amylose by extrapolating M_e to the “melt.” A marked difference in M_e,melt was found: 3.2 × 10³ for cellulose and 2.5 × 10⁴ for amylose. The value of M_e,melt for cellulose, which is composed of β‐(1,4) bonding of D ‐glucose units, is very close to those for polysaccharides with a random‐coil conformation such as agarose and gellan in BmimCl. The much larger M_e,melt for amylose can be attributed to the helical nature of the amylose chain, α‐(1,4)‐linked D ‐glucose units. The effect of concentration on the zero‐shear viscosity for the solutions of cellulose and amylose was also examined. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011     

Phase separation in mixtures of ionic liquids and water

The phase separation of ionic liquids (ILs) in water is studied by laser light scattering (LLS). For the ILs with longer alkyl chains, such as [C(8)mim]BF(4) and [C(6)mim]BF(4) (mim = methylimidazolium), macroscopic phase separation occurs in the mixture with water. LLS also reveals the coexistence of the mesoscopic phase, the size of which is in the order of 100-800 nm. In aqueous mixtures of ILs with shorter alkyl chains, such as [C(4)mim]BF(4), only the mesoscopic phase exists. The mesoscopic phase can be effectively removed by filtration through a 0.22 μm filter. However, it reforms with time and can be enhanced by lowering the temperature, thus indicating that it is controlled by thermodynamics. The degree of mesoscopic phase separation can be used to evaluate the miscibility of ILs with water. This study helps to optimize the applications of ILs in related fields, as well as the recycling of ILs in the presence of water.     

Polyimidazolyl acetate ionic liquid grafted on cellulose filter paper as thin-film extraction phase for extraction of non-steroidal anti-inflammatory drugs from water

Recently, pharmaceuticals and personal care products in the water environment exhibited potential risks to both human and aquatic organisms. In order to improve the sensitivity and accuracy of pharmaceutical detection, the polyimidazolyl acetate ionic liquid was synthesized by Radziszewski reaction and coated on cellulose filter papers as a thin-film extraction phase for extraction of non-steroidal anti-inflammatory drugs from water. The attenuated total reflection-infrared spectrometry, thermogravimetric analysis, and scanning electron microscope analyses demonstrated that the polyimidazolyl acetate ionic liquid was successfully prepared and attached to the surface of the cellulose filter paper through chemical bonding. The adsorption capacity of the homemade thin-film extraction material for the four non-steroidal anti-inflammatory drugs was greater than 8898 ng/cm² under the optimum conditions, and the desorption rate was over 90%. Then, a paper-based thin-film extraction phase-high-performance liquid chromatography-tandem mass spectrometry method was established for the extraction of non-steroidal anti-inflammatory drugs in water. This method provided limits of detection and limits of quantification were in the range of 0.02–0.15 and 0.17–0.50 μg/L, respectively. Hence, the obtained thin-film extraction phase showed excellent recovery and reproducibility for the target non-steroidal anti-inflammatory drugs with carboxyl groups from water.     

Extraction of proteins from biological fluids by use of an ionic liquid/aqueous two-phase system

An ionic liquid/aqueous two-phase system based on the hydrophilic ionic liquid 1-butyl-3-methylimidazolium chloride (BmimCl) and K(2)HPO(4) has been employed for direct extraction of proteins from human body fluids for the first time. Proteins present at low levels were quantitatively extracted into the BmimCl-rich upper phase with a distribution ratio of about 10 between the upper and lower phase and an enrichment factor of 5. Addition of an appropriate amount of K(2)HPO(4) to the separated upper phase results in a further phase separation, giving rise to an improved enrichment factor of 20. FTIR and UV spectroscopy demonstrated that no chemical (bonding) interactions between the ionic liquid and the protein functional groups were identifiable, while no alterations of the natural properties of the proteins were observed. The partitioning of proteins in the two-phase system was assumed to have been facilitated by the electrostatic potential difference between the coexisting phases, as well as by salting out effects. The system could be applied successfully for the quantification of proteins in human urine after on-line phase separation in a flow system. The use of an ionic liquid, as a green solvent, offers clear advantages over traditional liquid-liquid extractions, in which the use of toxic organic solvents is unavoidable.     

Dissolution capacity and rheology of cellulose in ionic liquids composed of imidazolium cation and phosphate anions

Cellulose is one of the most abundant natural polymer sources, but the applications of cellulose are limited due to difficulty in dissolving cellulose in water and common chemical solvents. In the past decades, ionic liquids have been studied to dissolve cellulose efficiently, sustainably, and in an eco‐friendly manner. In this study, a series of imidazolium‐based ionic liquids were synthesized to explore as solvents for cellulose, including 1,3‐dimethylimidazolium dimethylphosphate ([mmim]dmp), 1‐ethyl‐3‐methylimidazolium dimethylphosphate ([emim]dmp), 1‐butyl‐3‐methylimidazolium dimethylphosphate ([bmim]dmp), 1‐hexyl‐3‐methylimidazolium dimethylphosphate ([hmim]dmp), 1‐ethyl‐3‐methylimidazolium diethylphosphate ([emim]dep), 1,3‐diethylimidazolium diethylphosphate ([eeim]dep), and 1‐butyl‐3‐ethylimidazolium diethylphosphate ([beim]dep). Rheology experiments were conducted to study the flow behavior of cellulose in these ionic liquids and cosolvents. We found that the dissolution capacity of cellulose increases with decreasing viscosity of the solvent and that the rheological properties depend most strongly on the concentration of cellulose dissolved. Systems composed of cellulose in [mmim]dmp, [emim]dmp, and [emim]dep behave as viscoelastic gels, while formulations of cellulose in [bmim]dmp, [hmim]dmp, [eeim]dep, and [beim]dep show viscoelastic liquid behavior. These results will impact development of new solvents for processing of cellulose‐based polymeric materials.