纤维素基磁性聚偕胺肟树脂的研究——锌副族金属离子在树脂上的吸附

研究了Ｚｎ２＋、Ｃｄ２＋、和Ｈｇ２＋离子在碱式纤维素基磁性聚偕胺肟树脂（ＢＭＡＯ）上的吸附动力学。结果表明，吸附速度受粒内扩散所控制。测得粒内扩散系数分别是１．２２×１０－４、２．４２×１０－４和３．９０×１０－４ｃｍ２·ｓ－１；Ｈｇ２＋离子在树脂上的吸附行为符合Ｆｒｅｕｎｄｌｉｃｈ和Ｌａｎｇｍｕｉｒ等温吸附方程；浓集因数随Ｈｇ２＋离子浓度降低而上升，有利于从稀溶液中除去Ｈｇ２＋离子。将树脂加至Ｚｎ２＋、Ｃｄ２＋或Ｈｇ２＋离子浓度为５０ｐｐｍ的溶液中，离子去除率分别是９６．１、９９．９和９９．３％。     

笼形聚偕氨肟树脂的研究：酸处理树脂的吸附性能

笼形聚偕氨肟树脂（ＣＡＯ）经盐酸处理垢，伯胺基转变成胺盐。酸处理笼形聚偕氨肟树脂（ＡＣＡＯ）对Ｍｇ＾２＋，Ｃａ＾２＋，Ｂａ＾２＋，Ｍｎ＾２＋，Ｃｏ＾２＋，Ｎｉ＾２＋离子不吸附；对Ｚｎ＾２＋，Ｃｄ＾２＋，Ｃｕ＾２＋，Ｐｂ＾２＋离子的吸附效率在２０％以下，但对Ｈｇ＾２＋离子的吸附效率则高达７１．２％；对一些金属络阴离子的吸附效率顺序是Ｆｅ（ＣＮ）＾２－６＞Ｃｒ２Ｏ＾２－７＞ＭｏＯ＾２－４＞ＰｔＣｌ＾２     

笼形聚氨肟树脂的研究：碱处理对吸附性能的影响

研究碱处理的笼形聚氨肟树脂（ＢＣＡＯ）对二价金属离子的吸附行为。吸附结果若生成２：１配的，得Ｍｇ＾２＋，Ｃａ＾２＋，Ｂａ＾２＋，Ｍｎ＾２＋，Ｃｏ＾２＋，Ｎｉ＾２＋，Ｚｎ＾２＋，Ｃｄ＾２＋，Ｐｂ＾２＋，Ｃｕ＾２＋离子的吸附效率分别是２７．１、２９．２、３０．４、２９．０、２７．１、３０．８、４５．０、３９．８、６０．３、６２．１％，Ｈｇ＾２＋离子的吸附效率高达１０５％，表明在吸附过程中同时生成２：１     

纤维素基磁性聚偕胺肟树脂的研究：—PdCl2在树脂上的吸附动力学

ＰｄＣｌ２在碱式纤维素基磁性聚偕胺肟树脂上的吸附行为与Ｈ２ＰｄＣｌ４不同，主要表现在高的超当量吸附。动力学研究表明，Ｈ２ＰｄＣｌ４在碱中和过程中逐步转变为Ｎａ２ＰｄＣｌ４、ＰｄＣｌ２、和［Ｐｄ（ＯＨ）２Ｃｌ２］２，它们被树脂吸附时首先形成ＡＯ－Ｐｄ２和ＡＯ２－Ｐｄ３络合物，随后被还原为单质钯，汇聚成微粒吸着在树脂表面。     

纤维素基磁性聚偕胺肟树脂的研究──(NH_4)_2IrCl_6在树脂上的吸附

碱式纤维素基磁性聚偕胺肟树脂（ＢＭＡＯ）吸附（ＮＨ４）２ＩｒＣｌ６是快速过程，属超当量吸附。吸附结果生成ＡＯ－Ｉｒ和ＡＯ２－Ｉｒ３络合物，随后Ｉｒ（Ⅳ）被偕胺肟基还原为Ｉｒ（０），聚集成球状晶簇附着在树脂表面。     

硅胶负载壳聚糖树脂的制备及其对金属离子的吸附性能

将壳聚糖（ＣＴＳ）负载于层析硅胶上，然后于乙二醇中用Ｂ－６３树脂对其进行化学交联，合成了标题化合物（Ｓｉ－ＢＣＴＳ）。研究了ＣＴＳ的浓度、碱的浓度、交联剂的用量及时间等条件对树脂的负载率及时间等因素对金属离子的吸附性能的影响。考察了时间对上述树脂对 Ｃｕ２＋、 Ｎｉ２＋、 Ｚｎ２＋、 Ｃｏ２＋的吸附量的影响。结果表明：１）最佳合成条件是：温度为１２０℃，反应时间为５ｈ，－ＮＨ２与环氧基的比例为１～２： ２～１． ２）上述树脂具有吸附速度快、沉降迅速和对金属离子吸附性能好等特点，其对Ｃｕ２＋、Ｎｉ２＋、Ｚｎ２＋、Ｃｏ２＋的吸附量分别可达到０．４５～０．７５，０．３４～０．６４， ０．０１～０．０２，０．０８～０．２１ｍｍｏｌＭ２＋／ｇ ｒｅｓｉｎ．     

硅胶负载壳聚糖树脂的制备及其对金属离子的吸附性能

将壳聚糖（ＣＴＳ）负载于层析硅胶上,然后于乙二醇中用Ｂ－６３树脂对其进行化学交联,合成了标题化合物（Ｓｉ－ＢＣＴＳ）。研究了ＣＴＳ的浓度、碱的浓度、交联剂的用量及时间等条件对树脂的负载率及时间等因素对金属离子的吸附性能的影响。考察了时间对上述树脂对Ｃｕ２＋、Ｎｉ２＋、Ｚｎ２＋、Ｃｏ２＋的吸附量的影响。结果表明：１）最佳合成条件是：温度为１２０℃,反应时间为５ｈ,－ＮＨ２与环氧基的比例为１～２：２～１。２）上述树脂具有吸附速度快、沉降迅速和对金属离子吸附性能好等特点,其对Ｃｕ２＋、Ｎｉ２＋、Ｚｎ２＋、Ｃｏ２＋的吸附量分别可达到０．４５～０．７５,０．３４～０．６４,０．０１～０．０２,．０．０８～０．２１ｍｍｏｌＭ２＋／ｇｒｅｓｉｎ．     

D315树脂吸附脱除SO^2—4研究

本文研究了用Ｄ３１５树脂吸附脱除蚕蛹复合氨基酸水解液中ＳＯ＾２－４的方法。试验结果表明：Ｄ３１５树脂对ＳＯ＾２－４的静态交换容量为１０ｍｇ／ｍｌ树脂，吸附平衡时间４０分钟，ｐＨ４．５０。被吸附的ＳＯ６２－４可用６．６ＢＶ，１ｍｏｌ／ｌ的氨水以１．５ＢＶ／ｈｒ的流速完全洗脱。     

红外光谱法研究螯合树脂对金属离子的选择性Ⅰ．氨基膦酸型树脂对过渡元素的选择吸附

本文用ＫＢｒ压片法测定了氨基膦酸树脂ＮＰ－５００，ＳＬ—４６７，ＳＬ—４１１的Ｈ型、Ｎａ型以及分别吸附了Ｃｕ２＋，Ｎｉ２＋，Ｃｏ２＋离子后的红外光谱图．谱图分析发现，在相同的吸附条件下，同一种树脂分别吸附了Ｃｕ２＋，Ｎｉ２＋，Ｃｏ２＋后，其吸附量愈大，谱图中Ｃ－Ｎ－Ｃ谱峰的位移值越大，则树脂对该金属离子的选择性愈高。结果表明，ＮＰ－５００，ＳＬ—４６７，ＳＬ－４１１树脂对过渡元素Ｃｕ２＋，Ｎｉ２＋，Ｃｏ２＋的选择性顺序为Ｃｕ２＋＞Ｎｉ２＋＞Ｃｏ２＋。另外，本文还观察到谱图中Ｃ－Ｎ－Ｃ谱峰的位移值随金属离子的负载量的增加而增大，有可能通过红外光谱法来研究氨基膦酸树脂对金属离子的负载量。     

纤维素基磁性聚偕胺肟树脂吸附锂

研究了氯化锂浓度、树脂含量和溶液的ＰＨ对碱式纤维素基磁性聚偕胺肟树脂吸附Ｌｉ＾＋离子能力的影响。在适当条件下，每个偕胺肟基可吸附两个Ｌｉ＾＋离子。     

纤维素的功能化

综述近年来纤维素功能化和功能材料的发展情况,介绍了通过化学改性、特殊物理加工、表面改性等获得纤维素功能的功能的各种功能化的主最新的功能设计思路,并介绍了纤维素功能材料的应用,未来潜在的应用领域和发展前景。     

Preparation of Cellulose Oligomers from Cellulose Triacetate (Standard Procedure)

This communication reports the detailed procedure for the cleavage of cellulose triacetate (30 g scale) with pivalic anhydride and boron trifluoride etherate in dichloromethane (pivaloylysis). With this mild and efficient method the cellulose oligomers up to the octasaccharide can be obtained in gram scale. Full characteristic data of this compounds are given.     

珠状纤维素的粒径分布研究

本文研究了反相悬浮技术制备珠状纤维素的过程中，纤维素溶液的粘度、分散剂的种类和用量、分散相及反应温度、搅拌速度、相比等诸因素对纤维素珠体的粒径影响及其变化规律。     

Recent development in food emulsion stabilized by plant-based cellulose nanoparticles

In this review, we discuss the application of cellulose nanoparticles as a sustainable and cost-effective source of green stabilizers for formulation of foodstuff. Fibrillar cellulose nanocrystal and nanofibril stabilize Pickering systems because of their ability to adsorb at the oil/water interfaces, forming protective layers. They also form associative structures in the continuous phase, increasing their viscoelastic properties and preventing flocculation. We describe the chemical and structural features of nanocelluloses and discuss the principles that support their utilization as stabilizers, especially in the context of recent prospects in food and health domains, given safety and regulatory advances. In addition, we describe the benefits of combining nanocelluloses with other food ingredients to extend their functional attributes. Particularly, nanocellulose-based Pickering emulsions are used to create edible soft materials with multiple functionalities. This article is expected to stimulate the use of nanocelluloses as functional ingredients to create food products with improved performance and novel properties.     

Characterization of cellulose molecules in bio-system studied by modeling methods

Cellulose chains in bio-system were examined. A model system, in which molecular chains were fixed at one end in an aqueous environment, was analyzed as a model bio-system of cellulose. Five cellulose chains (DP = 40), whose one end was fixed (like a cantilever), were placed in 20.0 × 2.8 × 2.8 nm³ cell which was filled up with water molecules. This model cell was thoroughly annealed and then piled up three-dimensionally. The molecular dynamics simulation was applied to this model system at room temperature (298 K) with time step of 1.0 femto-second in AMBER force field with parameter sets for carbohydrates. The molecular motion of cellulose chains in cantilever condition was found to be more moderate compared with case of free chains. The water molecules around the cellulose chains were interrupted directly forming hydrogen bondings among the cellulose chains. This result suggests that degree of crystallinity of cellulose in bio-system is low. The result also reminds us that the cellulose chains are originally able to hold water molecules giving them a gel property, although dried cellulose is not soluble in water. Conformational and Packing Analysis of Polysaccharides, Part 4. Presented at 22nd International Carbohydrate Symposium, July 23–27, 2004.     

Physical and mechanical testing of essential oil-embedded cellulose ester films

Polymer films made from cellulose esters are useful for embedding plant essential oils, either for food packaging or air freshener applications. Studies and testing were done on the physical and mechanical properties of cellulose ester-based films incorporating essential oils (EO) from lemongrass (Cybopogon citratus), rosemary pepper (Lippia sidoides) and basil (Ocimum gratissimum) at concentrations of 10 and 20% (v/w). Results obtained showed that, in all films, the addition of the essential oil caused a decrease in the water vapor permeability due to the hydrophobic nature of the oil. The use of 20% of EO caused lower transparency of the films, although the change was not observed visually. Mechanical testing was done on cellulose acetate, cellulose acetate propionate and cellulose acetate butyrate. It was found that incorporation of lemongrass, basil and rosemary pepper EO significantly affected the Young's modulus, tensile strength and elongation at break of the cellulose ester films. The results suggested that the essential oils interacted with the polymers like plasticizers. The results were confirmed with thermal and microscopic studies.     

Crystalline transformation of native cellulose from cellulose I to cellulose ID polymorph by a ball-milling method with a specific amount of water

We have demonstrated for the first time that a mechano-chemical treatment of native cellulose with a specific amount of water (30 wt%) present ID the cellulose solid state caused the crystalline transformation from cellulose I into cellulose ID polymorph. X-ray diffractometry was used to show that the extent of transformation into cellulose ID increased with milling time. This specific phenomenon can be explained by considering the chain mobility ID the cellulose–water system, because ₁ ^1H measurement shows that cellulose molecules are most mobile when the water content ID around 30 wt%, and thus are favorable for molecular rearrangement under external forces.     

Preparation of cellulose and cellulose derivative azo compounds

Wood pulp and cotton linter are the most common sources of cellulose forindustrial use. Methyl cellulose (MC) and cellulose sulfate (CS) were preparedusing bleached wood pulp and cotton linter. Coloured azo compounds were alsoprepared from coupling cellulose, wood pulp, MC and CS with aromatic diazoniumsalt. The presence of electron-releasing or withdrawing substituents affectedthe electrophilic substitution reaction. The produced azo compounds werecharacterized by FT-IR methodology, as well as mass spectrometry, in which thefunctional groups and the ion fragments of the products were analyzed.     

Molecular conformations at the cellulose–water interface

¹³C-NMR chemical shifts were measured for C-4 and C-6 in a collection of eight crystalline glucoses and glucosides. The influence of the hydroxymethyl conformation was greater at C-4 than at C-6, with mean chemical shifts for gauche–trans molecules displaced 3.1 ppm (C-4) and 2.5 ppm (C-6) relative to gauche–gauche molecules. This information was used to interpret ¹³C-NMR spectra of crystalline celluloses. Chemical shifts for C-4 in the crystallite cores of celluloses I and II differed by just 0.2 ppm, but the corresponding chemical shifts for well-ordered crystallite surfaces differed by 3.0 ppm. The separation between crystallite-surface signals was attributed to different hydroxymethyl conformations at the cellulose–water interface, i.e., gauche–gauche and gauche–trans on crystallites of cellulose I and cellulose II, respectively. A broad C-4 signal in the spectrum of cellulose II indicated gauche–gauche conformations in disordered cellulose. Chemical shifts for C-6 were consistent with these conformations.