Cellulose Functionalization via ATRP Grafting of Glycidyl Methacrylate for Cr（VI） Adsorption

Cellulose was first grafted with glycidyl methacrylate （GMA） in an ionic liquid via atom transfer radical polymerization （ATRP） and then the introduced epoxy groups were reacted with ethanediamine （EDA） to obtain an amino adsorbent. The grafting copolymer and the obtained adsorbent were characterized by FTIR, aH NMR, TEM and SEM. The results showed that the grafted copolymers had grafted polymer chains with well-controlled molecu- lar weight and polydispersity, the polymerization was a controlled system. The cellulose adsorbent had numerous micropores on the surface and showed high performance for Cr（VI） adsorption. The adsorption behavior was pH dependent and the sorption equilibrium was achieved within 2 h on the adsorbent.     

Sorption properties of cellulose filters with covalently immobilized thiosemicarbazide

A novel thin-layer cellulose adsorbent bearing chemically immobilized thiosemicarbaside is synthesized. The adsorbent is used for the preconcentration of cobalt(II), mercury(II), and cadmium(II) followed by their X-ray fluorescence quantification in the concentrate. The physicochemical parameters of metal sorption are determined.     

Dendrimer PAMAM为手臂的LDL吸附剂制备及性能研究

树状高分子聚酰胺-胺(Dendrimer PAMAM)是一种具有大量活泼氨基末端的对称大分子.通过官能团转化,可将其变为具有不同端基的新性能的树状高分子.本文研究了不同代数的Dendrimer PAMAM作为血液净化吸附剂的"手臂"对配基牛磺酸的连接和对LDL吸附性能的影响.初步研究树状高分子的手臂效应,证明使用枝化手臂是一种能提高吸附剂吸附性能的有效方法.     

载铁(β-FeOOH)球形棉纤维素吸附剂去除地下水砷(Ⅲ)的研究

制备了一种载铁(β-FeOOH)球形棉纤维素吸附剂,并用于地下水中As(Ⅲ)的去除.吸附剂对As(Ⅴ)和As(Ⅲ)在吸附容量、选择性和速率等方面都具有良好的性能,无需预氧化As(Ⅲ),其适用pH范围宽,不必调节原水的pH.吸附剂孔隙度大,机械强度好,活性成分铁的载入量高,吸附As(Ⅲ)的活性好.Langmuir和Freundlich方程能较好地描述吸附平衡方程,其吸附动力学符合Lagergren准二级方程.吸附As(Ⅲ)的最佳pH范围为6-9.SO42-和Cl-等干扰离子均不影响As(Ⅲ)的去除.柱吸附实验表明,即使在较高流速和As(Ⅲ)进水浓度下,吸附剂对As(Ⅲ)的去除依然具有很高的穿透容量和饱和容量.吸附剂可以用NaOH溶液再生,洗脱和再生效率较高.活性成分β-FeOOH形态稳定,柱实验和再生时铁均无泄漏.     

Hierarchical porous cellulose/activated carbon composite monolith for efficient adsorption of dyes

Cheap and efficient adsorbents to remove contaminants of toxic dye molecules from wastewater are strongly in demand for environmental reasons. This study provides a novel design of a monolithic adsorbent from abundant materials via a facile synthetic procedure, which can greatly reduce the problems of the tedious separation of adsorbents from treated wastes. A hierarchically porous cellulose/activated carbon (cellulose/AC) composite monolith was prepared by thermally-induced phase separation of cellulose acetate in the presence of AC, using a mixture of DMF and 1-hexanol, followed by alkaline hydrolysis. The composite monolith had alarge specific surface area with mesopore distribution. It not only showed high uptake capacity towards methylene blue (MB) or rhodamine B (RhB) but could also simultaneously adsorb MB and RhB from their mixture, in which the adsorption of one dye was not influenced by the other one. Remarkable effects of solution pH, initial concentration of dye (C ₀), contact time, adsorbent dosage and temperature on the adsorption of MB and RhB onto the composite monolith were demonstrated. The binding data for MB and RhB adsorption on the composite monolith fitted the Freundlich model well, suggesting a heterogeneous surface of the composite monolith. The monolith could retain around 90% of its adsorption capacity after 8 times reuse. These data demonstrate that the cellulose/AC composite monolith has a large potential as a promising adsorbent of low cost and convenient separation for dye in wastewater.     

Preparation and adsorption properties of PAA-grafted cellulose adsorbent for low-density lipoprotein from human plasma

A new low-density lipoprotein (LDL) adsorbent with good adsorption performance has been obtained by use of a simple preparation procedure. Graft copolymerization of acrylic acid (AA) on to macroporous cellulose beads was performed with cerium ammonium nitrate (CAN) as a redox initiator. The effects of initiator concentration, monomer concentration, and reaction time on grafting were examined. In adsorption tests, several factors affecting adsorption of lipoproteins were investigated in detail. In-vitro study showed that this adsorbent could remove total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), and triglyceride (TG) at levels of 5.55, 4.46, and 2.48 mg g⁻¹, respectively, from human plasma without substantially affecting high-density lipoprotein-cholesterol (HDL-C) and total proteins (TP). The adsorbent prepared in this work might be further studied for potential clinical application.     

Characteristic and mechanism of Cr(Ⅵ) adsorption by ammonium sulfamate-bacterial cellulose in aqueous solutions

A new adsorbent, ammonium sulfamate-bacterial cellulose (ASBC), was prepared through chemical modifications of bacterial cellulose. The process of adsorbing Cr(Ⅵ) including its isotherm and kinetics, was measured and studied. The results showed that pH value was a very important parameter to the adsorbing efficiency. The adsorption kinetics can be described by a pseudo-second rate model and a particle diffusion equation. Both physical and chemical adsorptions existed in the adsorption process, but chemical adsorption was more dominatant. And particles internal diffusion was not the only rate controlling step. The adsorption equilibrium can be described by the Langmuir type, which indicated that a typical single-molecule layer adsorption of Cr(Ⅵ) by ASBC could be described. And the rate of adsorption followed the Slips model well, which indicated that ASBC had some multiphase and asymmetry. The coordination adsorption and ion exchange effect were the main mechanisms of chemical adsorption. The absorbed Cr(Ⅵ) can be desorbed effectively by 0.5 mol/L EDTA or HCl from the adsorbent, which could make it be reusable.     

可再生纤维素/环糊精聚合物对水中亚甲基蓝吸附行为

利用甘蔗渣提取纤维素修饰环糊精聚合物,成功制备可再生纤维素/环糊精聚合物（SUG-EPI-CDP）吸附剂。采用傅利叶红外光谱仪（FT-IR）与热重分析仪（TGA）对材料进行表征,同时考察了该材料对水中亚甲基蓝（MB）吸附特性和机理的影响。结果表明：在溶液pH值为7、温度为30 ℃的条件下,SUG-EPI-CDP可在120 min内有效去除MB,去除率达80.9%。通过模型拟合发现,SUG-EPI-CDP对MB的吸附是自发且吸热的过程,符合准二阶动力学方程和Langmuir等温线模型。该吸附剂实验最大吸附量达8.1 mg/g,远高于其他废料所制备的吸附剂。结果表明,利用可再生纤维素修饰可有效提高环糊精聚合物的吸附性能,同时为甘蔗渣资源化利用提供了新途径。     

Synthesis of tapioca cellulose-based poly(hydroxamic acid) ligand for heavy metals removal from water

A graft copolymerization was performed using free radical initiating process to prepare the poly(methyl acrylate) grafted copolymer from the tapioca cellulose. The desired material is poly(hydroxamic acid) ligand, which is synthesized from poly(methyl acrylate) grafted cellulose using hydroximation reaction. The tapioca cellulose, grafted cellulose and poly(hydroxamic acid) ligand were characterized by Infrared Spectroscopy and Field Emission Scanning Electron Microscope. The adsorption capacity with copper was found to be good, 210 mg g^?1 with a faster adsorption rate (t_1/2 = 10.5 min). The adsorption capacities for other heavy metal ions were also found to be strong such as Fe³⁺, Cr³⁺, Co³⁺ and Ni²⁺ were 191, 182, 202 and 173 mg g^?1, respectively at pH 6. To predict the adsorption behavior, the heavy metal ions sorption onto ligand were well-fitted with the Langmuir isotherm model (R² > 0.99), which suggest that the cellulose-based adsorbent i.e., poly(hydroxamic acid) ligand surface is homogenous and monolayer. The reusability was checked by the sorption/desorption process for six cycles and the sorption and extraction efficiency in each cycle was determined. This new adsorbent can be reused in many cycles without any significant loss in its original removal performances.     

Facile Synthesis and Adsorption Properties of Phosphonated Cellulose Beads for Selective Removal of Low-density Lipoprotein

Hyperlipemia, which induced by the abnormally elevated level of lipids in plasma such as cholesterol and triglyceride (TG), now has been widely recognized as a major risk factor of coronary heart disease1. Low-density lipoprotein (LDL) particles are the m…     

Improvement of pesticide adsorption capacity of cellulose fibre by high-energy irradiation-initiated grafting of glycidyl methacrylate

Cellulose as a renewable raw material was used for preparation of adsorbent of organic impurities in wastewater treatment. Hydrophobic surface of cellulose substrate was developed by grafting glycidyl methacrylate in simultaneous grafting using gamma irradiation initiation. Water uptake of cellulose significantly decreased while adsorption of phenol and a pesticide molecule (2,4-dichlorophenoxyacetic acid: 2,4-D) increased upon grafting. Adsorption equilibrium data fitted the Freundlich isotherm for both solutes.     

Removing Cd2+ by Composite Adsorbent Nano-Fe3O4/Bacterial Cellulose

A new composite adsorbent, nano-Fe3O4/bacterial cellulose(BC), was prepared through blending method. The process of adsorbing Cd2+ including its isotherm and kinetics measured was studied. The results show that the adsorption efficiency is improved because of huge surface area and surface coordination of nano-Fe3O4 particles. Its adsorption capacity is 27.97 mg/g and the maximum of Cd2+ removal is 74%. The adsorption kinetics can be described by pseudo-second rate model and the adsorption equilibrium by Langmuir type. The superparamagnetism of nano-Fe3O4 particles can help to solve the difficult separation of single BC adsorbent and lead to the quick separation of composite adsorbent from the liquid if a magnetic field was applied. Cd2+ can be desorbed effectively by EDTA and HCl from the composite adsorbent, which can make it be reused.     

Preparation and characterization of a novel adsorbent for removing lipophilic organic from water

The initial twelve persistent organic pollutants (POPs) in Stockholm Convention on Persistent Or-ganic Pollutions include many organochlorinated pes-ticides (OCPs) and some industrial by-products from manufacture processes, most of which are lipophilic or…     

IDA型Cu~(2 )-螯合亲和膜色谱法对牛肝过氧化氢酶纯化的研究(英文)

首次采用以改性纤维素为基质、亚氨二乙酸（ＩＤＡ）为取代配基的铜离子螯合膜色谱法对牛肝过氧化氢酶（ＢＬＣ）的分离纯化进行了研究。缓冲液的ｐＨ值对ＢＬＣ与螯合配基的结合影响显著。在选定的色谱条件下，ＢＬＣ粗酶液经ＩＤＡ型Ｃｕ２＋－螯合膜色谱柱一步纯化，比活性平均提高４．７倍，回收率为６７．７％。金属螯合膜色谱柱可用含０．２ｍｏｌ／Ｌ的咪唑或５０ｍｍｏｌ／ＬＥＤＴＡ－１ｍｏｌ／ＬＮａＣｌ的缓冲液再生，反复使用，后者比前者对柱子的再生效果更好。     

Cellulose/cysteine based thiol-ene UV cured adsorbent: removal of silver (I) ions from aqueous solution

Cellulose - In the present study, a novel, eco-friendly, and simple polymeric adsorbent was obtained from cellulose acetate butyrate (CAB) and cysteine (Cys) to remove silver (I) ions in the...     

IDA型Cu~(2+):-螯合亲和膜色谱法对牛肝过氧化氢酶纯化的研究(英文):

首次采用以改性纤维素为基质、亚氨二乙酸（ＩＤＡ）为取代配基的铜离子螯合膜色谱法对牛肝过氧化氢酶（ＢＬＣ）的分离纯化进行了研究。缓冲液的ｐＨ值对ＢＬＣ与螯合配基的结合影响显著。在选定的色谱条件下,ＢＬＣ粗酶液经ＩＤＡ型Ｃｕ２＋－螯合膜色谱柱一步纯化,比活性平均提高４．７倍,回收率为６７．７％。金属螯合膜色谱柱可用含０．２ｍｏｌ／Ｌ的咪唑或５０ｍｍｏｌ／ＬＥＤＴＡ－１ｍｏｌ／ＬＮａＣｌ的缓冲液再生,反复使用,后者比前者对柱子的再生效果更好。     

载铁(Ⅲ)-配位体交换棉纤维素吸附剂对饮用水中砷(Ⅴ)和氟联合去除的研究

使用新型载铁(Ⅲ)-配位体交换棉纤维素吸附剂,通过静态和动态吸附实验,研究了饮用水中砷酸钠[砷(Ⅴ)]和氟化钠(氟)联合去除的效果和浓度因素的影响以及吸附剂经过反复吸附-洗脱再生-再吸附后性能的稳定性.结果表明,该吸附剂能够高效、高选择性地联合去除高砷(Ⅴ)和高氟.吸附柱的饱和吸附容量可高达15mg/g干重,反复使用中饱和体积的相对标准偏差小于0.5%,柱处理出水的各项有关指标均符合我国生活饮用水卫生标准,特别是砷(Ⅴ)的质量浓度低于0.010mg/L,符合世界健康组织(WHO)推荐的饮用水严格砷标准.说明该吸附剂在砷氟共存的地区具有很好的应用前景.     

Acid-base interactions and complex formation while recovering copper(II) ions from aqueous solutions using cellulose adsorbent in the presence of polyvinylpyrrolidone

The sorption properties of nontreated cotton cellulose and cellulose modified with polyvinylpyrrolidone with respect to copper(II) ions are investigated. It is established that modified cellulose adsorbents have high sorption capability associated with the formation of new sorption centers during treatment with nitrogen-containing polymer. A mechanism is proposed for acid-base interactions in aqueous solutions of acids, bases, and salts during copper(II) cation recovery using cellulose adsorbent with the participation of polyvinylpyrrolidone.     

Adsorption behavior of water soluble polymers with lower critical solution temperature

The adsorption behavior of hydroxylpropyl cellulose (HPC), ethyl hydroxylethyl cellulose (EHEC) and poly-vinylalcohol (PVA) polymers, which have a lower critical solution temperature (LCST), have been studied in comparison with the behavior of hydroxylethyl cellulose (HEC) with no LCST. The saturated amount of adsorption (A _s ) for the polymers with LCST depended significantly on the adsorption temperature and theA _s , e. g., for HPC obtained at the LCST, the amount was 1.5 times as large as the value at room temperature. The highA _s values obtained at the LCST were maintained over a long period at room temperature, and the dense adsorption layer formed on the latex particles at the LCST showed a strong protective action against flocculation. Furthermore, the effect of the surface nature of the adsorbent on the polymer adsorption at the LCST has been investigated using six kinds of synthetic latices with different surface natures. It was found that the hydrophobic interaction between the polymer and the adsorbent plays an important role in inducing the adsorption, and the trend of increasing the hydrophilic character of the latex surface prevents the formation of the adsorption layer of the polymer.     

Effect of flexibility and polarity of polymer chains on the kinetics of their adsorption from solutions of polymer blends at various adsorbent-to-solution ratios

The kinetics of adsorption of cellulose acetate and poly(butyl methacrylate) with different thermodynamic flexibility parameters at various amounts of adsorbent in binary solutions of polymers and their blends has been studied by IR spectroscopy. For various stages of adsorption, the values of adsorption; the fraction of bound segments; the energy of adsorption interaction; and the diffusion coefficients of macromolecules, which characterize the rate of adsorption, are estimated in relation to the concentrations of solutions and adsorbent-to-solution ratios. The rate of attaining adsorption equilibrium is shown to depend on the polarity and flexibility of macromolecular chains. As the amount of adsorbent is increased, macromolecules of the flexible-chain polymer (poly(butyl methacrylate)) undergo more substantial conformational transformations than macromolecules of stiff-chain polymer (cellulose triacetate) during the formation of equilibrium conformations.