Synthesis of lysozyme imprinted column with macroporous structure and enhanced selectivity: Utilization of cryogelation technique and electrostatic functional monomers

Applicability of molecularly imprinted polymers (MIP) in conventional protein separation processes demands monolithic construction of columns with macroporous structure in addition to the high specificity and adsorption capacity. In this study, therefore, lysozyme (Lyz) imprinted monolithic cryogel columns were synthesized using electrostatic functional monomers (EFMs) to provide strong interactions between template and polymer, leading to specific recognition and capture of Lyz. SEM images and FTIR spectroscopy analysis confirmed the macroporous structure and presence of EFMs in the samples. Adsorption isotherms, heterogeneity, and breakthrough curves as well as selectivity of the molecularly imprinted cryogels (EFMs‐MIC) and non‐imprinted cryogels (EFMs‐NIC) were investigated. Results showed effective imprinting with a maximum adsorption capacity of 211 mg/g and a high imprinting factor (IF) of 4.2 at low Lyz concentrations. A high relative selectivity coefficient of 7.24 was obtained for Lyz over cytochrome c, a competing protein, indicating that the imprinted sites could well distinguish Lyz. Reusability of MICs was also examined, where insignificant changes were observed in the cryogel adsorption/desorption characteristics after four cycles. Therefore, it is suggested to use EFMs and cryogelation in the synthesis of imprinted monolithic cryogels column for application in conventional protein separation processes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42880.     

Complexation of macroporous amphoteric cryogels based on N,N‐dimethylaminoethyl methacrylate and methacrylic acid with dyes,surfactant, and protein

Macroporous amphoteric cryogels based on N,N‐dimethylaminoethylmethacrylate and methacrylic acid p(DMAEM‐co‐MAA) crosslinked by N,N′‐methylenebisacrylamide (MBAA) were synthesized by radical copolymerization of monomer mixtures in cryoconditions. The structure and morphology of cryogels were evaluated by FTIR and SEM. Cryogels exhibited interconnected porous structure with pore size ranging from 40 to 80 µm, which depended on their crosslinking degree. The value of the isoelectric point (IEP) of equimolar amphoteric cryogel determined from the water flux was equal to 4.4, while the IEP of cryogel with the excess of DMAEM units was equal to 7.1. The mechanical strength of equimolar amphoteric cryogels increases with increasing amount of crosslinking agent. The complexation ability of amphoteric cryogels with respect to surfactant, dyes, and protein was demonstrated. The adsorption isotherms with respect to anionic surfactant—sodium dodecylbenzene sulfonate (SDBS) and protein—lysozyme correspond to Langmuir equation, while adsorption isotherms of anionic and cationic dyes—methylene blue (MB) and methyl orange (MO) are well described by Freundlich equation. It was found that the binding ability of p(DMAEM‐co‐MAA) with respect to various low‐ and high‐molecular weight compounds changes in the following order: SDBS > lysozyme ? MO > MB. The preferential adsorption of MB from the mixture of protein and MB was shown. The quantitative release of protein, surfactant and dye molecules from the matrix of cryogels takes place at the IEP of cryogel. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43784.     

Ag+ ions imprinted cryogels for selective removal of silver ions from aqueous solutions

ABSTRACT

The removal of heavy metal ions from aquatic media or any conditions is crucial. Silver ions turn out to be the important example of this problem on earth when these are released to the environment. In the present study, silver ions (Ag⁺) imprinted poly(hydroxyethyl methacrylate) (PHEMA)-based cryogels were prepared using N-methacryloyl-L-cysteine as functional monomer, to be chelated with Ag⁺ ions. The maximum adsorption capacity of Ag⁺-imprinted polymeric cryogel was found to be 49.27 mg/g from aqueous solutions. To investigate the affinity of Ag⁺-imprinted PHEMAC cryogel column, photographic film material from the natural silver ion source was used. The recovery results were 72.8% for the Ag⁺-imprinted PHEMAC cryogel and 0.62% for the non-imprinted PHEMAC cryogels. These values clearly showed the selectivity of the Ag⁺-imprinted PHEMAC cryogel column. The adsorption–desorption cycle was performed more 10 times with use of the same Ag⁺-imprinted PHEMAC cryogel for the determination of reuse. These molecularly imprinted cryogels were used in adsorption process for a long time with no significant loss.     

Influence of grafting conditions on the properties of polyacrylamide-based cation-exchange cryogels grafted with 2-acrylamido-2-methyl-1-propanesulfonic acid

The effects of grafting conditions on the properties of a novel cation-exchange cryogel by grafting of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA) onto polyacrylamide-based cryogel (pAAm cryogel) using potassium diperiodatocuprate (Cu(III) solution) as initiator were investigated experimentally. The basic cryogels were saturated with the initiator solution followed by the solution of monomers to get the expected sulfo groups under various grafting conditions, such as concentrations of monomers and initiator, graft reaction time, graft temperature and the volume ratio of Cu(III) to NaOH. The results showed that these factors influenced the liquid dispersion behaviors and the flow resistance as well as the protein binding capacity of the grafted cryogels. Protein binding capacity increased with the increase of concentration of AMPSA and Cu(III), the graft temperature and the graft reaction time in a wide range under the present conditions. Compared with these factors, the volume ratio of Cu(III) to NaOH in the initiator solution in the considered situations had a relatively weaker influence on the cryogel microstructures and protein binding capacity. The maximum binding capacity of lysozyme reached 2.5 mg/mL cryogel in these grafted cryogels.     

Structural,morphological and thermal characterization of poly (2-hydroxyethyl methacrylate-co-acrylonitrile) (P (HEMA-co-AN)) Cryogels: evaluation of water sorption potential and cytotoxicity

Cryogels are macroporous hydrogels which are synthesized through cryogelation method. In the present study cryogels of poly (2-hydroxyethyl methacrylate-co-acrylonitrile) (P (HEMA-co-AN)) were synthesized by copolymerization of 2-hydroxyethyl methacrylate (HEMA) and acrylonitrile (AN) monomers by redox polymerization using cryogelation technique. The synthesized cryogels were characterized by FTIR, SEM, XRD, DSC and TGA techniques. Different compositions of the cryogels were prepared by varying concentrations of the monomers and redox initiators in the feed mixture. These cryogels were then subjected to swelling studies and porosity determination. The swelling behavior was studied as function of concentration of the monomers, redox initiators, temperature, pH, and simulated biological fluids. The prepared cryogels were also characterized for their network parameters using water sorption data. The biocompatibility of P (HEMA-co-AN) cryogel was evaluated by in vitro cytotoxicity test. The results indicated that the P (HEMA-co-AN) cryogel had macroporous morphology and exhibited good water absorption capacity. Moreover, the cryogel was thermally stable and biocompatible in nature.     

Poly(vinyl alcohol)/polyethyleneimine (PVA/PEI) blended monolithic cryogel columns for the depletion of haemoglobin from human blood

We have synthesized PVA/PEI monolithic cryogel columns chelated with Cu²⁺ ions as a model adsorbent, which is capable of binding haemoglobin (Hb) from human blood. The goal of this study is to perform the depletion of Hb via a single and easy process to be useful in proteomic studies. PVA/PEI-Cu²⁺ cryogel columns were subjected to adsorption studies of Hb from both aqueous solution and human plasma to evaluate the extent of interaction between cryogel columns and Hb. The effects of experimental parameters, such as pH, Hb equilibrium concentration, adsorption time, temperature, and ionic strength, on Hb adsorption capacity were investigated.     

甲基橙印迹磁性壳聚糖聚合物的制备及吸附特性

以通过溶胶-凝胶法自制的Fe₃O₄@壳聚糖（CTS）微球为载体,甲基橙（MO）为模板分子,采用水溶液聚合法制得磁性壳聚糖表面分子印迹聚合物（MMIPs）。通过SEM、XRD、FT-IR和VSM表征了MMIPs的结构和性能,并探究了其对MO的识别与选择性吸附特性。研究表明：与非印迹聚合物（NIMPs,饱和吸附量为20.56 mg/g）相比,在相同条件（pH值6.5、25℃）下,MMIPs对MO具有明显的特异性吸附能力,在60 min左右吸附饱和,饱和吸附量（Q_e）可达113.16 mg/g;MMIPs对MO的吸附符合Langmuir等温吸附模型和准二级吸附动力学模型;在其他干扰染料的存在下,MMIPs的选择性系数（K）最高可达2.85,对MO具有选择识别性;此外,吸附完成后MMIPs可在磁场作用下快速分离,解吸附后循环使用5次,吸附率均在90%以上。     

Preparation and characterization of poly(vinyl alcohol) cryogel‐silver nanocomposites and evaluation of blood compatibility,cytotoxicity, and antimicrobial behaviors

In this investigation, cryogels composed of poly(vinyl alcohol) (PVA) were prepared by repeated freeze‐thaw method. The prepared cryogels served as templates for producing highly stable and uniformly distributed silver nanoparticles via in situ reduction of silver nitrate (AgNO₃) using alkaline formaldehyde solution as reducing agent. The structure of the PVA/Ag cryogel nanocomposites was characterized by a Fourier transform infrared and Raman spectroscopy. The morphologies of pure PVA cryogels and PVA/Ag nanocomposites were observed by a scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The SEM analysis suggested that cryogels show a well defined porous morphology whereas TEM micrographs revealed the presence of nearly spherical and well separated Ag nanoparticles with diameter about 100 nm. XRD results showed all relevant Bragg's reflections for crystal structure of silver nanoparticles. The amount of silver in cryogel nanocomposites and thermal stability were determined by inductively coupled plasma atomic emission spectrometry (ICP‐AES) and thermogravimetric analysis measurements. Mechanical properties of nanocomposites were observed in terms of tensile strength. The antibacterial studies of the synthesized nanosilver containing cryogels showed good antibacterial activity against both gram‐negative and gram‐positive bacteria. The prepared PVA/Ag nanocomposites were also investigated for swelling and deswelling behaviors. The results reveal that both the swelling and deswelling process depends on the chemical composition of the cryogel silver nanocomposites, number of freeze‐Thaw cycles and pH and temperature of the swelling medium. The biocompatibility of the prepared nanocomposites was judged by in vitro methods of percent hemolysis and protein (BSA) adsorption. POLYM. COMPOS., 36:1983–1997, 2015. © 2014 Society of Plastics Engineer     

锌铝水滑石的控制合成及吸附性能研究

采用简单的水热法和均匀共沉淀法合成了不同形貌的锌铝水滑石（Zn Al-LDHs）,通过XRD、SEM、N2吸附等对合成的试样进行了表征;研究了甲基橙在Zn Al-LDHs上的吸附性能,考察了酸碱度和温度等对其吸附性能的影响。结果表明：采用水热法,添加乙二醇可合成出海胆状Zn Al-LDHs,添加乙醇可合成出花状Zn Al-LDHs;采用均匀共沉淀法可合成出片状Zn Al-LDHs。其中海胆状Zn Al-LDHs的比表面积最高,达147.3 m2/g,对甲基橙具有优异的吸附性能。在25℃,初始p H=3的条件下,0.2 g/L海胆状Zn Al-LDHs对100 mg/L甲基橙的吸附容量和去除率分别达368 mg/g和73.65%,其吸附动力学和吸附等温线分别符合准二级速率方程和Langmuir方程。     

Preparation of Zn2+‐chelated poly(HEMA‐MAH) cryogel for affinity purification of chicken egg lysozyme

Supermacroporous poly(2‐hydroxyethyl methacrylate) [poly(HEMA)]‐based monolithic cryogel column was prepared by radical cryocopolymerization of HEMA with N‐methacryloyl‐L ‐histidine methyl ester (MAH) as functional comonomer and N,N′‐methylene‐bisacrylamide (MBAAm) as crosslinker directly in a plastic syringe for affinity purification of lysozyme from chicken egg white. The monolithic cryogel containing a continuous polymeric matrix having interconnected pores of 10–50 μm size was loaded with Zn²⁺ ions to form the metal chelate with poly(HEMA‐MAH) cryogel. Poly(HEMA‐MAH) cryogel was characterized by swelling studies, FTIR, scanning electron microscopy, and elemental analysis. The equilibrium swelling degree of the poly(HEMA‐MAH) monolithic cryogel was 5.62 g H₂O/g cryogel. Poly(HEMA‐MAH) cryogel containing 45.8 μmol MAH/g was used in the adsorption/desorption of lysozyme from aqueous solutions. The nonspecific adsorption of lysozyme was very low (7.5 mg/g). The maximum amount of lysozyme adsorption from aqueous solution in phosphate buffer was 209 mg/g at pH 7.0. It was observed that lysozyme could be repeatedly adsorbed and desorbed with the poly(HEMA‐MAH) cyogel without significant loss of adsorption capacity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Poly(acrylamide‐allyl glycidyl ether) cryogel as a novel stationary phase in dye‐affinity chromatography

Poly(acrylamide‐allyl glycidyl ether) [poly(AAm‐AGE)] cryogel was prepared by bulk polymerization which proceeds in an aqueous solution of monomers frozen inside a glass column (cryo‐polymerization). After thawing, the monolithic cryogel contains a continuous polymeric matrix having interconnected pores of 10–100 μm size. Cibacron Blue F3GA was immobilized by covalent binding onto poly(AAm‐AGE) cryogel via epoxy groups. Poly(AAm‐AGE) cryogel was characterized by swelling studies, FTIR, scanning electron microscopy, and elemental analysis. The equilibrium swelling degree of the poly(AAm‐AGE) monolithic cryogel was 6.84 g H₂O/g cryogel. Poly(AAm‐AGE) cryogel containing 68.9 μmol Cibacron Blue F3GA/g was used in the adsorption/desorption of human serum albumin (HSA) from aqueous solutions and human plasma. The nonspecific adsorption of HSA was very low (0.2 mg/g). The maximum amount of HSA adsorption from aqueous solution in acetate buffer was 27 mg/g at pH 5.0. Higher HSA adsorption value was obtained from human plasma (up to 74.2 mg/g). Desorption of HSA with a purity of 92% from Cibacron Blue F3GA attached poly(AAm‐AGE) cryogel was achieved using 0.1M Tris/HCl buffer containing 0.5M NaCl. It was observed that HSA could be repeatedly adsorbed and desorbed with poly(AAm‐AGE) cryogel without significant loss in the adsorption capacity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Supermacroporous polydivinylbenzene cryogels with high surface area: Synthesis by solvothermal postcrosslinking and their adsorption behaviors for carbon dioxide and aniline

Cryogels are supermacroporous but restricted by lack of surface area in utilization to date. We here propose a method for fabrication of supermacroporous polydivinylbenzene (PDVB) cryogels with high surface area by redox-initiated cryopolymerization combined with solvothermal postcrosslinking technique. The PDVB precursor cryogels are prepared by redox-initiated cryopolymerization, followed by postcrosslinking of residual double bonds to form hypercrosslinked cryogels under solvothermal conditions. The hypercrosslinked cryogels maintain the original supermacroporosity and display very high surface area up to 1462 m² g⁻¹. We demonstrate the utilization of the resultant cryogel in uptake of carbon dioxide (7.9 wt % at 1 bar and 62.2 wt % at 25 bar, respectively) and uptake of aniline (333.3 mg g⁻¹ at room temperature) from aqueous solutions. The adsorption behaviors of aniline on the hypercrosslinked cryogels are found to follow Langmuir model as well as Freundlich model in equilibrium adsorption and to follow pseudo-second-order model in kinetic adsorption, respectively. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47716.     

HSA immobilized novel polymeric matrix as an alternative sorbent in hemoperfusion columns for bilirubin removal

HSA immobilized poly(2-hydroxyethylmethacrylate), HSA-P[HEMA], cryogel monolith was examined as an alternative sorbent to be used in hemoperfusion columns for bilirubin removal from serum. The cryogel monolith synthesis was performed by free radical polymerization using MBAA as crosslinker, APS and TEMED as redox pair. Cyanogen bromide (CNBr) was used as a matrix-activating agent for the preparation of immobilized cryogels. Control cryogel monolith, P[HEMA], and HSA-P[HEMA] were characterized by swelling test, SEM images, porosity and surface area measurements, and blood compatibility tests. Activation and immobilization processes were optimized. The removal of bilirubin from plasma samples overloaded with bilirubin was performed using P[HEMA] cryogel monoliths containing different amounts of immobilized HSA in continuous mode. Several factors affecting adsorption capacity of the matrix such as incubation time, HSA concentration, bilirubin concentration in plasma and temperature were analysed. The maximum bilirubin removal from plasma was 25.4 mg/g at 37.5 °C. The desorption agent was 0.1 M NaOH and 1.0 M NaCl containing solution. The reusability was tested for 10 consecutive adsorption–desorption cycles. The adsorption isotherm models and kinetics of process were also studied.     

Magnetic Multi-Wall Carbon Nanotubes for Methyl Orange Removal from Aqueous Solutions: Equilibrium,Kinetic and Thermodynamic Studies

The magnetic iron oxide nanoparticles (SPION) were prepared using the co-precipitation method. The magnetically modified multi-wall carbon nanotubes (MWCNT) were obtained by the same method. The magnetic nanoparticles were used as adsorbents for methyl orange (MO) removal from aqueous solutions. The surface properties of adsorbents were analyzed by XRD, TGA, FTIR, and SEM. The adsorption was carried out on batch type. The kinetic, equilibrium and thermodynamics parameters were obtained by experimental results. The maximum adsorption capacity was obtained at pH 3 for both of the adsorbents. Theoretical adsorption capacities were found as 0.31 mg/g for SPION and 10.54 mg/g for MWCNT/SPION composites from Langmuir isotherm parameters. The MWCNT/SPION composites can adsorb 95% of methyl orange from water. The kinetic parameters and thermodynamic parameters were calculated.     

Inhibition of the corrosion of stainless steel by poly-N-vinylimidazole and N-vinylimidazole

In this study, we investigated the inhibition of the corrosion of stainless steel (SS) in acidic solution by N-vinylimidazole monomer (NVI) and poly-N-vinylimidazole (PNVI). First, we have synthesized a polymer sample of PNVI from the monomer NVI. A stainless steel electrode was coated with this polymer as a thin film by dipping method. Corrosion rates of SS electrodes coated with PNVI films of different thicknesses were determined and compared with the results of the bare electrode in acidic solution. Corrosion rates of the bare SS electrodes were also compared with the rates in the presence of monomer and polymer, respectively, in the acidic solution. The corrosion currents were obtained by Tafel extrapolation from anodic and cathodic polarization curves. Electrochemical impedance spectroscopy (EIS) measurements were also carried out. Values of percent inhibition, wetted area and porosity were obtained for SS electrodes coated with PNVI films of different thicknesses.     

In situ preparation of polyaniline within neutral,anionic, and cationic superporous cryogel networks as conductive,semi‐interpenetrating polymer network cryogel composite systems

Polyaniline [p(An)], one of the most known conducting polymers, was prepared within superporus nonionic polyacrylamide [p(AAm)], anionic poly(2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid sodium salt) [p(AMPS)], and cationic poly(3‐acrylamidopropyltrimethyl ammonium chloride) [p(APTMACl)] cryogels. After they were synthesized, washed, and dried, the neutral p(AAm), anionic p(AMPS), and cationic p(APTMACl) cryogels were soaked in an ammonium persulfate/aniline solution (1:1.25 ratio) in 1 M hydrochloric acid for the in situ oxidative polymerization of p(An) with the cryogel matrices as templates or reactors. The prepared p(AAm)/p(An), p(AMPS)/p(An), and p(APTMACl)/p(An) semi‐interpenetrating polymer network (semi‐IPN) conductive cryogel composites were characterized with scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and conductivity analysis. The SEM images revealed that the superporus cryogel networks were almost completely filled with p(An) conductive polymers (CPs). Among the cryogel–CP semi‐IPNs, we found that p(AAm)/p(An) semi‐IPN conductive cryogel composites provided the highest conductivity values of 1.4 × 10^?2 ± 4 × 10^?4 S/cm; this was a 6.4 × 10⁶ fold increase in the conductivity from the values of 2.2 × 10^?9 ± 1 × 10^?10 for p(AAm) cryogels. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44137.     

Application of superporous magnetic cationic cryogels for persistent chromate (toxic chromate and dichromate) uptake from aqueous environments

Poly((3‐Acrylamidopropyl)trimethylammonium chloride) (p(APTMACl)) cryogels were prepared with cryopolymerization technique and employed for the removal of toxic chromate and dichromate anions from aqueous media. The maximum adsorption capacities of 94 mg/g and 135 mg/g for chromate and dichromate anions, respectively, were determined with the application of the Langmuir isotherm. These values are very close to the experimental values of about 77 and 128 mg/g from 100 mL, 100 ppm chromate, and dichromate solutions using 0.03 g cryogel. The removal efficiency of chromate and dichromate anions were increased with the increase in the amount of cryogel and the removal percentage of chromate and dichromate toxic anions were estimated as 99.21 and 93.61%, respectively, for 0.15 g of p(APTMACl) cryogels used in 100 mL, 100 ppm chromate, and dichromate solutions. Furthermore, magnetic p(APTMACl) cryogels were also prepared and used in the removal of chromate and dichromate, and the maximum adsorption capacities were 30 mg/g and 40 mg/g, respectively. Additionally, the adsorption of these anions were investigated from different media such as drinking water, tap water, seawater, and creek water; and the maximum adsorption amounts in drinking water were 65.5 ± 15, and 125.5 ± 11 mg/g for chromate and dichromate anions, respectively. The reusability of p(APTMACl) cryogels for the removal of chromate and dichromate anions was also investigated, and it was found that the adsorption capacity for chromate anions decreased to 71.23 ± 4.3 from 97.37 ± 4.5 mg/g, whereas the adsorption capacity of dichromate anions only decreased to 123.69 ± 3.5 mg/g from 129.9 ± 7 mg/g at the end of five adsorption‐desorption cycles. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43438.     

Histidine Containing Macroporous Affinity Cryogels for Immunoglobulin G Purification

A supermacroporous cryogel was prepared to obtain an efficient and cost effective purification of IgG from human plasma. N-methacryloyl-(L)-histidine methyl ester (MAH) was chosen as the pseudospecific ligand and/or comonomer. Poly(hydroxyethyl methacrylate-N-methacryloyl-(L)-histidine methylester) [PHEMAH] cryogel was produced by free radical polymerization initiated by N,N,N′,N′-tetramethylene diamine (TEMED) and ammonium persulfate (APS) pair in an ice bath. PHEMAH cryogel had a specific surface area of 38.6 m²/g. PHEMAH cryogel was characterized by swelling studies, scanning electron microscopy and elemental analysis. PHEMAH cryogel containing 113.7 µmol MAH/g was used in the purification of IgG from human plasma. Compared with the poly(hydroxyethyl methacrylate) (PHEMA) cryogel (0.4 mg/g), the IgG adsorption capacity of the PHEMAH cryogel (24.7 mg/g) was improved significantly due to the MAH incorporation into the polymeric matrix. The maximum amount of IgG adsorption from aqueous solution in phosphate buffer was observed at pH 7.4. The IgG adsorption amount from human plasma was 97.3 mg/g with a purity of 94.6%. It was observed that IgG could be repeatedly adsorbed and eluted with PHEMAH cryogel without significant loss in the adsorption capacity.     

Crystal violet dye sorption and transport in/through biobased PVA cryogel membranes

Cryogels based on poly(vinyl alcohol) [PVA] and three types of bioinsertions such as scleroglucan, cellulose microfibers, and zein, respectively, have been prepared using capacity of PVA to crosslink by repeated freezing–thawing cycles. The effect of the incorporation of biopolymers on the properties of PVA cryogel has been studied by using several techniques such as: scanning electron microscopy, differential scanning calorimetry, and Fourier transform infrared studies. The obtained biobased cryogel membranes were subjected to sorption and to diffusion experiments using Crystal Violet (CV), a dye commonly used in the textile industry and in medicine. Image analysis with CIELAB system was used both to monitor the cryogels loading with CV and to gain insight in the dye state into the gel, in correlation with the bioinsertion type and gels morphology. Dye diffusion but also sorption capacity of the cryogels was found to be closely related to the type of biopolymer. In this article the equilibrium (sorption isotherms) and transport properties (diffusion and permeability coefficients) of CV, in/through physical cross‐linked PVA hydrogel membranes with bioinsertions has been reported. The highest efficiency for the CV removal from aqueous solutions was obtained for the PVA/Scl cryogels. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41838.     

水热界面反应制备二氧化钛空心微球

采用水热法,在油酸/水/乙醇体系中,钛酸四丁酯前驱体分解团聚得到具有空心结构的TiO2微球。利用扫描电子显微镜(SEM)、X射线衍射(XRD)、N2吸附脱附(BET)对样品进行表征,并通过对甲基橙的紫外光催化降解评价样品的光催化性能。结果表明该空心微球为锐钛相,粒径约为1～2μm,随着时间的延长其结晶性增强。BET结果显示该空心微球具有较大的比表面积300.20m2.g-1,内部颗粒之间形成介孔结构。利用SEM研究了该空心微球的生长特点和生长机理,结果表明钛酸四丁酯在油水界面反生分解缩聚反应,然后经过由内向外的Ostwald ripening(OR)过程得到空心微球,通过调节水油的比例可以调控微球的形貌和粒径。光催化性能测试表明这种空心微球结构的TiO2材料具有较高的催化活性。