New poly[Acrylamide/N‐vinyl pyrrolidone/3‐(2‐hydroxyethyl carbamoyl)acrylic acid], poly [AAm/NVP/HECA], chelating hydrogels with different composition of HECA monomer have been prepared via free radical solution polymerization using N,N‐methylene bisacrylamide as a crosslinker. The hydrogels obtained were loaded with metal ions and characterized by FT‐IR spectroscopy, Scanning Electron Microscope (SEM) and Thermogravimatric analysis (TGA). The removal of Cu2+ and Ni2+ from aqueous solutions by the hydrogel was examined by a batch equilibrium method. The influence of treatment time, pH, initial concentration of the metal ions and HECA content in the feed compositions on the amount of adsorbed metal ions was studied. Swelling of the hydrogel was also carried out in distilled water and metal ion solutions. The removal of the metal ions followed the following order: Ni2+>Cu2+. The amount of metal ions removed increased with increasing HECA content in the feed composition, treatment time, pH of the medium and initial concentration of metal ions. The desorption of metal ions were carried out using 1 N HCl and 0.5 N H2SO4. The poly[AAm/NVP/HECA] hydrogels could be used many times without significantly decreasing their adsorption capacity. 相似文献
To detect the quality of medicinal human albumin by capillary electrophoresis, we produced a fused‐silica capillary coated with thermally cross‐linked poly(vinyl pyrrolidone) to prohibit protein adsorption. This type of capillary was easily obtained by injecting an aqueous poly(vinyl pyrrolidone) solution into a fused‐silica capillary and thermally annealing it at 200°C. Notably, stable and low electro‐osmotic flow was obtained in the poly(vinyl pyrrolidone)‐coated capillary at pH 2.20–9.00, and the separation of a mixture of four basic proteins indicated that the poly(vinyl pyrrolidone)‐coated capillary exhibits excellent repeatability and separation efficiency; moreover, the separation of these four basic proteins could even be achieved at pH 7.00. The protein recovery percentage of human serum albumin in a single‐protein solution and a mixed blood proteins solution was determined to be 97.03 and 95.40% in the poly(vinyl pyrrolidone)50–3 (representing the concentration of the capillary‐injected poly(vinyl pyrrolidone) aqueous solution, 50 mg/mL, and thermal annealing time, 3 h) capillary, respectively. Based on these results, we used the poly(vinyl pyrrolidone)50–3‐coated capillary to quantify the protein content of human albumin, and the results obtained from run to run, day to day and capillary to capillary demonstrated that the coated capillary could be used for quality testing commercially available human albumin. 相似文献
Summary: Superhydrophilic modification of poly(propylene) and poly(ethylene terephthalate) films' surfaces was realized by the UV‐initiated surface photografting of a N‐vinyl pyrrolidone/N,N′‐methylenebisacrylamide inverse microemulsion. AFM characterization of the treated films' surface revealed that it was the grafted quasi‐bimodal (ca. 45 and 110 nm) particles of cross‐linked poly(N‐vinyl pyrrolidone) that led to superhydrophilicity of the surface. The grafted nanometer‐scale particles showed little influence on the transparency of the substrate's surface, but endowed long‐term stability to the superhydrophilicity.
The surface morphology of the PP film grafted with a NVP/MBA inverse microemulsion via a one‐step method. Quasi‐bimodal particles (ca. 45 nm and 110 nm) were tethered on the film's surface, and the corresponding surface water CA fell below 5°. 相似文献
Thiol polymer, which is known as a reactive and functional polymer, is synthesized and evaluated quantitatively by the modified Ellman method. The synthesis was accomplished by 1) hydrolysis of an isothiouronium salt that is the adduct of 4‐chloromethylstyrene (CMS) homopolymer or CMS‐styrene (St) copolymer with thiourea; 2) hydrolysis of a precursor copolymer made from 4‐vinylbenzyl N‐ethyldithio‐carbamate (VBEC) and St or N‐vinyl‐2‐pyrrolidone (NVP); 3) solvolysis of an iminium salt polymer obtained from the reaction of CMS‐NVP copolymer with N,N‐dimethylthioformamide (TDMF). When a higher thiol content is desired, more severe hydrolysis conditions are required which however, also increase the loss of thiol. Hence, it is clear that the best synthesis of thiol polymers is Method 3. A quantitative yield of functional thiol polymer is obtained by this method, and the product is soluble in DMSO, DMF, and CHCI3.相似文献
New polymer networks were prepared by free radical initiated copolymerization of crystallizable α,ω‐bismethacrylate‐terminated poly(octadecyl vinyl ether) (polyODVE) with butyl acrylate (BA). The polyODVE bismacromonomers were obtained by end‐capping the bifunctionally living cationic polymerization of ODVE with 2‐hydroxyethyl methacrylate (HEMA). The segmented networks show a high degree of phase separation over a wide range of compositions. The shape memory properties of a material containing 20 wt.‐% of polyODVE are reported. 相似文献
Local depletion of intestinal phosphate triggers changes in bacterial phenotypes that adversely affect the health of the host. This article describes a process for encapsulating phosphates in crosslinked poly(ethylene glycol) diacrylate (PEGDA) nanoparticles using inverse miniemulsion polymerization as a drug delivery approach for sustained release of phosphates to the intestinal epithelium. The effects of crosslinker, PEGDA co‐monomer, N‐vinyl pyrrolidone, (NVP) and surfactant concentrations on the nanoparticle size distribution, swelling ratio and monomer conversion are investigated. Increased surfactant and PEGDA concentrations result in smaller particle size and swelling ratio. A copolymerization model of crosslinking is used to predict conversion and gelation dynamics as a function of polymerization conditions. The model assumes that bulk polymerization can be used to approximate inverse miniemulsion polymerization with an aqueous‐phase initiator. The initiator efficiency is used as an adjustable parameter to simulate the conversion dynamics, thus accounting for radical confinement effects and interaction with emulsifier molecules. 相似文献
The monomer 3‐ethyl‐1‐vinyl‐2‐pyrrolidone ( 3 ) and the homopolymer poly(3‐ethyl‐1‐vinyl‐2‐pyrrolidone) ( 5 ) have been synthesized. Polymer 5 is soluble in water and shows a critical temperature (Tc) of 27 °C. The presence of cyclodextrin causes a slight shift of the Tc. The lower critical solution temperature (LCST) could be varied between 27 and 40 °C by copolymerization with N‐vinyl‐2‐pyrrolidone. A linear correlation between the Tc and the copolymer composition is observed.
An improved kinetic model for the radical polymerization of N‐vinyl‐pyrrolidone (NVP) in aqueous medium is developed. Quantum chemical simulations reveal that the transfer to polymer is of minor importance whereas the transfer to monomer by hydrogen abstraction in 3‐position of the pyrrolidone ring leads to a radical with a double bond which initiates a new chain bearing a terminal double bond (TDB). The resulting dead chains with one, two, or more TDB are the main source for a strong increase of molar mass in batch reactors at high conversion due to long chain branching and crosslinking. This can be a source for gel formation and fouling in continuous reactors. 相似文献
While conventional approaches have been studied for removal of ruthenium(III) ions (Ru(III)), this work focuses on the applicability of ion‐imprinted poly(methyl methacrylate‐vinyl pyrrolidone)/poly(vinylidene fluoride) blending membranes (Ru(III)–ion‐imprinted membrane[IIM]) for selective removal of Ru(III) from acidic water solutions. In order to measure the effectiveness of these imprinted membranes, after fabrication, binding experiments were done with aqueous Ru(III) solutions. The results showed that Ru(III)‐IIMs were fabricated successfully at various blending ratios, and their chemical components, microstructures, hydrophilicity, and water fluxes were measured. In pH range 0.5 to 5.0, binding capacity (Qe) of Ru(III) onto Ru(III)‐IIM increases remarkably with pH and then reaches to a maximum value (53.52 mg/g) at pH 1.5. After that, Qe gradually decreases. Compared with a nonimprinted membrane, Ru(III)‐IIM demonstrates higher selectivity for Ru(III) at pH 1.5 in the presence of Ni(II) and Cu(II) ions, and its selectivity coefficients for Ru(III)/Ni(II) and Ru(III)/Cu(II) are 3.70 and 3.32, respectively. Also, Ru(III)‐IIM shows a good chemical stability and reusability. C─N and C═O bonds within poly(vinyl pyrrolidone) segments of poly(methyl methacrylate‐vinyl pyrrolidone) (P(MMA‐VP)) participate the uptake of Ru(III). Ru(III)‐IIM exhibited excellent hydrophilicity and Ru(III) selective adsorption ability and reusability and has potential to be used for Ru(III) removal from acidic water solutions. 相似文献