Advanced Materials Research Vols. 306-307

Abstract: Molecular imprinting technology was employed to produce one kind of Phenylalanine ( Phe) molecularly imprinted polymers (MIP)by precipitation polymerization using Phe, anhydrous alcohol, acrylamide, ethylene glycol dimethacrylate, and azobisisobutyronitrile as template, porogen, functional monomer, cross-linker and initiator respectively. In this study, the polymerization conditions were optimized. The template on particle size and morphology of polymers were investigated in detail by scanning electron microscopy (SEM) and adsorption isotherm determination. The binding properties of Phe on imprinted polymers were evaluated in water by equilibrium rebinding experiments, and the maximum number of adsorption was 0.60 mmol/g. It is indicated that the existence of binding sites in imprinted polymers was proved and the binding sites showed good specific and selective capability to the template molecule Phe. So the polymers would be used to separate Phe from medicine and food.

Abstract: The synthesis chitosan modified by N,N-dimethylformamide(DMF) grafted β-CD (CTS), adsorption experiments of lanthanide ions, a new type water treatment agent, are discussed in this paper. First, the chitosan was modified by DMF, and then β-cyclodextrin (β-CD) was grafted onto chitosan skeleton by epoxy chloropropane. The effects of temperature, pH value, adsorption time on adsorption content were studied. The water treatment agent have a high lanthanide adsorption rate up to 98% compared to chitosan, b-CD and chitosan derivative bearing β-cyclodextrin.

Abstract: In this paper, molecular imprinted polymer for quercetin was synthesized by precipitation polymerization with acrylamide as functional monomer, ethylene glycol dimethacrylate as cross-linker, 2,2-azobisisobutyronitrile as initiator and acetone as the solvent. The polymers’ adsorption properties were characterized. As results shown that the synthesized imprinted polymer is microspheres with particle size in the nanometer scale, the adsorption capacity of quercetin imprinted polymers is 1.1×10^-5mol/g, adsorption temperature is 60°C, adsorption time is 30 min. The molecular imprinting technology was introduced in interference test with a satisfactory result in selectivity.

Abstract: On the basis of kinetic equations constructed in the isothermal vulcanization of natural rubber (NR), a new numerical computation expression of cure degree under non-isothermal conditions is established by the incremental method. The numerical simulation of the vulcanization stage in injection molding processes of NR is performed by the finite element method, and then the time and position-dependent changes in the cure degree are analyzed numerically. The simulation results are consistent with the results described in the previous literatures. The valuable vulcanization characteristics obtained in the simulation will help engineers in the optimum design of processing conditions.

Abstract: Polymer flooding represents one of the most efficient processes to enhance oil recovery, but the poor thermostability and salt tolerance of the currently-used partially hydrolyzed polyacrylamide (HPAM) impeded its use in high-temperature and high-salinity oil reservoirs. “Smart” thermoviscosifying polymers (TVPs) may overcome the deficiencies of HPAM. Steady and dynamic rheological behaviors against temperature of a novel TVP were examined in this work in comparison with a commercial HPAM polymer. It was found when increasing temperature, both apparent viscosity and elastic modulus increase for TVP aqueous solution, but decrease for HPAM solution. The results indicate that TVP shows some potential to be used in enhancing oil recovery from high-temperature and high-salinity oil reservoirs.

Abstract: The curing process of self-healing microcapsules containing epoxy resin was studied with different shell material such as Poly (urea-formaldehyde), poly (melamine-urea-formaldehyde), Poly (urea-formaldehyde) modified by polyvinyl alcohol, and Poly (urea-formaldehyde) modified by phenol, respectively. The activation energy (ΔE) and the reaction order (n) have been obtained based on Kissinger method, Crane theory and Arrhenius equation. The results showed that: the curing process of epoxy resin as core material in self-healing microcapsules becomes more difficult compared with non-microencapsulated. The stability of shell material impacts on the cure process of core material. The resulting decomposition products of shell materials may participate in the curing reaction. So choosing suitable shell material is particularly important to self-healing microcapsules.

Abstract: One novel highly cross-linked, shape-controllable molecularly imprinted sol-gel film (MISF) with good thermal and chemical stability and three-dimensional network porous structure has been developed. The binding characteristic of the imprinted film to bifenthrin was evaluated by equilibrium binding experiments and imprinting-induced promotion of binding. The MISF was modified into the wells of 96 micro-well plate combined with chemiluminescence (CL) technology to establish the molecular imprinting-chemiluminescence (MI-CL) sensor. The high throughput and high selective detection sensor of bifenthrin was applied in vegetable and food samples with satisfactory results.

Abstract: A technical condition for the reaction of preparing superabsorbent by orthogonal test was investigated. Test results were as follows: reaction temperature was 30 °C, reaction time was 2 h, monomer ratio is 0.045, monomer was 12 g, neutralization degree was 90%, initiator concentration was 0.167 wt% and crosslinker concentration was 0.0125 wt%. The maximum of distilled water absorbency was 699 times, the maximum of 0.9% saline water absorbency was 70 times. Analysis from FTIR and SEM showed that starch grafting with acrylic acid and acrylamide was successful, while a three-dimensional network structure was formed in superabsorbent.

Abstract: A Novel Polyfluorene Derivative, Poly[(9,9-Bis(3'-(N,N-Dimethylamino)propyl)-2,7- Fluorene)-Alt-2,7-(9,9- P-Divinylbenzene)] (P-1) Was Synthesized by the Palladium-Catalyzed Suzuki Coupling Reaction and it’s Quaternized Ammonium Polyelectrolyte Derivatives Was Obtained through a Postpolymerization Treatment on the Terminal Amino Groups. the Electrochemical and Optical Properties of the Resulting Copolymers Was Fully Investigated. the Results Showed that the New Polyfluorene Derivative Had Potential Useful in Used as Materials for Electronic Conductivity, Chemical and Biological Sensors that Derive from its Highly Conductive and Strong Fluorescence.

Abstract: A novel thermo-sensitive poly(N-acryloyl alanine methyl ester) (PAAME) was synthesized by radical polymerization. The structures of the corresponding monomer and polymer have been confirmed by ¹H NMR and FTIR measurements. The thermo-sensitivity of PAAME was investigated by measuring their lower critical solution temperatures (LCST) in pure water and at different pH solution. The results indicated that PAAME exhibited a reversible thermo-sensibility in its aqueous solutions at 17.7 °C. The drug release study showed that 72% caffeine was released from hydrogel at 37 °C after 6 hours, while more than 94% caffeine was gradually diffused into the medium at 18 °C.