In order to develop a nontoxicity, biocompatibility, pH-sensitive hydrogel system with potential ability to immobilize and absorb proteins, the hydrogel membranes of poly(N-vinylpyrrolidone) (PVP) and carboxymethylated chitosan (CM-chitosan) blend were prepared with electron beam (EB) irradiation at room temperature. The FTIR spectroscopic, mechanical property, swelling behavior, and surface property of the hydrogel membrane were measured. The capacity of these gel membranes to adsorb bovine serum albumin (BSA) was investigated with varying content of CM-chitosan by static adsorption experiment at pH 7.4. The mechanical and swelling properties were improved obviously after adding CMchitosan into PVP hydrogels. The changes of contact angles of water, glycerin and octane drops on the blend membranes surface with increasing CM-chitosan content indicated that the CM-chitosan molecules were more hydrophilic than PVP molecules, and cause a larger polar component of surface free energy. The incorporation of CM-chitosan introduced the protein adsorptive property into blend system. From these preliminary evaluations, it is possible to conclude that these materials have potential for applications in the biomedical field.

Carboxymethyl cellulose (CMC) and poly(N-vinyl pyrrolidone) (PVP) were blended to synthesize hydrogels by 60Co c-ray irradiation. A series of hydrogels were prepared with three compositions, i.e. PVP:CMC=5:5, 6:4 and 7:3. The properties of the hydrogels such as gel fraction, gel strength, swelling behavior and moisture retention were investigated. Compared with pure PVP and CMC hydrogels, PVP/CMC blend hydrogels possessed improved gel strength, flexibility and transparency. As the content of PVP in PVP/CMC blend hydrogels increased, the gel fraction increased while the swelling rate decreased. The hydrogels with optimal properties were obtained in a composition of PVP/CMC = 6/4 with sterilization dose (25 kGy) and further characterized by FT-IR and SEM. Properties concerning the application of wound dressing were performed by comparison with a commercial hydrogel wound dressing to find a similar moisture retention capability and improved swelling rate. The improved properties as well as the cheapness of the materials suggest that PVP/CMC blend hydrogel can be good candidate as wound dressing.

Hydroxypropyl methylcellulose phthalate (HPMCP) gel was synthesized from the sodium form of HPMCP by radiation-induced crosslinking, followed by converting the phthalate groups on HPMCP to non-ionic forms via ion exchange. The non-ionic H-type gels showed different phase transition behaviors from Na-type gels. Significant antipolyelectrolyte swelling behavior of this amphiphilic gel was observed in various aqueous salt solutions, comparing with the polyelectrolyte swelling behavior of ionic HPMCP gels. After immersed in aqueous salt solution, the morphology of H-type HPMCP gels changed from heterogeneous structure to homogeneous structure. The swelling behavior of the gels in several circumstances with potential applications, for instance, solutions with different temperature and pH, surfactants, and typical drug models, were investigated. H-type HPMCP gels showed similar temperature and pHstimuli responses to that of Na-type HPMCP gels. Furthermore, H-type HPMCP gels showed different swelling behaviors in cationic surfactant (C12TAB) and anionic surfactant (SDS) solutions. The investigations regarding drug embedment and release of this amphiphilic gel in inorganic salt and BSA solutions revealed that the embedment amount and release ratio were both high due to the improved swelling ability in saline condition of H-type HPMCP gels.

Novel pH/temperature sensitive hydrogel was synthesized by radiation induced copolymerization and cross-linking of dimethylaminoethyl methacrylate (DMAEMA) and diallyldimethyl ammonium chloride (DADMAC). Reactivity ratio of DADMAC (r1) and DMAEMA (r2) was determined as 1.02 and 0.98, which means that poly(DMAEMA-co-DADMAC) is an azeotropic copolymer. Content of DADMAC, i.e., charge density of the hydrogel was found to influence their properties significantly. Compared with polyDMAEMA hydrogel, poly(DMAEMA-co-DADMAC) showed enhanced equilibrium degree of swelling (EDS). Low critical solution temperature (LCST) of the hydrogel increased with the charged density. Content of DADMAC had no effect on the pH dependence of the final gel. Aiming at its application as a carrier for Chinese herb extract delivery system, the embedment and pH/temperature dependence of controlled release were investigated using notoginsenoside as a model drug. The maximum embedment amount of notoginsenoside was obtained in a gel containing 3 mol.% DADMAC. The temperature dependence and pH dependence of notoginsenoside release followed the same trend as that of EDS, for instance, higher ratio of notoginsenoside release occurred at 25℃and pH 1.7, at which higher EDS was obtained. By these means, the release of notoginsenoside can be controlled by adjusting the pH, ionic strength, temperature of solution as well as the composition and structure of the gel.

Using-radiation technique, dimethylaminoethyl methacrylate (DMAEMA) was grafted onto ethylene–tetrafluoroethylene (ETFE) membrane (ETFE-g-PDMAEMA), and then ETFE-g-PDMAEMA membrane was protonized to prepare anion exchange membrane, while PDMAEMA grafted onto ETFE membrane was changed into poly(methacryloxyethyl dimethyl ammonium chloride) (PMAOEDMAC) (denoted as ETFE-g-PMAOEDMACanion exchange membrane (AEM)). Micro-FTIR spectra testified thatPDMAEMAwas successfully grafted onto ETFE membrane. Water uptake and ion exchange capacity (IEC) of the AEM increased with grafting yield (GY), while area resistance decreased. At 40% GY, the AEM showed higher IEC and lower area resistance than Nafion117 membrane. In particular, the AEM had very low permeability of vanadium ions just as expected due to coulomb repulsion between the cation groups of the AEM and vanadium ions. Permeability of vanadium ions through the AEM with 40% GY has been reduced to 1/20 to 1/40 of that through Nafion117 membrane, which is favorable to reduce crossover of vanadium ions in vanadium redox battery (VRB). Finally, the open circuit voltage measurement showed that the VRB assembled with the AEM could maintain voltage for more than 50 h, which was much longer than that with Nafion117 membrane. The improved properties as well as the low cost suggest that the AEM can be good candidate for the VRB.

Natural oligosaccharide-derived room temperature ionic liquids (RTILs) were prepared from 1-ethyl-3-methylimidazolium hydroxide (EMIMÆOH) and carboxymethylated chitosan (CM-chitosan) by acid–base neutralization reaction. These EMIMÆCM-chitosan ionic liquids exhibited good ionic conductivity and thermal stability, as well as low glass transition temperature, implying their potential wide applications in direct electrochemistry, biosensors, and biocatalysis.

The radiation effect on a hydrophobic room temperature ionic liquid (RTIL), 1 butyl methyl imidazolium bis[(trifluoromethyl)sulfonyl]imide ([C4mim][NTf2]), was studied by 7 irradiation under nitrogen atmosphere. Accompanied by color darkening and increase of light absorbance in a wide wavelength range, a distinct absorption peak at around 290nm for irradiated [C4mim][NTf2] appeared when acetonitrile was used as solvent, and the intensity of the peak enhanced with increasing dose. The spectrophotometric study on the irradiated RTILs containing 1,3 dialkylimidazolium cations associated with different inorganic anions revealed that the peak is ascribed to the radiolysis products of the [C4mim]+. Arid the wavelength of the peak was affected by alkyl chain length on imidazolium cation, while the intensity of the peak was influenced by anions. With incorporating a little amounts of oxidants, such as KMnO4 and HNO3 into irradiated [C4mim][NTf2], the intensity of the peak at 290nm decreased obviously and the decoloration of [C4mim][NTf2] occurred, suggesting that the peak at 290nm is assigned to the colored species and the species can be oxidized.

A facile ultraviolet (UV) light irradiation method to synthesize gold nanoparticles (AuNPs) in the alkalic carboxymethylated chitosan (CMchitosan) solution was first proposed in this paper. CM-chitosan, a water soluble polysaccharide derivative, served as both reducing agent for gold cations and stabilizing agent for AuNPs. The pH, the concentration of HAuCl4 and irradiation time had obvious influence on the size, amount and morphology of AuNPs, which traced by UV–visible spectrometer and high resolution transmission electron microscopy. AuNPs synthesized in this method can be dispersed stably in alkalic CM-chitosan solution for more than 6 months. The possible stability mechanism of AuNPs was discussed based on the change of carboxyl group of CM-chitosan chain with pH and FTIR analyses. XRD pattern confirmed the cubic crystal structure of AuNPs. The fluorescence emission band of AuNPs with an excitation wavelength of 316 nm can be observed at 400 nm, which was affected remarkably by irradiation time and concentration of HAuCl4.

Adsorption behavior of Sr(Ⅱ) ions was investigated using gel adsorbents based on three types of polysaccharide derivates: carboxymethylated cellulose (CMC), carboxymethylated chitosan (CMCts) and hydroxypropyl methylcellulose phthalate (HPMCP). Maximum adsorption capacities were reached in about 0.5 h for CMCts, 1 h for CMC, and 2 h for HPMCP. The adsorption capacity increased with increasing pH, and decreasing ionic strength. The maximum adsorption capacity of Sr(Ⅱ) ions into CMC, CMCts and HPMCP gels at 25 ◦C were 108.7, 99.0, and 83.3 mg/g gel, respectively, based on the Langmuir isotherms. XPS analysis indicates that Sr(Ⅱ) ions are adsorbed into the three adsorbents according to the ion-exchange mechanism. Desorption of Sr(Ⅱ) ions could be carried on by immersing the adsorbents in the solutions with low pH or high ionic strength, or heating the adsorbents in the moist hot environment.

Silica-based adsorbent was prepared by radiation-induced grafting of dimethylaminoethyl methacrylate (DMAEMA) onto the silanized silica followed by a protonation process. The FTIR spectra and XPS analysis proved thatDMAEMAwas grafted successfully onto the silica surface. The resultant adsorbent manifested a high ion exchange capacity (IEC) of ca. 1.30 mmol/g and the Cr (Ⅳ) adsorption behavior of the adsorbent was further investigated, revealing the recovery of Cr (Ⅳ) increased with the adsorbent feed and the equilibrium adsorption could be achieved within 40 min. The adsorption capacity, strongly depended on the pH of the solution, reached a maximum Cr(Ⅵ) uptake (ca. 68 mg/g) as the pH was in the range of 2.5-5.0. Furthermore, even in strong acidic (4.0 mol/L HNO3) or alkaline media (pH 11.0), the adsorbent had a sound Cr(Ⅵ) uptake capacity (ca. 22 and 30 mg/g, respectively), and the adsorption followed Langmuir mode. The results indicated that this adsorbent, prepared via a convenient approach, is applicable for removing heavy-metal-ion pollutants (e.g. Cr(Ⅵ)) from waste waters.