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  • Author or Editor: Bao Borong x
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Abstract  

A series of condensed ethylene glycol acrylate monomers with differentmolecular weight was grafted to polyethylene films by means of pre-irradiation.The effect of the molecular weight of monomer and co-solvent system on thegrafting reaction and the properties of the grafted sample were studied. Theexperimental results showed that the initial rate of grafting reaction decreasedand the molar degrees of grafting linearly decreased with the increment ofmolecular weight of the monomer. The grafting degree was increased with theswelling degree of the grafted film. The biocompatibility and blood compatibilityof the grafted PE films were evaluated by the determination of hydrophilicityand anti-thrombus.

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Abstract  

A new68Ge/68Ga generator using CeO2 as absorbent for68Ge has been developed. Sharp elution curves were obtained by using 0.02 mol/l HCl as eluent. About 56% of68Ga formed on the column was concentrated in 0.5 ml of eluate. Neither radioactive impurities, nor dissolved cerium were found in the eluate.

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Abstract  

The extractant HBMPPT (4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione) was synthesized from HBMPP. Its m.p. was 106–108°C. The synergistic extraction of U(VI) and Th(IV) from nitric acid solution by HBMPPT and TOPO in toluene was studied. The extraction ability of HBMPPT was not so high as that of its parent (HBMPP), but when a little tri-n-octylphosphine oxide (TOPO) was added the ability to extract U(VI) and Th(IV) was seriously improved. The synergistic extracted complexes may be presented as UO2NO3·BMPPT·TOPO and UO2(BMPPT)2·TOPO for U(VI), and Th(NO3)3·BMPPT·TOPO and Th(NO3)2(BMPPT)2·TOPO for Th(IV) respectively.

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Abstract  

Some popular neutral extractants (PSO-petroleum sulfoxide, DOSO-di-n-octyl sulfoxide, TBP-tributylphosphate etc.) were chosen as synergist to study the synergistic effect on the extraction reaction with HBMPPT (4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione) for U(VI), and the synergistic separation ability of HBMPPT for U(VI) and Th(IV). The synergistic extraction ability shown by the studied systems for U(VI) is as follows: PSO>DOSO>TBP, and the same sequence was also verified for the separation coefficient of U(VI) and Th(IV). The synergistic complexes may be presented as: UO2NO3·BMPPT·S and UO2(BMPPT)2·S for U(VI) (S is PSO, DOSO or TBP).

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Abstract  

A new anti-thrombosis dialytic membrane with a hydrophilic-hydrophobic microphase structure was prepared by pre-irradiation grafting of -hydroxyethyl methacrylate (HEMA) and styrene (St) onto polyethylene (PE) membranes. The effects of reaction conditions on the degree of grafting were determined, and the properties of the grafted films were investigated. Compared with PE grafted with hydrophilic monomer, the antithrombogenicity and permeability of the PE-g-(HEMA-co-St) were 30 and 15 times higher than that of the ungrafted films, respectively, if the volume ratio (HEMA:St) is about 1:1.

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Abstract  

In order to obtain a more ideal hydrogel wound dressing, crosslinked hydrogel films blended with polyvinyl alcohol (PVA), polyvinyl pyrrolidone, kappa-carrageenan (KC), and powder silk were prepared by electron beam, and their physiochemical properties were investigated as a combination of function factors. The experimental results showed that the gel fraction of the hydrogel films depended mainly on irradiation dose and the monomer concentration of the polymers, the properties of hydrogel could be greatly extended or improved by blending homopolymers. The rate of gel formation of the hydrogel was raised, and the water evaporation from hydrogel could be retarded after mixing with KC, while the tensile strength of hydrogel films were obviously increased after mixing with silk. Toxicity and healing effect of PVA/PVP/KC/silk blended hydrogel films as wound dressings were evaluated. The irradiated blended hydrogel showed satisfactory properties for wound dressing, the hydrogel did not induceany acute general toxic effects, and it is effective for fast healing of wound.

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Abstract  

Interpenetrating polymer network (IPN) hydrogels were prepared by grafting of acrylamide (AAm), N-methylol acrylamide (NMA) and acrylic acid (AAc) onto preirradiated polypropylene (PP) membrane. To obtain PP-g-AAc/AAm/NMA IPN hydrogels, at first, AAc were grafted onto preirradiated PP and then AAm were grafted onto the PP-g-AAc membranes. Finally NMA were grafted onto PP-g-AAc/AAm membranes. In the different stages of grafting under different reaction conditions, trapped radicals in the membrane samples were probed by electron spin resonance (ESR). The temperature response behaviors of the IPN hydrogels were studied. Reversible behavior and controlled release of drug tests made reflecting the switching to on state at higher temperatures and to off state at lower temperatures were achieved. By increasing the grafted content of NMA, higher transition temperature of the hydrogel could be attained.

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Abstract  

In this paper, nine N,N,N,N-tetraalkyldiamides have been synthesized and the extracting ability for uranium and thorium under different conditions has been studied. All results were compared with those obtained by using tributyl phosphate (TBP) under exactly the same conditions. The extracting ability of thorium and uranium for different N,N,N,N-tetraalkyldiamides is discussed.

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Abstract  

The extracting abilities for thorium, uranium and some fission products by five sulfoxides are given. The results show that di(2-ethylhexyl) sulfoxide (DEHSO) is not only completely miscible with kerosene, but also superior to tri-n-butyl phosphate in some properties. The extraction behavior of uranium, thorium and some fission products such as zirconium, niobium and ruthenium from aqueous nitric acid with DEHSO in kerosene has been studied over a wide range of conditions. DEHSO extracted uranium and fission products better than TBP under all conditions and is similar to TBP in extraction of thorium. A study of extraction mechanism indicates that U and Th are extracted as disolvates, whereas HNO3 is extracted as monosolvate. Extraction of the two actinides decreases with increasing temperature, indicating the extraction to be exothermic. Preliminary studies show that -ray irradiated DEHSO extracts Zr and Nb to a smaller extent than irradiated TBP in the range of 104–107 rad.

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Abstract  

In this work, ten disubstituted amides have been synthesized and the extracting ability for U and Th fission products (mainly Zr, Nb and Ru) and the tendency of third phase formation have been studied. From the preliminary studies, two disubstituted amides, N-octylcaprolactam (OCLA) and N-(2-ethyl) hexylcaprolactam (EHCLA) were chosen for further studies. All studies were compared with those obtained by using TBP under exactly the same conditions. The dependence of aqueous nitric acid concentration, extractant concentration, temperature, -ray irradiation on extraction of Th, U and some fission products were studied. Back extraction of Th and U from organic phases and third phase formation were also studied. The studies of the reaction mechanism indicate that Th and U are extracted as disolvates, whereas HNO3 is extracted as monosolvate. Extraction distribution of Th and U decrease with increase of temperature, indicating the extraction reaction to be exothermic. Preliminary studies show that OCLA and EHCLA have better -irradiation stabilities compared with TBP.

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