Advanced Materials Research Vols. 236-238

Abstract: To find out the penetration of PF into the wood cell wall and its effects onthe mechanical properties in the cellular level, the elastic modulus and hardness of secondary wall (S₂ layer) and compound corner middle lamella (CCML) near PF bond line region were determined by nanoindentation. Compare to the reference cell walls (unaffected by PF), PF penetration into the wood tissues showed improved elastic modulus and hardness. And the mechanical properties decreased slowly with the increasing the distance from the bond line, which are attributed to the effects of PF penetration into S₂ layer and CCML. The reduced elastic modulus variations were from18.8 to 14.4 GPa for S₂ layer, and from10.1 to 7.65 GPa for CCML. The hardness was from 0.67 to 0.52 GPa for S₂ layer, and from 0.65 to 0.52 GPa for CCML. In each test viewpoint place, the average hardness of CCML was almost as high as that of S₂ layer, but the reduced elastic modulus was about 50% less than that of S₂ layer. But the increase ratio of mechanical properties was close. All the results showed PF penetrates into the CCML. The penetration behavior and penetration depth from bond line were similar in both S₂ layer and CCML.

Abstract: Geniposidic acid is hydrolyzed to produce genipinic acid by the co-immobilized enzyme,and the type of amino acids which react with genipinic acid to produce gardenia red pigment and some reaction conditions are optimized,we also studied on the methods of purifying gardenia red pigment by macroporous resin. Optimized conditions are: pH of reaction solution of genipinic acid and amino acid is 4.0, the temperature is 40 °C, reaction time is 42 hr, glutamic acid is better for producing gardenia red pigment than other amino acids, molar ratio of glutamic acid and genipinic acid is 2:1,molar ratio of citric acid and genipinic acid is 6:1.Gardenia red pigment is adsorbed by HPD100 macroporous resin,then elute by ammonia water of pH 11, the eluent is dried under 50°C,the violet black powder is obtained,it’s color value can reach 92.32 (E^1%_1cm,528nm). To prepare gardenia red pigment from geniposidic acid by the co-immobilized enzyme has advantages of low cost, environmental friendly and easy to mass production.

Abstract: In-situ surface modificated nano-zinc oxide was prepared in sol-gel method and the microscopic structure of the zinc oxide particles was analyzed by transmission electron microscopy (TEM). The influence of the nano-zinc oxide on the physical properties of NR vulcanizates was investigated, and the vulcanizates heat-resistant oxygen aging property was studied by the hot air accelerated aging method. Therefore, not only can the strength and elongation properties of vulcanizates greatly be improved, but aslo the heat oxygen aging property of vulcanizate rubber was extremely promoted.

Abstract: The influences of jet flow rate and temperature on cathodic polarization of nickel deposits have been studied in this paper. The results indicate that increasing jet flow rate and temperature of the electrolyte make the equilibrium electrode potential decrease. When jet flow rate increases from 1.0 L/min to 6.0 L/min, the grain size of nickel deposits decreases from 22.6 nm to 18.9 nm. X-ray diffraction patterns show that increasing jet flow rate results in (111) preferred growth orientation for nickel deposits.

Abstract: By means of aqueous solution polymerization method, the composites of polyacrylic acid (PAA)/Bacterial cellulose (BC)/Na-MMT and PAA/Na-MMT were prepared respectively. The effects of Na-MMT content on the properties of PAA/Na-MMT and BC content on the properties of PAA/BC/Na-MMT composites were investigated. The results show that with appropriate increasing Na-MMT, the composites has good salt-resistant ability and thermal stability, mean while, the water-absorbing capacity of PAA/Na-MMT composites is significantly increased. Comparing with that of the PAA/Na-MMT hydrogel, with addition of BC content, the water-absorbing capacity and thermal stability of PAA/BC/Na-MMT are enhanced in a certain degree. The SEM analysis indicate that there are more network structure in the composites hydrogel. XRD result shows that the layered structure of Na-MMT is stripped and the prepared composites achieves peel compound.

Abstract: Polyethylene Glycol Oleate was synthesized by esterification of polyethylene glycol and Oil acid using DMAP as a catalyst. The double bonds of the product in the core of micelles were cross-linked by the initiation of (NH₄)₂S₂O₈ during the micelles formed. Applications of the noncross-linked and cross-linked polyethylene glycol oleate in drug delivery were studied, which indicates that drug efficiency decreased after micelles were core cross-linked, but release rate of MTX from core cross-linked micelles seems slower than that from noncross-linked micelles.

Abstract: In the present study, we report the preparation of silver nanocrystals encapsulated in mesoporous silica nanoparticles (Ag-MSN) with increased stability and enhanced anti-bacterial potency. The morphology of the nanoparticles was characterized by scanning electron microscopy and transmission electron microscopy. X-ray diffraction analyses proved that the silver nanocrystals were truly embedded in the mesoporous silica nanoparticles. The antibacterial effect of silver nanoparticles was proved by plate count method and bacterial growth curve. Moreover, the marine bacterium V. natriegens showed weak attachment to the aluminum coated with Ag -MSN. The mechanism of reducing microbiological adhesion was also discussed.

Abstract: Two series of novel organotin retinoates were synthesized by the reaction of di-n-butyltin oxide with corresponding retinoids in 1: 2 (3a~3d) and 1: 1 (4a~4d) molar ratio. These organotin retinoates were characterized by (¹H, ¹³C, ¹¹⁹Sn) NMR, MS and IR and they presented two type of different structures. The results of their biological activity in Hela, LCC, A549, T9 cancer cell showed that all of them exhibited better anticancer activity.

Abstract: A new chitosan derivate (CMC-g-RA) was prepared by grafting ricinoleic acid anhydride (RA) on carboxymethy chitosan (CMC) molecules. The reaction factors such as molecular weight, mole ratio of anhydride to amino, temperature and solvent were examined. Nanoparticles were obtained by blending botanical insecticide capsaicin (Cap) and CMC-g-RA. Surface shape, particle size, polydispersity index, surface charge, LE and stability of Cap/CMC-g-RA nanoparticles were characterized. The results showed that lower molecular weight was of advantage to higher degree of RA substitution. CMC-g-RA and Cap formed drug delivery nanoparticles with spherical shape and negative surface charge in water. The increased concentration of drug or carrier resulted in higher zeta potential and narrower polydispersity index (PDI) of Cap/CMC-g-RA. The loading efficiency (LE) of nanoparticles was up to 0.86, which provided efficiently protection for Cap, extended drug releasing period and dosage.

Abstract: In order to study Antibacterial properties of nanometer TiO₂ thin films, nanometer M³⁺-TiO₂ films have been prepared on glass by RF magnetron co-sputtering method. The films were characterized by SEM, XRD, and AFM. The influence of Fe, Sb elements and calcination temperature on the films structure was investigated. The bactericidal activity for the bacteria cells was estimated by relative number of bacteria survived calculated from the number of viable cells which from colonies on the nutrient agar plates. The nanometer M³⁺-TiO₂ thin films exhibited a high antibacterial activity, which was enhanced with the increase of the temperature of thermal treatment and formation of anatase crystalline structure.