Advanced Materials Research Vols. 236-238

Abstract: This text adopted the thin film method to prepare the vitamin E liposomes, the influence of proportion of components in vitamin E liposomes, and experiment condition on the envelopment rate were studied. The results showed that the optimum condition of the making technology of the vitamin E liposomes was:temperature42°C,m(vitamin E):m(lecithin)=1:25,m(vitamin E) :m(the cholesterol )=1:3, m(vitamin E) :m(the octadecylamine )=5:1, the phosphate buffer solution was 20 ml. In this case, the entrapment efficiency of the vitamin E liposomes was 76% .This method was accurate, and applicable for the preparation of vitamin E liposomes, and the property of it was very stable.

Abstract: Mn doped ZnS nanowires with typical wurtzite single-crystalline structure were successfully synthesized via H₂ assistant chemical evaporation deposition method. The investigations indicated that the diameter of Mn/ZnS Nanowire with high aspect ratio is 25~40nm, EDS results show that the content of Mn element is about 4.45at%. HRTEM and SAED results demonstrated that the Mn/ZnS nanowires grow along [101] direction, which was different from the common direction reported in literatures. Room temperature photoluminescence properties were also examined, showing a strong green emission centered at 523.04 nm, and a weak emission at 382.53 nm was also observed, showing a red shift of 45.53 nm comparing to the intrinsic luminescence.

Abstract: Hyperbranched polyesters, poly(4-hydroxycinnamic acid-co-3, 4-dihydroxycinnamic acid) [P(4HCA-co-DHCA)], were synthesized by the heat-transesterification of bio-based monomers 4HCA and DHCA. The P(4HCA-co-DHCA) nanoparticles were formed after two homogeneous copolymer solutions were mixed in DMF and TFA solutions, which are both good solvents for the copolymer P(4HCA-co-DHCA). For the potential application of the nanoparticles composed of cinnamic acid derivatives, water-dispersible nanoparticles were prepared by introduction of Pluronic F127 into the P(4HCA-co-DHCA) nanoparticles. The photo-reactivities of the nanoparticles were investigated.

Abstract: In order to improve water-resistant ability silk fibroin (SF) and SF/P(LLA-CL) blended nanofibrous scaffolds for tissue engineering applications, methanol vapor were used to treat electrospun nanofibers. SEM indicated SF and SF/ P(LLA-CL) scaffolds maintained nanofibrous structure after treated with methanol vapor and possessed good water-resistant ability. Characterization of ¹³C NMR clarified methanol vapor induced SF conformation from random coil or α- helix to β-sheet. Moreover, treated SF/ P (LLA-CL) nanofibrous scaffolds still kept good mechanical properties. Methanol vapor could be ideal method to treat SF and SF/ P(LLA-CL) nanofibrous scaffolds for biomedical applications.

Abstract: We have developed a theoretical method to obtain a single-walled carbon nanotube (SWCNT) with a high density of topological defects. Carbon nanotubes (CNTs) sustain elastic elongation up to 15-30% at low temperature because of the sufficiently high barrier of bond rotations. A large number of topological defects are activated simultaneously and widely distributed over the entire tube wall after heating the stretched tube to an elevated temperature. This is driven by the internal energy of the strained carbon nanotubes. The manner in which topological defects are distributed is affected by the initial strain and the heating temperature. Nanotubes with a large number of topological defects achieve the elongation without breaking.

Abstract: The pH-shifting treatment (including acid treatment and alkali treatment) caused partly denaturation and degrading of myofibril. The pH-shifting treatment increased the surface hydrophobicity, surface -SH content and total -SH content, reduced the Ca-ATPase activity. Acid treated myofibril (ACM) did not show any endothermic transition peak in differential scanning calorimetry (DSC); while alkali treated myofibril (AKM) showed reduced T _max value for myosin and actin. The SDS-PAGE indicated that acid treatment caused severe degrading of myosin heavy chain. High turbidity of ACM indicated more myofibril aggregated during acid treatment. The final G’ was in the decline order of M (550 Pa), AKM (135 Pa), and ACM (25 Pa). In conclusion, the alkali treatment was milder than the acid treatment.

Abstract: A method for simultaneous determination of trace levels of Cd(II), Cu(II), Pb(II) and Zn(II) in food additives by inductively coupled plasma atomic emission spectrometry ( ICP–AES ) after soluble membrane filter pre-concentration was developed. Based on collection of the chelates of metal ions(II) with 2-(5-bromo-2-pyridylazo)-5- diethylaminophenol ( 5-Br-PADAP ) on soluble membrane filter, the analyte ions were pre-concentrated and separated from sample matrix solutions. Multi-channel membrane filter device and soluble mixed cellulose ester membrane were selected. Analytical parameters such as pH, amount of 5-Br-PADAP, sample volume, etc. were optimized. Under the matrix of Na⁺, K⁺ and Mg²⁺, the limits of detection were 0.02 – 0.03, 0.14 – 0.23, 0.31 – 0.53, 0.10 – 0.15 μg L^-1 for Cd(II), Cu(II), Pb(II) and Zn(II) respectively. The developed method was successfully applied to sodium benzoate, potassium sorbate and basic magnesium carbonate with spiked recoveries of 94% – 115%. Some sample analysis results were checked by inductively coupled plasma mass spectrometry ( ICP–MS ) directly.

Abstract: C₃₂H₄₅N₂O₈Cl₂Cu Monoclinic, P2/1, a = 10.665(2)Å, b = 12.4197(2)Å, c = 12.1995(3)Å, α = 90.00°, β = 90.201(1) ^o, γ = 90.00 ^o, V = 1615.96(6)ų, Z = 2, R_gt(F) = 0.028, wR_ref(F²) = 0.083, T = 153K.

Abstract: In this study, the microcapsule was prepared by emulsion crosslinking method, using trisodium trimetaphosphate (TSTP) as crosslinking agent. The microcapsule was named OMA-MPs because the mixture of Octenyl succinic starch ester(OSA-starch)，maltodextrin starch and arabic gum were used as raw material. Orthogonal experiment was used in this work to find the relationship between the small diameter of OMA - MPs and preparation factors. The better condition is that the small diameter of OMA-MPs technique was that the stirring rate 400 rpm, the materials concentration 15%, the crosslinking agent concentration 1%, and the volume ratios(w₂/w₁) 120:100. Due to the processing route without the use of toxic organic solvents, it is expected that these microparticles can be used as delivery vehicles for controlled release of food and drug.

Abstract: The extraction of flavonoids from peony leaves was studied recently. We carried out a research on the optimum technology of extracting flavonoids by single and orthogonal factor experiment. Finally we found the optimum conditions were: the ultrasonic temperature is 60 degrees, the ultrasonic time is 20min, the ultrasonic power is 600w, solid-liquid ratio is 1:25. Under this condition, the yield of flavonoids was 1.47% and the content was 8.34%.