Advanced Materials Research Vols. 415-417

Abstract: Gelatin microspheres (GMSs) were prepared by the inverse suspension cross-linking reaction, using glutaraldehyde as the cross-linking reagent. The GMSs was characterised by scanning electron microscopy and laser particle size analyzer. The effects of various experimental parameters, such as pH, temperature, adsorbent dosage and contact time were investigated in a batch-adsorption technique. The optimum conditions for removal of the cationic red X-GRL (CRX) dye were found to be pH 9, temperature 40 °C, 0.9 g/L of adsorbent dosage and adsorption time of 120 min, respectively. The adsorption capacity increased from 402.16 to 510.82 mg/g with the increase of stirring rate from10 to 300 rpm and decreased from 479.35 to 412.54 mg/g with the increase of sodium sulphate concentration from 0 to 8 g/L. The biomass GMSs had a substantial potential for removing cationic dye from wastewater owing to great adsorption capacity and adsorption rate to dye.

Abstract: Solid phase extraction (SPE) is a sample pretreatment technique which is increasingly popular and widely used. However, most of the traditional SPE material has poor selectivity. Molecular imprinting is an emerging technology for the preparation of functionalized materials with molecular recognition ability. Using the imprinted polymers as new sorbent, a molecularly imprinted on-line solid phase extraction coupled with chromatography or other techniques has become one of the most interesting applications of MIP, which has not only the extraction efficiency of SPE but also the high selectivity of imprinted polymers. This paper focuses on the recent states, advantages and outlooks of molecularly imprinted on-line solid phase extraction in sample pretreatment. This mini review may promote the extensive application of MIP in food safety.

Abstract: A new synthesis method namely hydrolysis precipitation was used to prepare Zn₃(PO₄)₂•4H₂O. Structural characteristics of products were investigated by X-ray Diffraction, scanning electron microscope and chemical analysis. The electrochemical corrosion inhibitions of title zinc phosphate were studied by electrochemical impedance of coating immersion test. The results show that the obtained product is a highly crystalline, micronized and lamellar Zn₃(PO₄)₂•4H₂O. Comparing with commercial zinc phosphate, the synthesized lamellar microcrystalline product has excellent anticorrosive property and dispersibility.

Abstract: When the articular cartilage defect accompanies with the subchondral bone defect, using bilayer scaffolds which can integrate with surrounding host cartilage and bone tissue respectively as the tissue engineering scaffolds will be conducive to the repair of tissue defects. This paper reports a new method for preparing bilayer scaffolds. Firstly, hydroxyapatite (HA)/silk fibroin(SF) composite porous materials which have high porosity were prepared by a isostatic compaction molding method, then it was fully immersed in silk fibroin solution, and finally SF/HA bilayer scaffolds were obtained by freeze-drying. The structure of the bilayer scaffolds were investigated through scanning electron microscopy, X-ray diffraction, Fourier transform-infrared spectroscopy, electron excitation spectroscopy and electron microprobe. The results indicated that the upper layer of SF/HA bilayer scaffolds is porous SF component, the under layer is the porous HA/SF composite component and the interface of the two layer is closely connected. Furthermore, mesenchymal stem cells from mouse bone marrow were seeded into the bilayer scaffolds and the results showed that the cells had a well adhesion and growth after culturing for 3 days.

Abstract: Electron beam radiation effects of PET have been investigated. Microstructural changes in poly(ethylene terephthalate) subjected to electron beam irradiation at doses of 50kGy, 100kGy, 200kGy, 400kGy were investigated by Attenuated total reflectance infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD) , Atomic force microscopy (AFM) and scanning electron microscopy (SEM). Irradiated samples showed a increase of crystallinity with a minimum at 200kGy, which is attributed to secondary crystal and then an decrease at further doses due to some degradation effect. The chemical structure and surface topography has only a slight change with irradiation.

Abstract: Curcumin is a kind of compound with various biological activities. However, curcumin suffers from low aqueous solubility, instability and poor bioavailability in vivo, which restrained it from clinical application. In this paper, novel water soluble curcumin prodrug monomer was synthesized by reacting curcumin with methacryloyl polyethylene glycol (MA-PEG), and succinic anhydride. IR, MS and 1H NMR spectroscopy were carried out to verify the products. We studied and modified the reaction conditions. The drug load rate of the monomer was 26.9%, which was 2-4-fold than previous report, and the solubility of it could be increased to 1.17g/L, which was about 150 times higher than previous report. The monomer is used to prepare comb-like polymer prodrugs.

Abstract: Fluorescent dyes based on 3-(2'-benzothiazolyl)coumarin were synthesized by a simple condensing reaction in this study. The chemical structures of synthesized compounds were subjected to FT-IR, 1H-NMR, Mass and UV/Vis analysis for color characteristics. Polyester fabrics dyed with the compounds were evaluated by color strength and color fastness to washing, perspiration and light of ISO. The results showed that all dyes decide after identified by IR, MS and ¹H-NMR the structure is correct. And then all dyes were used to the dyeing of polyester fabrics. It was clearly that color strength increased with the increasing of the amount of carbon in the 7-position of coumarin ring. The level of color fastness to washing and perspiration were 4-5 or more, while the level of color fastness to light decreased with an increase of carbon chain length.

Abstract: A series of organofunctional long-chain alkylfunctional silanes have been synthesized for the purpose of derivatization of micro- and nanoparticles and generation of molecular monolayers and films on the substrates. 11-bromoundecylsilane and 1, 10-disiladecane are evaluated to interact with a variety of clean hydrogenated metal and metalloid including titanium, silicon and silicon dioxide. The surface of those treated substrates has been analyzed by X-ray photoelectron spectroscopy (XPS) and reflection-absorption infrared spectroscopy (RAIRS). Our preliminary results indicate that self-assembled monolayer has been well formed on titanium metal and silicon wafer, minimally on silicon-dioxide. The discussion of experimental results is also provided.

Abstract: To eliminate thermal stress during laser cladding and to raise the bonding strength between substrate and coating, composition gradient coatings are designed and fabricated by using wide-band laser cladding technique on a Ti alloy. The rare earth Nd₂O₃ was added to improve the properties of the bioceramic coating. The experimental results indicate that when the adding of Nd₂O₃ reaches 0.6wt%, the characteristic peaks of HA and β-TCP are the highest, which demonstrates the amount of HA and β-TCP is the largest. However, when the content of Nd₂O₃ is up to 0.8wt%, the peaks of HA and β-TCP conversely goes down. The biocompatibility and bioactivity are related to the amount of HA and β-TCP catalyzed by Nd₂O₃. When the content of Nd₂O₃ is 0.6wt%, the number of cells proliferated and the ALP secreted on coatings is the most, which indicate the biocompatibility and bioactivity of gradient bioceramic coating is the best.

Abstract: High pressure electrostatic (HPE) was applied to prepare microcapsules, and the operation parameters of HPE were investigated in this paper. When ecletrocity voltage is 20 kV and the distance between two electrodes is 5 cm, the diameter of micro-beads can be around 500 μm that is the optimal diameter for dispersing in water. The release rate of BSA was coming up to 45% after 120 min in AGF and even to 89% after 240 min in AIF at 37°C to basically meet the release in full. The amount of bacteria in 2% (w/v) Na-alginate microparticles declined to 4.08 log cfu per ml which is 4 times more than that of free bifidobacteria after 120 min in AGF with incubation time by 5 log cycles.