Advanced Materials Research Vol. 506

Abstract: The borosilicate glasses doped with TiO₂ were prepared by the melt-quenching technique in compositions SiO₂B₂O₃CaO-Na₂O, and investigate their physical, optical and antibacterial properties. The result found that, after dope TiO₂, the density was decreased. The densities of glasses are not depending on TiO₂ concentration. The cutoff wavelength was shifted to longer wavelength with increasing of TiO₂ concentration from 360 nm (undoped TiO₂) to 395 nm at 7.5 % of TiO₂ concentration. The E. coli. was decreased due to TiO₂ generates reactive oxygen species from photocatalysis phenomena.

Abstract: soflavones, a special phenolic group found in soybean, have been found to act as antioxidant and are widely used in pharmaceutics and nutraceuticals. Due to the storage and handling problem, the extract has been prepared in dry form by spray drying technique. The condition of extract solution prior to spray drying has been reported to affect the property of dried powder. The aim of this work was to evaluate the effect of diluents on the physical properties of soybean extracted powder. The experiment was carried out by a Büchi B-290 Mini Spray Dryer. Four types of diluents were applied, they weremannitol, maltrodextrin, and 2 types of modified starch The comparison was then made among those with diluents and without diluent as a carrier. The physicochemical property was then characterized for flowability, moisture content, morphology, particle size and X-ray diffraction. From the results, the addition of all diluents could improve the physicochemical properties of soybean extracted powder indicating the improvement in morphology and hence the better flow property .The types of diluent also had the effect on the extracted powder. Maltodextrin and modified starch exhibited the best carrier in term of improvement of flow property. Therefore, the spray drying technique was successfully used to prepare microparticles of soybean extracted powder and by taking into consideration of the selection of suitable diluents, the good quality of soybean extracted powder could be achieved.

Abstract: Ketoprofen transdermal patches (KTPs) were fabricated using an acrylic pressure sensitive adhesive (PSA) polymer. The influence of different factors (amount of PSA, drug content, and pressure applying on the backing membrane during preparation) on the characteristics of ketoprofen patch (thickness, W/A ratio, and adhesiveness of matrix film) and in vitro drug release behavior were investigated. The results revealed the successful fabrication and a good physical appearance of KTPs using acrylic PSA. Microscopic observations, FTIR spectra, and DSC thermograms were permitted to demonstrate that the drug was dispersed molecularly in the polymer. As the amount of PSA in the adhesive matrix was increased, the release rate of ketoprofen was decreased. Contrarily, the drug release rate was increased corresponding to the increase of ketoprofen content in the adhesive matrix. There was no significant difference in the release rate when the pressure applying on the backing membrane was varied. The kinetic of ketoprofen release from acrylic matrix type transdermal patches followed the Higuchis diffusion model.

Abstract: The antimicrobial activities of propolis against some bacterial strains have been studied. However, there are few reports on biopolymers from propolis. Polycaprolactone (PCL) is a biodegradable polymer that has a long history of use in the biomedical field. In this work, the polymer nanofiber was grown from a Brazillian propolis extract solution on PCL using an electrospinning technique. Antimicrobial activities were investigated by the disc diffusion method. The propolis extract and polymer nanofiber could inhibit some human pathogenic bacteria. In addition, the inhibitory effects on tested microorganism depended on the concentration of propolis extract mixed with the polymer nanofiber. Such properties of the propolis/PCL nanofiners can be further developed for biomedical applications.

Abstract: Nanofibers are currently used in modern medicine. Various materials including biodegradable, non-degradable, and natural materials have been used to produce the novel nanofibers. Electrospinning technique enables the creation of continuous fibers with dimensions on the scale of nanometers from a wide range of natural and synthetic polymers. Our research was focused on producing nanofibers from the mixture polyvinylalcohol (PVA) and Thai honey by using the elecotrospinning method. The morphology of fibers was observed by SEM. Also, the biological properties (antibacterial and antioxidant properties) were described.

Abstract: The aim of this study was to determine the antimicrobial activities present in newly formulated propolis cream and compare them with an organic solvent extract of propolis. The antimicrobial activities were examined using the agar well diffusion method and measuring the growth inhibition zone. The skin pathogen gram-positive organisms used were Micrococcus luteus, Staphylococcus epidermidis, Streptococcus pyogenes, Methicillin resistant Staphylococcus aureus (MRSA), and Staphylococcus aureus. The propolis cream and extracts showed satisfactory inhibitory effects on the microbial growth.

Abstract: This research studied the effects of 4 types of additives, , wood powder, UV-absorber, impact modifier and pigment, on UV-stability of PVC/Wood-Pallet prepared by extrusion process. The amount of additive used was varied from 0 35 %w/w. The central composite design (CDD) was employed to experimentally design the formulation of PVC/Wood-Pallet, in order to practically reduce the total number of experiments from 625 pipes (Full factorial design for 4 factors and 5 levels) to 30 pipes without losing the credibility of the results achieved. The photodegradation of the PVC/Wood-Pallet was performed by an outdoor exposure test. The progress of photodegradation was followed by determining the changes in mechanical properties, physical properties and appearance, and thermal properties as a function of exposure time. The results showed that the PVC/Wood-Pallet No.30 had better mechanical properties than the others over period of exposure time. In addition, it was found that UV exposure could actually improve short-term mechanical properties due to postcuring phenomenon.

Abstract: Polydiacetylene (PDA) was used as a colorimetric indicator depended on temperature and time. This paper presents a new time-temperature indicator based on PDA vesicle and amphiphilic polymer. The 10,12-pentacosadiynoic acid (PCDA) was prepared with different concentration of Pluronic F127 which was varied from 0 to 4 % w/v, respectively. After that, there was obtained in different temperature (30-50°C) until clearly color change. This solution could gradually change from blue to red color which it could observe by UV-Vis spectrophotometer. The absorbance in each solution was reported at 640 and 540 nm, respectively, and then calculated by the color response (CR). In addition, the CR increased that directly related with temperature and time, when the concentration of F127 was constant. Also, the CR increased that directly related with temperature and concentration of F127, when time was constant. This method could have potential application as a new time-temperature indicator.

Abstract: Alkyd resins were cheap and can perform good properties depend on the modification. In this study, commercial alkyd resins were blended with various proportions of phthalic anhydride and oil on solid. The solvent system showed a clear single phase solution and a clear coat of binder. All the blends were applied on duplex paperboards. The evaluation of coat ability in terms of drying time, adhesion, glossiness, rub resistance, and physical appearance were investigated.

Abstract: The present studies are on the production and properties of particle boards produced from the giant sensitive plant using epoxy resin and urea formaldehyde as binder phases. The boards were made by applying pressure on the mixture of matrix and binder phases in the ratio of 1:2, 1:2.5 and 1:3 to form squared particle boards with the size of 20 cm and 0.6 cm thickness. The physical and mechanical properties of the samples such as density, bending test, tensile test and impact test were investigated. The results showed that the epoxy binder phase promote a good particle boards. The successfully of this study shown epoxy resin was feasibility to instead of the synthesis particle boards.