Lim C.K.,Universiti Sains Malaysia |
Halim A.S.,Universiti Sains Malaysia |
Zainol I.,Sultan Idris University of Education |
Noorsal K.,Advanced Materials Research Center Berhad
International Journal of Polymer Science | Year: 2011
Chitosan is a copolymer of N-acetylglucosamine and glucosamine. A bilayer chitosan porous skin regenerating template (CPSRT) has been developed for skin tissue engineering. The pore size of the CPSRT was assessed using a scanning electron microscopy (SEM). The in vitro cytocompatibility of the CPSRT was tested on primary human epidermal keratinocyte (pHEK) cultures by measuring lactate dehydrogenase (LDH) levels and skin irritation by western blot analysis of the interleukin-8 (IL-8) and tumor necrosis factor-α (TNF-α) secretions. The ability of the CPSRT to support cell ingrowth was evaluated by seeding primary human dermal fibroblasts (pHDFs) on the scaffold, staining the cells with live/dead stain, and imaging the construct by confocal microscopy (CLSM). The CPSRT with pore sizes ranging from 50 to 150 μm was cytocompatible because it did not provoke the additional production of IL-8 and TNF-α by pHEK cultures. Cultured pHDFs were able to penetrate the CPSRT and had increased in number on day 14. In conclusion, the CPSRT serves as an ideal template for skin tissue engineering. Copyright © 2011 Chin Keong Lim et al.
Raju G.S.,Universiti Sains Malaysia |
Raju G.S.,Rubber Research Institute of Malaysia |
Haris M.R.H.M.,Universiti Sains Malaysia |
Azura A.R.,Universiti Sains Malaysia |
And 2 more authors.
Journal of Rubber Research | Year: 2013
This paper reports preparation, mechanical properties, water uptake and toluene absorbency of biocomposites comprising different loadings of chitosan CTS (5, 10, 15, 20 and 30 p.h.r.) into matrixes of ENR50 and LENR50 (high and low molecular weight epoxidised natural rubbers with epoxy content of about 50%, respectively). It is found that the increase in CTS loading increased cure torque, tensile strength and modulus at 100% but there was a decline in cure time and elongation at break for CTS-ENR50 biocomposites. Similar trends were observed for CTS-LENR50 biocomposites except for cure torque and tensile strength, with no significant changes upon increase in CTS loading. SEM micrographs of the tensile-fractured materials showed that at 15p.h.r. loading, for example, CTS underwent a breakout, indicating good interactions in the CTS-ENR50 biocomposites. TGA data revealed that thermal stability of both CTS-ENR50 and CTS-LENR50 biocomposites remained fairly close to that of their respective unloaded rubber matrix. Results of the water uptake study revealed that increase in CTS loading led to an increase in water uptake of CTS-LENR50 biocomposites, found to be considerably higher at every loading compared with that of CTS-ENR50 biocomposites. Results of the toluene absorbency study revealed that LENR50 is a superior sorbent for toluene compared to ENR50. However, increase in CTS loading led to a decrease in toluene absorbency of both CTS-LENR50 and CTS-ENR50 biocomposites.
Siow P.C.,National University of Malaysia |
Ghani J.A.,National University of Malaysia |
Talib R.J.,Advanced Materials Research Center Berhad |
Talib R.J.,University Technology of MARA |
And 2 more authors.
InterCeram: International Ceramic Review | Year: 2015
The properties of titanium carbonitride (TiCN) are a result of its composition, which can be adjusted by controlling the material's C-N ratio to a precise level. An experimental study was conducted to vary the composition and properties of TiCN. The substrate used for cathodic arc physical vapour deposition (CAPVD) was tungsten carbide (WC-6Co), which was prepared in-house by a powder metallurgy process. Pure titanium (Ti) was used as a cathode and source of Ti. Methane (CH4) and nitrogen (N2) gases were used as sources of C and N to form the Ti(C,N) coating applied in the CAPVD process. Tests showed that the composition and properties of Ti(C,N) were successfully varied by controlling the CH4-N2 ratio. The surface microhardness of coated carbide samples improved and the coefficient of friction declined as the carbon content incorporated within the Ti(C,N) coating increased.
Khairuldin M.I.,Advanced Materials Research Center Berhad |
Aziz N.M.A.,Advanced Materials Research Center Berhad |
Nashaain N.M.,Advanced Materials Research Center Berhad |
Wedianti S.,Advanced Materials Research Center Berhad |
And 4 more authors.
Advanced Materials Research | Year: 2014
Low-Density Polyethylene (LDPE) films doped with Eu(TTA) 3phen complex (TTA=2- thenoyltrifluoroacetone, phen=1,10-phenanthroline) were fabricated by hot-blowing technique for thickness of 100 μm. The films were doped with 0.1% of Eu(TTA) 3phen to the total weight of LDPE and exposed to UV irradiation from deuterium lamp for 5, 10, 20, 40 and 60 hours to investigate the effect of its optical properties. The films were characterized by Spectrofluorometer, UV/VIS Spectrophotometer and FT-IR Spectrometer to measure their emission spectra, lifetimes, transmission transparency and chemical bonding. Photoluminescence of the room-temperature Eu(TTA) 3phen doped films consist of typical Eu3+ emission transition lines with hypersensitive 5D0 → 7F2 emission band at 610 nm. After 20 hours UV treatment, the peak intensity dropped by 90% and shortened the luminescent lifetimes from 0.654 ms to 0.305 ms. Longer UV treatment also has accelerated degradation in doped LDPE films shown by significant reducing in absorption peak of FTIR at 3395, 3186 and 1645 cm-1. The results would provide a mechanism to improve the lifetime of the LDPE by utilizing the light-manipulation property of Eu(TTA) 3phen complex to absorb UV spectrum and covert into red emission. © (2014) Trans Tech Publications, Switzerland.
Othman A.R.,Universiti Sains Malaysia |
Sardarinejad A.,Universiti Sains Malaysia |
Masrom A.K.,Advanced Materials Research Center Berhad
International Journal of Advanced Manufacturing Technology | Year: 2014
The solid-state interfacial state of aluminum powders was investigated upon inert gas, ball number and size, milling time, speed, and processing control agent (PCA) under high energy planetary mechanical alloying in sub-micron scale. The study observed significant variations in morphology of the milled powders at different milling parameters due to the fracturing and cold welding mechanisms. The uses of different ball numbers and sizes, and with higher rotating speed have resulted in further agglomeration. However, the adding of methanol as the PCA has provided the effective fracture mechanisms, by modifying the surface properties of the deforming particles to overcome the cold welding, hence reducing the particle sizes and changing the morphological shape to granular structures. The milling parameters have been proposed to also include 100 stainless steel balls with 10 mm in diameter, 200 rpm rotational speed, performed under the argon gas for 30 h to effectively produce finer particles and homogeneity in the particle distribution for future sintering process. © 2014, Springer-Verlag London.