Displaying publications 81 - 100 of 242 in total

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  1. Fulltext Synthesis of polymeric nanogel via irradiation of inverse Micelles technique
    Yusof Hamzah, Naurah Mat Isa, Wan Md Zin Wan Yunus
    Pertanika Journal of Science & Technology, 2012;20(2):401-407.
    MyJurnal
    Covalently cross-linked nanogels were prepared via irradiation of inverse micelles that had been preparedfrom radiation crosslinkable polymer, water, oil and surfactant. A mixture of polymer, water, heptane andsodium dioctyl sulfosuccinate (AOT) at certain compositions forms inverse micelles with the size rangingfrom 2 to 8 nm. The hydrophilic head of the surfactant facilitates encapsulation of water soluble polymer.If the entrapped polymer is radiation crosslinkable, it is expected that upon irradiation, polymerizationshall take place in such small and confined space, leading to formation of nano-sized polymeric gel.Meanwhile, emulsion at 2 nm size was chosen for gamma irradiation process. The formation of thenano-sized discreet gel using irradiation of inverse micelles technique was proven at a dose as low as 5kGy to obtain nanogel sized ~ 95 nm.
    Matched MeSH terms: Polyethylene Glycols
  2. Fulltext Effect of abiotic stress on carotenoids accumulation in pumpkin plants under light and dark conditions
    Norshazila, S., Othman, R., Jaswir, I., Yumi Zuhanis, H.H.
    International Food Research Journal, 2017;24(101):0-0.
    MyJurnal
    In nature, environmental factors highly influence the carotenoid composition in pumpkin plants and these factors were difficult to control; thus, carotenoid content is varied quantitatively and qualitatively. However, certain parameters can be controlled and this can be conducted in the laboratory through biogenesis manipulation. This approach uses environmental stress as a tool to alter the carotenoid pathway in the plants. The main objective of this study was to observe the inhibiting and enhancing effect of abiotic stress on individual carotenoid accumulation in pumpkin plants under light and dark conditions. The abiotic stresses used were plant elicitors which consisted of Ultra Violet light exposure, Polyethylene Glycol 4000, Salicylic Acid, and half strength nutrients using Murashige and Skoog Salt. After two weeks of treatments, the pumpkin leaves and stems were harvested, freeze dried and extracted to determine the carotenoids compound using High-Performance Liquid Chromatography (HPLC). Results showed that there was a significant difference (p
    Matched MeSH terms: Polyethylene Glycols
  3. Fulltext Effect of PEG on the biodegradability studies of Kenaf cellulose -polyethylene composites
    Behjat, T., Russly, A.R., Luqman, C.A., Yus, A.Y., Nor Azowa, I.
    International Food Research Journal, 2009;16(2):243-247.
    MyJurnal
    Several blends of cellulose derived from bast part of kenaf (Hibiscus cannabinus L.) plant, with different thermoplastics, low density polyethylene (LDPE) and high density polyethylene (HDPE), were prepared by a melt blending machine. Polyethylene glycol (PEG) was used as plasticizer. Biodegradability of these blends was measured using soil burial test in order to study the rates of biodegradation of these polymer blends. It was found that the cellulose/LDPE and cellulose/HDPE blends were biodegradable in a considerable rate. The bio-composites with high content of cellulose had higher degradation rate. In addition, biodegradability of the bio-composites made up using PEG was superior to those of the bio-composites fabricated without PEG, due to the improved wetting of the plasticizer in the matrix polymer. The results were also supported by the scanning electron microscopy (SEM).
    Matched MeSH terms: Polyethylene Glycols
  4. Fulltext Effect of exogenous emulsifier on growth performance, fat digestibility, apparent metabolisable energy in broiler chickens
    Tan, Hui San, Abdoreza Soleimani Farjam, Goh, Yong Meng, Idrus Zulkifli, Evi Croes, Sarathi Karmakar Partha, et al.
    Journal of Biochemistry, Microbiology and Biotechnology, 2016;4(1):7-10.
    MyJurnal
    This research was done to evaluate the effect of a commercial exogenous emulsifier
    (polyethylene glycol ricinoleate (PEGR)) with high hydrophilic-to-lipophilic balance (HLB)
    supplementation to broiler chicken diets on growth performance, digestibility of fat and
    apparent metabolisable energy (AME) content in week 1, 3 and 5. A total of 360 one-day-old
    male Cobb broiler chicks were assigned in groups of 30 to 12 battery cages. The chicks were
    randomly assigned to two dietary treatments, with 6 replicate cages per treatment. The diets
    were either standard broiler starter and finisher, with rice bran oil (RBO) as supplemented fat
    source or similar diets + 0.05% emulsifier (RBOV). Feed intakes of RBOV groups significantly
    increased compared to those of RBO groups from week 2 till 4 while body weights of RBOV
    diets significantly increased in week 4 and 5. Both RBOV and RBO groups had similar FCR
    except for week 5. Addition of this strongly hydrophilic emulsifier showed no significant
    difference in fat digestibility of both RC and RV groups but higher AME was noted for the
    treatment than for the control groups at week 5. Therefore, supplementing the exogenous
    emulsifier into a broiler diet enriched with rice bran oil improved body weight and AME
    content at week 5 with minimal effect on fat digestibility.
    Matched MeSH terms: Polyethylene Glycols
  5. Fulltext Hydrogel Fluorescence Microsensor with Fluorescence Recovery for Prolonged Stable Temperature Measurements
    Hashim H, Maruyama H, Akita Y, Arai F
    Sensors (Basel), 2019 Nov 29;19(23).
    PMID: 31795304 DOI: 10.3390/s19235247
    This work describes a hydrogel fluorescence microsensor for prolonged stable temperature measurements. Temperature measurement using microsensors has the potential to provide information about cells, tissues, and the culture environment, with optical measurement using a fluorescent dye being a promising microsensing approach. However, it is challenging to achieve stable measurements over prolonged periods with conventional measurement methods based on the fluorescence intensity of fluorescent dye because the excited fluorescent dye molecules are bleached by the exposure to light. The decrease in fluorescence intensity induced by photobleaching causes measurement errors. In this work, a photobleaching compensation method based on the diffusion of fluorescent dye inside a hydrogel microsensor is proposed. The factors that influence compensation in the hydrogel microsensor system are the interval time between measurements, material, concentration of photo initiator, and the composition of the fluorescence microsensor. These factors were evaluated by comparing a polystyrene fluorescence microsensor and a hydrogel fluorescence microsensor, both with diameters of 20 µm. The hydrogel fluorescence microsensor made from 9% poly (ethylene glycol) diacrylate (PEGDA) 575 and 2% photo initiator showed excellent fluorescence intensity stability after exposure (standard deviation of difference from initial fluorescence after 100 measurement repetitions: within 1%). The effect of microsensor size on the stability of the fluorescence intensity was also evaluated. The hydrogel fluorescence microsensors, with sizes greater than the measurement area determined by the axial resolution of the confocal microscope, showed a small decrease in fluorescence intensity, within 3%, after 900 measurement repetitions. The temperature of deionized water in a microchamber was measured for 5400 s using both a thermopile and the hydrogel fluorescence microsensor. The results showed that the maximum error and standard deviation of error between these two sensors were 0.5 °C and 0.3 °C, respectively, confirming the effectiveness of the proposed method.
    Matched MeSH terms: Polyethylene Glycols
  6. Comparison between Nucleate Pool Boiling Heat Transfer of Graphene Nanoplatelet- and Carbon Nanotube- Based Aqueous Nanofluids
    Akbari A, Mohammadian E, Alavi Fazel SA, Shanbedi M, Bahreini M, Heidari M, et al.
    ACS Omega, 2019 Nov 19;4(21):19183-19192.
    PMID: 31763542 DOI: 10.1021/acsomega.9b02474
    An increase of nucleate pool boiling with the use of different fluid properties has received much attention. In particular, the presence of nanostructures in fluids to enhance boiling was given special consideration. This study compares the effects of graphene nanoplatelet (GNP), functionalized GNP with polyethylene glycol (PEG), and multiwalled carbon nanotube (CNT) nanofluids on the pool boiling heat transfer coefficient and the critical heat flux (CHF). Our findings showed that at the same concentration, CHF for functionalized GNP with PEG (GNP-PEG)/deionized water (DW) nanofluids was higher in comparison with GNP- and CNT-based nanofluids. The CHF of the GNP/DW nanofluids was also higher than that of CNT/DW nanofluids. The CHF of GNP-PEG was 72% greater than that of DW at the concentration of 0.1 wt %. There is good agreement between measured critical heat fluxes and the Kandlikar correlation. In addition, the current results proved that the GNP-PEG/DW nanofluids are highly stable over 3 months at a concentration of 0.1 wt %.
    Matched MeSH terms: Polyethylene Glycols
  7. Optimization of injection molding and solvent debinding parameters of stainless steel powder (SS316L) based feedstock for metal injection molding
    MUHAMMAD ILMAN HAKIMI CHUA, ABU BAKAR SULONG, MOHD FAZURI ABDULLAH, NORHAMIDI MUHAMAD
    Sains Malaysiana, 2013;42:1743-1750.
    In this study, injection molding parameters, including green strength, surface quality and green part density, were optimized using the L18 Taguchi orthogonal array. The L25 Taguchi method was used to optimize the green density of solvent debinding parameters. The feedstock consisted of stainless steel powder (SS316L), with powder loading fractions of 63, 63.5 and 64 v/o. The binder compositions used in the study were polyethelene glycol (PEG-73 wt. %), polymethyl methacrilate (PMMA-25 wt. %) and stearic acid (2 wt. %). The Taguchi method was used to optimize the injection parameters. The obtained optimum parameters were as follows: mold temperature of 65oC, injection temperature of 145oC, injection pressure of 650 bar, injection flow rate of 20 m3/s, holding time of 5 s and powder loading of 64% v/o. Analysis of variance results showed that mold temperature has the greatest influence in the production of good green part surface quality and that powder loading gave the best green part strength. Immersion time and temperature were used to optimize for solvent debinding parameters. By optimizing the solvent debinding parameters, an immersion temperature of 61oC and immersion time of 5 h produced the highest density which is the optimum value gain in this study.
    Matched MeSH terms: Glycols
  8. Liquid biphasic flotation for the purification of C-phycocyanin from Spirulina platensis microalga
    Chew KW, Chia SR, Krishnamoorthy R, Tao Y, Chu DT, Show PL
    Bioresour Technol, 2019 Sep;288:121519.
    PMID: 31128541 DOI: 10.1016/j.biortech.2019.121519
    Liquid biphasic flotation (LBF), an integrated process of liquid biphasic system (LBS) and adsorptive bubbles flotation, was used for the purification of C-phycocyanin from S. platensis microalgae. Various experimental parameters such as type of phase forming polymer and salt, concentration of phase forming components, system pH, volume ratio, air flotation time and crude extract concentration were evaluated to maximise the C-phycocyanin recovery yield and purity. The optimal conditions for the LBF system achieving C-phycocyanin purification fold of 3.49 compared to 2.43 from the initial LBF conditions was in polyethylene glycol (PEG) 4000 and potassium phosphate combination, with 250 g/L of polymer and salt concentration each, volume ratio of 1:0.85, system pH of 7.0, air flotation duration of 7 min and phycocyanin crude extract concentration of 0.625 %w/w. The LBF has effectively enhanced the purification of C-phycocyanin in a cost effective and simple processing.
    Matched MeSH terms: Polyethylene Glycols
  9. UV-VIS spectral evaluation of CR-39 detector exposed with diagnostic dosage
    Nur Sha'dah Z, Iskandar S, Azhar A, Suhaimi M, Nur Lina R, Halimah M
    Sains Malaysiana, 2014;43:953-958.
    The effects of the X-ray irradiation and chemical etching on the physical and optical properties of cR-39 plastic detectors were investigated for different doses of X-ray. cR-39 detectors were etched in the solution of the 3 M of NaOH after irradiation for revelations of the track. The tracks formed on cR-39 either by irradiated X-ray or due to the effect of environment. The changes in the thickness after exposed have significant decrease in 60 kVp and started to increase in the range of 70 kVp up to 100 kVp due to the formation of oxidation layer on surface by free radicals. The optical band gaps before etching and after etching were determined by using Ultraviolet-visible (uv-Vis) spectroscopy. The optical band gap is attributed to the indirect transition due to its amorphous nature which is significantly decline trend energy in increase of the energy fluence of radiation. The Urbach's energy, is defined as the width of the tail localized states in the forbidden band gap which change increment trend as increase in dose delivered due to the distortion structure of the cR-39 in terms of the electron charges in valences electron hence attributes to the induced modification of angle bond between the neighboring atoms.
    Matched MeSH terms: Polyethylene Glycols
  10. Fulltext Nanocellulose Reinforced Thermoplastic Starch (TPS), Polylactic Acid (PLA), and Polybutylene Succinate (PBS) for Food Packaging Applications
    Nazrin A, Sapuan SM, Zuhri MYM, Ilyas RA, Syafiq R, Sherwani SFK
    Front Chem, 2020;8:213.
    PMID: 32351928 DOI: 10.3389/fchem.2020.00213
    Synthetic plastics are severely detrimental to the environment because non-biodegradable plastics do not degrade for hundreds of years. Nowadays, these plastics are very commonly used for food packaging. To overcome this problem, food packaging materials should be substituted with "green" or environmentally friendly materials, normally in the form of natural fiber reinforced biopolymer composites. Thermoplastic starch (TPS), polylactic acid (PLA) and polybutylene succinate (PBS) were chosen for the substitution, because of their availability, biodegradability, and good food contact properties. Plasticizer (glycerol) was used to modify the starch, such as TPS under a heating condition, which improved its processability. TPS films are sensitive to moisture and their mechanical properties are generally not suitable for food packaging if used alone, while PLA and PBS have a low oxygen barrier but good mechanical properties and processability. In general, TPS, PLA, and PBS need to be modified for food packaging requirements. Natural fibers are often incorporated as reinforcements into TPS, PLA, and PBS to overcome their weaknesses. Natural fibers are normally used in the form of fibers, fillers, celluloses, and nanocelluloses, but the focus of this paper is on nanocellulose. Nanocellulose reinforced polymer composites demonstrate an improvement in mechanical, barrier, and thermal properties. The addition of compatibilizer as a coupling agent promotes a fine dispersion of nanocelluloses in polymer. Additionally, nanocellulose and TPS are also mixed with PLA and PBS because they are costly, despite having commendable properties. Starch and natural fibers are utilized as fillers because they are abundant, cheap and biodegradable.
    Matched MeSH terms: Butylene Glycols
  11. Effect of short-chain alcohols on the physicochemical properties of d-phenothrin emulsions and their insecticidal activity against Aedes aegypti
    Mohsin SMN, Hasan ZAA
    Colloids Surf B Biointerfaces, 2023 Jan;221:113025.
    PMID: 36403417 DOI: 10.1016/j.colsurfb.2022.113025
    Oil-in-water (o/w) emulsion is utilized as an insecticide delivery system for mosquito control. However, evaporation inhibition adjuvant is needed to prevent fog drift, inhibit release of insecticidal actives and prolong suspension time. In the current study, we evaluated the effect of different short-chain alcohols, namely, propylene glycol, 1,3-propanediol, glycerol and crude glycerol, as adjuvants on the physicochemical properties of d-phenothrin o/w emulsion system. The bioactivity of optimized formulations containing 20 wt% glycerol (D1), 20 wt% propylene glycol (D2) and without added alcohol (negative control) were tested against larvae, pupae and adult Aedes aegypti (Ae. aegypti). It was found that propylene glycol produced smaller droplets at lower concentrations but poor long-term stability at higher concentrations, whereas glycerol had an appreciable effect on initial droplet size and stability with increasing concentration. According to the dose-response bioassays and room size chamber testing, the highest larvicidal, pupicidal and adulticidal activities were observed with D2, followed by D1 and negative control. Overall, the above study demonstrated improved emulsion stabilities and potency against Ae. aegypti larvae, pupae and adults using glycerol as adjuvant for effective mosquito control.
    Matched MeSH terms: Propylene Glycols
  12. Fulltext Crystallization of Electrodeposited Germanium Thin Film on Silicon (100)
    Abidin MSZ, Matsumura R, Anisuzzaman M, Park JH, Muta S, Mahmood MR, et al.
    Materials (Basel), 2013 Nov 06;6(11):5047-5057.
    PMID: 28788375 DOI: 10.3390/ma6115047
    We report the crystallization of electrodeposited germanium (Ge) thin films on n-silicon (Si) (100) by rapid melting process. The electrodeposition was carried out in germanium (IV) chloride: propylene glycol (GeCl₄:C₃H₈O₂) electrolyte with constant current of 50 mA for 30 min. The measured Raman spectra and electron backscattering diffraction (EBSD) images show that the as-deposited Ge thin film was amorphous. The crystallization of deposited Ge was achieved by rapid thermal annealing (RTA) at 980 °C for 1 s. The EBSD images confirm that the orientations of the annealed Ge are similar to that of the Si substrate. The highly intense peak of Raman spectra at 300 cm(-1) corresponding to Ge-Ge vibration mode was observed, indicating good crystal quality of Ge. An additional sub peak near to 390 cm(-1) corresponding to the Si-Ge vibration mode was also observed, indicating the Ge-Si mixing at Ge/Si interface. Auger electron spectroscopy (AES) reveals that the intermixing depth was around 60 nm. The calculated Si fraction from Raman spectra was found to be in good agreement with the value estimated from Ge-Si equilibrium phase diagram. The proposed technique is expected to be an effective way to crystallize Ge films for various device applications as well as to create strain at the Ge-Si interface for enhancement of mobility.
    Matched MeSH terms: Propylene Glycols
  13. Palm-Based Neopentyl Glycol Diester: A Potential Green Insulating Oil
    Raof NA, Yunus R, Rashid U, Azis N, Yaakub Z
    Protein Pept Lett, 2018;25(2):171-179.
    PMID: 29359647 DOI: 10.2174/0929866525666180122095056
    BACKGROUND: The transesterification of high oleic palm oil methyl ester (HOPME) with neopentyl glycol (NPG) has been investigated. The present study revealed the application of low-pressure technology as a new synthesis method to produce NPG diesters. Single variable optimization and response surface methodology (RSM) were implemented to optimize the experimental conditions to achieve the maximum composition (wt%) of NPG diesters.

    OBJECTIVE: The main objective of this study was to optimize the production of NPG diesters and to characterize the optimized esters with typical chemical, physical and electrical properties to study its potential as insulating oil.

    METHODS: The transesterification reaction between HOPME and NPG was conducted in a 1L three-neck flask reactor at specified temperature, pressure, molar ratio and catalyst concentration. For the optimization, four factors have been studied and the diester product was characterized by using gas chromatography (GC) analysis. The synthesized esters were then characterized with typical properties of transformer oil such as flash point, pour point, viscosity and breakdown voltage and were compared with mineral insulating oil and commercial NPG dioleate. For formulation, different samples of NPG diesters with different concentration of pour point depressant were prepared and each sample was tested for its pour point measurement.

    RESULTS: The optimum conditions inferred from the analyses were: molar ratio of HOPME to NPG of 2:1.3, temperature = 182°C, pressure = 0.6 mbar and catalyst concentration of 1.2%. The synthesized NPG diesters showed very important improvement in fire safety compared to mineral oil with flash point of 300°C and 155°C, respectively. NPG diesters also exhibit a relatively good viscosity of 21 cSt. The most striking observation to emerge from the data comparison with NPG diester was the breakdown voltage, which was higher than mineral oil and definitely in conformance to the IEC 61099 limit at 67.5 kV. The formulation of synthesized NPD diesters with VISCOPLEX® pour point depressant has successfully increased the pour point of NPG diester from -14°C to -48°C.

    CONCLUSION: The reaction time for the transesterification of HOPME with NPG to produce NPG diester was successfully reduced to 1 hour from the 14 hours required in the earlier synthesis method. The main highlight of this study was the excess reactant which is no longer methyl ester but the alcohol (NPG). The optimum reaction conditions for the synthesis were molar ratio of 2:1.13 for NPG:HOPME, 182°C, 0.6 mbar and catalyst concentration of 1.2 wt%. The maximum NPG diester yield of 87 wt% was consistent with the predicted yield of 87.7 wt% obtained from RSM. The synthesized diester exhibited better insulating properties than the commercial products especially with regards to the breakdown voltage, flash point and moisture content.

    Matched MeSH terms: Glycols
  14. Uranium concentration in blood samples of Southern Iraqi leukemia patients using CR-39 track detector
    Al-Hamzawi AA, Jaafar MS, Tawfiq NF
    J Radioanal Nucl Chem, 2013 11 05;299(3):1267-1272.
    PMID: 26224958
    The simple and effective technique of fission track etch has been applied to determine trace concentration of uranium in human blood samples taken from two groups of male and female participants: leukemia patients and healthy subjects group. The blood samples of leukemia patients and healthy subjects were collected from three key southern governorates namely, Basrah, Muthanna and Dhi-Qar. These governorates were the centers of intensive military activities during the 1991 and 2003 Gulf wars, and the discarded weapons are still lying around in these regions. CR-39 track detector was used for registration of induced fission tracks. The results show that the highest recorded uranium concentration in the blood samples of leukemia patients was 4.71 ppb (female, 45 years old, from Basrah) and the minimum concentration was 1.91 ppb (male, 3 years old, from Muthanna). For healthy group, the maximum uranium concentration was 2.15 ppb (female, 55 years old, from Basrah) and the minimum concentration was 0.86 ppb (male, 5 years old, from Dhi-Qar). It has been found that the uranium concentrations in human blood samples of leukemia patients are higher than those of the healthy group. These uranium concentrations in the leukemia patients group were significantly different (P 
    Matched MeSH terms: Polyethylene Glycols
  15. Degree of conversion and physicomechanical properties of newly developed flowable composite derived from rice husk using urethane dimethacrylate monomer
    Azlisham NAF, Johari Y, Mohamad D, Yhaya MF, Mahmood Z
    Proc Inst Mech Eng H, 2023 Dec;237(12):1339-1347.
    PMID: 38014749 DOI: 10.1177/09544119231208222
    This study evaluated the use of urethane dimethacrylate (UDMA) as a base monomer to prepare the newly developed flowable composite (FC) using nanohybrid silica derived from rice husk in comparison to bisphenol A-glycidyl methacrylate (Bis-GMA) on the degree of conversion and physicomechanical properties. The different loadings of base monomer to diluent monomer were used at the ratio of 40:60, 50:50, and 60:40. The bonding analysis confirmed the presence of nanohybrid silica in the newly developed FC. Independent t-test revealed a statistically significant increase in the degree of conversion, depth of cure and Vickers hardness of the UDMA-based FC, while surface roughness showed comparable results between the two base monomers. In conclusion, UDMA-based FC demonstrated superior performance with 60%-65% conversions, a significantly higher depth of cure exceeding 1 mm which complies with the Internal Standard of Organization 4049 (ISO 4049), and a substantial increase in Vickers hardness numbers compared to Bis-GMA-based FC, making UDMA a suitable alternative to Bis-GMA as a base monomer in the formulation of this newly developed FC derived from rice husk.
    Matched MeSH terms: Polyethylene Glycols
  16. Fulltext Ethnomedical Knowledge of Plants Used for the Treatment of Tuberculosis in Johor, Malaysia
    Sabran SF, Mohamed M, Abu Bakar MF
    Evid Based Complement Alternat Med, 2016;2016:2850845.
    PMID: 26881002 DOI: 10.1155/2016/2850845
    This study documented ethnomedical knowledge of plants used for the treatment of tuberculosis (TB) and its related symptoms as practiced by the Jakun community of Kampung Peta, situated in Endau Rompin Johor National Park, Johor, Malaysia. Eight key informants were selected by snowball sampling technique and data about medicinal plants were collected by semistructured interviews, participatory observations, and focus group. Qualitative analysis was undertaken using thematic analysis. There were 23 species of plants (22 genera, 20 families) documented and herbarium specimens were deposited at the UTHM Herbarium. Dipterocarpus sublamellatus was recorded for the first time with ethnomedical uses while other species were previously reported. The qualitative approach employed in this study demonstrates the emic perspective in terms of perceptions on traditional herbal medicine, transfer of knowledge, significant taboos related with medicinal plants, and their conservation efforts. Local and biomedical terminology in treatment of TB showed substantial correspondence. The outcomes obtained in the study are worth being further investigated for conservation strategies and are worthy of verifying their ethnomedical claims scientifically.
    Matched MeSH terms: Propylene Glycols
  17. Low-melting-point polymeric nanoshells for thermal-triggered drug release under hyperthermia condition
    Dabbagh A, Mahmoodian R, Abdullah BJ, Abdullah H, Hamdi M, Abu Kasim NH
    Int J Hyperthermia, 2015;31(8):920-9.
    PMID: 26670340 DOI: 10.3109/02656736.2015.1094147
    The aim of this paper was to synthesise core-shell nanostructures comprised of mesoporous silica core and a low melting-point polyethylene glycol (PEG) nanoshell with a sharp gel-liquid phase transition for rapid drug release at hyperthermia temperature range.
    Matched MeSH terms: Polyethylene Glycols/chemistry
  18. Production of γ-cyclodextrin by Bacillus cereus cyclodextrin glycosyltransferase using extractive bioconversion in polymer-salt aqueous two-phase system
    Lin YK, Show PL, Yap YJ, Ariff AB, Mohammad Annuar MS, Lai OM, et al.
    J Biosci Bioeng, 2016 Jun;121(6):692-696.
    PMID: 26702953 DOI: 10.1016/j.jbiosc.2015.11.001
    Aqueous two-phase system (ATPS) extractive bioconversion provides a technique which integrates bioconversion and purification into a single step process. Extractive bioconversion of gamma-cyclodextrin (γ-CD) from soluble starch with cyclodextrin glycosyltransferase (CGTase, EC 2.4.1.19) enzyme derived from Bacillus cereus was evaluated using polyethylene glycol (PEG)/potassium phosphate based on ATPS. The optimum condition was attained in the ATPS constituted of 30.0% (w/w) PEG 3000 g/mol and 7.0% (w/w) potassium phosphate. A γ-CD concentration of 1.60 mg/mL with a 19% concentration ratio was recovered after 1 h bioconversion process. The γ-CD was mainly partitioned to the top phase (YT=81.88%), with CGTase partitioning in the salt-rich bottom phase (KCGTase=0.51). Repetitive batch processes of extractive bioconversion were successfully recycled three times, indicating that this is an environmental friendly and a cost saving technique for γ-CD production and purification.
    Matched MeSH terms: Polyethylene Glycols/chemistry*
  19. Fulltext Palm oil derived trimethylolpropane triesters synthetic lubricants and usage in industrial metalworking fluid
    Chang TS, Yunus R, Rashid U, Choong TS, Awang Biak DR, Syam AM
    J Oleo Sci, 2015;64(2):143-51.
    PMID: 25748374 DOI: 10.5650/jos.ess14162
    Trimethylolpropane triesters are biodegradable synthetic lubricant base oil alternative to mineral oils, polyalphaolefins and diesters. These oils can be produced from trimethylolpropane (TMP) and fatty acid methyl esters via chemical or enzymatic catalyzed synthesis methods. In the present study, a commercial palm oil derived winter grade biodiesel (ME18) was evaluated as a viable and sustainable methyl ester source for the synthesis of high oleic trimethylolpropane triesters (HO-TMPTE). ME18 has fatty acid profile containing 86.8% oleic acid, 8.7% linoleic acid with the remaining minor concentration of palmitic acid, stearic acid and linolenic acid. It's high oleic property makes it superior to produce synthetic lubricant base oil that fulfills both the good low temperature property as well as good oxidative stability. The synthetic base oil produced had a viscosity of 44.3 mm(2)/s at 40°C meeting the needs for ISO 46 oils. It also exhibited an excellent viscosity index of 219 that is higher than some other commercial brands of trimethylolpropane trioleate. Properties of base oil such as cloud point, density, acid value, demulsibility and soap content were also examined. The oil was then used in the formulation of tapping oil and appraised in term of adaptability, stability and field test performance.
    Matched MeSH terms: Propylene Glycols/chemistry*
  20. Fulltext The influence of green surface modification of oil palm mesocarp fiber by superheated steam on the mechanical properties and dimensional stability of oil palm mesocarp fiber/poly(butylene succinate) biocomposite
    Then YY, Ibrahim NA, Zainuddin N, Ariffin H, Yunus WM, Chieng BW
    Int J Mol Sci, 2014;15(9):15344-57.
    PMID: 25177865 DOI: 10.3390/ijms150915344
    In this paper, superheated steam (SHS) was used as cost effective and green processing technique to modify oil palm mesocarp fiber (OPMF) for biocomposite applications. The purpose of this modification was to promote the adhesion between fiber and thermoplastic. The modification was carried out in a SHS oven at various temperature (200-230 °C) and time (30-120 min) under normal atmospheric pressure. The biocomposites from SHS-treated OPMFs and poly(butylene succinate) (PBS) at a weight ratio of 70:30 were prepared by melt blending technique. The mechanical properties and dimensional stability of the biocomposites were evaluated. This study showed that the SHS treatment increased the roughness of the fiber surface due to the removal of surface impurities and hemicellulose. The tensile, flexural and impact properties, as well as dimensional stability of the biocomposites were markedly enhanced by the presence of SHS-treated OPMF. Scanning electron microscopy analysis showed improvement of interfacial adhesion between PBS and SHS-treated OPMF. This work demonstrated that SHS could be used as an eco-friendly and sustainable processing method for modification of OPMF in biocomposite fabrication.
    Matched MeSH terms: Butylene Glycols/chemistry*
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