Papers by Keyword: Tween 20

Abstract: Nanoparticles' unique properties, such as their huge surface area, higher thermal conductivity, and increased dielectric strength, make them appealing candidates for high voltage insulation applications. The choice of a suitable surfactant is critical in the creation of nanofluids. The ratio of hydrophilic to lipophilic (HLB) values, which ratio up the hydrophilic and lipophilic structure of the surfactant, is normally considered in the selection of suitable surfactant for the nanofluid. Surfactant with HLB value less than 6 is said to be more suitable for oil base nanofluids. Recent research, however, indicated that the sediment generated by high and low HLB value surfactants is not significantly different. Tween 20 surfactant, while rarely used in this context due to its high HLB value, is an intriguing option due to its affordable cost and excellent properties. Its distinct features, such as low toxicity, and strong emulsification capacity, make it an appealing candidate for stabilizing and dispersing nanoparticles in nanofluid compositions. In this research, tween 20 was used in the preparation of palm oil (PO) and palm fatty acid ester oil (PFAE) based nanofluids. Iron (II,III) Oxide (Fe₃O₄) nanoparticle was introduced to the nanofluids at high, medium and low concentrations. The nanofluids were evaluated in terms of its breakdown strength and dielectric properties. The alternating current (AC) breakdown and dielectric properties were conducted based on the IEC 60156 and ASTM D924 Standard respectively. Tween 20 has positive impact on shortening down the sonication period by 10 % and 33.3 % for PO and PFAE based nanofluids, respectively, while elongating the sedimentation period for PO nanofluids. The breakdown voltage improved by 40% and 18% for PO based nanofluid and PFAE based nanofluid, respectively. Even at low concentrations, the inclusion of Fe₃O₄ nanoparticles improved breakdown strength, and breakdown voltage distributions offered useful information. The addition of nanoparticles slightly increases the relative permittivity of the base oils. Fe₃O₄ nanoparticle and tween 20 surfactant has successfully improved the dielectric loss of the base oil with the lowest value recorded at 0.05 g/L, with 72.4 % and 36.8 % improvement for PO and PFAE based nanofluids, respectively. These results proved that tween 20 is suitable for oil-based nanofluids applications.

Abstract: Clove oil is a volatile oil that is extracted from clove buds of Syzygium aromaticum. It was reported for antibacterial and antifungal activities. Microemulsions (ME) are a stable emulsion system composed of oil, surfactant mixture (SM, surfactant and co-surfactant) and water. In this study clove oil-loaded microemulsions (CM) were fabricated using Tween 20 as surfactant. Co-surfactants used in CM were ethanol and isopropanol. CM with different concentrations of clove oil (10-50% w/w) and SM (40-80% w/w) at Tween 20:co-surfactant ratios of 1:2 were formulated and characterized for their physico-chemical properties. All CM was clear liquid with thermodynamic stability. The size of all CM prepared from both ethanol and isopropanol was less than 100 nm. At lower oil and SM concentrations, the CM was o/w ME. When the concentration of oil or SM increased, the conductivity values decreased to less than 10 μS/cm indicating that the obtained CM was w/o ME. All CM formulations exhibited strong antioxidant activity as tested by the DPPH scavenging method (92.79 - 94.95% inhibition). Changing the type of co-surfactants (ethanol or isopropanol) or changing the oil to co-surfactant ratio did not significantly alter the antioxidant activity. Therefore, considering both physicochemical properties and antioxidant activity of CM, the CM containing 10% clove oil is the recommended formulation for commercial development.

Abstract: In biomineralization, self-organization of organic based templates provides scaffolding for the assembly of QDs materials. The host-guest relationship between these protein cages and the encapsulated material is based primarily on a complementary electrostatic interaction. Zinc selenide (ZnSe) were synthesized in the cavity of the apoferritin from horse spleen (HsAFr) and the reaction condition was optimized by adding tween 20 to avoid ferritin agglomeration. The obtained nanodots were characterized by TEM, and absorption measurements. In addition, the protein concentration of ZnSe-ferritin was precisely measured by the Bradford protein assay method. From the results, it was concluded that the ZnSe nanocrystals were successfully synthesized in the core of ferritin and it can be applied as a potential functional material such as transistors, biosensor materials or medical imaging.