Characterization of Microemulsions Prepared using Isopropyl Palmitate with various Surfactants and Cosurfactants

Purpose: To investigate the effect of various surfactants and  cosurfactants, and their ratio on microemulsions prepared with isopropyl palmitate (IPP)Methods: Tween 20, 40, 60, and 80 were used separately as surfactant with methanol, ethanol, 1-propanol, 1-butanol or 1-pentanol as cosurfactant, and IPP as oil phase to prepare various microemulsions. Various surfactant to cosurfactant ratios (1:1, 2:1, 3:1, 4:1, and 1:0) were used in the preparation. Pseudoternary phase diagram was used to define the microemulsion area, and samples from the best combinations, i.e., those that produced the largest volume of microemulsion, were subjected to further characterization by polarized light microscopy, differential scanning calorimetry (DSC), zetasizer, rheometer, and for stability.Results: Based on the microemulsion areas produced in the pseudoternary phase diagrams, the the surfactants were ranked in the following order of effectiveness: Tween 80 > 60 > 40 > 20 while the alcohols (co-surfactants) were ranked as follows: 1-butanol > 1-pentanol > 1-propanol > ethanol =methanol. The best surfactant to cosurfactant ratio for microemulsion preparation was 3:1.Conclusion: The selected surfactant/co-surfactant combination (i.e., Tween 80:1-butanol, 3:1) produces a stable microemulsion possesses a good potential as a drug delivery system Keywords: Microemulsion, Palm oil, Thermal analysis, Tween 80, Alcoho

Characterization of Microemulsions Prepared using Isopropyl Palmitate with various Surfactants and Cosurfactants

Purpose: To investigate the effect of various surfactants and  cosurfactants, and their ratio on microemulsions prepared with isopropyl palmitate (IPP)Methods: Tween 20, 40, 60, and 80 were used separately as surfactant with methanol, ethanol, 1-propanol, 1-butanol or 1-pentanol as cosurfactant, and IPP as oil phase to prepare various microemulsions. Various surfactant to cosurfactant ratios (1:1, 2:1, 3:1, 4:1, and 1:0) were used in the preparation. Pseudoternary phase diagram was used to define the microemulsion area, and samples from the best combinations, i.e., those that produced the largest volume of microemulsion, were subjected to further characterization by polarized light microscopy, differential scanning calorimetry (DSC), zetasizer, rheometer, and for stability.Results: Based on the microemulsion areas produced in the pseudoternary phase diagrams, the the surfactants were ranked in the following order of effectiveness: Tween 80 > 60 > 40 > 20 while the alcohols (co-surfactants) were ranked as follows: 1-butanol > 1-pentanol > 1-propanol > ethanol =methanol. The best surfactant to cosurfactant ratio for microemulsion preparation was 3:1.Conclusion: The selected surfactant/co-surfactant combination (i.e., Tween 80:1-butanol, 3:1) produces a stable microemulsion possesses a good potential as a drug delivery system Keywords: Microemulsion, Palm oil, Thermal analysis, Tween 80, Alcoho

Millimeter-sized marine plastics: a new pelagic habitat for microorganisms and invertebrates

Millimeter-sized plastics are abundant in most marine surface waters, and known to carry fouling organisms that potentially play key roles in the fate and ecological impacts of plastic pollution. In this study we used scanning electron microscopy to characterize biodiversity of organisms on the surface of 68 small floating plastics (length range = 1.7–24.3 mm, median = 3.2 mm) from Australia-wide coastal and oceanic, tropical to temperate sample collections. Diatoms were the most diverse group of plastic colonizers, represented by 14 genera. We also recorded ‘epiplastic’ coccolithophores (7 genera), bryozoans, barnacles (Lepas spp.), a dinoflagellate (Ceratium), an isopod (Asellota), a marine worm, marine insect eggs (Halobates sp.), as well as rounded, elongated, and spiral cells putatively identified as bacteria, cyanobacteria, and fungi. Furthermore, we observed a variety of plastic surface microtextures, including pits and grooves conforming to the shape of microorganisms, suggesting that biota may play an important role in plastic degradation. This study highlights how anthropogenic millimeter-sized polymers have created a new pelagic habitat for microorganisms and invertebrates. The ecological ramifications of this phenomenon for marine organism dispersal, ocean productivity, and biotransfer of plastic-associated pollutants, remains to be elucidated