Novel hydrophobic ligand-containing hydrogel membrane matrix: Preparation and application to ?-globulins adsorption

In this study, phenylalanine as a hydrophobic ligand was covalently attached to the co-monomer methacrylochloride. Then, poly(2-hydroxyethylmethacrylate-co-methacrylamidophenyalanine) [poly(HEMA-MAPA)] membranes were prepared by UV-initiated photopolymerization of HEMA and methacrylamidophenyalanine. The ?-globulins adsorption onto these affinity membranes from aqueous solutions containing different amounts of ?-globulins at different pH was investigated in a batch system. The ?-globulins adsorption capacity of the membranes was increased as the ligand density on the membrane surface increase. The non-specific adsorption of the ?-globulins on the pHEMA membranes was negligible. The adsorption phenomena appeared to follow a typical Langmuir isotherm. The maximum adsorption capacity (qm) of the poly(HEMA-MAPA4) membrane for ?-globulins was 2.37 mg g-1dry membrane. The equilibrium constant (kd) value was found to be 1.61×10-1mg ml-1. More than 87% (up to 100%) of the adsorbed ?-globulins were desorbed in 120 min in the desorption medium containing 50% ethylene glycol in 1.0 M NaCl. Copyright © 2001 Elsevier Science B.V

Thermal properties and flame retardance of Al(OH)3/polypropylene composites modified by polypropylene grafting with acrylic acid

The effect of polypropylene grafting with acrylic acid, PP-g-AA (FPP), on crystallization and melting behavior, thermal degradation, and limiting oxygen index of Al(OH)3/PP composites were investigated. The results indicated that crystallization temperature of PP shifted to high temperature with increasing content of Al(OH)3 because of the interfacial heterogeneous nucleation of Al(OH)3 and further increased by the addition of FPP and with increasing FPP content because of the improvement of the dispersion of Al(OH)3 in PP matrix and the increase in the nucleating sites of Al(OH)3. With adding Al(OH)3 and increasing the content of Al(OH)3, limiting oxygen index values of composites increased and further improved by adding FPP. This is attributed to the presence of an interfacial interaction between FPP and Al(OH)3. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci

Functionalization of low molecular weight atactic polypropylene: Part I. Spectroscopic studies

Low molecular weight atactic polypropylene (APP) was functionalized with 4-allyl-2-methoxyphenol (eugenol), 4-allyl-1,2-dimethoxybenzene (DMAB), 4-propenylanisole(trans-anethole), cis-2,4,5-trimethoxypropenylbenzene (?-asarone) and 4-allyl-2,6-dimethoxyphenol (ADMP) in the presence of dicumyl peroxide (DCP) at 170°C. Amount of grafted eugenol, DMAB and anethole on APP and characterization of the products were carried by UV-VIS and FTIR spectroscopies respectively. The effects of the reaction time, concentrations of the functional compounds and DCP on the extent of grafting were examined. © Springer-Verlag 1999

Evaluation of novel thermo-resistant Micractinium and Scenedesmus sp for efficient biomass and lipid production under different temperature and nutrient regimes

Despite the vast interest in microalgae as feedstock for biodiesel production, relatively few studies examined their response to diurnal temperature fluctuation. Here, we describe biomass and lipid productivities and fatty acid profiles of thermo-resistant Micractinium sp. and Scenedesmus sp. grown in batch cultures in a laboratory set-up that mimics a typically warm summer day in Central Anatolia with a 16-h light temperature of 30 degrees C and 8-h dark temperature of 16 degrees C (30 degrees C (day)/16 degrees C (night)). Both strains can survive a temperature range of 10-50 degrees C. We found the lipid productivities of Micractinium sp. and Scenedesmus sp. as 30/21 mg L-1 d(-1) and 6/7 mg L-1 d(-1), respectively during the 30 degrees C (day)/16 degrees C (night) cycle. Saturated fatty acid content increased with increasing temperature. Additionally, we cultured Micractinium sp. under Nitrogen (N) and Phosphorus (P) limiting conditions. Highest lipid productivity of 85.4 +/- 2 mg L-1 d(-1) was obtained under P-depletion during exponential growth phase. Oleic acid amount also increased eight fold during P-deplete

Phenolic compounds, carotenoids, and antioxidant capacities of a thermo-tolerant Scenedesmus sp. (Chlorophyta) extracted with different solvents

The human body can fight against the adverse effects of chronic exposure to environmental pollutants and stress by consumption of a diet rich in antioxidants. Although fruits and vegetables are the predominant sources, alternative sources of antioxidants such as microalgae are also being explored. Here, we investigate the antioxidant capacity, total phenolic, flavonoid, and carotenoid contents of novel thermo-resistant green microalga Scenedesmus sp. ME02. This strain has previously been shown to have a high polyunsaturated fatty acid content. Four different solvents were used for extraction and the antioxidant capacity was determined to be 3.71 +/- 0.11 and 47.01 +/- 3.14molTroloxeq.g(-1)DW in ethanol/water mixture by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays, respectively. Total phenolic, flavonoid, and carotenoid contents in ethanol/water were measured as 5.40 +/- 0.28mggallic acideq.g(-1)DW, 1.61 +/- 0.76mgquercetineq.g(-1)DW, 0.61 +/- 0.05mgg(-1), respectively. This is one of the few studies that reports the presence and quantification of total flavonoids in microalgae. The correlation between the total phenolic content and FRAP assay, but not the DPPH assay, was statistically significant. Finally, 12 different phenolic compounds were analyzed by reverse-phase HPLC and ethyl acetate extract showed substantial amounts of quercetin (0.84 +/- 0.12mgg(-1)DW) and rutin (0.11 +/- 0.08mgg(-1)DW). Quercetin amount was also high in the ethanol/water extract along with gallic acid, 4-hydroxy benzoic acid, and chlorogenic acid. To the best of our knowledge, this is the first study that reports significant amounts of quercetin and rutin in a microalgal species