Effect Of PEG Addition Research Articles

Structure and thermal behaviour of different concentration PEG loaded PVA nanofibers

Poly vinyl alcohol (PVA) has established its credibility in the fields of filtration, biomedical and pharmaceutical areas. In this paper different concentration of poly (ethylene) glycol were added to PVA to prepare gel and its nano fibres. PEG is water soluble similar to PVA can give a uniform gel and a strong intermolecular bonding can be achieved by the addition of PEG in PVA. Fibres were prepared by having high wt.% of PEG loaded PVA nano fibres. Nano fibre mat having 0, 0.2,0.4 and 0.6 g PEG having low molecular weight was added in the 8.6 wt.% PVA solution and then fibres were prepared by using electro spinning technique. Nano fibres so prepared were characterised by SEM, XRD and DSC. SEM results reveal that increase of PEG concentration separated the nano fibres and increased the gap of the mesh size. SEM micro graphs depicts that produced nano fibres are homogenous in nature and there were no apparent gap between the PVA and PEG nano fibre. It may be explained that due to the high electric potential developed during the electro spinning process which helped the nano fibres to get stretched XRD patterns exhibited the crystal size increased on adding PEG in the PVA gel. Effect of PEG addition on Tm of PVA nano fibres has been determined by running their DSC scans. An additional peak of 158.13°C is observed for the sample having 0.4 g PEG. Melting temperature shifted from 215° C to 219°C due to increase in crystal size of PEG added PVA nano fibres.

Effect of PEG Addition on the Behavior of Aluminum Sol, Dry Gel, and Film

Effect of PEG Addition on the Behavior of Aluminum Sol, Dry Gel, and Film

A comparative study on the self-cleaning behavior and antibacterial activity of Portland cement by addition of TiO2 and ZnO nanoparticles

In the present study, the photocatalytic effect of the addition of nano-TiO2/ZnO particles with different molar ratios of polyethylene glycol on the self-cleaning behavior and antibacterial activity of Portland cement was investigated to evaluate its potential for dye decolorization, and inactivation of Escherichia coli and Streptococcus mutans. Moreover, the effect of PEG addition on the hydration and tensile strength properties of the cement samples was evaluated. Furthermore, to study the self-cleaning behavior of the cement samples, an azo dye was selected as an organic pollutant. The modified cement samples were characterized using x-ray diffraction, Fourier-transform infrared spectroscopy, energy-dispersive x-ray spectroscopy, and scanning electron microscopy to assess the pozzolanic reactivity of the cement paste in the presence of TiO2 and ZnO nanoparticles. The results showed that the bactericidal properties of the modified cement specimens were dependent on the hydration time and composition of the samples. Accordingly, the maximum inhibitory effect was observed for the specimens hydrated for 7 d. Additionally, the surface of the samples was able to effectively decompose the azo dye. This novel modified cement has a promising potential to be used as a self-cleaning and antibacterial coating for urban constructions.

α-Glucosidase inhibitory activity of mangiferin-loaded F127/PEG micellar system

Abstract Mangiferin-loaded F127/PEG micellar systems were evaluated regarding the effect of PEG addition at different molecular weights, where the system with best mangiferin solubility response (0.5 wt% of PEG in 1 wt% F127 aqueous solution) was chosen to be a potential drug delivery system (DDS), which solubilized 7.92 mg dL−1 of mangiferin. Subsequently, the chosen mangiferin-loaded DDS was evaluated in regard the inhibition of enzyme α-glucosidase, which showed a more effective inhibition, around 95.42%, when compared to the standard acarbose (92.59%) and to the free-form mangiferin (90.42%). The same micellar system was also evaluated for its cytotoxicity, where no significative values of LDH activity was observed. No study has been done yet with both mangiferin and DDSs regarding in vitro α-glucosidase inhibitory activity. This work proposes a “new” alternative towards diabetes treatment.

Effect of PEG addition on pore morphology and biocompatibility of PLLA scaffolds prepared by freeze drying

Purpose A 3wt% poly(L-lactic acid) (PLLA) with different concentrations of polyethylene glycol (PEG, 0~9wt%) was blended and lyophilized to evaluate the morphology and the biocompatibility of the PLLA/PEG scaffolds. The purpose of this study is to investigate the biocompatibility of the PLLA/ PEG blends. Morphology, degradation rate, cytotoxicity, skin sensitization, acute systemic toxicity, and intradermal reactivity are examined.

Tailoring of magnetite powder properties for enhanced phosphate removal: Effect of PEG addition in the synthesis process

This study demonstrates that PEG-assisted hydrothermal synthesis provides a convenient and eco-friendly route to fabrication of mesoporous magnetite with enhanced capacity for phosphate removal, excellent potential for magnetic separation and good reusability. Adsorption of phosphate onto 4 laboratory prepared magnetite powders was investigated in a systematic manner. Powders were synthesized in poly(ethylene) glycol-free or -assisted conditions (PEGs 400 and 20,000 at varied PEG/water ratio), and characterized in terms of crystalline structure, and magnetic, morphological, textural, and acid–base properties. PEG acted as a powerful pore-forming agent, the PEG/water ratio being the key factor in developing the surface area and mesoporosity of magnetite. Uptake capacity for phosphates increased with an increase in surface area and pore volume. PEG 20,000 at a ratio of 3:1 gave the best result. This mesoporous (Dmax=11nm), nano-scale (<10nm) magnetite was ca. 9 times more efficient than nonporous micrometric powder derived from PEG-free synthesis (Langmuir maximum capacity, qm=26.2 vs. 3.0mgg−1). The adsorption was pH-dependent, in accord with variations in zeta potential of magnetite. Opposite shifts of isoelectric point and point of zero charge confirmed specific adsorption of phosphates at water/magnetite interface which proceeded via replacement of surface hydroxyls and sulfates.

Effect of PEG Addition on the Properties of YAG:Ce Phosphor Synthesized via a Homogeneous Precipitation Method

Abstract YAG:Ce precursors were synthesized via a homogeneous precipitation method with the addition of different molecular mass of PEG (PEG 6000 and PEG 10000) used as dispersant. The FT-IR spectra show that no significant difference is found between the precursors. SEM images indicate that the size of the primary particles with PEG is much smaller than that of the sample without PEG. Confirmed by the DSC traces and X-ray diffraction (XRD), the crystallization of YAG is a one-step process without any intermediate phase. The crystallization of YAG is significantly promoted and the oxidation of Ce3+ is inhibited by addition of PEG, which enhances the luminescent properties of YAG:Ce phosphor.

Mechanism of the positive effect of poly(ethylene glycol) addition in enzymatic hydrolysis of steam pretreated lignocelluloses

The efficiency of enzymatic hydrolysis of lignocellulses can be increased by addition of surfactants and polymers, such as poly(ethylene glycol) (PEG). The effect of PEG addition on the cellulase adsorption was tested on various steam pretreated lignocellulose substrates (spruce, willow, hemp, corn stover, wheat straw, sweet sorghum bagasse). A positive effect of PEG addition was observed, as protein adsorption has decreased and free enzyme activities (FP, β-glucosidase) have increased due to the additive. However, the degree of enhancement differed among the substrates, being highest on steam pretreated spruce. Results of lignin analysis (pyrolysis-GC/MS, 31P NMR) suggest that the effect of PEG addition is in connection with the amount of unsubstituted phenolic hydroxyl groups of lignin in the substrate. Adsorption experiments using two commercial enzyme preparations, Celluclast 1.5L ( Trichoderma reesei cellulase) and Novozym 188 ( Aspergillus niger β-glucosidase) suggested that enzyme origins affected on the adsorptivity of β-glucosidases.

Effect of poly(ethylene glycol) on enzymatic hydrolysis and adsorption of cellulase enzymes to pretreated lignocellulose

There is a need to develop the enzymatic hydrolysis of cellulose for production of ethanol from biomass. In recent years the inhibitory effects of lignin in lignocellulosic substrates has been the focus of several studies. This points to the importance of understanding the interactions between cellulose degrading enzymes and lignin. Surface active substances have been shown to adsorb to lignin surfaces resulting in reduction of unproductive enzyme binding. It is essential to understand the surface properties of both enzymes and lignin to develop pretreatment methods, surface active additives and engineering of cellulose degrading enzyme systems. This study investigates the PEG–lignin interaction as well as interactions between lignin and the enzyme modules of the Hypocrea jecorina ( Trichoderma reesei) enzymes Cel7A and Cel7B. Interactions were monitored with 14C labelled PEG 4000 and by measuring the enzymatic activity in solution. It was found that the dominating driving force of PEG adsorption on lignin is hydrophobic interaction. The effect of PEG addition on enzyme conversion of lignocellulose increased with higher temperature due to increased adsorption of PEG on lignin, thus resulting in a higher surface density of PEG on the surface. The hydrophobic adsorption of enzymes to lignin induces denaturation of enzymes on lignin surfaces. The addition of PEG to the enzyme hydrolysis at a temperature of 50 °C is suggested to hinder deactivation of enzymes by exclusion of enzymes from lignin surfaces. The adsorption of full-length Cel7B to lignin was stronger than for Cel7A. A more hydrophobic surface on the flat face of the cellulose binding module (CBM) together with an additional exposed aromatic residue on the rough face of Cel7B CBM compared to Cel7A CBM gives a higher affinity to lignin for the Cel7B enzyme.

加水分解法によるジルコニア合成における界面活性剤添加の影響

Yttria-stabilized zirconia powder was synthesized by a hydrolysis method using zirconium oxychloride and yttrium chloride as a starting materials. The effect of PEG addition was investigated on the hydrolysis of zirconium oxychloride and characteristics of the obtained yttria-stabilized zirconia powder. By the addition of PEG, the initial hydrolysis of zirconium oxychloride was promoted and the well-dispersed hydrous zirconia powder was obtained. In this case, however, a slight amount of un-reacted zirconium oxychlodride remained even after 115hrs. On the other hand, for the sample without PEG, hydrolysis of starting material was nearly completed after 115hrs but large aggregates of hydrous zirconia were formed. From the results of pH titration, it was found that difference of surface properties of yttria-stabilized zirconia powder prepared with PEG between before and after milling in water was smaller than that of the powder obtained without PEG. Furthermore, the yttria-stabilized zirconia powder containing PEG showed higher content of tetragonal phase than the powder without PEG. These results indicated that zirconium hydroxide as seed particles for hydrolysis reaction was dispersed well by the action of PEG and as a consequence highly dispersion of hydrous zirconia and homogeneous mixing of yttrium hydroxide were achieved.

The effect of PEG addition in vitro on dry matter and nitrogen digestibility of Calliandra calothyrsus and Leucaena leucocephala leaf

A modified two stage in vitro digestion method was used to study the effects of rate of PEG addition (0–1100 mg/g DM) on dry matter (IVDMD) and nitrogen digestibility (IVND) of freeze dried leaf material from actively growing shoots of Calliandra calothyrsus (Calliandra) and Leucaena leucocephala cv. Cunningham (Leucaena). For both species, IVDMD and IVND increased asymptotically with PEG rate; the IVND response being markedly greater for Calliandra. There was a three-fold greater amount of PEG bound to the residue after Stage 1 (rumen fluid/buffer) digestion with Calliandra than with Leucaena (105 versus 33 mg/g DM). The presence of PEG in the residue, which was not reduced after Stage 2 (acid–pepsin) digestion, resulted in a higher residue weight and therefore an underestimated IVDMD. Quantification of the PEG in the residue enabled a corrected IVDMD (CIVDMD) to be estimated. PEG did not bias estimates of nitrogen digestibility in the same way. In a second experiment, estimates of CIVDMD and IVND were made after Stage 1 and after Stage 2 in the presence and absence of PEG at 160 mg/g sample. For Leucaena, there were small, but significant, effects of PEG, whereas with Calliandra there were large responses to PEG and to timing of addition. When measured after Stage 1, IVND in the absence of PEG was not significantly different to zero (compared with 57% for Leucaena), whereas with PEG, IVND was 75% (compared with 68% for Leucaena). The low IVND for Calliandra was associated with low NH 4 N levels in the rumen fluid/buffer after Stage 1. In summary, about 160 mg PEG/g sample is appropriate for most studies with tropical tanniniferous shrub legumes to estimate any deleterious tannin effect. The use of PEG to estimate this effect on IVDMD is not valid without accounting for the PEG bound to the residue. For estimation of the adverse effect of tannins on IVND the use of PEG may be more appropriate.

Photoelectrochromism of poly(aniline) derivatives in a Ru complex-methylviologen system containing a polymer electrolyte

Photo-oxidation (photoelectrochromism) of poly(aniline) was performed using photoinduced electron transfer between Ru complex (Ru(bpy) 2+ 3) and methylviologen molecules. Especially, effect of electrode structure on the photoelectrochromism was at first analysed in solution system. The electrode structure to increase the probability that poly(aniline) and Ru(bpy) 2+ 3 came into contact or very nearly so was effective to proceed the photoelectrochromism. Further, employment of poly(ethylene glycol) (PEG, Mw=400) as additive into Flemion matrix revealed to enable the present photoelectrochromism even in all solid state. Effect of PEG addition was also discussed.

Photoelectric properties of solid state Ru complex-viologen bilayer cell containing PEG

A solid state photoelectrochemical bilayer cell was fabricated with Ru(bpy) 2+ 3+PEG+Nafion layer and MV 2+ pendant polysiloxane (PSiO-MV 2+) layer. The effect of PEG addition on the photoelectric properties was discussed especially with charge transport in the Nafion layer. Increase in photoelectric properties produced by PEG addition to the Nafion layer was found for the solid state cells. Solid state voltammetry indicated that this increase was attributed to the increase in D app for Ru(bpy) 2+ 3 in the Nafion layer. From emission lifetime of Ru(bpy) 2+ 3 in the Nafion film, spatial distribution and local motion of the Ru(bpy) 2+ 3 molecules in the Nafion film were estimated to analyse charge transport process, physical diffusion and/or electron hopping, in detail. As a result, PEG addition would affect the electron hopping reaction between Ru(bpy) 2+ 3 and Ru(bpy) 3+ 3 molecules in the Nafion film, resulting in the increase in photoelectric properties for the cell containing PEG.