Dosage Of Polyethylene Glycol Research Articles

Preparation optimization by response surface and performance characterization of PEG-urea-dialdehyde starch adhesive

In this study, a new kind of green, pollution-free, renewable and formaldehyde-free starch adhesive was prepared by using corn starch as raw material, which was oxidized into dialdehyde starch by sodium periodate, and then grafted and cross-linked with polyethylene glycol (PEG) and urea. The PEG-urea-dialdehyde starch adhesive has good dry shear strength and certain hydrophobicity. The preparation parameters of PEG-urea-dialdehyde starch adhesive were optimized by response surface methodology and it characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscope (SEM) and X-ray spectroscopy (EDAX). The results showed that when the dosage of PEG was 54% (w/w, dry starch basis), the dosage of urea was 70% (w/w, dry starch basis), the reaction time was 2.4 h, and the reaction temperature was 40 °C, the comprehensive properties of the adhesive were better. The dry shear strength of the PEG-urea-dialdehyde starch adhesive can reach 3.01 MPa, and the water contact angle was 61.76°. When the adhesive was used to bond paper-based materials, the tensile strength, burst strength and ring crush strength of the paper were increased by 17.0%, 16.0% and 42.0%, respectively. This paper provided a new idea for the preparation of the high quality starch-based adhesive, which has a wide application prospect in paper adhesive.

Efficacy of single-versus split-dose polyethylene glycol for colonic preparation

Background: Before a colonoscopy, polyethylene glycol (PEG) is often used to prepare the colon. PEG dosage recommendations are still up for discussion. In this randomized controlled experiment, the effectiveness and acceptability of PEG administered in single vs. split doses for colonic preparation was compared. Methods: A total of 120 individuals were randomized to either split-dose PEG for colonic preparation or a single-dose PEG at Department of Gastroenterology, Hayatabad medical complex. The Boston Bowel Preparation Scale (BBPS) was used for assessing the rate of bowel cleaning for the colonoscopy. A visual analog scale was used to evaluate the preparation's acceptability and tolerability. Results: The quality of colonic preparation was considerably greater in the split-dose PEG group than in the single-dose PEG group, as shown by the BBPS score, which was significantly higher in the split-dose PEG group (7.5±1.2) than in the single-dose PEG group (6.3±1.3) (P0.001). Patient satisfaction did not vary significantly between the two groups, but the split-dose PEG group had a higher completion rate of colonoscopies (97% vs. 95%) as well as greater patient acceptability and tolerance.

One-step synthesis of Enteromorpha graphene aerogel modified by hydrophilic polyethylene glycol achieving high evaporation efficiency and pollutant tolerance

Photothermal evaporation using solar energy is a sustainable way to produce fresh water from seawater. Aiming to explore functional materials as a solar-energized evaporator with enhanced evaporation rate and pollutant tolerance, this study was to synthesize a self-floating composite graphene aerogel (GA) doped with Enteromorpha and modified polyethylene glycol (PEG), named as PEGA using solar energy for desalination. Physio-chemical properties and evaporative mechanism of PEGA were experimentally investigated and analyzed with respect to molecular weight, PEG dosage, and ratio of Enteromorpha and graphene oxide. Experimental data revealed that the modification of PEG improved hydrophilic functional ability of PEGA, resulting in increasing the evaporation rate and photothermal conversion efficiency up to 2.55 kg/(m2·h) and 105.71 %, respectively. The ion removal rate of seawater exceeds 99.99 % via the PEGA conducted solar evaporation. Furthermore, PEGA possessed an excellent property of salinity emulsion pollution tolerance. Particularly, the evaporation rate of the PEG-modified biomass-based aerogel was 2.84 kg/(m2·h) in a 15 wt% NaCl solution (1 sun, 6 h) and 2.50 kg/(m2·h) at 1 h. The formation of hydrogen bonds between –OH of PEG and water molecules assist to conduct water along the graphene matrix to improve water evaporation. The cost of the graphene aerogel modified by Enteromorpha was reduced by 38.88 % less than the original graphene aerogel. The results from this study will greatly promote the application of graphene aerogel for desalination via solar evaporation.

Exploration of offsetting the negative effects of polyethylene glycol admixture on mortar performance: Using diethanol-isopropanolamine

• The co-mixing accelerates the hydration of C 4 AF compared to samples added PEG alone. • The co-mixing can increase the microviscosity of the solution and the CBC. • The co-mixing of PEG and DEIPA increased susceptibility of leaching. • Leaching arises from the changes of pore structure, Ca/Si ratio, products morphology. Polyethylene glycol (PEG) is a viscosity modifying admixture that can effectively increase the viscosity of concrete pore solution and retard the diffusion of Cl - . However, to ensure excellent anti-chloride diffusion performance, the dosage of PEG is usually large enough to retard cement hydration and even to reduce the chloride chemical binding capacity of cement matrix due to the conversion inhibition from AFt to AFm. Diethanol-isopropanolamine (DEIPA), a commonly used alkanolamine grinding aid during cement production, seems to be a good candidate to offset these side effects introduced by PEG through promoting the conversion from AFt to AFm and refining the pore structure of cementitious materials. In this paper, we explored the possibility of using DEIPA to offset the negative effects of PEG. The cement hydration, mechanical strength, chloride diffusion capacity, pore structure, and micro-morphology of mortars containing both DEIPA and PEG are systematically investigated. The results indicated that the addition of DEIPA indeed reduces the porosity and increases the chloride binding capacity of mortars. Yet the coarsening of pore structure is still observed. Besides, the co-mixing of DEIPA can increase the mortar compressive strength at 90 d when the DEIPA dose is appropriate. Unfortunately, the co-mixing increased the susceptibility of the matrix to leaching, which reduces the resistance to chloride diffusion. The higher degree of leaching may arise from three reasons: the coarsening of the pore structure, the increase in the Ca/Si ratio of C-S-H, and the thinning of the hydration products morphology. This study draws attention to the durability issues when alkanolamine grinding aids and water-soluble viscosity modifying admixtures are coexisted in cementitious materials.

High-Performance Polymeric Surfactant of Sodium Lignosulfonate-Polyethylene Glycol 4000 (SLS-PEG) for Enhanced Oil Recovery (EOR) Process

Recently, the increase in fuel oil demand was not supported by petroleum production due to the low productivity of old wells. Furthermore, an appropriate technology, such as Enhanced Oil Recovery (EOR) technology, is needed to maximize the productivity of the old well. Therefore, the purpose of this study was to synthesize a polymeric surfactant for the EOR process from sodium lignosulfonate (SLS) and polyethylene glycol (PEG) in various SLS to PEG ratios, namely 1:1 (PS1), 1:0.8 (PS2), and 1:0.5 (PS3). The surfactants were characterized using several methods, such as Fourier Transform-Infrared spectroscopy (FT-IR), compatibility, stability, viscosity, and phase behavior tests. The performance of the surfactants for the EOR process in different brine solution concentrations (16,000 ppm and 20,000 ppm) was also studied. The result showed that the introduction of the PEG molecule to the surfactant had been successfully conducted as FT-IR analysis confirmed. The surfactant's hydrophilicity increased with the introduction of PEG due to the increase of the ether group. A Winsor Type I or lower phase microemulsion was formed due to the high hydrophilicity. The highest oil yield (79 %) was obtained by PS1 surfactant, which has the highest PEG dosage, in a brine solution of 1,600 ppm. Therefore, it was concluded that the introduction of PEG could increase the hydrophilicity, viscosity, and EOR performance.

Hydration of α-pinene catalyzed by oxalic acid/polyethylene glycol deep eutectic solvents

A series of carboxylic acid-functionalized deep eutectic solvents(DES) wereconstructed by a natural organic dicarboxylic acid, oxalic acid (OA), as the hydrogen bond donor and the polyethylene glycol (PEG)with different polymerization degrees as the hydrogen bond acceptors, which are used in the hydration of α-pineneto produce α-terpineol. Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (1H NMR), and thermogravimetric analysis (TGA) were used to prove the hydrogen bonding between OA and PEG. It is found that the presence of PEG has a less impact on the acid strength of DES. However, an increase in both molecular weight and dosage of PEG results in a decrease in total acidity and catalytic activity.Among them, OA/0.6PEG200, a DES catalyst prepared by PEG with the smallest molecular weight, exhibits a favorable catalytic performance. Under an optimal reaction condition with 0.03 mol of DES (based on OA), 0.06 molof α-pinene, 0.3 mol of water,at 75°C for 8 h, anα-pinene conversion of 81.5% and an α-terpineol selectivity of 51.2% are obtained. The catalyst phase can be separated by refrigerating overnight after reaction and reused directly with relatively stable catalytic performance. Thus, OA/0.6PEG200, as a DES catalyst prepared by a simple and highly atom economical process, will offer a clean catalytic route for the one-step production of α-terpineol.

Effect of Polyethylene Glycol in Self-Curing of Self Compacting Concrete

The objective of this research is to evaluate the strength characteristics of self-compacting concrete as self-curing material by using water soluble Polyethylene Glycol 400. The objective of self-curing agent is to decrease concrete water disposal, thus increasing concrete's water retention ability in comparison with conventional curing. Self curing Concrete is a modern method, which performed to meet the water needs of the concrete without external curing. This research discusses the compressive, flexural, and split tensile strength of the concrete having the self-curing agent. Polyethylene glycol (PEG) of Molecular Weight 400 (PEG 400).The percentage of self-curing used from 0.5, 0.1, 1.5 and 2 percent by weight of cement. From the experimental results it is observed that optimal dosage PEG 400 is achieved at one percent being maximum strength. It is also found that the increase in PEG dosage decreases the strength of concrete.

Defective FXR-FGF15 signaling and bile acid homeostasis in cystic fibrosis mice can be restored by the laxative polyethylene glycol.

The gastrointestinal phenotype of cystic fibrosis (CF) features intestinal bile acid (BA) malabsorption, impaired intestinal farnesoid X receptor (FXR) activation, and consequently reduced fibroblast growth factor 19 (FGF19, FGF15 in mice) production. The osmotic laxative polyethylene glycol (PEG) has been shown to decrease intestinal mucus accumulation in CF mice and could, by doing so, improve BA reabsorption. Here we determined the effect of PEG on BA excretion and FXR-FGF15 signaling in CF mice. Male Cftr-/-tm1Unc (CF) and wild-type (WT) littermates were administered PEG 4000 in drinking water and fed either chow or a semisynthetic diet. PEG was withdrawn for 3 days before termination. Fecal BA excretion was measured at PEG dosages of 37 g/l (100%) and 0 g/l (0%). Ileal FXR activation was assessed by gene expression of its downstream targets Fgf15 and small heterodimer partner ( Shp). In CF mice, PEG withdrawal increased fecal BA excretion on either diet compared with full PEG dosage (chow, 2-fold, P = 0.06; semisynthetic, 4.4-fold, P = 0.007). PEG withdrawal did not affect fecal BA excretion in WT mice on either diet. After PEG withdrawal, gene expression levels of intestinal FXR target genes Fgf15 and Shp were decreased in CF mice but unaffected in WT littermates. PEG did not affect the gene expression of the main intestinal BA transporter apical sodium-dependent bile acid transporter (ASBT). PEG treatment ameliorates intestinal BA malabsorption in CF mice and restores intestinal FXR-FGF15 signaling, independent from Asbt gene expression. These findings highlight the potential of PEG in the prevention and treatment of the gastrointestinal phenotype of CF. NEW & NOTEWORTHY A gastrointestinal feature of cystic fibrosis is bile acid malabsorption and consequent impairment of farnesoid X receptor (FXR)-fibroblast growth factor 15 (FGF15) signaling. FXR-FGF15 signaling regulates various metabolic processes and could be implicated in metabolic and gastrointestinal complications of cystic fibrosis, such as diabetes and liver disease. In cystic fibrosis mice, treatment with the osmotic laxative polyethylene glycol is associated with decreased fecal bile acid loss and restoration of FXR-FGF15 signaling.

Feed resource selection of Criollo goats is the result of an interaction between plant resources, condensed tannins and Haemonchus contortus infection

The tropical deciduous forest (TDF) is an ecosystem with a heterogeneous array of plant species containing different condensed tannin (CT) content. Recent studies explored the effect of polyethylene glycol (PEG) or Haemonchus contortus infection on the intake and feed resource selection of goats. These factors have not been investigated simultaneously. The present study evaluated the role of infection with the abomasal parasitic nematode Haemonchus contortus and the effect of neutralizing CT with PEG on the feed resource selection of Criollo goats in a cafeteria trial. A group of 22 Criollo goats (31.7 ± 4.8 kg) habituated to browse the TDF, were assigned to four groups: two groups were artificially infected with H. contortus (6000 L3per os) and received PEG (50 mg/day) (INF + PEG group) or no PEG (INF group) and the other two groups were kept free of infection with moxidectin (0.4 mg/kg BW sub-cutaneously) and received either PEG (MOX + PEG) or no PEG (MOX). Intake and resource selection of four shrub plant species (Havardia albicans, Gymnopodium floribundum, Leucaena leucocephala and Piscidia piscipula) by goats, and the dynamics of faecal H. contortus egg excretion were determined daily. Intake varied depending on the interaction between plant resource and the infection level (P < 0.001), and between plant resource and whether goats were dosed with PEG (P < 0.001). Excretion of H. contortus eggs was decreased by 69% and 72% for groups with and without PEG administration, respectively. Infected groups had a higher CT intake. The use of PEG reduced intake of L. leucocephala and increased the selection of H. albicans, a high-CT and high crude protein (CP) resource. Animals infected with H. contortus ingested more high-CT resources. Furthermore, CP intake was lower in PEG dosed goats, possibly to reduce the energetic cost associated with urinary nitrogen excretion. Selection of feed resources varied depending on parasite infection, PEG dosage and plant resource. We concluded that biological interactions influencing intake and selection of feed resources in goats are complex, rather than arising from a single factor such as parasite infection or secondary compounds such as CT. These findings support that goats’ resource selection is a complex process aimed at nutritional optimization.

Simethicone improves bowel cleansing with low-volume polyethylene glycol: a multicenter randomized trial.

For bowel preparation, using a reduced volume of polyethylene glycol (PEG) solution without influencing its effectiveness would be preferable. While simethicone shows great potential as an adjunctive agent, data on its use are limited. We aimed to clarify whether simethicone added to low-volume PEG solution improved bowel cleansing. PATIENTS AND METHODS : Consecutive adult patients registered for colonoscopy were recruited from seven medical centers in South China between 15 April and 15 July 2015 and prospectively randomized into two groups: 2 L PEG (conventional group) and 2 L PEG plus simethicone (simethicone group). The primary endpoint was the effectiveness of bowel cleansing according to the Boston Bowel Preparation Scale (BBPS). Secondary endpoints included cecal intubation time, adenoma detection rate (ADR), patient safety and compliance, and adverse events. RESULTS : We included 290 and 289 patients in the conventional and simethicone groups, respectively, for analysis. The proportion with acceptable bowel cleansing (BBPS ≥ 6) was significantly higher in the simethicone group than in the conventional group (88.2 % vs. 76.6 %; P < 0.001). The mean (SD) BBPS score was significantly lower in the conventional group (6.5 [1.8] vs. 7.3 [1.7]; P < 0.001), as was the bubble score (2.5 [0.7] vs. 2.8 [0.5]; P < 0.001). The average cecal intubation time was significantly shorter in the simethicone group (6.3 [3.1] vs. 7.5 [5.1] minutes; P < 0.001). The ADR in the right colon was higher in the simethicone group than in the conventional group (16.6 % vs. 10.3 %; P = 0.03). Safety and compliance, including the taste, smell, and dosage of PEG, were similar for both groups. Simethicone added to low-volume PEG solution improves bowel-cleansing efficacy, with similar safety and compliance, shorter cecal intubation time, and higher ADR.

The Effectiveness of Personalized Bowel Preparation Using a Smartphone Camera Application: A Randomized Pilot Study.

Background We aimed to investigate the effectiveness of a smartphone application that analyzes and judges the optimal dosage of polyethylene glycol (PEG) for bowel preparation. Methods Patients were assigned to use the smartphone camera application (app group) or written instructions (non-app group). The smartphone camera application was programmed to analyze the bowel preparation quality and automatically determine the dosage of PEG from an analysis of stool images. In contrast, the non-app group consumed PEG solution according to the manual. Results The primary outcome was the quality of the bowel preparation based on blinded ratings using the Ottawa bowel preparation scale (OBPS). There was no statistically significant difference in the mean OBPS scores between the two groups (P = 0.950). However, the app group consumed a lower dose of PEG than the non-app group (mean dosage (mL): 3713.2 ± 405.8 versus 3979.2 ± 102.06, P = 0.001). The app group (5-point Likert scale; mean score 4.37 ± 0.895) had high acceptance of the application. Conclusions Although the app group consumed a lower PEG dose, the bowel preparation quality was similar in the two groups. Moreover, use of the smartphone camera application enhanced compliance with the bowel preparation.

Bisurfactant‐assisted preparation of amorphous silica from fly ash

AbstractAmorphous silica (white carbon black) has been prepared via a one‐step hydrochloride acidification of fly ash with the assistance of cetyl‐trimethylammonium bromide (CTAB) and polyethylene glycol (PEG). The effects of surfactant types and their concentration on the properties of amorphous silica have been investigated by X‐ray diffraction (XRD), particle size analysis and dibutyl phthalate (DBP) absorption value measurement. The results show that both the dispersity and hydrophobicity of the prepared silica modified by the mixed surfactants of CTAB and PEG are better than those modified by either CTAB or PEG individually. The particle size and DBP absorption value of the silica products are 3.2 µm and 3.11 cm3 · g−1 at the optimized CTAB concentration of 9 × 10−4 mol · L−1 and PEG dosage of 0.5 wt%, respectively. Consequently, the filtration time for the obtained silica is shortened as little as 3 min. It is worth mentioning that the purity of the products has been improved with the aid of the mixed surfactants. Copyright © 2016 Curtin University of Technology and John Wiley &amp; Sons, Ltd.

Effect of Polyethylene Glygol on Preparation and Performance of Ni-Mo Hydrodesulfurization Catalysts

Ni-Mo catalyst precursors were prepared by the precipitation method. Ni-Mo bulk hydrodesulfurization catalysts were obtained from these precursors after proper drying, molding, and calcination. The effect of polyethylene glycol (PEG) with different molecular weights and in various dosages on the structure and catalytic properties of these catalysts was investigated by applying X-ray diffraction, low-temperature BET N2 adsorption analysis, and scanning electron microscopic methods. It is shown that the structure, surface properties, and activity of the catalysts can be improved by adding PEG. The pore volume, specific surface area, and pore size of the catalysts increase gradually with increasing PEG dosage, and the dispersion of the active ingredient increases initially and then decreases.

Effects of polyethylene glycol on the structure and filtration performance of thin-film PA-Psf composite forward osmosis membranes

ABSTRACTIn forward osmosis, internal concentration polarization is related to the properties (e.g., hydrophilicity, porosity, structural resistant) of membrane support layer. In this work, polyethylene glycol with a low molecular weight of 400 Da was introduced as a support layer additive during the fabrication of thin-film polyamide-polysulfone composite forward osmosis membranes. The forward osmosis performances including water flux and reverse salt flux of the membranes were tested in the mode of AL-FS where the membrane active layer faced toward feed solution. Results showed that the addition of polyethylene glycol would reduce internal concentration polarization and improve membrane performance in forward osmosis by means of enhancing membrane hydrophilicity and changing pore morphologies of membrane support layer. The membrane prepared with 6 wt.% polyethylene glycol was found to exhibit the highest water flux of 47.4 Lm−2h−1 with a reverse salt flux of 7.6 gm−2h−1 when using DI water and 2.0 M NaCl as the feed and the draw solution, respectively, indicating an optimal polyethylene glycol dosage of 6 wt.% in this work.

3-L split-dose is superior to 2-L polyethylene glycol in bowel cleansing in Chinese population: a multicenter randomized, controlled trial.

Large volume (4 L) of polyethylene glycol (PEG) solution would ensure a better quality of bowel cleansing but might be poorly tolerated. Due to the smaller body size, lower body weight, and different diet habits, the large volume of 4-L PEG might be poorly tolerated by the Chinese population. In view of this, a balance should be made between the volume and effectiveness. This study aimed to compare the effectiveness, compliance, and safety between 3-L split-dose and 2-L PEG in Chinese population.Consecutive patients scheduled for colonoscopy were recruited from 5 tertiary medical centers in South China between April and July, 2014. Patients were prospectively randomized into 2 groups: 3-L split-dose PEG (3L-group) and 2 L PEG (2L-group). The primary endpoint was bowel cleansing and was defined according to Ottawa Bowel Preparation Scale (OBPS). The safety and compliance were also evaluated.A total of 318 patients were included in the analysis. The mean total OBPS score was significantly higher in 2L-group than in 3L-group (4.4 ± 2.7 vs 2.9 ± 2.4, P < 0.001). Both the intention-to-treat and per-protocol analysis found that rates of successful and excellent bowel preparation were much higher in 3L-group (89.9% and 78.0%) than 2L-group (79.2% and 48.4%), respectively (P < 0.001). The average cecum intubation time was significantly shorter in 3L-group (8.2 ± 3.7 min) than in 2L-group (10.3 ± 4.2 min) (P = 0.04). Adenoma detection rate in right colon was slightly higher in 3L-group than in 2L-group (17.6% vs 12.6%, P = 0.21). The safety and compliance including the taste, smell, and dosage of PEG were similar between 2 groups (P > 0.05).3-L split-dose PEG is superior to 2-L PEG by better bowel cleansing, improved safety and compliance, shorter cecum intubation time, and potentially higher adenoma detection rate in rightward colon in Chinese population.

Polyethylene glycol as a green solvent for effective extractive desulfurization of liquid fuel at ambient conditions

Today there are serious regulations to reduce sulfur content of fuels because the SOx produced during the combustion of fuels containing sulfur compounds make the air polluted and have dangerous environmental impacts. With the aim of replacement of the present volatile, flammable and toxic organic solvents or inefficient, corrosive and expensive ionic liquids (ILs), the polyethylene glycol (PEG) was introduced as a green, effective, non-toxic, non-corrosive and also recyclable molecular solvent for extractive desulfurization (EDS) of benzothiophenic compounds from liquid fuel in this work for the first time. PEG shows excellent EDS and it has the higher extraction efficiency for dibenzothiophene (DBT) (76% within 90s) than those of ILs. Using this extractant, the BDT content was reduced from 512 to 10ppmw (98%) only within three extraction stages, the minimum number of cycles within shortest time reported up to now, and the deep desulfurization was achieved. Effect of some important parameters including initial concentration of sulfur compound, PEG dosage, time and temperature of extraction on the EDS process was investigated. It was fond that extraction performance of PEG is independent to temperature and initial sulfur content, which is an excellent finding for industrialization. The feasibility of PEG for extraction of different thiophenic compounds was observed in the order of dibenzothiophene>benzothiophene>4,6-dimethyldibenzothiopene. Finally, the PEG was reused in several cycles and then it was regenerated by adsorption method. The results of the present work hopefully provide useful information for future industrial application of PEG as an efficient green solvent for the EDS of liquid fuels.

Polyacrylonitrile membranes via thermally induced phase separation: Effects of polyethylene glycol with different molecular weights

We report the effects of polyethylene glycol (PEG) as a polymeric additive on the phase behavior of polyacrylonitrile (PAN)/dimethyl sulfone (DMSO2) mixtures and the structure formation of PAN membranes via thermally induced phase separation (TIPS). DMSO2 was chosen as a crystallizable diluent, while PEG was considered in terms of molecular weight (Mw) and dosage. Their effects on the phase behavior and the droplet growth kinetics of PAN/DMSO2/PEG ternary system were systematically derived from optical microscopy and differential scanning calorimetry as well as the solubility parameter theory. We found that the addition of PEG brings about the ternary system thermodynamically less stable, facilitates liquid–liquid (L–L) phase separation and suppresses the crystallization of DMSO2. The L–L phase separation can be promoted by raising the Mw or the dosage of PEG, and is accompanied by an increase in the growth rate of droplets. These results match with the pore size of the obtained PAN membranes. SEM images indicate that needle-like pores are obvious in the membrane when 10wt% PEG-200 is added, whereas lacy pores gradually appear as the Mw of PEG increases from 200 to 1000. In addition, cellular pores can be created by raising the dosage of PEG-200 or reducing the cooling rate. Correspondingly, the membrane presents relatively high water flux (1528L/m2h) and porosity (83.6%) when the ternary system contains 10wt% PEG-1000 and cools in air bath at 30°C. Besides, the presence of PEG in membrane matrix was examined by FTIR spectroscopy. PEG with different Mw almost completely leaches out and the pore structure keeps well after immersing the membrane in water for 144h.

Effect of PEG additive on the morphology and performance of polysulfone ultrafiltration membranes

Flat sheet asymmetric polysulfone membranes were prepared by phase inversion method. Dimethyl acetamide was used as solvent and water was used as coagulant. Polyethylene glycol (PEG) of different molecular weights or different dosage of PEG 400 was used as the polymeric additives in the casting solution. The morphology of membranes was analyzed by scanning electron microscope and performance of membranes was evaluated in terms of pure water flux (PWF), protein rejection, porosity, contact angle, tensile strength, and elongation at break. Results show that PEG additive is a pore former and the addition of PEG additive can improve the hydrophilicity of membranes. PWF and porosity of membranes increase with increase in molecular weight of PEG or dosage of PEG 400. With increase in molecular weight of PEG from 400 to 20,000, the PWF increases from 340 L m − 2 h − 1 to 1390 L m − 2 h − 1 . With increase in dosage of PEG 400 from 0% to 10%, the PWF increases from 0.81 L m − 2 h − 1 to 420 L m − 2 h − 1 . The molecular weight cutoff (MWCO) of membrane keeps at 70,000 Da, and the pore size distribution of membrane skin layer becomes narrower. More PEG dosage weakens the mechanical properties of membrane; the tensile strength at break with PEG 1500 is maximum and the value is 5.62 MPa.

Bioassay for measuring tannin effects based on gas production technique. 2. Dosage of polyethylene glycol

Tannins are secondary compounds that can bind protein and other nutrients and reduce their availability to the animals. Polyethylene glycol (PEG) has a great affinity with tannins and when it is added to the feed it is bound to tannins and releases the protein and other nutrients. There is no information about the amount of PEG that is needed to obtain the maximum precipitation of tannin and the minimum tannin effect. Some assays are conduced using doses of PEG according to the tannin content, but the activity of tannins can vary and this imply that the tannin analysis has to be done prior. The aim of this work was to evaluate doses of polyethylene glycol to minimize the effect of tannins on rumen fermentation.

Mesoporous properties of nanosized anatase titania powders prepared by urea hydrolysis with PEG dispersant

Titania has three polymorphs: anatase, rutile and brookite. Nanosized titania has received extensive investigation because of its specific physico-chemical properties and wide applications in photoconductor, highly pigments, filler, coatings, dielectric materials and catalysts support [1–4]. The studies on the preparation, morphology, particle size and crystalline phase transformation of the nanosized titania powders are very extensive, but the textural properties and pore characterization of the nanosized anatase titania with mesostructure are little investigated. In this paper, we report the preparation of this material by homogeneous precipitation of titanium sulfate (Ti(SO4)2) and urea in aqueous solution of polyethylene glycol (PEG). The pore characterizations of as-synthesized and calcined powders were investigated. Ti(SO4)2 and urea were used as starting materials. PEG (average molecular weight from 200 to 19 000) was used as dispersant to give static hindrance to the precipitating particles. The urea and Ti(SO4)2 with controlled mole ratio between 2.67 and 10.0 were dissolved in deionized water at room temperature to obtain Ti(SO4)2 solution in concentration of 0.4 mol/L. To this solution, different dosage of PEG was added and then the mixture was heated with reflux condenser to reach a constant temperature (104 ◦C). Urea hydrolyzed gradually till no gas could be detected. The resulting precipitates, washed with deionized water to eliminate SO2− 4 ions, and then washed with absolute ethanol for several times, were dried at room temperature in air. The calcination of the powders was carried out at 360 ◦C in air for 5 h. The precipitate morphology and electron diffraction patterns were examined by transmission electron microscopy (TEM) in a Jeol JEM2010 operating at 200 kV. The crystalline phase identification was performed by X-ray diffraction (XRD) (Model D/max-2400, Rigaku, Japan) method using Cu Kα radiation. The reflection of the plane (101) was used for the crystallite size determination by Scherrer formula. The specific surface areas of as-synthesized and calcined powders were measured by Brunauer-Emmett-Teller (BET) method using nitrogen adsorption apparatus (Model ASAP 2000, Micromeritics). When the starting solution was heated at average rate of 2 ◦C/min for about 50 min, the reaction temperature could be fixed at 104 ◦C because the reaction was carried out on the Florence flask with reflux condenser. Urea hydrolyzed gradually above 60 ◦C bringing turbid solution, which showed precipitates were produced. Throughout this process, the pH value of solution increased with reaction time. Fig. 1 shows the pH value during the prepared process as a function of reaction time at different urea/Ti4+ mole ratio. At the time of pH value staying at a fixed value, the urea hydrolysis was over. Fig. 2 shows the pH value during the prepared process with different molecular weight of PEG as a function of reaction time. From these two figures, it can be seen that the urea concentration affects pH value of the solution, while the molecular weight of PEG has little significant effect on the pH value. Increasing