Effect Of Polyethylene Glycol Addition Research Articles

Effect of polyethylene glycol additives on the polymorph and crystal habit of carbamazepine

The effect of polyethylene glycol (PEG) with different molecular weights on carbamazepine (CBZ) crystallization was investigated by experiments and molecular dynamics (MD) simulations. The influence of PEG on the crystal morphology and solvent-mediated phase transition of CBZ was studied. It was found that PEG inhibited the CBZ III nucleation and CBZ II transition. The crystal morphology changes significantly from needle to rod when adding PEG with a molecular weight greater than 1500. MD simulations show that the binding energy sequence between the additive and the crystal surface is: Eb(1 –1 –1) > Eb(2 –2 1) > Eb(2 –1 0), which explains the suppression of axial crystal growth. The results provide a possible method to stabilize the metastable crystal form of CBZ and improve crystal morphology.

The Effect of Polyethylene Glycol Addition on Wettability and Optical Properties of GO/TiO2 Thin Film.

Modification has been made to TiO2 thin film to improve the wettability and the absorption of light. The sol-gel spin coating method was successfully used to synthesize GO/TiO2 thin films using a titanium (IV) isopropoxide (TTIP) as a precursor. Different amounts of polyethylene glycol (PEG) (20 to 100 mg) were added into the parent sol solution to improve the optical properties and wettability of the GO/TiO2 thin film. The effect of different amounts of PEG was characterized using X-ray diffraction (XRD) for the phase composition, scanning electron microscopy (SEM) for microstructure observation, atomic force microscopy (AFM) for the surface topography, ultraviolet–visible spectrophotometry (UV-VIS) for the optical properties and wettability of the thin films by measuring the water contact angle. The XRD analysis showed the amorphous phase. The SEM and AFM images revealed that the particles were less agglomerated and surface roughness increases from 1.21 × 102 to 2.63 × 102 nm when the amount of PEG increased. The wettability analysis results show that the water contact angle of the thin film decreased to 27.52° with the increase of PEG to 80 mg which indicated that the thin film has hydrophilic properties. The optical properties also improved significantly, where the light absorbance wavelength became wider and the band gap was reduced from 3.31 to 2.82 eV with the presence of PEG.

The effect of polyethylene glycol addition on the synthesis of solid acid catalyst and its applications in esterification reaction

Synthesis of a catalyst by a sol-gel method is commonly conducted using a template to form pores to increase the number of active sites. In this work, mesoporous silica-carbon composites were prepared by sol-gel method using polyethylene glycol (PEG) 6000 as the template. Sodium silicate, commercially known as water glass, a cheap material, was used as the silica source. Here, PEG 6000 served as both the carbon source and the template. The silica-PEG composite was then carbonized at 550°C for 1 h to obtain silica-carbon composite. The sulfonate group was grafted into the composite by sulfonation with sulfuric acid at 100°C for 5 h. The sulfonated silica-carbon catalyst had a surface area of approximately 1490.8 m2/g. The very high surface area was able to hold a large amount of sulfonate group resulting an ion capacity of approximately 2.09. The composite was successfully be used as heterogeneous catalyst for esterification of acetic acid with ethanol with a conversion of 90.27%, higher than that of commercially Flotrol F-007.

Effect of Polyethylene Glycol Addition on Nutritive Value of Green and Black Tea Co-products in Ruminant Nutrition

Effect of Polyethylene Glycol Addition on Nutritive Value of Green and Black Tea Co-products in Ruminant Nutrition

Effect of polyethylene glycol additives on structure, stability, and biocatalytic activity of ormosil sol–gel encapsulated yeast cells

Biohybrid materials based on ormosil encapsulated yeast cells were synthesized through a one-step sol–gel route with base-catalyst (NaF) using tetraethoxysilane (TEOS), methyltriethoxysilane (MTES) and polyethylene glycol (PEG) with different molar weights as a structure-controlling agent. Phase contrast microscopy and scanning electron microscopy were employed to evidence possible structures of the materials. The addition of PEG during cell encapsulation has induced structural changes within the biohybrids, which depend on PEG molecular weights. The biocatalytic activity of the living hybrids has been investigated by a biosensor which was based on the Clark-type oxygen electrode.

Synthesis of porous magnesia fibers with enhanced performance as a binder for molten electrolyte

This paper describes the synthesis and properties of the porous MgO fibers used as a binder of the electrolyte for thermal batteries. Porous MgO fibers with controlled pore size were prepared by a facile hydrothermal method in the presence of polyethylene glycol (PEG). The effect of PEG addition on the pore sizes of the porous MgO fibers was systematically investigated. The influence of porous MgO fibers having different pore sizes on the electrolyte (LiCl-KCl) leakage and electrochemical performances of the corresponding model cells were measured. The results show that a large amount of PEG leads to porous MgO fibers having high specific surface area and total pore volume, and reaching the maximum, 13.65m2g−1 and 0.097m3g−1 respectively, at 1.5mol% of PEG addition. The model cell fabricated with porous MgO fiber having high surface area and pore volume shows low deformation and electrolyte leakage, as well as high discharge capacity. Electrochemical impedance spectroscopy (EIS) analysis shows that, the ionic conductivity of the cell increases as the porous MgO fiber pore size increasing. These performances are much better than the performances of cell fabricated with traditional MgO powders. The dimensional stability and large surface area contact of porous MgO fibers with molten electrolyte should account for the superior physical and electrochemical performances of model cell fabricated with porous MgO fibers.

Effect of Polyethylene Glycol Addition on Metakaolin-based Geopolymer

Polyethylene glycol is a non-toxic water soluble polymer often used in many industrial applications. The aim of this paper is to study the effect of polyethylene glycol with relative molecular weight ranging between 400–20000 on the properties of geopolymer mortars composed of metakaolin and sodium silicate. Polyethylene glycol was added in the amount of 0.5 to 10% by mass of metakaolin. After 28 days of curing at ambient conditions, different tests were carried out: physico-chemical (density, porosity), mechanical (flexural and compressive strength) and structural (SEM). The results showed that a maximum compressive strength of 23.9MPa and a maximum flexural strength of 2.9MPa were achieved by adding 10% PEG 400.

Photocatalytic degradation of azo dyes by sol–gel TiO2 films: effects of polyethylene glycol addition, reaction temperatures and irradiation wavelengths

Two nanostructured sol–gel TiO2 films were prepared on a glass substrate by means of the dip-coating technique with titanium (IV) isopropoxide as a precursor with and without the addition of polyethylene glycol (PEG) as a structure-directing agent. The synthesized films were characterized by using thermal gravimetry, differential scanning calorimetry, micro-Raman spectroscopy, and atomic force microscopy (AFM). Results of the AFM analysis revealed that both films are nanostructured and that the TiO2 film prepared with the addition of PEG has higher values of roughness. The photocatalytic activity of the films was evaluated by the photocatalytic degradation of the methyl orange monoazo dye and the congo red diazo dye with predominant radiation wavelengths of 365 nm (UV-A) and 254 nm (UV-C). The effects of temperature (17.5, 25 and 35 °C) on the film stability and on the degradation process were also followed. The TiO2 film created with the addition of PEG showed heightened photoactivity at all reaction temperatures and higher degradation rates of both dyes were observed with the UV-C than with the UV-A radiation. In some cases, the total decolorization process was complete in 90 or 120 min, but the total mineralization of the dye solutions was not achieved after 120 min. The TiO2 films were stable at all three temperatures after more than 50 working hours. The degradation processes of dyes were monitored by means of the UV/VIS spectrophotometry and the liquid chromatography mass spectrometry together with the total organic carbon.

Fabrication and corrosion resistance of calcium phosphate glass-ceramic coated Mg alloy via a PEG assisted sol–gel method

To slow down the initial biodegradation rate of magnesium (Mg) alloy, crack-free CaO–P2O5–SrO–Na2O glass-ceramic coatings (CaPs) were synthesized using polyethylene glycol (PEG) assisted sol–gel method followed by a heat-treatment at 400°C. The thermal behaviors of the synthesized glass-ceramics were characterized by differential scanning calorimetry and thermogravimetric (DSC/TG). The glass transition temperature (Tg) of calcium phosphate system shifted to a lower temperature (~226°C) due to the addition of PEG, which promoted the crystal nuclei formation, thereafter induced a great amount of Ca2P2O7 at a relatively low temperature. The effects of PEG addition on the corrosion behaviors of the coated Mg alloys were investigated by the electrochemical measurements and immersion tests in simulated body fluid (SBF). It was found that the coatings comprised of massive crystalline phases could slow down the degradation rate and decrease the mass loss of the Mg alloy substrates from 78.04% to 3.81% in the 7th day test, showing a better anti-corrosion property than that of the calcium phosphate coatings without the addition of PEG. Moreover, protection effect of PEG assisted synthesis of calcium phosphate coating gradually declined after the initial soaking time, which was confirmed by electrochemical impedance spectroscopy (EIS) analysis. These results implied that crystallization induced by PEG addition would affect the corrosion resistance of the coated Mg alloy and subsequently influence the degradation rate.

Synthesis and Characterization of ZnO-SiO<sub>2</sub>/Epoxy Nanocomposite Coating by Sol-Gel Process

In this paper, we report preparation of hydrophilic hybrid nanocomposite coatings on glass substrates using Zinc acetate solutions based on 3-glycidoxypropyltrimethoxysilane (GPTMS), epoxy resin, aromatic amine (HY850), polyethylene glycol (PEG) and surfactant (polyoxyethylene(4)laurylether) by the sol-gel process. Furthermore, the effects of PEG addition to the precursor solutions on the hydrophilic property and microstructure of the resultant coating film were studied. The hydrophilic behavior study of the synthesized hybrid was performed by adding different amounts of polyethylene glycol precursor to the hybrid solution. Experimental results show that, among different amounts of PEGs, the best results are obtained by addition of PEGs (400) to the hybrid solution which can decrease the water contact angles down to 16 and using surfactant down to 0, and increase the free surface energy. Coated glass exhibits a higher strength than uncoated glass. Attenuated total reflectance infrared spectroscopic (ATR-IR) technique was used to characterize the structure of the hybrid films. The chemical structure of obtained network affects morphology of the coating. The morphology of the hybrid coatings was examined by transmission electron microscopy (TEM). The hybrid systems have a unit form structure and the inorganic phases were in the nanosize scale,

Physical and chemical properties of titanium dioxide printed layers

This study focuses on the preparation of the TiO 2 thin films from alkoxide solutions containing polyethylene glycol (PEG) as an anticracking agent by the sol–gel method on soda–lime glass plates. Sol application was carried out by inkjet printing using a modified office inkjet printer equipped with piezoelectric print head. The grey level of the printed image was varied in order to control the sol loading of the resulting printed pattern. The effect of PEG addition on the precursor and prepared layer properties was studied. Also, the influence of sol loading on physical properties and on photocatalytic activity of the printed layers was investigated. The thickness of prepared layer was studied by NanoCalc 2000 and the structure of prepared layers was evaluated by optical microscopy, AFM and SEM. The hydrophilic properties of TiO 2 thin films were studied by examining the contact angle of water on these films. Photocatalytic activity was investigated as a rate of 2,6-dichloroindophenol (DCIP) decomposition. In all cases, we prepared transparent thin layers of TiO 2 with varying thickness and surface morphology. PEG proved to be an efficient agent suppressing the formation of cracks.

POLYETHYLENE GLYCOL ADDITION DOES NOT IMPROVE EXOGENOUS SURFACTANT FUNCTION IN AN EXPERIMENTAL MODEL OF MECONIUM ASPIRATION SYNDROME

Meconium (MEC) is a potent inactivator of pulmonary surfactant. The authors studied the effects of polyethylene glycol addition to the exogenous surfactant over the lung mechanics and volumes. Human meconium was administrated to newborn rabbits. Animals were ventilated for 20 minutes and dynamic compliance, ventilatory pressure, and tidal volume were recorded. Animals were randomized into 3 study groups: MEC group (without surfactant therapy); S100 group (100 mg/kg surfactant); and PEG group (100 mg/kg porcine surfactant plus 5% PEG). After ventilation, a pulmonary pressure-volume curve was built. Histological analysis was carried out to calculate the mean alveolar size (Lm) and the distortion index (DI). Both groups treated with surfactant showed higher values of dynamic pulmonary compliance and lower ventilatory pressure, compared with the MEC group (P <.05). S100 group had a larger maximum lung volume, V30, compared with the MEC group (P <.05). Lm and DI values were smaller in the groups treated with surfactant than in the MEC group (P <.05). No differences were observed between the S100 and PEG groups. Animals treated with surfactant showed significant improvement in pulmonary function as compared to nontreated animals. PEG added to exogenous surfactant did not improve lung mechanics or volumes.

Effect of Polyethylene Glycol Additives on Pulse Electroplating of SnAg Solder

Eutectic Sn-3.5wt.%Ag alloy is one of the most promising lead-free solders in low temperature processes for wafer bumping. Near eutectic composition of deposited alloy films could be readily acquired by pulse electroplating with a proper combination of active ingredients including K4P2O7, KI, Sn2P2O7, and AgI, as well as polyethylene glycol (PEG), with molecular weights of 200, 600, 2,000, and 4,000, as an inhibitive agent. Pulse electroplating was carried out with current in alternating polarity to conduct electroplating and electropolishing sequentially. As a result, alloy films with grains of less than 1 μm and uniform surface morphology can be obtained. The addition of PEG was necessary for the stabilization of the plating baths to promote a wider process window for the desirable eutectic composition. Electrochemical characterization established that PEG with molecular weight of 4,000 exhibited the strongest inhibition behavior. In contrast, PEG with molecular weight of 200 demonstrated the least interference. Energy dispersive X-ray and differential scanning calorimeter data confirmed the formation of eutectic alloy as a function of deposition current density. X-ray diffraction results indicated that a biphasic structures of β-Sn and e-Ag3Sn was present in the as-deposited film.

Feeding value of supplemented diet with black tea by‐product silage: Effect of polyethylene glycol addition to the diet on digestibility of protein fractions in goats

AbstractThe feeding value of black tea by‐product silage was studied both in vitro and in vivo. To estimate the effect of tannins in black tea by‐product on nutrient digestibility, polyethylene glycol (PEG) was also given to goats as a tannin‐binding agent. Regarding in vitro ruminal fermentation, supplementation of black tea by‐products silage to basal substrates at more than 1% on a dry matter (DM) basis decreased the ammonia‐N (NH3‐N) concentration in the medium, indicating that black tea by‐products suppressed protein degradation in rumen. In the in vivo digestibility trial, six castrated goats were fed diets of timothy hay + soybean meal (control), control + black tea by‐product silage (+BTS), and control + black tea by‐product silage + PEG (+PEG) in a replicated 3 × 3 Latin square design. Black tea by‐product silage was supplemented to the control diet at 5% on a DM basis. Black tea by‐product silage supply significantly decreased crude protein (CP) digestibility compared to the control diet (63.9 vs 67.5%), but the diminished digestibility tended to be improved by PEG addition (66.5%). Acid detergent insoluble N (ADIN) was slightly digested in control (1.5%), but the digestibility was negative (–19.1%) in +BTS. On the other hand, addition of PEG clearly improved the ADIN digestibility (2.9%). Urinary N output and ruminal NH3‐N concentration was altered in neither +BTS nor +PEG. Fecal N output was significantly higher in +BTS than in control, but it tended to be lower in +PEG. The amount of retained N was the highest in +PEG, followed by +BTS and control. This study confirmed indirectly that chemical compound in black tea by‐product silage that lowered protein digestibility was tannins. It was suggested that offering black tea by‐products silage at a 5% rate in a diet was such a high level that fecal N output was increased by tannin‐protein bindings fractionated as ADIN.

Effect of polyethylene glycol additive in sol on the humidity sensing properties of a TiO2 thin film

We describe the effect of polyethylene glycol (PEG) addition to the precursor solution on the humidity sensing properties of a TiO2 thin film. Thin films of TiO2 were prepared by sol–gel and spin coating techniques. An increase in humidity sensitivity has been observed after the addition of PEG. This increase in sensitivity is due to smaller crystallites and pores created during the combustion of the polymer. The response and recovery time of the sensor were about 10 and 176 s, respectively. An equivalent circuit has been proposed and fitted well with the experimental data. We demonstrate that a controlled amount of polymer addition leads to the sensor being highly sensitive in the lower humidity (<40% RH) region.

Mechanisms controlling protein release from lipidic implants: Effects of PEG addition

Different types of tristearin-based implants for controlled rh-interferon α-2a (IFN-α) release were prepared by compression and thoroughly characterised in vitro. Hydroxypropyl-β-cyclodextrin (HP-β-CD) was added as a co-lyophilisation agent for protein stabilisation and different amounts of polyethylene glycol (PEG) as efficient protein release modifier. To get deeper insight into the underlying mass transport mechanisms, the release of IFN-α, HP-β-CD and PEG into phosphate buffer pH 7.4 was monitored simultaneously and appropriate analytical solutions of Fick's second law of diffusion were fitted to the experimental results. Importantly, the addition of only 5–20% PEG to the lipidic implants significantly altered the resulting protein release rates and the relative importance of the underlying mass transport mechanisms. The release of IFN-α from PEG-free implants was purely diffusion controlled. In contrast, in PEG-containing devices other phenomena were also involved in the control of protein release: the IFN-α release rate remained about constant over prolonged periods of time and the total amounts of mobile IFN-α increased. Interestingly, the release of PEG itself as well as of HP-β-CD from the implants remained purely diffusion controlled, irrespective of the amount of added PEG. Thus, different mass transport mechanisms govern the release of the drug, co-lyophilisation agent and release modifier out of the lipidic implants.

Effect of Polyethylene Glycol Addition on NiO-MoO&lt;sub&gt;3&lt;/sub&gt;/Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; and NiO-MoO&lt;sub&gt;3&lt;/sub&gt;-P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;/Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; Hydrodesulfurization Catalyst

Addition of polyethylene glycol (PEG) as a water soluble organic compound to the impregnation solution during catalyst preparation was investigated to improve NiO-MoO3/Al2O3 and NiO-MoO3-P2O5/Al2O3 hydrodesulfurization catalysts. XPS measurement suggested that PEG addition increases the dispersion of nickel and molybdenum on the alumina support and improves dibenzothiophene and resid hydrodesulfurization activity. The effect of PEG addition was significant for catalyst prepared from alumina with lower specific surface area and higher phosphorus content, in which the active metal precursor tends to easily aggregate. PEG might block the aggregation of active metal precursors during the drying step and may increase the number of hydrodesulfurization active sites.

Effect of polyethylene-glycol on the chemical composition and nutrient availability of olive ( Olea europaea var. europaea) by-products

Total extractable polyphenols (TEP), total extractable tannins (TET), total extractable condensed tannins (TECT) and total condensed tannins (TCT) were quantified in two very important olive by-products: the two-stage dried olive cake (TSDOC) and the olive leaves (OL). The effect of polyethylene-glycol (PEG) addition (0, 20, 60, 100 and 200 g/100 g by-product) on the chemical composition, in vitro digestibility and in situ degradability was studied. The effect of PEG addition (0, 2 and 20 g/100 g by-product) to TSDOC and OL on the in situ–in vitro intestinal availability of both rumen undegraded and dietary protein was also studied using different approaches: (i) apparent intestinal digestibility of ruminal undegraded protein (AIDUP) or amino acids (AIDUAA); (ii) apparent intestinal digestibility of dietary protein (AIDDP); (iii) ruminally degradable and intestinally digestible dietary protein (100−ADF-N). Results obtained in Granadina goats and Segureña sheep were compared. The nitrogen fraction attached to acid detergent fibre (ADF-N) decreased significantly ( P<0.01 and <0.001 for TSDOC and OL, respectively) by PEG addition. A significant effect was observed in TEP ( P<0.05 and <0.01 for TSDOC and OL, respectively), TET ( P<0.001 for both TSDOC and OL) and TECT ( P<0.001 for both TSDOC and OL). A significant decrease in cell wall components was only observed in OL treated with PEG. The in vitro digestibility, which was significantly higher when rumen liquor from goats was used in comparison with sheep, especially for TSDOC, significantly increased by the PEG addition. This effect was observed in both, TSDOC (from 0.202 to 0.328 IVOMD) and in OL (from 0.349 to 0.446 IVOMD). The effect of the animal species on the characteristics of the ruminal degradation of TSDOC and OL was variable and concerning effective degradability (ED) it was significantly higher in goats than in sheep (0.490 and 0.424, respectively) for OL protein. The effect of PEG addition was more pronounced in TSDOC than in OL. All the parameters of the TSDOC rumen degradation profiles increased significantly with increasing amounts of PEG (from 0.435 to 0.765 for ED of TSDOC protein). On the contrary, only the ED of OL dry matter increased ( P<0.01) by the addition of 2 g of PEG (from 0.535 to 0.582). The availability of ruminal undegraded and dietary protein in the small intestine, estimated in situ–in vitro with different approaches, significantly increased by the addition of two grams PEG/100 g by-product, while a further increase in the amount of PEG resulted in a decrease of intestinal availability. Although low tannin content in TSDOC and OL, addition of 2 g of PEG/100 g of by-product improved nutrient availability either at the rumen and intestine level. The effect was more important for sheep than goats.

Hydration and Some Other Properties of Polyethylene Glycol Modified Cement Products

Effect of polyethylene glycol addition to ordinary Portland cement on its properties like heat of hydration, setting time, compressive and tensile strength has been studied by adding 0.1 to 5.0 percent additive by weight of cement. Corrosion resistance of the resulting product has been tested against sea water and 0.1 and 1.0 N HCI and H2SO4 respectively. Water absorption/open porosity have also been determined and the microstructures examined. It was observed that strength, hardness, toughness and corrosion resistance increase up to 3.0% addition of polyethylene glycol in ordinary Portland cement. The polymeric phase was interspersed in cement causing decrease in water absorption/porosity and also its interaction with hydrating cement caused additional bond formation leading to increase in strength.