Presence Of Water-soluble Polymers Research Articles

Water-Soluble Polymer Polyethylene Glycol: Effect on the Bioluminescent Reaction of the Marine Coelenterate Obelia and Coelenteramide-Containing Fluorescent Protein.

The current paper considers the effects of a water-soluble polymer (polyethylene glycol (PEG)) on the bioluminescent reaction of the photoprotein obelin from the marine coelenterate Obelia longissima and the product of this bioluminescent reaction: a coelenteramide-containing fluorescent protein (CCFP). We varied PEG concentrations (0-1.44 mg/mL) and molecular weights (1000, 8000, and 35,000 a.u.). The presence of PEG significantly increased the bioluminescent intensity of obelin but decreased the photoluminescence intensity of CCFP; the effects did not depend on the PEG concentration or the molecular weight. The photoluminescence spectra of CCFP did not change, while the bioluminescence spectra changed in the course of the bioluminescent reaction. The changes can be explained by different rigidity of the media in the polymer solutions affecting the stability of the photoprotein complex and the efficiency of the proton transfer in the bioluminescent reaction. The results predict and explain the change in the luminescence intensity and color of the marine coelenterates in the presence of water-soluble polymers. The CCFP appeared to be a proper tool for the toxicity monitoring of water-soluble polymers (e.g., PEGs).

Preparation of Nanosized Particles of Cobalt in the Presence of Water-Soluble Polymers

Preparation of Nanosized Particles of Cobalt in the Presence of Water-Soluble Polymers

Bioinspired composite materials: sorbents for chromatography, bone-like structures and substrates for cell cultures

Abstract. Simulation of calcium and silicon biomineralization made it possible to obtain various composite particles containing an inorganic component and an organic polymer. These particles exist in a variety of forms, from stable aqueous dispersions to solid materials. New composite materials are promising for creating functionalized coatings and three-dimensional structures of different morphology. We prepared composites of calcium carbonate and phosphate by forming an inorganic phase in the presence of water-soluble polymers. The potential of new materials as sorbents for chromatography, 3D bone-like structures, and coatings for cell growth was demonstrated.

Density, Viscosity and Ultrasonic Velocity of Brij-35 in Presence of Water-Soluble Polymers

Density, Viscosity and Ultrasonic Velocity of Brij-35 in Presence of Water-Soluble Polymers

Synthesis and Stabilization of Gold Nanoparticles Using Water-Soluble Synthetic and Natural Polymers.

Gold nanoparticles (AuNPs) were synthesized and stabilized using the one-pot method and growth seeding, through utilization of synthetic polymers, including poly(N-vinylpyrrolidone) (PVP), poly(ethylene glycol) (PEG), and poly(vinylcaprolactame) (PVCL), as well as natural polysaccharides, including gellan, welan, pectin, and κ-carrageenan. The absorption spectra, average hydrodynamic size, ζ-potential, and morphology of the gold nanoparticles were evaluated based on various factors, such as polymer concentration, molecular mass of polymers, temperature, and storage time. The optimal polymer concentration for stabilization of AuNPs was found to be 4.0 wt % for PVP, 0.5 wt % for gellan, and 0.2 wt % for pectin, welan, and κ-carrageenan. The values of the ζ-potential of polymer-stabilized AuNPs show that their surfaces are negatively charged. Most of the AuNPs are polydisperse particles, though very monodisperse AuNPs were detected in the presence of a 0.5 wt % gellan solution. At a constant polymer concentration of PVP (4 wt %), the average size of the PVP–AuNPs decreased with the decrease of molecular weight, and in the following order: PVP 350 kDa (~25 nm) > PVP 40 kDa (~8 nm) > PVP 10 kDa (~4 nm). The combination of Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy revealed that the functional groups of polymers that are responsible for stabilization of AuNPs are lactam ring in PVP, carboxylic groups in gellan and welan, esterified carboxylic groups in pectin, and SO2 groups in κ-carrageenan. Viscometric and proton nuclear magnetic resonance (1H NMR) spectroscopic measurements showed that the temperature-dependent change in the size of AuNPs, and the gradual increase of the intensity of AuNPs at 550 nm in the presence of gellan, is due to the rigid and disordered conformation of gellan that affects the stabilization of AuNPs. The AuNPs synthesized in the presence of water-soluble polymers were stable over a period of 36 days. Preliminary results on the synthesis and characterization of gold nanorods stabilized by polymers are also presented.

Effect of Ultrasonic Treatment on Properties of Aqueous Dispersions of Inorganic and Organic Particles in Presence of Water-Soluble Polymers

Effect of Ultrasonic Treatment on Properties of Aqueous Dispersions of Inorganic and Organic Particles in Presence of Water-Soluble Polymers

Effect of Ultrasonic Treatment on Stability of TiO2 Aqueous Dispersions in Presence of Water-Soluble Polymers

Effect of Ultrasonic Treatment on Stability of TiO2 Aqueous Dispersions in Presence of Water-Soluble Polymers

Gas hydrate nucleation and growth in the presence of water-soluble polymer, nonionic surfactants, and their mixtures

We investigated the effect of mixtures of commercial nonionic surfactants Sintanol ALM-7 (A7), Sintanol ALM-10 (A10), Surfynol 465 (S6), Surfynol 485 (S8), and well-known kinetic hydrate inhibitor Luvicap 55W (sample P) on nucleation and growth of sII gas hydrate. The ramp method (cooling at a constant rate of 1 °C × h−1) was employed to determine hydrate onset temperature and subcooling of individual and mixed samples. The dosage of reagents varied within 0.25–1.0 mass% range. A7 and A10 were tested at concentrations of 1.6∙10−4–2.5∙10−3 mass% (about or lower than CMC) as well. All surfactants were found to be weak antinucleators of gas hydrates. The inhibition performance of the surfactants was significantly lower in comparison with Luvicap 55W. We observed that ethoxylated fatty alcohols (A7 and A10) at low concentrations demonstrated a hydrate-inhibiting action at nucleation and growth stages.The Luvicap 55W – surfactant mixtures were tested as KHIs with a total dosage of 0.5 mass%, and in the ratio of 1:1, 1:2, and 1:5. Several mixed samples (1:1 P + A10), (1:2 P + A10), (1:2 P + S6) have demonstrated the same or higher efficacy in inhibition of hydrate nucleation than pure KHI. The results obtained indicate the presence of a synergistic effect of kinetic inhibition of gas hydrate with mixtures of the polymer and ethoxylated nonionic surfactants. Among the mixtures, the best results were obtained for the sample (1:2 P + S6). Surfynol 465 is characterized by high solubility in water, low foaming (compared to other surfactants), and lower cost than vinyl lactam-based KHI. Thus, the Surfynol 465 is a promising synergist for the vinyl lactam polymeric KHI and allows reducing the dosage of the expensive polymer.

Modification of microstructure of cement mortars by water-soluble polyvinyl alcohol

The scanning electron microscopy (SEM) was used to describe the morphology and condition of hydrate crystals. This work is designed to investigate the simultaneous effect of both polymers to cement ratio (p/c) and water to cement ratio (w/c) ratios on flexural strength of type I ordinary Portland cement mortar containing PVA. The obtained results confirmed the effect of the added polymer and an optimum value for p/c equal to 1.6% at optimum w/c of 0.30 was recommended due to highest obtained flexural strength, which is two times of the strength of unmodified mortar. SEM images present an abundant crystal of cement mortar growth noticed at the air void surfaces of the modified mortars where the presence of water-soluble polymers is expected. Possible film formation on the surface of cement grains due to PVC addition was studied by examining the influence of the curing conditions on the flexural strength.

Influence of Polyelectrolytes on the Processes of Structure Formation of Copper Powders

The results of the studies on the synthesis of ultrafine copper powders are described in the article. The mechanisms of formation of ultrafine powders, using water-soluble polyacrylamide and polyvinyl-pyrrolidone polymers, as particle growth inhibitors, are presented. The processes occurring in the presence of water-soluble polymers and their influence on the structure of the obtained ultrafine copper powders are described. The interaction of the matrix of polymer composite materials with filler particles is analyzed. The kinetics of crystallization and transformation of crystalline phases of the powder, due to the process in the presence of water-soluble polymers, as stabilizers of particle growth, are investigated.

Sulfur nanoparticles stabilized in the presence of water-soluble polymers

A method was developed to prepare sulfur nanoparticles (nanosulfur) via reaction between sodium thiosulfate and sulfuric acid in the presence of water-soluble poly-N-vinylpyrrolidone (PVP) with different molecular weights. Polymeric hydrogel ointments were prepared from agar-agar, PVP, poly(ethylene glycol) solutions with virable concentrations of sodium thiosulfate and sulfuric acid. The ointment samples showed antibacterial and antifungal activities against Staphylococcus aureus, Escherichia coli and Candida guilliermondii.

Cyclodextrin solubilization of celecoxib: solid and solution state characterization

The low aqueous solubility of celecoxib (CCB) hampers its oral bioavailability and permeation from aqueous environment through biological membranes. The aim of this study was to enhance the aqueous solubility of CCB by complexation with cyclodextrin (CD) in the presence of water-soluble polymer. The effects of different CDs (αCD, βCD, γCD, 2-hydroxypropyl-β-cyclodextrin and randomly methylated β-cyclodextrin (RMβCD)) and mucoadhesive, water-soluble polymers (hydroxypropyl methylcellulose (HPMC), chitosan and hyaluronic acid) were investigated. The phase solubility profiles and CCB/CD complex characteristics were determined. RMβCD exhibited the greatest solubilizing effect of the two CDs tested. However, γCD was also selected for further investigations due to its safety profile. Addition of polymer to the aqueous CD solutions enhanced the CD solubilization. Formation of CCB/RMβCD/HPMC and CCB/γCD/HPMC ternary complexes resulted in 11 and 19-fold enhancement in the apparent complexation efficiency in comparison to their CCB/CD binary complex, respectively. The size of ternary complex aggregates in solution were determined to be from about 250 to about 350 nm. The data obtained from Fourier transform infra-red, differential scanning calorimetry and powder X-ray diffraction indicated presence of CCB/CD inclusion complexes in the solid state. Proton nuclear magnetic resonance data demonstrated that CCB was partially and totally inserted into the hydrophobic central cavities of RMβCD and γCD.

Polypyrrole nanotubes: The tuning of morphology and conductivity

Polypyrrole nanotubes rank among important functional materials with high application potential. They are prepared by the oxidative polymerization of pyrrole usually in the presence of methyl orange and represent conducting polymers with the highest bulk conductivity, 40–50 S cm−1. The role of methyl orange in promoting the nanotubular morphology of polypyrrole is discussed on the basis of FTIR and Raman spectra. The model based on the organization of acid form of methyl orange molecules to an in-situ-generated solid template is proposed. Various factors controlling the morphology and conductivity of polypyrrole have been identified. Higher acidity of reaction medium or the addition of ethylene glycol increased the diameter of nanotubes or even converted nanotubes to globules, and the conductivity was reduced. Nanotubes have not been obtained at temperature elevated to 60 °C but one-dimensional polypyrrole morphology was surprisingly produced even when the oxidation of pyrrole took place in frozen reaction medium, in ice, at −24 °C. The counter-ions in iron(III) salt used for the oxidation and the presence of water-soluble polymers had virtually no influence on morphology and conductivity. On the other hand, a series of organic dyes used as replacement of methyl orange had substantial effect on both the nanotubular morphology and conductivity. The role of template formation is discussed by comparing methyl orange and ethyl orange dyes. While the former dye precipitates under acidic conditions and supports the growth of nanotubes, the latter does not and globules are obtained instead.

A Facile Green Synthesis of Silver Nanoparticles Based on Poly-L-Lysine.

In this paper, we report a novel synthesis method for silver nanoparticles with facilely controllable morphology under mild conditions. The particles were synthesized by reducing silver nitrate in the presence of water soluble polymer of poly-L-Lysine (PLL) which was used as reducing agent and stabilizer. Experimental results revealed that size variation and overall formation mechanism of the resulting silver particles were mostly determined by the conformation of PLL which was in turn controlled by pH of solution and temperature. Due to biological activity and response ability of PLL to outer stimuli, the method provides a facile and controllable method for producing silver particles with different morphologies. We believe that the synthesis method will contribute to applications of the PLL and silver particles in biomaterials.

Electrochemical Deposition of Zinc Oxide on the Surface of Composite Membrane Polysulfone-Graphene-Polystyrene in the Presence of Water Soluble Polymers

The aim of this study consisted in the development of an alternative synthesis procedure for hybrid ultrafiltration membranes for water purification. The membranes were obtained by wet-phase inversion method based on aliquots of polysulfone (PSF) and graphene nanoplatelets modified with poly(styrene) (G-PST). The hybrid materials were modified by electrochemical deposition of zinc oxide (ZnO) on one side of the membranes in the presence of water soluble polymers. Raman, XPS, and TGA analyses were used to characterize the chemical and thermal characteristics of the PST-G. SEM analysis showed the formation of asymmetric porous configuration in all cases and the generation of ZnO with different shapes/structures on the bottom surface of the membrane or inside the porous channels. EDS analysis confirmed the formation of ZnO.

EFFECT OF METHYL-Β-CYCLODEXTRIN COMPLEXATION ON THE HYPOGLYCEMIC AND HYPOLIPIDEMIC EFFECTS OF KHELLIN: EXPERIMENTAL STUDY

Objective: The present work tackled the development and evaluation of inclusion complex of khellin (KH) and methyl-β-cyclodextrin (MβCD). In addition, it tested its possible hypoglycemic and hypolipidemic effects.Methods: Inclusion complexes of KH-MβCD in the presence of water-soluble polymer were prepared by freeze drying (FD), co-evaporation (EV) and kneading methods (KN). The selected ternary complex was characterized by Fourier transform infrared spectrophotometry (FTIR), x-ray diffractometry (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy [1]. Assessment of the hypoglycemic effect of the selected ternary complex versus the standard drug metformin was studied. Two different doses of the ternary complex were administered orally to streptozotocin (STZ)-induced type 2diabetic rats. Their hypoglycemic and hypolipidemic effects were evaluated by measuring the fasting blood glucose level (BGL), total cholesterol (TC) and triglycerides levels (TG) along the study period.Results: The FD complex showed the highest drug dissolution rate. All the performed characterization analysis confirmed the formation of a KH-MβCD inclusion complex. The in vivo study declared that both doses showed a marked hypoglycemic and hypolipidemic effects compared to metformin.Conclusion: In conclusion, this study points for the first time that the complexation of KH with MβCD could notably improve the dissolution rate and hence the bioavailability of KH. Moreover, this study demonstrated that this compound has a hypoglycemic and hypolipidemic effect. Thus, it can be a promising natural supportive treatment in type 2 diabetes mellitus (T2DM).

Investigation of nickel chemical precipitation kinetics

The results of investigation of nickel hypophosphite reduction reaction kinetics in the bulk solution depending on the pH, temperature, oxidant content, nature and concentration of the activator, the presence of water-soluble polymer - polyvinylpyrrolidone are presented.The main objective of the study was to investigate the kinetics and establish optimum conditions for nickel chemical precipitation in the bulk solution. It is found that the process of chemical precipitation of the metal in the alkalescent environment is characterized by the high rate and small induction period at a temperature of 60–70 oС. The presence of polyvinylpyrrolidone in the solution affects the induction period duration and the reduction reaction rate. The nature of the polyvinylpyrrolidone effect depends strongly on the pH. It is proved that using preformed nickel hydrosols as the activator makes it possible to significantly shorten the induction period of the reduction reaction at low temperatures.The results are used in the development of technology and substantiation of the process parameters of synthesis of composite metal-filled polyvinylpyrrolidone copolymers with (meth) acrylates and hydrogel materials on their basis by a combination of metal polymerization and reduction processes.

Effect of Substrate Nature and Electrolysis Modes on Ultramicron and Nanosized Electrolytic Powders Formation Regularities

This article presents the research on the effect of substrate nature and electrolysis modes on ultramicron and nanosized electrolytic powders formation regularities. It was found that the preliminarily electropolishing of titanium cathode in combination with impulse electrolysis mode for nickel and copper powders obtaining provides for the predomination of nanosized fraction. The presence of water soluble polymers in the electrolyte for copper powder obtaining, polyvinylpyrrolidone (PVP) and polyacrilamide (PAA) allows forming stable dendritic powders with low agglomeration. Using of powders stabilized by polymers allows obtaining compositions with uniform particle distribution across the whole volume of the sample which provides for heightened wear resistance of composition materials.

Micro/nanostructures of PANI obtained in the presence of water soluble polymers and their electrochemical sensing properties

Polyaniline (PANI) micro/nanostructures are synthesized by electrochemical polymerization, and characterized by field-emission scanning electron microscopy, Fourier transform infrared spectroscopy and UV-visible spectroscopy. It is revealed that the PANI microwires are produced with high yield with diameters of about 2 μm and lengths of several hundreds of micrometers, while nanostructures in the presence of PAA have diameters of about 500 nm. The micro/nanostructured PANI films are very stable and show high electrocatalytic reduction toward H2O2, which makes it an ideal substrate for H2O2 detection and offers great promise for biosensing applications.

Electrochemical oxidation and removal of arsenic using water-soluble polymers

In this work, the electrochemical oxidation of arsenite and its subsequent removal was studied using water-soluble poly[glycidyl methacrylate N-methyl-d-glucamine], P(GMA–NMG), and poly[2-(acryloyloxy)ethyl]trimethylammonium chloride, P(ClAETA). In the first stage, the electroanalysis of arsenic (via oxidation of arsenite to arsenate) by cyclic voltammetry in the presence of water-soluble polymers was conducted. The type of polymer, electrode (gold or platinum), polymer concentration, and pH were evaluated. The study indicated that using P(GMA–NMG) and a gold electrode, oxidation peaks were obtained at approximately +0.5 V versus Ag/AgCl. In the case of P(ClAETA), wide oxidation peaks were obtained at +0.8 V versus Ag/AgCl using a platinum electrode. The optimum concentration for both polymers was 0.05 mol L−1. For P(GMA–NMG), the oxidation potential was influenced by a change of pH. The quantitative oxidation of As(III) to As(V) was conducted using metallic electrodes with higher surface areas. The conversion of arsenic as a function of applied potential was also evaluated. The results showed an efficient oxidation in the presence of both water-soluble polymers. Finally, 60 % of the As(V) could be removed through polymer-enhanced ultrafiltration. The results demonstrated an increase in the removal of pre-oxidized arsenic.