Hydrophylic Polymer Research Articles

Electrospinning of Fibres Using Mixed Compositions Based on Polyetherurethane and Hydrophylic Polymers for the Production of Membrane Materials

Electrospinning of Fibres Using Mixed Compositions Based on Polyetherurethane and Hydrophylic Polymers for the Production of Membrane Materials

Synthesis of Ag3PO4 using Hydrophylic Polymer and Their Photocatalytic Activities under Visible Light Irradiation

The highly active Ag3PO4 photocatalysts were successfully synthesized using the hydrophylic polymer of PVA (polyvinyl alcohol), PEG (polyethylene glycol) and PVP (polyvinyl pyrrolidone). The products were characterized using X-ray diffraction (XRD), Diffuse reflection spectroscopy (DRS), Field emission scanning electron microscope (FE-SEM), Brunauer–Emmett–Teller (BET) specific surface area, and X-ray photoelectron spectroscopy (XPS). Photocatalytic activities were evaluated using decomposition of Rhodamine B (RhB) under visible light irradiation. The results showed that the PVA, PEG, and PVP increased the specific surface area and enhanced the photocatalytic activity of Ag3PO4. The highest photocatalytic activity could be observed in Ag3PO4 synthesized with PVA, mainly due to an increase in electron excitation induced by PVA chemically adsorbed on the surface.

The influence of hydrophylic polymers on the release rate of calcium dobesilate in hydrogel formulation assessed in vitro using porcine ear skin

Abstract A shortage of available experimental data exists in the available bibliography on the release rate of calcium dobesilate (CD) from hydrogel formulations. Thus, the aim of the study was to evaluate the effect of selected hydrophilic nonionic polymers and anionic polymers on the release rate of CD from formulation provided for dermal application, as compared to the reference product in the market. The work utilized excised pork skin, while, Methylcellulose (MC), hydroxypropyl methylcellulose (HPMC), and anionic polymers (copolymers of acrylic acid) were used as CD carriers. The release study was executed by the pharmacopoeial paddle method, with extraction cells and fresh excised porcine skin as a membrane. CD in aqueous acceptor fluid was quantified by UV-VIS spectrometry at 300 nm. Subsequently, the kinetic curves were fitted to a zero-order kinetics model, a first-order kinetics model, a second-order kinetics model, as well as to the Higuchi model. The work saw that porcine ear skin influences the release pattern of the CD, compared to the artificial membrane. In the study, the evaluated formulations with MC, polyacrylic acid (PA) and polyacrylate crosspolymer 11 (PC-11) deliver over 60% of the active component (AC), within 250 min, through the excised porcine ear skin, to the acceptor compartment. Moreover, the release observed via porcine ear skin to the aqueous acceptor compartment is congenial to zero-order or first-order kinetics. In addition, the formulations prepared on the basis of MC and PA appear to control AC delivery, independently of actual concentration of AC.

Histologic findings following use of hydrophilic polymer with potassium ferrate for hemostasis

Hydrophilic polymer with potassium salt is a hemostatic agent marketed for use by healthcare professionals and as an over-the-counter product available to healthcare consumers. In particular, dermatologic surgeons may use hydrophilic polymer for hemostasis in wounds left to heal by secondary intention. Foreign body reaction to hydrophilic polymer was recently reported. The microscopic findings in four additional patients treated with hydrophilic polymer are presented. The wounds of three patients were treated with hydrophilic polymer following a dermatologic surgical procedure while one patient used over-the-counter hydrophilic polymer on an abrasion. Three patients developed a foreign body reaction. Histopathologic examination revealed angulated fragments of deep purple material representing hydrophilic polymer admixed with round orange-red bodies and yellow-brown granules representing potassium ferrate. The components were found both free in the dermis and within multinucleated giant cells. Hydrophilic polymer must be differentiated from other materials observed in re-excision specimens, including ferric subsulfate, aluminum chloride and Gelfoam(®) (Pharmacia and Upjohn Co., New York, NY, USA).

A novel way to maintain resorcinol–formaldehyde porosity during drying: Stabilization of the sol–gel nanostructure using a cationic polyelectrolyte

The formation of monolithic porous carbon having a BET surface area of ca. 725 m 2/g is achieved by carbonization of a resorcinol/formaldehyde (RF) resin prepared in the presence of a cationic polylectrolyte (polydialyldimethylammonium chloride, PDADMAC). The porosity of the resin is maintained during air drying due to the stabilizing effect of a cationic polyelectrolyte on the sol–gel nanostructure. While carbon made of RF resins prepared in the presence of cationic polyelectrolyte show a large surface area, those prepared in the presence of a negatively charged polyelectrolyte (poly(styrenesulfonate), PSS), a neutral hydrophylic polymer (poly(vinyl alcohol), PVA) or in the absence of polymeric additives renders carbon materials having negligible surface areas (<10 m 2/g). It seems that positively charged polymer stabilizes the negatively charged resin nanoparticles, suggesting a new mechanism of action for cationic species in porous RF formation. The method simplifies greatly the fabrication of porous carbon by making unnecessary to use complex (e.g. supercritical) drying procedures. It also does not require long curing times and cumbersome solvent exchange. Avoiding the use of organic solvents makes the process friendlier to the environment. The carbon material presents large electrochemical specific capacitance ( ca. 210 Fg −1 in acid media and 110 Fg −1 in neutral media) making it suitable for supercapacitor applications. The ion exchange properties, related with the double layer charging/discharging processes are investigated using Probe Beam Deflection techniques.

Novel Nanostructural Hybride Materials for Photodynamic Theraphy

AbstractPhotodynamic theraphy (PDT) is a clinically approved method for treatment of cancer and some other diseases. It employs the combination of a drug (photosensitizer) and light to induce photoxicity towards the cancerous cells. The efficiency of currently used photosensitizers is limited due to their aggregation in aqueous media and low chemical purity; usually a mixture of various isomers is used. This paper presents the results of our studies on the development of nanostructural materials for PDT. They are constructed from porphyrin (Po) which is covalently attached to the chain of hydrophylic polymer such as poly(methacrylic acid) (PMA) or poly(ethylene glycol) (PEG) and solubilized in lipid bilayer of liposome vesicles. The attachment of Po to the polymer chain improves its solubility in water while the solubilization in liposome carriers helps the dye to penetrate the cell membranes. Physicochemical and photophysical properties of those systems were determined. The in vitro studies on cancer cell lines demonstrated that the photosensitizers are efficiently accumulated in the cells. Their dark toxicity is negligible, while phototoxicity is very high.

Efficacy of graded doses of polymers on processing quality of tomato Cv. Co.3

A study was undertaken at Horiticultural College &amp; Research Institute, Coimbatore in tomato cv. Co.3 to optimize graded dose hydrophylic polymers and its effect on quality parameters. A total of three hydrophylic polymers viz., Terra Cottem, Polyvinyl alcohol and Polyacrylamide were selected for the study. The treatment included six levels each of Terra Cottem (T, to T, at 1.5, 3.0, 4.5, 6.0, 7.5 and 9.0 g per plant). Polyvinyl alcohol (T, to T,, at 3.0, 6.0, 12.0, 15.0 and 18.0 per plant), Polyacrylamide (T, to Tis at 2.5, 5.0, 7.5, 10.0, 12.5 and 15.0 per plant) and control (T,, at one part red earth, one part sand and one part farmyard manure). The results stated that the graded doses of 4.5, 15.0 and 10.0 g per plant of Terra Cottem, Polyvinyl alcohol and Polyacrylamide enhanced the TSS, flesh thickness, ascorbic acid, acidity, lycopene and shelf life of the fruit, which were not influenced significantly with further increase in doses of respective polymers.

Standardisation of hydrophylic polymers on growth and yield of tomato

An experiment was conducted at Horticultural College &amp; Research Institute, Tamil. Nadu Agricultural University, Coimbatore to standardise the hydrophylic polymers on growth and yield of tomato. Three commercially available polymers viz. TerraCotten (TerraCottem International. Belgium). Polyvinyl alcohol (Aquatrols corp. of America, USA) and Polyacrylamide (Viterras, Germany) were chosen for the study and used as soil conditioners for temato cv.Co.3. The results indicated that TerraCottem 4.5g plant (T) improved the plant height, branches per plant, rout length, root dry weight, fruits per plant, fruit weight, yield per plant and dry matter production. The results were on par with higher doses of respective polymers.

Crystal polymer interaction with new injectable bone substitute; SEM and Hr TEM study

A composite constituted of calcium phosphate (CaP) granules and a hydrophilic polymer as a carrier (hydroxy-propyl-methyl cellulose, HPMC) was developed to be an injectable bone substitute (IBS, CNRS patent). IBS is a composite and not an ionic cement. The composite obtained is ready to use and sterile. Chemical interactions between organic and inorganic components appeared during the association of the two. The interactions of the CaP and the polymer have been studied using scanning electron microscopy (SEM), electron microprobe (EDX), and high-resolution transmission electron microscopy (HrTEM) SEM revealed a degradation of the granules into smaller particles while EDX was unable to show significant changes in the Ca/P ratio during aging of the composite. With Hr TEM, however, we observed hydrolysis (process of dissolution and precipitation) from the surface to about 13 nm into the HA crystals and occasional dissolution with precipitation of beta-TCP crystals. In HA, the first zone of interaction consisted of a single layer of small globular crystals of 2 to 3 nm in diameter. Numerous lattice patterns in all three axes could be observed. Under the globular crystals zone, the inter-reticular distances of the single crystals appeared enlarged by 1.2% (from 0.817 to 0.827 nm). The enlargement seems to correspond to diffusion of HPO(4) into the crystal lattice. In beta-TCP crystals, dissolution was observed to be several nanometers deep, but globular surface precipitation rarely was observed. With time or after steam sterilization, no changes were observed. These data demonstrate the strong interactions of the hydrophylic polymer with calcium phosphate, but only in the first several nanometers of thickness.

Regularities of Multicomponent Transport in Polymer Systems for Controlled Drug Release

Abstract A mathematical model predicting the behavior of systems consisting of hydrophylic polymer, water, and a low-molecular compound has been developed. The model takes into account the process of swelling of polymers during water sorption, the existence of the embedded form of drug in polymer matrix and some other factors. The dependence of physico-chemical parameters on concentration of water, drug and on mechanical properties of polymer were confirmed by corresponding experimental results. Different ratios of kinetic parameters determined in this study enable us to predict the effect of matrix characteristics on controlled release of drugs.

A hydrophylic polymer system enhanced articular cartilage regeneration in vivo

This study describes a new method for the repair of large articular cartilage defects in the knee joint and compares the effect of two polymer systems on the quality of the repair tissue. The two systems are a newly developed hydrophylic system, based on poly-ethyl-methacrylate (PEMA) polymer and tetra-hydro-furfuryl-methacrylate (THFMA) monomer and the conventional bone cement polymer system, based on poly-methyl-methacrylate (PMMA) polymer and methyl-methacrylate (MMA) monomer. Thirty adult Sandy-lop rabbits were used. Both knees were operated on in each animal, the one defect received either PEMA/THFMA or conventional bone cement and the contralateral defect received no biomaterial (control group). Femora were retrieved at six weeks and the repair tissue was studied by histology, histochemistry and immuno-histochemistry. PEMA/THFMA enhanced the quality of the repair significantly (p<0.0001). By six weeks hyaline-like articular cartilage was the predominant tissue covering the defects and it was fully integrated with the surrounding normal articular cartilage. Immuno-localization showed cartilage components, including collagen type II, distributed evenly throughout its matrix. PMMA/MMA on the other hand did not improve significantly the repair tissue, which was predominately fibro-cartilaginous, poorly bonded to the adjacent normal articular cartilage. The method of implantation is simple and easily reproducible and the new polymer has been well-accepted by the rabbits.

Use of Hydrophylic Polymers in Horticulture

Hydrophylic polymers are synthetic, water-absorbing monomers of high molecular weight. They have been used as absorbents in the diaper industry for the past 30 years. Polymers differ from each other in the specific monomer building block, amount of water absorbed per gram of material, particle size and distribution, response to salinity, and cost. While there are only four different monomers used in the production of polymers, there are several dozen polymers available commercially under different trade names. Benefits derived from polymer application to soil or artificial medium include: increase in water-holding capacity, increase in pore size/number, increase in soil nutrient reserves, and reduction in soil compaction. Initial use of polymers was reported in greenhouse production in the late 1970s, but is now used in the production of fruits, vegetables, and turf. Development of application equipment has the potential to expand the use of polymers to large commercial growers.

The Modeling of the Simultaneous Transport of Solvent and Low-Molecular Compounds in Swelling Polymers

Abstract Mathematical model has been developed in order to predict the behavior of systems consisting of hydrophylic polymer, water, and low-molecular compound. The model has taken into account the processes of swelling of polymers during water sorption. the existence of embedded form of drug in polymer matrix and some others processes. The dependencies of physico-chemical parameters on concentration of water, drug and on mechanical properties of poiymer were justified by corresponding experimental results. Different ratios of these parameters enable to predict the behavior of matrix systems for controlled release of drugs.

Water Absorption of Hydrophylic Polymers (Hydrogels) Reduced by Media Amendments

Abstract Water absorbency of 4 commercially available hydrophylic polymers (hydrogels) (Agrosoke, Liqua-gel, Mizuace and Terra-sorb HB) in response to 4 media amendments (Micromax, Osmocote 18N-2.6P-10.0K (18-6-12), gypsum and dolomitic limestone) and the combination of 4 amendments was determined. Water absorbency of 4 hydrogels was reduced by all amendments except Osmocote added to Liqua-gel. Generally, hydrogel absorbency was reduced most by Micromax and the combination of media amendments, followed by gypsum, Osmocote, and dolomitic limestone. None of the hydrogels functioned as advertised.

Effect of Hydrophylic Polymer Amendment on Growth of Container Grown Landscape Plants

Abstract Four experiments were conducted over 3 years to determine the influence of a water-absorbing polymer (hydrogel), Mizuace4, on the growth of container grown landscape plants. Amending the 100% pine bark growth medium with 0,0.9, 1.8, 2.7, or 3.6 kg/m3 (0, 1.5, 3.0, 4.5, 6.0 lb/yd3) hydrogel did not affect irrigation frequency. Foliar and growth medium nutrient levels were minimally affected, and shoot and root growth were reduced or not affected by increasing rates of hydrogel.

Hydrophylic Polymers as a Carrier for VA Mycorrhizal Inoculum

Four techniques of inoculating rooted Carissa grandiflora cuttings with the mycorrhizal fungus Glomus intraradices were evaluated. Placement of a root inoculum around the root systems of Carissa or totally incorporated into potting medium resulted in higher colonization levels than dipping cutting root systems in suspensions of inoculum in Viterra or Terrasorb hydrophyllic polymers. Growth responses, especially top dry weight, showed little difference among the inoculation techniques. Mycorrhizal mediated growth benefits for the tops were realized for all treatments. Storage of root inoculum for 12 weeks at 4.4°C (40 °F) had little effect on colonization levels by the fungus in Carissa roots.

Smectite-polymer interactions in aqueous systems

AbstractNeutron scattering studies have indicated that the non-coordinated water at smectite surfaces has a similar mobility to that of bulk water, but that the water coordinated to the cations is immobile on the time scale of the neutron measurements. Thus hydrophylic polymers can readily displace the non-coordinated water and bind to the silicate surface, and to the exchangeable cations through a water-bridge mechanism. Poly(ethylene oxide) molecules with molecular weights up to 4000 appear to be bound to Na-montmorillonite in flattened conformations at the clay surface. Poly(vinyl alcohol) is extensively bound by Na-montmorillonite and by Na-Laponite (a synthetic hectorite-like clay); as binding progresses fewer molecule segments can contact the surface and so at the higher levels of adsorption extensive loops of polymer extend away from the silicate surface. Some polyanions provide good protection for smectites against flocculation with salt. The abilities of such polymers to protect the clays is dependent both on the extents of the charges and on the solution conformations which these polymers can assume.

Preparation and polymerization of 1,2‐epoxypropyl 2,3,4,6‐tetra‐O‐acetyl‐β‐D‐glucopyranoside

AbstractAllyl D‐glucopyranoside tetraacetate is prepared by reaction of acetobromo‐D‐glucose with allyl alcool. The glycoside is not readily polymerized by free radical mechanism but on conversion to the epoxide with peracids, polymerization is easily induced with triethylaluminum. The product with a D. P. of 250 is soluble in organic solvents. On alkaline deacetylation the hydrophylic polymer is water soluble but the aqueous solution possess comparatively low viscosity.