Performance Of Polyvinyl Alcohol Research Articles

Comparing Protein and Gene Expression Signature between Nasal Polyps and Nasal Fluids in Chronic Rhinosinusitis

Introduction: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a serious inflammatory condition. Nasal fluids (NFs) present a noninvasive alternative to nasal biopsy for studying CRSwNP pathogenesis. We aimed to compare the protein and mRNA inflammation signature between nasal polyps (NPs) and NFs. Method: The performance of polyvinyl alcohol (PVA) sponges and NFs absorbable device (NFAD) for collecting NFs from 20 patients with CRSwNP was compared using the Luminex assay. The other group consisted of four healthy controls and an additional 21 CRSwNP patients (including eosinophilic CRSwNP [ECRSwNP] and non-eosinophilic CRSwNP [NECRSwNP]) for protein quantification by Olink platform and gene expression evaluation by RNA-sequencing. Spearman’s analysis was performed to detect correlations between protein expression levels in NFs and clinical assessment variables. Results: NFAD-collected NFs contained at least a 2-fold higher concentration of cytokines than that obtained using PVA sponge, and these cytokines levels are significantly associated with NPs (ρ > 0.45, p < 0.05). Differentially expressed proteins between NFs and NPs were significantly correlated in the ECRSwNP subgroup compared with controls (ρ = 0.41, p < 0.01). Levels of Th2/IL-13, MCP4, and CCL4, characteristic of eosinophilic infiltration, were increased in ECRSwNP patients. A significant correlation between gene and protein expression was observed (ρ = 0.34, p < 0.01). PDL2 levels in NFs were positively correlated with ECRSwNP postoperative recurrence, the nasal VAS, and SNOT-22 scores (ρ > 0.68, p < 0.05 for all). Conclusion: Our study revealed similarities and discrepancies in inflammatory signatures between NPs and NFs in the same CRSwNP patient.

Effect of ultrafine grinding and ultrasonication duration on the performance of polyvinyl alcohol (PVA) agave gigantea cellulose micro fiber (CMF) bio-composite film

ABSTRACT This paper aims to assess the effect of ultrafine grinding and ultrasonication treatment on the bio-composite characteristics of polyvinyl alcohol (PVA) Agave gigantea (AG) Cellulose Micro Fiber (CMF) bio-composite film performance. This study included five different types of samples. FESEM investigation of PVA/CMF revealed a fiber diameter of 10–15 μm. According to X-ray diffraction, the CMF bio-composite has the highest crystallinity index (87%). The bio-composite film was as transparent as the pure PVA film, demonstrating that the CMF was uniformly dispersed throughout the film. Tensile testing revealed that the ultrafine grinding and ultrasonication treatment for 2 h (PVA/U2) increased tensile strength by 43% compared to the untreated PVA/CMF sample. This finding is confirmed by thermogravimetry analysis (TGA) and derivative (DTG) analyses, which show that the PVA/U2 sample has the most significant degree of thermal stability when compared to other samples. An ANOVA output supports the results of this experiment with an R2 value of 0.94600232 at a 95% confidence level. The p-value of 0.000079 and F-value of 10.80004 for ultrafine grinding and ultrasonication duration on AG leaf-based PVA bio-composite revealed a statistically significant influence on the studied parameters.

Hypergravity field induced self‐assembly of 2D MXene in polyvinyl alcohol membrane matrix and its improvement of alcohol/water pervaporation

AbstractHydrophilic nanomaterials were always used to improve the pervaporation (PV) performance of polyvinyl alcohol (PVA) membrane in the process of ethanol dehydration. In this work, the PVA/MXene composite membrane with high water flux and separation factor was fabricated with spin coating method. Induced by the hypergravity force, the MXene nanosheets were segregated and stacked layer‐by‐layer between the interface of the PVA/MXene layer and the support. The self‐assembly 2D MXene in the PVA not only improved the binding force between the separation layer and the support but also enhanced the PV performance. The water flux and separation factor of the PVA/SSA/MXene composite membrane reached 1.22 kg·m−2·h−1 and 1577, respectively. Both were higher than those of most reported PVA membranes. Nano indentation and scratch tests also revealed that due to the high modulus and hardness of the PVA/SSA/MXene composite membrane, 0.2822 and 0.019 GPa, strong binding force was existed between the separation layer and the support. Partly based on this reason, the structure of the PVA/SSA/MXene composite membrane remained stable during 300 hours of the PV test. It is believed that the prepared PVA/SSA/MXene composite membrane has a broad application prospect in the PV process for ethanol dehydration.

Performance of Polyvinyl Alcohol and Polypropylene Fibers under Simulated Cementitious Composites Pore Solution

The thermal properties of polymer fibers namely polyvinyl alcohol fiber (PVA) and polypropylene fiber (PP) have been taken for study to carry out this present work. Simulated pore solution (SPS) is prepared by using the combination of chemicals NaOH, KOH, and Ca(OH)2 with distilled water to study the effect of C-S-H gel formation on fibers. The fibers are dipped in the solution for 35 days. The thermal properties of raw and SPS-dipped fibers are fetched out by performing various tests such as Fourier transform infrared (FTIR) analysis, thermo gravimetric analysis (TGA), differential scanning calorimetry analysis, and scanning electron microscopy (SEM). On analysis, the thermal properties of SPS-dipped fiber have better properties when compared with raw fiber. In FTIR analysis the first broad peak of both raw and SPS-dipped fibers are observed between 3000 cm−1 to 2800 cm−1 indicating that fibers have strong bond. In TGA analysis noted that the residual mass of raw fiber (77.19%) is higher than SPS-dipped fiber (52.33%) due to the formation of C-S-H gel formation. DSC analysis showed both endothermic and exothermic reaction under N2 atmosphere.

Performance of Polyvinyl Alcohol/Bagasse Fibre Foamed Composites as Cushion Packaging Materials

This work was designed to determine the mechanical properties and static cushioning performance of polyvinyl alcohol (PVA)/bagasse fibre foam composites with a multiple-factor experiment. Scanning electron microscopy (SEM) analysis and static cushioning tests were performed on the foamed composites and the results were compared with those of commonly used expanded polystyrene (EPS). The results were as follows: the materials had a mainly open cell structure, and bagasse fibre had good compatibility with PVA foam. With increasing PVA content, the mechanical properties of the system improved. The mechanical properties and static cushioning properties of the foam composite almost approached those of EPS. In addition, a small amount of sodium tetraborate obviously regulated the foaming ratio of foamed composites. With increasing sodium tetraborate content, the mechanical properties of foamed composites were enhanced. The yield strength and Young’s modulus of the material prepared by reducing the water content to 80.19 wt% were too high and not suitable for cushioned packaging of light and fragile products.

Effect of PAA-coated magnetic nanoparticles on the performance of PVA-based hydrogels developed to be used as environmental remediation devices

In the present work, the effect of the incorporation of polyacrylic acid (PAA)–coated magnetic nanoparticles (MNPs) on the performance of polyvinyl alcohol (PVA)–based hydrogels for water remediation was studied. Ferrogels from PVA and PAA-coated MNPs were prepared through the ecocompatible freezing–thawing physical cross-linking method, and then they were completely characterized. Two different lab-made PAA-coated iron oxide MNPs, characterized in a previous work, were prepared by coprecipitation method from two different low PAA molecular weights, Mw 1800 g/mol and 5000 g/mol. The effect of MNP content and the PAA Mw on ferrogel final properties was determined. In addition, adsorption of methylene blue (MB) and cadmium (Cd+2) was carried out to analyze the possible application of the developed materials as environmental remediation devices. The capture of a ferrogel by an external field occurs due to the force that the field gradient exerts on single magnetic particles, which is then transferred onto the polymer matrix. This force was measured as a function of the distance to a permanent magnet, and the condition to magnetically recover the sample was established. The results obtained demonstrated that the ferrogels presented in this work are able to adsorb heavy metals and then be magnetically separated.

Investigation of properties and performances of Polyvinyl Alcohol (PVA) fiber-reinforced rubber concrete

In this study, the Polyvinyl Alcohol (PVA) fiber was introduced to improve the performance of the rubberized concrete. This study experimentally investigated the mechanical performance and durability of Polyvinyl Alcohol (PVA) fiber-reinforced rubber concrete. The waste rubber particles (mesh size #10–#30) were selected to partially replace fine aggregates in the plain concrete. In addition, the rubber particles were pre-treated with an alkali solution to enhance the interface bond with cement paste. The fiber-reinforced rubber concrete samples were prepared with different fine aggregate replacement ratios based on the volume of fine aggregate (15%, 20%, and 25%) and a selected fiber content (0.5% based on the total volume of the mixture). For those samples, the mechanical properties, including compressive strength, flexural behavior, and fracture energy were evaluated to compare with control samples. The results showed that fiber-reinforced samples can largely improve the post-cracking extension and fracture energy. The results of electrical resistivity test indicated the reduced permeability in the fiber-reinforced rubber concrete. The durability performance including Alkali-Silica reaction (ASR) expansion, drying shrinkage and freeze-thaw resistance were also investigated and compared with the control samples. All the durability performances were enhanced through rubber stress release and fiber crack bridging. Therefore, the PVA-fiber reinforced rubber concrete can improve durability and ductility of cementitious materials for structure construction and also can facilitate the recycling of waste rubber into cementitious materials.

Effect of superabsorbent polymer (SAP) on the performance of polyvinyl alcohol (PVA) fiber-reinforced strain-hardening cement composites

This paper reports the effect of superabsorbent polymer (SAP), a promising chemical admixture for multifunction cement composites, on the fresh and hardened properties of polyvinyl alcohol (PVA) fiber-reinforced strain-hardening cement composite (PVA-SHCC). Two types of PVA-SHCC mixtures were prepared and investigated to evaluate the effect of SAP introduction. The PVA fiber volume content was fixed at 2.0% and content of SAP was 1.0% by the binder mass. It was found that the SAP particles lead to the deterioration in the slump. It is also confirmed that the addition of SAP within 1% into cement composite improves the hardened properties, such as compressive, flexural and direct tensile performances, of PVA-SHCC due to internal curing in the cement matrix.

Insulating characteristics of polyvinyl alcohol for integrated electronics

The aim of this work is to evaluate the effects of molecular weight, hydrolysis degree, and cross-link on the performance of Polyvinyl Alcohol (PVA) when applied as dielectric material in organic field effect transistors. For this purpose, metal–insulator-structures and polymeric films were characterized. The polymer structure was analyzed by thermogravimetry and calorimetry, and the electrical characterization of the films was performed through current–voltage and capacitance–voltage curves; and dielectric spectrometry. Cross-linkage, followed by hydrolysis degree, presented the major impact on polymer properties, due to the strong influence on chain mobility. The chain mobility increases the dielectric response and decreases the insulation capacity, generating the need to compromise between these two properties. The largest drawback encountered was the high sensitivity of the films to ambient humidity. The best performance of the organic insulator was obtained from cross-linked films made of an incompletely hydrolyzed PVA.

Biodegradation ofo-cresol by polyvinyl alcohol–alginate immobilized mixed culture

AbstractThe performance of polyvinyl alcohol (PVA)–alginate immobilized biomass in the biodegradation of o-cresol was evaluated and compared with that of the suspended biomass. The effects of initial o-cresol concentration, initial pH, and immobilized biomass bead size on the biodegradation of o-cresol were investigated. Compared with the o-cresol biodegradation rate by suspended biomass, the biodegradation rate by immobilized biomass was barely affected at higher initial o-cresol concentration and extreme pH conditions suggesting that the immobilized biomass was protected by the PVA–alginate matrix. The reusability of the immobilized biomass beads up to three cycles of use could be achieved, but only at relatively lower initial o-cresol concentration.

Research on Miniature Thermoplastic Processing of Polyvinyl Alcohol Based Nanocomposites

This paper discusses the synthesis and preparation of polyvinyl alcohol based nanocomposites through the use of miniature thermoplastics processing technology. It studies the influence of different process conditions, the amount of raw materials and water on the processing performance, tensile strength and elongation at break of polyvinyl alcohol based nanocomposites. Studies have shown that using two miniature thermoplastic processes does not have much influence on the mechanical properties of polyvinyl alcohol based nanocomposites, different amount of polyvinyl alcohol will lead to enhancement of the tensile strength of the polyvinyl alcohol based nanocomposites system by the increasing amount of glycerin, and the water content has a great influence on the performance of polyvinyl alcohol based nanocomposites. To this end, according to the analysis of experimental results, it can obtain preparation conditions and influencing factors of polyvinyl alcohol based nanocomposites with the miniature thermoplastic processing conditions, and provide a new theoretical method and means for nanocomposites.

Preparation and Characterization of Chitosan-Based Flame Retardant and Its Thermal and Combustible Behavior on Polyvinyl Alcohol

A novel natural material-based flame retardant melamine chitosan phosphate (MPCS) has been prepared. Its impact on thermal properties and flammability performance of polyvinyl alcohol (PVA) was analyzed. Thermogravimetric analysis data exhibited that MPCS enhanced the thermal stability of materials at high temperature. The results of thermogravimetric analysis/infrared spectrometry (TGA-IR) showed that MPCS decreased the yield of flammable volatilized products greatly. Microscale combustion calorimetry (MCC) data showed that peak heat release rate (PHRR), total heat release (THR) and heat release capacity (HRC) all reduced, which indicated that MPCS improved the flame retardancy of materials.

Cross‐Linked Polyvinyl Alcohol Films as Alkaline Battery Separators

Cross‐linking methods have been investigated to determine their effect on the performance of polyvinyl alcohol (PVA) films as alkaline battery separators. The following types of cross‐linked PVA films are discussed: (i) PVA‐dialdehyde blends post‐treated with an acid or acid periodate solution (two‐step method, and (ii) PVA‐dialdehyde blends cross‐linked during film formation (drying) by using a reagent with both aldehyde and acid functionality (one‐step method). Laboratory samples of each cross‐linked type of film were prepared and evaluated in standard separator screening tests. Then pilot‐plant batches of films were prepared and compared to measure differences due to the cross‐linking method. The pilot‐plant materials were then tested in nickel oxide‐zinc cells to compare the two methods with respect to performance characteristics and cycle life. Cell test results are compared with those from tests with Celgard.