Poly Vinyl Chloride Matrix Research Articles

Modification of opto‐electrical behavior of polyvinyl chloride by infusion of SrTiO3 nanofiller synthesized via green route

AbstractEnhancing the opto‐electrical properties of polymer is crucial for optoelectronic devices. This study emphasis the synthesis of strontium titanate (SrTiO3) nanoparticles using a green sol–gel method and incorporates them into polyvinyl chloride (PVC) to create nanocomposite films via solution casting. The structural, optical, thermal, and electrical properties of PVC with SrTiO3 at concentrations of 1, 3, and 5 wt.% were examined. Better crystallinity was obtained with filler incorporation. Fourier transform infrared shows the physical interaction between nanofiller and the matrix. SEM results suggested that SrTiO3 nanofiller are well distributed in PVC surface. UV–Vis spectroscopy was used to study optical behavior of the nanocomposites. Optical bandgap energy decreased from 3.2 to 2.5 eV with increased concentration of SrTiO3 in PVC matrix. Photoluminescence results show the reduction of electron hole recombination rate. The integration of SrTiO3 nanofiller into the PVC matrix improved the thermal stability, dielectric constant, and the overall performance of the prepared nanocomposite films, making them suitable for high‐temperature optoelectronic and energy storage applications. The green synthesis of SrTiO3 nanofiller also ensures the environmental benefits, high purity, and homogeneity, leading to consistent enhancements in the PVC/SrTiO3 composites. These improvements highlight their potential for advanced optoelectronic devices requiring efficient and durable materials.

Novel approaches to improving gas separation: Ionic liquids coated coke/ NH2-UiO-66-based mixed matrix membranes for CO2/N2 separation

Permeability and separation efficiency of mixed matrix membranes (MMMs) are two important aspects. Polymeric membranes offer excellent mechanical and physical properties; however, they have a low permeability. To enhance the permeability and separation performance of polyvinyl chloride (PVC) membranes, Cholinium amino acid-based (IL) were impregnated with activated coke/ NH2-UiO-66 (Zr) (AC/MOF) composite and then IL@AC/MOF filler was incorporated into PVC matrix. FTIR spectroscopy, TGA, SEM, EDX, and Brunauer-Emmett-Teller (BET) surface area measurement were used to characterize the MMMs prepared. The porous structure of MMMs nanocomposites causes AC/MOF composite to effectively accelerate gas the diffusion in the PVC matrix. The permeability measurements for CO2 and N2 were made at 288.15, 298.15, 308.15, and 318.15 K at pressure 3 bar The outcomes indicates that the incorporation of the IL@AC/MOF filler increased the permeability of the PVC/AC/MOF MMMs compared to the pure polymeric membrane. The mixed matrix membranes exhibit superior gas separation performance, surpassing the 2008 Robson's Upper Bound.

PVC-based mixed-matrix membranes based on IL@AC/NH2-MIL-101 nanocomposites for improved CO2 separation performance

Mixed matrix membranes (MMMs), an important class of organic-inorganic nanocomposite membranes, were developed to overcome some of the limitations of purely polymeric membranes. In this study to improve the separation performance of polyvinyl chloride (PVC) membranes, mixed matrix membranes (MMMs) were prepared from incorporating choline prolinate based ionic liquid (IL) in a the coke/metal-organic framework (MOF) (NH2-MIL-101(Cr)) as a filler in polyvinyl chloride (PVC), which can be viewed as a potential solution to the trade-off problem with polymeric membranes because of the combination of the processing versatility of polymers and the high gas separation capability. Coke/MOF/PVC and IL@AC/MOF/PVC MMMs with different filler loadings of 5, 10, and 15 wt% were prepared using solution casting method and characterized using Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) with Energy-Dispersive X-ray Spectroscopy (EDX) analyses, and Brunauer-Emmett-Teller (BET) surface area test. The porous structure of MMMs nanocomposites causes to which coke/MOF composite effectively accelerate gas diffusion in the PVC matrix. The permeability date was measured at 288.15, 298.15, 308.15 and 318.15 K and pressure up to 4 bar for CO2 and N2. According to the outcome, the addition of the IL([Cho][Pro]) filler, the permeability of the AC/MOF/PVC MMMs is increased compared to the pure PVC membrane. The MMMs have the highest gas separation efficiency and performance above Robson’s Upper Bound from 2008.

Evaluation and Comparison of UiO66 and Its Functionalized Variants for the Removal of Cu (II) Ions from Wastewater

This study examined the effectiveness of polyvinyl chloride (PVC) mixed matrix membranes incorporating UiO66 and UiO66-NH2 metal-organic frameworks (MOFs) for removing varying concentrations of Cu (II) ions from wastewater. The findings indicated that adding UiO66-NH2 to the functionalized UiO (FUiO) membrane enhanced its porosity, pore size, hydrophilicity, and pure water flux. Furthermore, integrating UiO66-NH2 into the PVC matrix led to an impressive Cu (II) ion removal efficiency exceeding 99%. The PVC-FUiO2 membrane also demonstrated about 93.5% reusability after the first cycle. Overall, the results confirmed that the PVC-FUiO2 (Functionalized UiO66) membrane exhibited superior performance in terms of Cu (II) removal efficiency and shorter separation times across various Cu (II) concentrations compared to the unmodified membrane.

A cutting edge potentiometric determination of baricitinib in synthetic wastewater and in tablet dosage form using modified carbon paste ion-selective membrane

After the recent hit of COVID-19, many drugs were successively administered to save patients’ lives and those drugs reached aquatic sources, one of those drugs was Baricitinib. Driven by the current situation, a potentiometric technique using an ion-selective membrane (ISM) recipe drop cast on a modified carbon paste electrode was optimized for the superior determination of Baricitinib (BAR). The molecular docking was customized to optimize the proper ionophores incorporated in the ISM, revealing that beta-cyclodextrin (β-CD) is the most compatible ionophore with the studied drug. A multivariate optimization experimental design was employed to optimize the best experimental condition for the analytical method. To this end; dual nanoparticles (multi-walled carbon nanotubes and copper oxide nanoparticles) were incorporated in the carbon paste electrode, and the ISM recipe was enriched with β-CD and cation-exchanger (phosphotungstic acid) in a polyvinylchloride matrix plasticized with dibutyl phthalate. A Nernstian slope equal to 19.97 mV/decade with a linearity range of 7.99 × 10−7–1.00 × 10−3 M was obtained. The validated sensor exhibited good recovery when used to determine the studied drug in synthetic wastewater and tablet dosage form. The greenness of the method was evaluated using the Complementary Green Analytical Procedure Index and Blue Applicability Grade Index.

Submersible voltammetric sensing probe for rapid and extended remote monitoring of opioids in community water systems

The intensifying global opioid crisis, majorly attributed to fentanyl (FT) and its analogs, has necessitated the development of rapid and ultrasensitive remote/on-site FT sensing modalities. However, current approaches for tracking FT exposure through wastewater-based epidemiology (WBE) are unadaptable, time-consuming, and require trained professionals. Toward developing an extended in situ wastewater opioid monitoring system, we have developed a screen-printed electrochemical FT sensor and integrated it with a customized submersible remote sensing probe. The sensor composition and design have been optimized to address the challenges for extended in situ FT monitoring. Specifically, ZIF-8 metal–organic framework (MOF)-derived mesoporous carbon (MPC) nanoparticles (NPs) are incorporated in the screen-printed carbon electrode (SPCE) transducer to improve FT accumulation and its electrocatalytic oxidation. A rapid (10 s) and sensitive square wave voltammetric (SWV) FT detection down to 9.9 µgL−1 is thus achieved in aqueous buffer solution. A protective mixed-matrix membrane (MMM) has been optimized as the anti-fouling sensor coating to mitigate electrode passivation by FT oxidation products and enable long-term, intermittent FT monitoring. The unique MMM, comprising an insulating polyvinyl chloride (PVC) matrix and carboxyl-functionalized multi-walled carbon nanotubes (CNT-COOH) as semiconductive fillers, yielded highly stable FT sensor operation (> 95% normalized response) up to 10 h in domestic wastewater, and up to 4 h in untreated river water. This sensing platform enables wireless data acquisition on a smartphone via Bluetooth. Such effective remote operation of submersible opioid sensing probes could enable stricter surveillance of community water systems toward timely alerts, countermeasures, and legal enforcement.Graphical abstract

Contributions of TCA-KTTO-modified quartz tailings and CPE toughener in PVC composites to enhance the mechanical-thermal performance

Large volumes of quartz tailings (QT) are currently stockpiled, which are difficult to treat effectively. Utilizing QT as a filler for high-demand polymeric materials is an effective strategy for large-scale and high-value utilization of solid waste. It is consistent with the goal of sustainable development. The mechanical performance and thermal stability of commercially available polyvinyl chloride (PVC)–based composites are limited due to the agglomeration of inorganic filler and low inorganic–organic interfacial compatibility. mQT/PVC and chlorinated polyethylene (CPE)–mQT/PVC composites were fabricated via dry modification, CPE toughening treatment, and open refining hot-pressing. The coupling agent molecules were grafted onto the mQT surface via Si-O-Ti bonding. mQT was uniformly dispersed and tightly adhered in the PVC matrix, particularly at a titanate coupling agent dosage of 2.0 wt%. The density, surface hardness, Young’s modulus, flexural modulus, and thermal conductivity of 50 wt%-mQT/PVC increased by 28.50%, 19.64%, 247.94%, 88.61%, and 153.11%, respectively, compared with those of pure PVC. T40 wt% for 50 wt%-mQT/PVC reached 487.39 °C. After toughening treatment, the impact strength of 15.0 phr-CPE-mQT/PVC increased by 47.38% compared to that of mQT/PVC. Pilot scale test results show that mQT/PVC and CPE-mQT/PVC composite plates, and CPE-QT/CaCO3/PVC co-extruded hollow floors met the Chinese standard GB/T 24508–2020. The mQT/PVC and CPE-mQT/PVC composites had excellent mechanical properties and high thermal stability, thermal conductivity, and glass transition temperature. This study provides an economical QT/PVC composite and proposes a sustainable strategy for the resource utilization of solid waste.

Synthesis, Characterisation, and In Vitro Evaluation of Biocompatibility, Antibacterial and Antitumor Activity of Imidazolium Ionic Liquids.

In recent decades, ionic liquids (ILs) have garnered research interest for their noteworthy properties, such as thermal stability, low or no flammability, and negligible vapour pressure. Moreover, their tunability offers limitless opportunities to design ILs with properties suitable for applications in many industrial fields. This study aims to synthetise two series of methylimidazolium ILs bearing long alkyl chain in their cations (C9, C10, C12, C14, C16, C18, C20) and with tetrafluoroborate (BF4) and the 1,3-dimethyl-5-sulfoisophthalate (DMSIP) as counter ions. The ILs were characterised using 1H-NMR and MALDI-TOF, and their thermal behaviour was investigated through DSC and TGA. Additionally, the antimicrobial, anticancer, and cytotoxic activities of the ILs were analysed. Moreover, the most promising ILs were incorporated at different concentrations (0.5, 1, 5 wt%) into polyvinyl chloride (PVC) by solvent casting to obtain antimicrobial blend films. The thermal properties and stability of the resulting PVC/IL films, along with their hydrophobicity/hydrophilicity, IL surface distribution, and release, were studied using DSC and TGA, contact angle (CA), SEM, and UV-vis spectrometry, respectively. Furthermore, the antimicrobial and cytotoxic properties of blends were analysed. The in vitro results demonstrated that the antimicrobial and antitumor activities of pure ILs against t Listeria monocytogenes, Escherichia coli, Pseudomonas fluorescens strains, and the breast cancer cell line (MCF7), respectively, were mainly dependent on their structure. These activities were higher in the series containing the BF4 anion and increased with the increase in the methylimidazolium cation alkyl chain length. However, the elongation of the alkyl chain beyond C16 induced a decrease in antimicrobial activity, indicating a cut-off effect. A similar trend was also observed in terms of in vitro biocompatibility. The loading of both the series of ILs into the PVC matrix did not affect the thermal stability of PVC blend films. However, their Tonset decreased with increased IL concentration and alkyl chain length. Similarly, both the series of PVC/IL films became more hydrophilic with increasing IL concentration and alkyl chain. The loading of ILs at 5% concentration led to considerable IL accumulation on the blend film surfaces (as observed in SEM images) and, subsequently, their higher release. The biocompatibility assessment with healthy human dermal fibroblast (HDF) cells and the investigation of antitumoral properties unveiled promising pharmacological characteristics. These findings provide strong support for the potential utilisation of ILs in biomedical applications, especially in the context of cancer therapy and as antibacterial agents to address the challenge of antibiotic resistance. Furthermore, the unique properties of the PVC/IL films make them versatile materials for advancing healthcare technologies, from drug delivery to tissue engineering and antimicrobial coatings to diagnostic devices.

Enhancing the performance of optoelectronic potential of CuO/Al nanoplats in a PVC for medium voltage cables applications

This study investigates the potential of incorporating CuO and Al nanoplates into a polyvinyl chloride (PVC) matrix to enhance the performance of medium voltage cables. The incorporation of nanoparticles into the PVC insulation material aims to improve the electrical, dielectric, and optical properties of the cable. The nanocomposite films were synthesized by dissolving PVC in tetrahydrofuran (THF) solvent and adding a mixture of 5 wt% CuO and Al nanoparticles. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the successful incorporation of the nanoparticles into the PVC matrix. The optical properties of the PVC/AlNPs and PVC/CuONPs + AlNPs nanocomposite films were characterized, revealing a decrease in band gap energy (4.35 eV) and Urbach tail energy (0.3702 eV) for the PVC/CuONPs + AlNPs film compared to the PVC/AlNPs film (4.5 eV and 0.41816 eV, respectively). Additionally, the PVC/CuONPs + AlNPs film exhibited higher absorption coefficients and increased electron delocalization and conjugation (carbon cluster value of 62.53). The dielectric properties of the CuONPs + AlNPs nanocomposites were investigated, with the sample containing 1.5% AlNPs demonstrating the highest AC conductivity (2.029 × 10−3 S/m), dielectric constant, and dielectric loss across the frequency range. Simulations of electric field distribution revealed that the PVC/CuONPs+1.5% AlNPs nanocomposite cable exhibited a more uniform electric field distribution compared to the PVC market cable, contributing to a reduction in electrostatic tension and a relative permittivity increase from 2.25 to 2.35. The electric potential distribution along the cable radius remained similar for both cable samples. These findings demonstrate the potential of nanocomposite insulation materials in enhancing the performance of medium voltage cables, paving the way for improved reliability, longevity, and efficiency.

Evaluation of PVC@Silver Nanocomposite as Sensor for Low Limit Detection of Cadmium Ion By Surface Plasmon Resonance Based Method

This study explores the development of a PVC@Silver nanocomposite for enhanced detection of cadmium ions in water samples. Various characterization techniques confirmed the successful incorporation of silver nanoparticles into the polyvinyl chloride (PVC) matrix across different concentrations (1–4%). X-ray diffraction revealed the face-centered cubic crystalline structure of the silver nanoparticles, with the intensities of the (111), (200), (220), and (311) peaks increasing with higher Ag concentrations. The average crystallite sizes ranged from 26.1 nm (3% Ag) to 30.0 nm (2% Ag). Dynamic light scattering showed nanoparticle sizes of 24–43 nm, while zeta potential values of -24 to -40 mV indicated reasonable colloidal stability. Brunauer–Emmett–Teller (BET) surface area analysis demonstrated a decreasing surface area from 30.09 m2/g (1% Ag) to 25.27 m2/g (3% Ag), attributed to pore filling by silver nanostructures. Significantly, the PVC@Silver nanocomposite facilitated sensitive detection of Cd(II) ions using surface plasmon resonance (SPR), exhibiting an SPR angle shift of 26.30° with intensity values ranging from 10.80 (4% Ag) to 12.19 (3% Ag). UV–vis spectra revealed a prominent surface plasmon resonance band at 420–430 nm, indicating the presence of silver nanoparticles. The optical band gap varied from 4.51eV (1% Ag) to 4.12eV (4% Ag).

Enhancing the Sustainability of Eco-Friendly Potentiometric Ion-Selective Electrodes for Stability-Indicating Measurement of Ethamsylate: Application in Bulk and Pharmaceutical Formulations.

Through the use of sustainable and green chemistry concepts, scientists need to decrease waste, conserve energy, and develop safe substitutes for hazardous compounds, all for protecting and benefiting society and the environment. Four novel eco-friendly ion selective electrodes (ISE) were generated to determine Ethamsylate (ETM) in bulk powder and different pharmaceutical formulations. The present electrodes were fabricated to clearly distinguish ETM from a variety of inorganic, organic ions, sugars, some common drug excipients and the degradation product, hydroquinone (HQ) of ETM, and thus used for stability-indicating methods. The electrodes fabrication was based on 2-nitrophenyl octyl ether (NPOE) that was employed as a plasticizer in electrodes 1, 2, and 3 within a polymeric matrix of polyvinyl chloride (PVC) except for electrode 4, in which dibutyl sebacate was used as a plasticizer. Electrodes 1 and 2 were fabricated usingtetradodecylammonium bromide as an anionic exchanger, adding 4-sulfocalix-8-arene as an ionophore only to electrode 2 and preparing electrode 1 without incorporation of an ionophore. The fabrication of electrodes 3 and 4 was based on ethamsylate-tetraphenylborate (ETM-TPB) as an ion-association complex in a PVC matrix. The environmental sustainability was assessed using the green analytical procedure index (GAPI), and analytical greenness metric for sample preparation (AGREEprep). Electrodes 1 and 2 had linear dynamic ranges of 10-1-10-5 mol/L and 10-1-10-4 mol/L, respectively, with a Nernstian slope of 49.6 and 53.2 mV/decade, respectively. Electrodes 3 and 4 had linear dynamic ranges of 10-1-10-4 mol/L, with a Nernstian slope of 43.9 and 40.2 mV/decade, respectively. The electrodes' selectivity coefficients showed good selectivity for ETM. The utility of 4-sulfocalix-8-arene as an ionophore had a significant influence on increasing the membrane sensitivity and selectivity of electrode 2 compared to other electrodes. Four novel eco-friendly ISEs were used for determination of ETM in bulk powder and different pharmaceutical formulations. Different experimental parameters were performed to optimize the determination conditions such as solvent mediators, dynamic response time, effect of pH, and temperature. Stability-indicating measurement of ETM in the presence of its degradate HQ and co-formulated drug tranexamic acid. Using new ecological assessment tools to determine whiteness and greenness profiles.

Application of titanium dioxide nanorod (TNr)@SiO2 with low photocatalytic effect and high UV resistance in poly(vinyl chloride) film

Ultraviolet (UV) radiation has a detrimental effect on the outdoor lifetime of PVC film materials. TiO2 nanoparticles, as commonly used UV absorbers, still suffer from poor transparency, high photocatalytic effect, and poor dispersion in PVC matrix. To mitigate these effects effectively, titanium dioxide nanorod @ silicon dioxide (TNr@SiO2) was synthesized and used as an anti-UV aging agent for polyvinyl chloride (PVC). The agglomeration effects of TiO2 nanoparticles in PVC films were solved by synthesizing TNr, and the catalytic effects of TiO2 was reduced by growing SiO2 on the TNr surface. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and UV-visible spectroscopy were utilized to demonstrate the excellent dispersion and low photocatalytic effects of the synthesized TNr@SiO2. Compared with pure PVC film, the color change of TNr@SiO2/PVC composite film is not evident after 800h of UV aging, and the retention of mechanical properties were 93.94%. Compared with TiO2/PVC, TNr@SiO2/PVC composite film has better transparency. Results show that TNr@SiO2 can maintain the properties of PVC better because the electrons of TNr@SiO2 are excited to form a positively charged hole after the absorption of UV light, and then the hole electron pairs are recombined and converted into thermal energy, which improves the durability of PVC. Therefore, this highly transparent TNr@SiO2/PVC composite film with low photocatalytic activity and high UV resistance will soon be applied in large-scale industrial production.

Development of a dual sensitive N,N,N’,N’,N”,N”-hexa-n-octylnitrilotriacetamide (HONTA) based potentiometric sensor for direct thorium(IV) estimation

A dual sensitive, simple, and rapid membrane-based potentiometric sensor was developed to determine thorium (Th) ion in nuclear fuel samples which does not require any prior chemical separation of other matrix elements. Sensor was prepared by incorporating N,N,N’,N’,N”,N”-hexa-n-octylnitrilotriacetamide (HONTA) in a polyvinyl chloride (PVC) matrix in presence of 2-nitrophenyl octyl ether (NPOE) and sodium tetraphenyl borate (NaTPB). The optimum membrane composition was found to be 14.1% HONTA, 3.2% NaTPB, 54.9% NPOE, 27.8% PVC, which showed a dual sensitive linear region in the calibration plot with sub-Nernstian and super-Nernstian slopes of 12.1 ± 0.4 mV/decade and 71.7 ± 3.5 mV/decade, respectively, with the corresponding linear dynamic ranges of 2.0 × 10−5 to 5.3 × 10−4 M and 3.8 ×10−3 to 1.4 × 10−2 M, respectively. The super-Nernstian sensitivity exhibited by the sensor increases with Th(IV) as well as HONTA concentrations in the membrane and can be thought to be due to micelle-mediated selective adsorption (MMSA) sensing of the metal ion. Solution speciation of Th(IV) in acetate buffer was determined by laser desorption/ionization mass spectrometry (LDI-MS) and Medusa software. Pristine and used membranes were characterized by Fourier transform infrared (FTIR), scanning electron microscopy–energy dispersive x–rays (SEM-EDS) and small angle neutron scattering (SAXS). Thorium was measured in an actual (Th–U) mixed solution and in a synthetic advance heavy water reactor (AHWR) fuel sample. The present study describes a new approach for the detection of Th(IV) ion through MMSA in an ion selective electrode (ISE).

The effect of dispersion degree of calcium carbonate particles in polyvinyl chloride matrix on the mechanical properties of composites

By establishing representative volume units of polyvinyl chloride (PVC) matrix composites filled with calcium carbonate (CaCO3) particles with different agglomeration degrees, finite element simulation analysis is conducted to predict the degree of improvement of the mechanical properties of the CaCO3/PVC composites by the dispersion degree of calcium carbonate particles. When the agglomeration coefficient is 0.4, the stress concentration phenomenon of the CaCO3/PVC composites is the weakest, and the stress distribution of the entire CaCO3/PVC composites is relatively uniform. At the same time, the reinforcement effect of the CaCO3/PVC composites’s stiffness is also the best, increasing by 13.8%.

Thermal dependence on electrical characteristics of Au/(PVC:Sm2O3)/n-Si structure

In this study, we investigated the current–voltage (I–V) characteristics of Au/n-Si structure with an interfacial layer of Samarium Oxide (Sm2O3) nanoparticles (NPs) in polyvinyl chloride (PVC) matrix within a temperature range of 80–320 K. Applying the thermionic emission (TE) theory, essential electrical parameters such as reverse saturation current (I0), ideality factor (n), zero bias barrier height (ΦB0), series resistance (Rs), and rectification rate (RR) were carefully derived from the I–V data. The mean values of BH and Richardson constant obtained from the modified Richardson plot were determined to be 0.730 eV and 111.4 A/(cmK)2, respectively. Remarkably, this A* value closely matches its theoretical counterpart for n-type Si. Thus, our findings successfully highlight the effectiveness of the thermionic emission (TE) mechanism with the Gaussian distribution of BHs in explaining the I-V-T characteristics of the fabricated Schottky structure, shedding light on the intricate interplay between temperature and diode behavior. These insights offer valuable guidance for designing and optimizing thermal-sensitive devices based on this innovative structure.

Simplistic approach to formulate an ionophore-based membrane and its study for nitrite ion sensing.

A polymeric membrane based on a N,N'-bis(salicylidene)ethylenediaminocobalt(ii) complex as a cobalt ionophore (CI) was fabricated and optimized for nitrite ion sensing application. The membrane contained CI, 2-nitrophenyl octyl ether (2-NPOE) as a plasticizer and hexadecyl trimethyl ammonium bromide (HTAB) as a cationic additive in a polyvinyl chloride (PVC) matrix. The Nernstian slope (-0.020 mV per decade), detection limit (1 × 10-7 M to 3 M), and response (107 milliseconds) and recovery (22 milliseconds) times were recorded for optimum membrane composition. The ionophore functionality in the polymer matrix and their interaction were studied using Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), environmental scanning electron microscopy (ESEM), energy-dispersive X-ray spectroscopy (EDS), and optical microscopy analyses.

Optoelectric characteristics of PVC/SrxZnO nanocomposite films

Poly(Vinyl)Chloride (PVC) films modified by SrxZnO nanoparticles (NPs) were prepared by a simple casting method utilizing its solution in tetrahydrofuran (THF). The PVC films contained 5 wt% of SrxZnO NPs. SrxZnO particles with 0.00, 0.025, 0.05, 0.075 and 0.1 Sr-doping levels were synthesized by the sol-gel method associated with a hydrothermal process. The PVC/SrxZnO films were characterized by XRD, FTIR, Raman, SEM, UV–Visible and PL spectroscopy. XRD analysis demonstrated that SrxZnO into PVC matric are well crystallized in the hexagonal ZnO structure with wurtzite phase, while PVC is in an amorphous state. The particle sizes of SrxZnO vary in the range of 17–31 nm in agreement with the Sr levels. The ATR and Raman spectroscopy verified the existence of a Zn–O bond related to the wurtzite phase. The SEM cross-section views of the films revealed the bulk nature as well as the thicknesses. Strong emission at 733 nm is observed from the PL analysis, associated with Sr content in the PVC/SrxZnO films. Reflectivity, transmittance, and absorption coefficient confirmed the contribution of the physics developed by SrxZnO NPs into the PVC matrix. Urback energies are Sr-level dependent, as a consequence of defects tailoring. Optical transitions (directly and indirectly allowed) decrease in some cases by close to 1 eV indicating a transition of PVC to a semi-crystalline material. Other optical properties including linear and nonlinear characteristics promoted PVC/SrxZnO as a serious candidate for antireflective coating, and a new generation of photovoltaic cells.

Hydrothermal carbonisation of polyvinyl chloride in ethanol-water/water system for solid fuels: Dechlorination, characteristics analysis of hydrochar, and reaction path

Polyvinyl chloride (PVC) waste plastic is a typical solid waste. In this paper, the dechlorination and carbonization behavior of PVC in ethanol-water/water system under different process parameters (temperature, residence time, solid-liquid ratio) was studied, and hydrothermal carbon was characterized by SEM, elemental analysis, TG-DTG, XPS, Py-GC/MS. The results show that temperature is the key to the hydrothermal dechlorination of PVC, and the dechlorination efficiency of PVC is the highest by parameter optimization (220°C-90 min-10% S/D-80% E/D), which can reach 96.33 %. With the removal of Cl, the surface of the PVC matrix changed from full and smooth flocculent to honeycomb with uniform pore size distribution. Thermogravimetric analysis shows that the combustion of hydrochar can be divided into three stages: HCl precipitation and volatile combustion, semi-coke and coke combustion, and fixed carbon combustion. The combustion parameters and kinetic parameters of hydrochar were measured, and it was found that the hydrothermal carbonization of PVC at higher temperatures and ethanol-water ratio could improve the combustion performance of hydrochar. The highest calorific value can reach 36.68 MJ/mol. Py-GC/MS analyzed the distribution of the pyrolysis products, and alkylbenzene and aliphatic were the main products of pyrolysis. The structural analysis of hydrochar showed that C–C and CC accounted for the largest proportion, accompanied by a small amount of C–O and CO and trace C–Cl. The possible reaction mechanism of the hydrothermal carbonization of PVC was analyzed based on the distribution of functional groups and compound composition. This work provides an effective and sustainable method for the recycling of refractory chlorinated plastics.

Quaternarized cationic poly[(vinyl chloride)‐co‐(vinyl chloroacetate)] binary copolymer as non‐migration antibacterial additive in PVC matrix

AbstractAntibacterial polyvinyl chloride (PVC) materials have drawn considerable attention since their wide application in medical devices. The objective of this study is to develop a novel quaternary ammonium cationic vinyl chloride copolymer, which can be potentially used as antibacterial additive in PVC matrix. Initially, the low average‐number molecular weight poly[(vinyl chloride)‐co‐(vinyl chloroacetate)] (PVC‐co‐PVCA) is synthesized by precipitation copolymerization. Subsequently, quaternary ammonium cationic moieties with different lengths of alkyl chains are introduced into the copolymers via quaternization reaction between alkyl‐dimethyl tertiary amines with acyl chloride groups. The successful synthesis of PVC‐co‐PVCA and quaternarized copolymers are carefully confirmed by Fourier transform infrared spectroscopy, nuclear magnetic resonance (1H NMR), and x‐ray photoelectron spectroscopy. The antibacterial behaviors of the quaternarized copolymers and its blends with PVC are investigated. The results reveal that all the PVC blends containing at least 5% by weight of quaternarized copolymer have superior bacteriostasis ratio (>99.6%) against both Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus) due to the incorporation of quaternary ammonium groups. Meanwhile, the cationic copolymer exhibits excellent antifouling and much lower migration rate (<0.4%). These interesting consequences endow the quaternarized copolymers as alternative antibacterial agents possess a great deal of potential for use in PVC materials.

Enhanced photocatalytic properties of graphene oxide/polyvinylchloride membranes by incorporation with green prepared SnO2 and TiO2 nanocomposite for water treatment

Photocatalytic membranes (PMR) have significant potential for utilization in energy-efficient water purification and wastewater treatment. The integration of membrane filtration's physical separation with photocatalysis's organic degradation is facilitated by their respective capabilities. In the present study, a more advanced graphene oxide (GO) membrane with improved photocatalytic properties was developed. This was achieved by incorporating tin dioxide (SnO2) and titanium dioxide (TiO2) nanoparticles (NPs) into a polyvinyl chloride (PVC) matrix, resulting in the fabrication of a microfiltration flat sheet membrane. The hydrophilicity of the membrane surface was investigated. The existence of NPs on membrane surfaces was demonstrated by FESEM images, Raman spectra, and FT-IR measurements. The porosity was affected by the addition of NPs; it increased from 59 to 76, and 92 for GO/TiO2, and GO/SnO2 respectively. The relationship between photocatalysis and filtration was investigated. Each nanocomposite membrane displayed a greater water flux and removal efficiency than a blank PVC membrane. Whereas the water flux enhanced from 1.3 to 17.6, and 20.5 for GO/TiO2, and GO/SnO2 respectively. Sunlight improves water flow and rejection compared to darkness. This research provides an alternative and highly efficient photocatalytic membrane for removing organic compounds from water, as the GO/SnO2 nanocomposites membrane exhibits the highest photocatalytic degradation up to a rejection rate of 98% when compared to an unmodified membrane.