Polyvinyl Research Articles

Contrasting the pharmacokinetic performance and gut microbiota effects of an amorphous solid dispersion and lipid nanoemulsion for a poorly water-soluble anti-psychotic

Increasing attention is being afforded to understanding the bidirectional relationship that exists between oral drugs and the gut microbiota. Often overlooked, however, is the impact that pharmaceutical excipients exert on the gut microbiota. Subsequently, in this study, we contrasted the pharmacokinetic performance and gut microbiota interactions between two commonly employed formulations for poorly soluble compounds, namely 1) an amorphous solid dispersion (ASD) stabilised by poly(vinyl pyrrolidone) K-30, and 2) a lipid nanoemulsion (LNE) comprised of medium chain glycerides and lecithin. The poorly soluble antipsychotic, lurasidone, was formulated with ASD and LNE due to its rate-limiting dissolution, poor oral bioavailability, and significant food effect. Both the ASD and LNE were shown to facilitate lurasidone supersaturation within in vitro dissolution studies simulating the gastrointestinal environment. This translated into profound improvements in oral pharmacokinetics in rats, with the ASD and LNE exerting comparable ∼ 2.5-fold improvements in lurasidone bioavailability, compared to the pure drug. The oral formulations imparted contrasting effects on the gut microbiota, with the LNE depleting the richness and abundance of the microbial ecosystem, as evidenced through reductions in alpha diversity (Chao1 index) and operational taxonomical units (OTUs). In contrast, the ASD exerted a ‘gut neutral’ effect, whereby a mild enrichment of alpha diversity and OTUs was observed. Importantly, this suggests that ASDs are effective solubility-enhancing formulations that can be used without comprising the integrity of the gut microbiota – an integral consideration in the treatment of mental health disorders, such as schizophrenia, due to the role of the gut microbiota in regulating mood and cognition.

Wall Drawing #736: Revealing Sol LeWitt’s Ink Mural Technique Using a Multi-Analytical Approach

Sol LeWitt, a pioneer of conceptual art, created during his career over 1350 wall drawings, including the Wall Drawing #736 (1993) at the Center for Contemporary Art Luigi Pecci in Prato (Prato, Italy). The painting, executed by Andrea Marescalchi and Antony Sansotta under LeWitt’s instructions, features a grid of coloured rectangles obtained by overlapping different layers of inks. During a 2021 restoration by the Wall Paintings and Stuccoes Department of the Opificio delle Pietre Dure (Firenze, Italy), an in-depth investigation of the composition and the materials used by LeWitt’s assistants in producing Wall Drawing #736 was performed. A multi-analytical approach entailing Raman spectroscopy, high-performance liquid chromatography coupled to diode array and high-resolution mass spectrometry, gas chromatography–mass spectrometry (GC–MS), and pyrolysis coupled with GC–MS was applied. Our results revealed the use of animal glue, shellac resin, paraffin wax, linseed oil, and various organic pigments. The binder in the preparation layer was identified as poly(vinyl acetate), while poly(n-butyl methacrylate) was determined as a fixative. This research provided valuable insights into LeWitt’s techniques. The acquired knowledge on the paint technique is highly relevant in supporting conservators in restoration and consolidating the many wall drawings produced exploiting the same technique all over the world.

The effects of some common inorganic soil components on the pyrolytic analysis of plastics

Plastics and microplastics are major hazards for the environment and human health. Plastic materials in the sedimentary record are a marker for modern anthropogenic activity. One environmental reservoir of plastics and microplastics is soil. One method to detect the presence of plastics in soil, and to thereby recognise the presence of its hazards, is pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). Yet soils are multicomponent mixtures and any analytical artefacts generated will reduce our ability to monitor the presence of plastics. We have studied the Py-GC-MS responses for the polymers polyethylene (PE), polypropylene (PP), polystyrene (PS) and poly(vinyl chloride) (PVC), in the presence of individual phyllosilicate (kaolinite, illite and montmorillonite) and iron oxyhydroxide/oxide (goethite and magnetite) minerals that may be present in soil. Our data show the distinctive polymer fingerprint becomes obscured when analysed with minerals. We have isolated the effects of some potential inorganic soil components so that responses from complex matrices can be deconvolved. The mineral-assisted aromatisation of compounds affects the diagnostic signals of the original polymer, particularly for those polymers (PE and PP) which have a large aliphatic hydrocarbon signature when analysed alone. Iron oxyhydroxide/oxide are shown to have a greater effect on the data than phyllosilicates. Our results will help guide future interpretations of Py-GC-MS data obtained when monitoring soils for plastic contamination. Py-GC-MS is most commonly applied as a qualitative method, yet detailed quantitation of the organic-inorganic reactions we have described, albeit analytically complex, would represent a useful future study.

Molecular Insights into Redox-Active Polymer Interfaces: Solvation and Ion Valency Effects on Metal Oxyanion Selectivity

Chemical separations are responsible for 10-15% of the world’s energy consumption. Minimizing energy and materials inputs in selective separations is imperative for a sustainable future. Ion-electrosorption mediated by redox-active metallopolymer interfaces has the unique advantage of selectively capturing and releasing metal oxyanions in a switchable manner by adjusting the applied potential, without any regenerants. Electrosorption addresses the need for selective separation approaches with low chemical and energy inputs. Previous studies on ferrocene metallopolymers have demonstrated the role of polymer structure and applied potential on selectivity—however, the ubiquitous role of solvation in redox-polymers has remained unexplored. Here, we investigate how solvation and ion valency influence selectivity of ReO4 - vs MoO4 2- for two redox-metallopolymers, poly(vinyl ferrocene) (PVFc) and poly(3-ferrocenylpropyl methacrylamide) (PFPMAm). Both polymers display time-dependent Re/Mo selectivity, with PVFc having higher selectivity compared to PFPMAm. Operando neutron reflectometry, ellipsometry, and electrochemical quartz-crystal microbalance show that both PVFc and PFPMAm swell in the presence of ReO4 - (with PFPMAm having higher solvation), but do not swell in contact with MoO4 2-. We find that the less solvated anion (ReO4 -) is preferably adsorbed by the more hydrophobic redox-polymer (PVFc). We expect that a deeper understanding of solvation and valency effects on selectivity mechanisms in redox interfaces will expedite the development of targeted selective ion-electrosorption systems. Figure 1

Dielectric Property Tuning via Electric Field Alignment in Mxene (Ti3C2)-Based Polymer Nanocomposites

Orientation control is crucial for fine-tuning the functional properties of two-dimensional (2D) nanomaterials. MXene (Ti3C2) alignment has drawn significant attention lately as the targeted properties can be controlled by manipulating the structural anisotropy. However, controlled MXene nanosheet orientation inside the polymer matrix is a complex and less understood mechanism. In this study, we applied an in-plane electric field to align the MXene nanosheets vertically inside the semicrystalline polyvinylidene fluoride (PVDF) (Tg⁓ -35°C) matrix in situ, where the amorphous phase assisted the electric field alignment at room temperature. These vertical orientations of the nanosheets were confirmed directly using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Our study reveals a significant correlation between MXene-orientation and dielectric property enhancement. PVDF- 5 wt.% MXene demonstrated the highest dielectric permittivity increase of ⁓500% because of the maximum surface polarization of the nano-capacitors inside the matrix. Interestingly, the loss value shows a sharp jump after the 5 wt. % MXene concentration, demonstrating a percolative network formation. Notably, our nanocomposite exhibited a low loss before (0.07) and after (0.66) applying the electric field, even at a high MXene concentration (20wt.%). Finally, to understand the effect of polymer domain structure on the electric field-induced orientation effect, we conducted a comparative study between non-ferroelectric poly vinyl alcohol (PVA) and ferroelectric (PVDF) polymer-based MXene nanocomposites. Interestingly, we observed a synergistic effect of the polymer chain and MXene orientation on the permittivity enhancement in the ferroelectric polymer-based nanocomposites at both high and low frequencies. This study provides fundamental insights for designing hybrid solid-state dielectric films for next-generation flexible electronics.

Exploring the optical and electric features of PMMA/PVAc blended polymers doped with TBAI/MWCNTs fillers for different applications

The present study focuses on the production of poly (methyl methacrylate)/poly (vinyl acetate)/tetrabutylammonium iodide/multi-walled carbon nanotubes (PMMA/PVAc/TBAI/x wt %MWCNTs) blended polymers. These blends show great potential for use in advanced optical, energy storage and electronics applications. X-ray diffraction (XRD) and scanning electron microscopy techniques was used to explore the structure and morphology of PMMA/PVAc/TBAI with x wt% MWCNTs blended polymers. The optical transmittance lowered to a minimum value of 53–63 % within the specific wavelength range as the blend contained 0.55 wt % multi-walled carbon nanotubes (MWCNTs). The sample containing 0.11 wt% MWCNTs demonstrated the highest reflectance (R) values, whereas the sample with 0.55 wt% MWCNTs showed the lowest R values. As the concentration of MWCNTs increased, these values consistently decreased. The smallest direct (4.55 eV) and indirect (4.45 eV and 2.48 eV) optical band gap (Eg) values were achieved when wt% of MWCNTs were 0.44 % and 0.55 %, respectively. The doped blend with wt% of 0.11 exhibited the highest refractive index values. Blend with x = 0.55 wt % MWCNTs has the highest dielectric constant. The energy density (U) increased non-uniformly as the blend was infused with MWCNTs. Elevating the temperature enhances the values of U for all blends. All blends adhered to the correlated barrier hopping (CBH) model. The effects of MWCNTs doping amount and temperature on the impedance and electric modulus of the host blend were investigated. The dc conductivity of the doped samples was observed to be greater than that of the undoped blend, except for the blend with x = 0.44, where it diminished. The undoped blend displayed activation energy (Ea) values of 1.71 eV and 0.6 eV, depending on the temperature range. When the host blend is doped with MWCNTs, the Ea values either rise or fall depending on the quantity of MWCNTs. All samples have non-ohmic characteristics.

THE EFFECT OF CHEMICAL STRUCTURE OF VINYL CHLORIDE BASED POLYMERS ON ITS THE COMPATIBILITY WITH POLYURETHANEUREA ELASTOMER

The effect of the chemical structure of vinyl chloride-based polymers, such as poly(vinyl chloride) (PVC), chlorinated PVC (cPVC), vinyl chloride/vinylidene chloride copolymer VCVD-40TM, vinyl chloride/vinyl acetate copolymer А-15TM on its compatibility with poly(ether-urethane)urea elastomer (PUU) was studied by DSC and FTIR spectroscopy. The segmented PUU was synthesized by prepolymer approach in N,N-dimethylformamide (DMF) solution using poly(propylene glycol) of number-averaged molecular weight (Mn) of 1000 Da, 2,4-tolylenediisocyanate and tolylene 2,4-diamine as a chain extender at a molar ratio of 1:2:1. PUU/vinyl chloride-based polymer blends was prepared by solution casting technique vie DMF solution. It was found a compatibility of PUU based blends containing 30 % PVC (PUU/30PVC blend) or cPVC (PUU/30cPVC) were initiated by strong hydrogen bonding. As a result, the blends are characterized by single wide relaxation transition. A glass transition temperature (Тс) of PUU/30PVC composite is similar to the theoretical one (ТFс), which is calculated using the Flory-Fox equation, whereas Тс value of PUU/30cPVC composite is higher than ТFс. Introducing polar vinyl acetate or vinylidene chloride fragments into vinyl chloride-based polymer macrochains suppresses the compatibility of components of the polymer blends and initiates the formation of a biphase microheterogeneous structure. The formation of intermolecular hydrogen bonding network at the interface in polymer-polymer blends is confirmed by FTIR spectroscopy. Comparative analysis of experimental and theoretically calculated (additive) tensile characteristics of polymer blends demonstrates their substantial dependence on interface interactions between the constituents. The highest strengthening effect was observed for cPVC or PVC-containing nanocomposites.

Semi-Interpenetrating Polymer Network Anion Exchange Membranes Based on Quaternized Polybenzoxazine and Poly(Vinyl Alcohol-Co-Ethylene) for Acid Recovery by Diffusion Dialysis.

Acid recovery from acidic waste is a pressing issue in current times. Chemical methods for recovery are not economically feasible and require significant energy input to save the environment. This study reported a semi-interpenetrating polymer network (semi-IPN) anion exchange membranes (AEMs) for acid recovery by diffusion dialysis with excellent dimensional stability, high oxidation stability, good acid dialysis coefficient (UH +) and high separation factor (S). Semi-IPN AEMs are prepared by ring-open cross-linked quaternized polybenzoxazine (AQBZ) with poly(vinyl alcohol-co-ethylene), where AQBZ is obtained by Mannich reaction and Menshutkin reaction. All four proportions of semi-IPNs exhibit clear micro-phase separation, which is conducive to ion transport. The water uptake (WU) of the four semi-IPNs ranges from 14.2 % to 19.2 %, while the swelling ratio (SR) remains between 8.7 % and 11.3 %. These results indicate that the cross-linked structure in the designed semi-IPNs effectively control swelling and ensure dimensional stability. The thermal degradation temperature (Td5) of semi-IPN4:6 to semi-IPN7:3 varies from 309 °C to 289 °C, with an oxidation stability weight loss rate (WOX) ranging from 91.5 % to 93.5 %, demonstrating excellent thermal stability and oxidation stability. The semi-IPNs also show good UH + values ranging from 11.9-16.3*10-3 m/h and high S values between 38.6 and 45.9, indicating the promising potential of the semi-IPNs.

Graphene and Silver Nanoparticle-Coated Poly(vinyl) Alcohol/Graphene Oxide/Dioctyl Terephthalate: Bis(2-hydroxyethyl) Terephthalate Composite Strain Sensors

Graphene and Silver Nanoparticle-Coated Poly(vinyl) Alcohol/Graphene Oxide/Dioctyl Terephthalate: Bis(2-hydroxyethyl) Terephthalate Composite Strain Sensors

Anisotropic 3D Aerogel of Graphene Oxide and Poly(Vinyl Alcohol) for Desalination by Interfacial Solar Vapor Generation

Anisotropic 3D Aerogel of Graphene Oxide and Poly(Vinyl Alcohol) for Desalination by Interfacial Solar Vapor Generation

Mechanical and Processing Properties of Plasticised PVC/Wood Composites.

The paper presents the results of testing the properties of wood-polymer composites (WPC) based on plasticised poly(vinyl chloride) (PVC-P). Materials with variable contents of wood filler (Arbocel C 320) or plasticiser (di-isononyl phthalate) were produced and then analysed. The share of wood flour in the material was up to 50 phr, and the plasticiser content was up to 40 phr. Functional properties, such as tensile properties, mechanical properties at variable temperature (DMTA), and water absorption, as well as processing properties such as rheological properties and analysis of the fusion process, were analysed. The influences of wood flour and plasticiser on the composites' properties in the solid and melted state were found. For example, with 40 phr of plasticiser, increasing the filler share from 0 phr to 50 phr resulted in an increased tensile modulus from 18 MPa to 274 MPa and viscosity at a share rate of 20 s-1, from 721 Pa·s to 1581 Pa·s. However, increasing the share of plasticiser from 20 phr to 40 phr with 30 phr of filler reduces the value of these properties from 1760 MPa to 112 MPa and from 2768 Pa·s to 1151 Pa·s, respectively. It was also found that increasing the share of wood flour in the composite noticeably reduces the effectiveness of the plasticiser.

Analysis of the Adsorption Behavior of Phenanthrene on Microplastics Based on Two-Dimensional Correlation Spectroscopy.

Microplastics (MPs), an emerging pollutant, widely co-occur with polycyclic aromatic hydrocarbons (PAHs) in the environment. Therefore, the interaction between MPs and PAHs has been the focus of much attention in recent years. In this study, three types of MPs, i.e., polypropylene, polystyrene, and poly(vinyl chloride), with the same main chain were selected as the adsorbents, with phenanthrene (PHE) as the representative PAHs. The adsorption mechanisms were explored from the perspective of the molecular spectral level using a combination of Fourier transform infrared spectroscopy (FT-IR) with a two-dimensional correlation technique. The adsorption kinetics results showed that the adsorption of PHE on the three MPs was dominated by chemisorption. However, the FT-IR analysis results indicated that no new covalent bond was created during the adsorption process. Based on the above research, a generalized two-dimensional (2D) correlation spectral technique was employed to investigate the sequence of functional group changes during the adsorption process for different MPs. Furthermore, the hybrid 2D correlation spectral technique explored the effect of side groups attached to the main chain molecules of MPs on adsorption. The results showed that for all three MPs, the functional groups in the side chain have a higher affinity for PHE, which is due to their higher hydrophobicity. This study provides a feasible way to analyze the adsorption of pollutants on MPs, and the results are important for understanding the adsorption interaction between PAHs and MPs in the aquatic environment.

Poly(vinyl chloride) composites reinforced with wood flour and calcinated halloysite

ABSTRACT Hybrid poly(vinyl chloride) composites were prepared by adding calcinated halloysite and wood flour to the PVC matrix by mixing in a molten state. The mechanical (DMTA analysis, tensile strength, strain at break, Young’s modulus, hardness and impact strength) and thermal (thermal stability, Vicat softening temperature and heat deflection temperature) properties of the composites were tested. The plastographometric analysis suggests that simultaneous addition of two fillers of different origins to the PVC matrix results in a longer gelation time and higher torque values than those observed for neat PVC. Moreover, the presence of calcinated halloysite in PVC/wood flour composites leads to the rise of weight loss temperature compared to PVC composites with only wood flour. When added to PVC/halloysite composites, wood flour improves their homogeneity by breaking halloysite agglomerates, which ensures approx. 116% better thermal stability (confirmed in the Congo red test) compared to unfilled PVC. The synergistic effect of the fillers used on the mechanical properties is demonstrated by the 14.4% higher stiffness and 22.5% higher tensile strength of the PVC composites containing wood flour and 5 wt% halloysite compared to the material loaded with wood flour only.

Dynamic Mechanical Analysis of Poly(Vinyl Alcohol)‐Based Gels with Boric Acid as Crosslinker

AbstractGels are soft materials made of a crosslinked polymer network immersed in a fluid. When water is the main component, these materials (hydrogels) find extensive use in the medical and pharmaceutical fields due to the high biocompatibility given by their high water content. The hydrogel ability to absorb water also makes it interesting for radiation shielding applications in space, since a high hydrogen content is helpful to reduce the damage caused by ionizing radiation on astronauts and electronic devices. In this work, crosslinked hydrogels are prepared using poly(vinyl alcohol) (PVA) with boric acid (BA) as crosslinking agent. Results in terms of chemical composition from Fourier transform infrared (FTIR) spectroscopy, mechanical properties from dynamic mechanical analysis (DMA), and swelling behavior are used to assess the BA capacity to form hydrogen and chemical bonds with the PVA macromolecules.

Modeling of Microplastics Migration in Soil and Groundwater: Insights into Dispersion and Particle Property Effects.

Migration of microplastics (MPs) in soil-groundwater systems plays a pivotal role in determining its concentration in aquifers and future threats to the terrestrial environment, including human health. However, existing models employing an advection-dispersion equation are insufficient to incorporate the holistic mechanism of MP migration. Therefore, to bridge the gap associated with MP migration in soil-groundwater systems, a dispersion-drag force coupled model incorporating a drag force on MPs along with dispersion is developed and validated through existing laboratory and field-scale experiments. The inclusion of the MP dispersion notably increased the global maximum particle velocity (vmaxp) of MPs, resulting in a higher concentration of MPs in the aquifer, which is also established by sensitivity analysis of MP dispersion. Additionally, increasing irrigation flux and irrigation areas significantly accelerates MP migration downward from soil to deep saturated aquifers. Intriguingly, vmaxp of MPs exhibited a nonlinear relationship with MPs' sizes smaller than 20 μm reaching the highest value (=1.64 × 10-5 m/s) at a particle size of 8 μm, while a decreasing trend was identified for particle sizes ranging from 20 to 100 μm because of the hindered effect by porous media and the weaker effect of the drag force. Moreover, distinct behaviors were observed among different plastic types, with poly(vinyl chloride), characterized by the highest density, displaying the lowest vmaxp and minimal flux entering groundwater. Furthermore, the presence of a heterogeneous structure with lower hydraulic conductivity facilitated MP dispersion and promoted their migration in saturated aquifers. The findings shed light on effective strategies to mitigate the impact of MPs in aquifers, contributing valuable insights to the broader scientific fraternity.

Safety assessment of the substances 'wax, rice bran, oxidised' and 'wax, rice bran, oxidised, calcium salt' for use in food contact materials.

The EFSA Panel on Food Contact Materials (FCM) assessed the safety of the substances 'wax, rice bran, oxidised' and 'wax, rice bran, oxidised, calcium salt', used as additives up to 0.3% in polyethylene terephthalate (PET), polyamide (PA), thermoplastic polyurethane (TPU), polylactic acid (PLA) and poly(vinyl chloride) (PVC) in contact with all food types for long-term storage at room temperature and below, after hot-fill and/or heating. The substances consist of the chemical classes wax esters, carboxylic acids, alcohols and calcium salts of acids, along with an unidentified organic fraction up to ■■■■■ w/w. Migration into 10% ethanol and 4% acetic acid was below 0.012 mg/kg for each chemical class, and about 0.001 mg/kg for the unidentified fraction. In isooctane, migration was up to 0.297 mg/kg food for wax esters, below 0.01 mg/kg food for the other chemical classes and about 0.02 mg/kg food for the unidentified fraction. The contact with dry food and food simulated by 20% ethanol were considered covered by the migration tests with aqueous simulants. Based on genotoxicity assays and compositional analyses, the constituents of the chemical classes did not raise a concern for genotoxicity. The potential migration of individual constituents or groups of chemically-related compounds of the unidentified fraction would result in exposures below (for aqueous food) and above (for fatty food) the threshold of toxicological concern for genotoxic carcinogens. Therefore, the FCM Panel concluded that the substances are not of safety concern for the consumer, if used as additives up to 0.3% w/w in PET, PLA and rigid PVC materials and articles intended for contact with all food types except for fatty foods, for long-term storage at room temperature and below, including hot-fill and/or heating up to 100°C for up to 2 h.

Effect on the performance of a hybrid rocket using AP in the PVC and HTPB-based hybrid fuel

Hybrid rocket is a type of chemical rocket propulsion system where the fuel and the oxidizer are stored separated and in different state of aggregation. Typically, the fuel is in the solid state and the oxidizer is either in the liquid or gaseous state. It offers various advantages over other type of chemical rockets such as throattability, controllability and reduced complexity. It also has some drawbacks such as low regression rate, poor combustion efficiency, higher sliver losses, etc. Various methods have been adopted to overcome these drawbacks and improve the performance of hybrid rocket. The present study focus on the improvement of regression rate with the addition of oxidizer particles in fuel content. Ammonium Perchlorate is used as an additive in Hydroxyl Terminated Polybutadiene (HTPB) and Poly Vinyl Chloride (PVC) based fuel grain. From the experimentations, it was observed that the thrust, pressure and regression rate of the HTPB fuel grain with additive have higher improvement than with the PVC based fuel grain. The sliver losses are also reduced due to uniform burning after addition of oxidizer in fuel grain. The overall study strongly suggests that addition of oxidizer in limited quantity can be used to overcome the drawbacks of hybrid propellant rocket.

Comprehensive evaluation of the impact of ionic liquid incorporation on the optical properties, Urbach energy, thin film morphology, and surface roughness of poly(vinyl chloride) based on ionic materials

Abstract A newly synthesis composite thin films of poly(vinyl chloride) has been refinement with ionic liquid, where PVC dissolved in THF with various concentrations of IL by casting method to form the composite thin films, without any reaction and IL dangles within PVC matrix. The thin films were examined by the diffusive reflectance device under the wavelength range (238–1300 nm). The XRD, EDX, and AFM techniques were utilized to discover the structure of the PVC matrix after additive IL. The XRD analysis illustrated the amorphous structure of the films, while the EDS analysis illustrated the main composition of pure PVC and composite PVC/IL. The optical properties and optical parameters were studied. The reflectance, extinction factor, transmittance, and imaginary dielectric constant declined, the absorption value was between (80–89 %), and the refractive index, real dielectric constant, and optical conductivity were increased. The indirect energy gap declined from 4.2 eV to 2.2 eV and the direct energy gap declined from 3.7 eV to 2.6 eV. The Urbach energy was increased from 2.09 eV to 15.45 eV revealing an increase in the disorders of electrons. The E d increased from 23.42 eV to 70.68 eV and E o increased from 7.00 eV to 10.88 eV. AFM analysis illustrated the roughness of the films increased after additive IL to the PVC Matrix from 1.08 nm to 4.45 nm and the root mean square of the particles ranged from 1.57 nm to 5.56 nm. The PVC composite thin films are utilized in solar cell and sodium-ion battery applications.

Preparation and characterization of poly(vinyl pyrrolidone)/cellulose nanofiber/Aloe Vera composites as a biocompatible hydrating facial mask

This study aimed to enhance the properties of polyvinylpyrrolidone (PVP) for use as biocompatible facial masks. To achieve this, nanofibers were developed by blending PVP with cellulose nanofibers (CNFs) and Aloe vera (AV) powder using electrospinning. The results showed that incorporating CNFs and AV into the PVP matrix led to the formation of smooth and uniform nanofibers. In particular, adding 3–6 wt% AV powder in PVP/CNF composites improved fiber diameter distribution and uniformity compared to pure PVP. The PVP/CNF/AV nanofibers exhibited desirable properties for facial mask applications. They displayed 86–93 % porosity, which allowed for efficient moisture absorption capacity of up to 1829 %, and excellent water vapor permeability rate of 3.92 g/m2h. The mechanical properties of the electrospun nanofiber composites were evaluated through tensile testing. The results showed that Young's modulus values decreased progressively with the addition of CNFs and AV powder to the PVP polymer matrix, indicating a plasticizing effect that enhances flexibility. The fracture strain remained similar across all composites, suggesting that CNFs and AV did not significantly weaken the PVP matrix. The tensile strength initially increased with CNF addition but decreased with incremental AV loading. Biocompatibility studies revealed that all nanofibers exhibited excellent fibroblast viability, surpassing 98 %. This indicates that incorporating CNFs and AV did not compromise cell viability, further highlighting the suitability of the PVP/CNF/AV composites for facial mask applications.

Spark discharge-initiated radical polymerization

A new spark discharge initiated radical polymerization (SDRP) was developed. Monomer radicals were generated by spark discharge emitted from a Tesla coil as a resonant transformer generating high frequency and high voltage, and the monomer itself acted as an initiator for propagation in polymerization at the initial stage. Poly(styrene), poly(acrylonitrile), and poly(styrene)/poly(vinyl benzoate) were successfully synthesized by the SDRP. The versatile SDRP was further developed using 2,2,6,6-tetramethylpiperidine 1-oxyl free radical (TEMPO) to create dormant species to perform nitroxide-mediated-radical-polymerization. We employed d-limonene as a solvent for the SDRP because limonene can effectively dissolve the polymers. Furthermore, solitons of polyacetylene were employed as a polymerization initiator. The solutions as a carrier in polyacetylene was generated with spark discharge. This can be referred to as "soliton-initiated polymerization".