Polyvinyl Alcohol Composites Research Articles

A review on green materials: Exploring the potential of poly(vinyl alcohol) (PVA) and nanocellulose composites.

Polyvinyl alcohol (PVA) and nanocellulose (NC) composite systems are promising candidates with exciting implications for sustainability, adaptability, and future uses. This research investigates the synergistic features of PVA and nanocellulose, focusing on their renewable and biodegradable nature as important contributors to sustainable material development. An overview of various processing techniques of PVA/NC composites, and their morphological, thermo-mechanical, barrier and biodegradable properties is examined, revealing its enhanced performance attributes compared to conventional materials. This review also discusses the numerous applications of PVA and nanocellulose composites in packaging, biomedical engineering, and environmental remediation. Furthermore, the discussion expands on the potential future applications of these composites, emphasizing their importance in tackling critical global concerns such as pollution reduction, resource conservation, and healthcare breakthroughs. With ongoing research focusing on functionalisation strategies and scalable production methods, PVA and nanocellulose composites are poised to revolutionize multiple sectors, offering sustainable solutions that align with the principles of circular economy and environmental stewardship. Finally, this review emphasises the enormous contributions of PVA and nanocellulose composites to sustainable material innovation, their broad applicability across industries, and their promise to shape a more resilient and environmentally friendly future.

Efficacy of a saline wash plus vancomycin/tobramycin-doped PVA composite (PVA-VAN/TOB-P) in a mouse pouch infection model implanted with 3D-printed porous titanium cylinders.

The efficacy of saline irrigation for treatment of implant-associated infections is limited in the presence of porous metallic implants. This study evaluated the therapeutic efficacy of antibiotic doped bioceramic (vancomycin/tobramycin-doped polyvinyl alcohol composite (PVA-VAN/TOB-P)) after saline wash in a mouse infection model implanted with titanium cylinders. Air pouches created in female BalBc mice by subcutaneous injection of air. In the first of two independent studies, pouches were implanted with titanium cylinders (400, 700, and 100 µm pore sizes) and inoculated with Staphylococcus aureus (1 × 103 or 1 × 106 colony-forming units (CFU)/pouch) to establish infection and biofilm formation. Mice were killed after one week for microbiological analysis. In the second study, pouches were implanted with 400 µm titanium cylinders and inoculated with S. aureus (1 × 103 or 1 × 106 CFU/pouch). Four groups were tested: 1) no bacteria; 2) bacteria without saline wash; 3) saline wash only; and 4) saline wash plus PVA-VAN/TOB-P. After seven days, the pouches were opened and washed with saline alone, or had an additional injection of PVA-VAN/TOB-P. Mice were killed 14 days after pouch wash. The first part of the study showed that low-grade infection was more significant in 400 µm cylinders than cylinders with larger pore sizes (p < 0.05). The second part of the study showed that saline wash alone was ineffective in eradicating both low- and high-grade infections. Saline plus PVA-VAN/TOB-P eradicated the titanium cylinder-associated infections, as manifested by negative cultures of the washouts and supported by scanning electron microscopy and histology. Porous titanium cylinders were vulnerable to bacterial infection and biofilm formation that could not be treated by saline irrigation alone. Application of PVA-VAN/TOB-P directly into the surgical site alone or after saline wash represents a feasible approach for prevention and/or treatment of porous implant-related infections.

Nanosized boron nitride-incorporated polyvinyl alcohol composites with TEMPO-oxidized cellulose nanofibers as ultrathin thermal interface materials

With the miniaturization and dense packing of electrical devices and mobility platforms, the effective thermal management at the interfaces of components in compact form factors is essential to overcome the performance limits and ensure the stability. Herein, we report the development of assembly of nanosized boron nitrides (BN) and TEMPO-oxidized cellulose nanofibers (T-CNFs) in polyvinyl alcohol (PVA) composites as ultrathin thermal interface materials (TIMs). BN nanoparticles (average thickness of 3.8–4.0 nm, lateral size of 90–100 nm, and aspect ratio of 25) were produced with a yield exceeding 80 % from the chemical treatment of hexagonal BN with NaOH and subsequent ball milling. TEMPO-oxidized cellulose nanofibers (T-CNFs) were added to mechanically reinforce the PVA-based matrix, while by the functionalization with OH– groups, the BN particles dispersed readily in the PVA solution, obtaining ultrathin nanosized BN/PVA/T-CNF composite films (∼50 µm). In contrast to the expected low thermal conductivity due to surface defects and high contact resistances typical of nanosized BN, composite films containing 50 wt% nanosized BN exhibited significantly high in-plane and through-plane thermal conductivities of 11.13 and 1.22 W/mK, respectively. Comparative analysis based on the Lewis–Nielsen model revealed that the size, shape, and agglomeration state of the BN particles could highly influence the thermal conductivity of composite films. Furthermore, heat dissipation experiments reflecting practical conditions demonstrated the outstanding performance and thermal stability of nanosized BN/PVA/T-CNF films as TIMs. This study will inspire rational strategies to facilely incorporate nanosized BN to diverse composites, offering advanced thermal characteristics with mechanical robustness.

A hybrid 3D-printed and electrospun bilayer pharmaceutical membrane based on polycaprolactone/chitosan/polyvinyl alcohol for wound healing applications

Skin injuries resulting from physical trauma pose significant health risks, necessitating advanced wound care solutions. This investigation introduces an innovative bilayer wound dressing composed of 3D-printed propolis-coated polycaprolactone (PCL/PP) and an electrospun composite of polyvinyl alcohol, chitosan, polycaprolactone, and diltiazem (PVA/CTS/PCL/DTZ). SEM analysis revealed a bilayer structure with 89.23 ± 51.47 % porosity and uniformly distributed nanofibers. The scaffold tensile strength, with pore sizes of 100, 300, and 500 μm, was comparable to native skin. However, smaller pore sizes reduced water vapor transmission from 4211.59 ± 168.53 to 2358.49 ± 203.63 g/m2. The incorporation of DTZ lowered the contact angle to 35.23 ± 3.65°, while the addition of PCL reduced the degradation rate and modulated the release of DTZ by approximately 50 %. Moreover, lower pH increased the degradation rate and decreased swelling. The inclusion of propolis enhanced antibacterial activity, and 10 % DTZ promoted the viability, proliferation, and migration of fibroblasts and adipose-derived stem cells. However, increasing DTZ concentration to 12 % reduced cell viability. In vivo tests on rats demonstrated effective wound healing and anti-inflammatory properties of the bilayer samples. Regarding the aforementioned results, the PCL/PP-PVA/CTS/PCL/DTZ (10 % w/w) bilayer wound dressing is a promising candidate for wound healing applications.

Development and characterization of highly conductive hybrid Moringa oleifera husk biocarbon and grape pulp cobalt oxide polyvinyl alcohol composites for microwave shielding

Development and characterization of highly conductive hybrid Moringa oleifera husk biocarbon and grape pulp cobalt oxide polyvinyl alcohol composites for microwave shielding

Developing flame retardant, smoke suppression and self-healing polyvinyl alcohol composites by dynamic reversible cross-linked chitosan-based macromolecule

With the increasing threat of white pollution to the public health and ecosystem, functional materials driven by green and sustainable biological macromolecule are attracting considerable attention. Inspired by the double-helix structure of DNA, a P–B–N ternary synergistic chitosan-based macromolecule (PBCS) was constructed to prepare flame retardant, smoke suppression and self-healing polyvinyl alcohol composite (PVA@PBCS) via dynamic reversible interactions. The limiting oxygen index value of PVA@PBCS increased from 19.6 % to 28.7 %, whereas the peak heat release rate and total heat release decreased by 47.04 % and 43.37 %, respectively. Besides, the peak smoke production rate and total smoke production of PVA@PBCS also decreased by 45.31 % and 54.98 %. With the presence of borate ester-based covalent and multiple hydrogen bonds, the tensile strength and elongation at break of PVA@PBCS increased by 19.50 % and 16.85 % compared to the control sample, and the healing efficiency for tensile strength and elongation at break was as high as 93.86 % and 90.57 %, respectively. This work developed an eco-friendly and effective scenario for fabricating flame retardant and smoke suppression PVA materials, stimulating the substantial potential of chitosan-based biomacromolecule and dynamic reversible cross-linked tactics in self-healing field.

Electromagnetic interference shielding behavior of flexible PVA composite made using betel nut husk biocarbon and steel microwire in E, F, I, and J band spectrum

AbstractThis study investigates the electromagnetic interference (EMI) shielding behavior of a flexible polyvinyl alcohol (PVA) composite fabricated using betel nut husk biocarbon and steel microwire in the E, F, I, and J band spectrum. The incorporation of steel microwire into the PVA based composite is novel approach since it provides flexibility along with good mechanical strength. The fabrication process involves the solution casting method, and the composite is characterized according to American society of testing and materials (ASTM) standards. The research focuses on analyzing dielectric behavior, EMI shielding effectiveness, and mechanical properties. Results indicates that, the composite with 5 vol.% of biocarbon and 5 vol.% of micro metal wire, exhibits exceptional relative permittivity of 7.6, 6.9, 6.3, and 1.5 for E, F, I, and J frequency bands and same composition delivers exceptional electromagnetic shielding with total shielding values of 17.7 dB, 25.5 dB, 31.7 dB, and 38.6 dB for E, F, I, and J frequency bands. In mechanical characteristics, composite with 5 vol.% of biocarbon and 5 vol.% of micro metal wire, exhibits high tensile strength of 73 MPa with lower elongation percentage of 109.2% and shore‐D hardness of 40, respectively. Thus, the inclusion of betel nut husk biocarbon and steel microwire into the PVA matrix enhanced the overall EMI shielding properties along with mechanical properties. These flexible EMI shielding composites could be used in applications such as defense, telecommunication, drones, and electronic gadget making segments.Highlights Flexible polyvinyl alcohol (PVA) composite is made with steel microwire and betel nut husk biocarbon. Biocarbon is derived from betel nut husk for first time and used as EM wave absorber. Composites were made via simple solution casting method for high flexibility index. Composite contains 5 vol.% biocarbon and 5 vol.% micro metal wire, shows high relative permittivity 7.6 for E frequency bands. The composites have high tensile strength of 73 MPa with a low elongation percentage of 109.2% and a shore‐D hardness of 40.

Design and development of lignin nanobottles: Toward developing novel multifunctional nanocomposites

The design of lignin nanostructures, which leverages interfacial interactions to enhance colloidal network entanglement, holds promise for expanding their applications in polyvinyl alcohol (PVA) composites. Herein, a novel approach is proposed for fabricating lignin nanobottles (LNBs) using biomass-derived γ-butyrolactone (GBL) to create hollow interiors connected to a single surface opening. The resulting LNBs exhibit uniform sizes of approximately 108 nm with an opening diameter of 34.94 nm. Incorporating LNBs into PVA composites enhances mechanical properties significantly, with a tensile strength of 64.96 MPa and an elongation at break of 611.6 %. Moreover, the nanocomposite films demonstrate notable antibacterial effects, UV protection, and hydrophobicity. Introducing LNBs improves photothermal conversion capacity, achieving a temperature of 62.1 °C in just 150 s. Furthermore, a meticulously designed 3D solar evaporator demonstrates remarkable evaporation performance, achieving a rate of up to 1.89 kg m-2h−1 with an outstanding efficiency of 96.55 %. When exposed to 1 sunlight, the thermoelectric material generates an output voltage of 0.83 V, indicating considerable potential for energy generation. Overall, Incorporating LNBs enhances lignin’s effectiveness in materials and provides a novel approach to augment lignin’s photothermal properties, enabling broader applications in solar-driven evaporation and thermoelectric materials.

Characteristics of Cellulose Acetate Composite Membranes (Ca/Cs, Ca/Pva, Ca/Peg) As Cu(Ii) Metal Ion Filtration Membranes

Industrial development in Indonesia has caused increased pollution, including water pollution by heavy metals, one of which is the metal ion Cu(II). Cellulose acetate composite membranes have been widely used to overcome the problem of Cu(II) metal ion content in water, however, studies on the performance of cellulose acetate membranes with various types of chitosan, polyvinyl alcohol (PVA) and polyethylene glycol (PEG) composites have not been widely reported. This research aims to analyze the characteristics of cellulose acetate composite membranes with chitosan, PEG, and PVA using FTIR and SEM and to determine the performance of these cellulose acetate composite membranes in filtering Cu(II) metal from the resulting rejection values. The membrane was made using the phase inversion method and the composite membrane was made using the dip-coating method. The results of characterization using FTIR showed that there were no new peaks in all cellulose acetate composites, so there were only physical interactions in the composites. SEM analysis shows that the surface of the composite membrane is more irregular and the porosity increases. The performance of the composite membrane in filtering Cu(II) metal is better than the pure cellulose acetate membrane.

Electrochemical incorporation of PVA-ZnO composite on Screen printed carbon electrode as dopamine sensor

In this study, a composite of zinc oxide (ZnO) nanoparticles and polyvinyl alcohol (PVA) on a screen-printed carbon electrode (SPCE), termed SPCE/PVA/ZnO electrode, was utilized to develop an enhanced electrochemical sensor for dopamine (DA) detection. A novel method for synthesizing ZnO nanoparticles using almond gum at room temperature was introduced. X-Ray Diffraction (XRD) analysis confirmed the crystallinity of the ZnO nanoparticles. The SPCE/PVA/ZnO electrode was fabricated and characterized using Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-ray Spectroscopy (EDX). Cyclic voltammetry was employed to measure DA, revealing a linear increase in the electrochemical oxidation signal of DA at the SPCE/PVA/ZnO composite from 100 to 600 μM. The sensor demonstrated a limit of detection of 0.1208 mM and a sensitivity of 0.01822 μAμM−1cm−2. The SPCE/PVA/ZnO sensor showed acceptable performance in evaluating dopamine in real sample study.

Phosphonitrile hybrid metal-polyphenol network: An effective strategy for developing functional PVA composites with flame retardancy, antibacterial and UV resistance

The white pollution caused by non-degradable plastics poses a serious threat to human society and the environment, thus developing biodegradable material is urgent. In this work, a novel phosphonitrile hybrid metal-polyphenol network was constructed and used for the preparation of flame retardant, UV resistant and antibacterial multifunctional polyvinyl alcohol composite (PVA@HCPD-Ag). The limiting oxygen index (LOI) value of PVA@HCPD-Ag was improved to 33.5%, while the peak heat release rate (PHRR) and total heat release (THR) decreased by 35.62% and 47.76%. Besides, the ultraviolet protection factor (UPF) value of PVA@HCPD-Ag was significantly improved from 4.63 of the original PVA to 482.79, while the tensile strength was increased by 10.23%. Furthermore, the inhibition efficacy of PVA@HCPD-Ag for E. coli and S. aureus was up to 98.12% and 99.99%. This work explored the synergistic flame retardant effect of in-situ reduced Ag0 and phosphonitrile crosslinked polyphenol network and proposed an advanced strategy for developing high value-added functionalized PVA materials.

Synthesis of flexible magneto‐electric polyvinyl alcohol composites using hybrid filler particles of carbon quantum dots and cobalt nano for electromagnetic interference shielding application

AbstractThe main objective of the study is to synthesis and characterization of flexible magneto‐electric Polyvinyl Alcohol (PVA) composites for Electromagnetic Interference (EMI) shielding applications, by incorporating carbon quantum dots extracted from lychee fruit husks and cobalt nanoparticles sourced from Plectranthus amboinicus. Comprehensive mechanical, dielectrical, magnetic, and shielding tests were conducted to assess the performance of these novel materials. The mechanical characteristics of the composites were assessed to gauge their flexibility and robustness. In this regard, PV4 displayed a substantial tensile strength of 68 MPa, while PV6 exhibited an enhanced shore‐D hardness rating of 47. PV6 demonstrates superior dielectric properties, including a higher dielectric constant and a lower loss tangent, which are crucial for optimizing EMI shielding efficiency. When it comes to magnetic characteristics such as magnetization, retentivity, and coercivity, the PV6 composite designation outperforms the other composites. Additionally, PV6 exhibits higher electromagnetic interference (EMI) shielding effectiveness, measuring at approximately 49.8 dB in the E band and 56.5 dB in the F band. Findings demonstrate that the integration of carbon quantum dots and cobalt nanoparticles into the matrix resulted in flexible composites with enhanced mechanical strength. The incorporation of cobalt contributed to notable magnetic properties, increasing the materials' magnetization and retentivity. The tests on electromagnetic interference (EMI) showed that the shielding effectiveness got improved. The composite materials were able to reduce interference from electromagnetic waves in the tested frequency ranges. These flexible magneto‐electric PVA composites, developed using sustainable sources such as lychee fruit husks and Plectranthus amboinicus, exhibit promising potential for EMI shielding applications in diverse industries, including telecommunications, aerospace, and electronics, where reliable interference control is essential for optimal performance and safety.Highlights Cobalt nanoparticles sourced from Plectranthus amboinicus. Carbon quantum dots are prepared from lychee fruit husks via controlled pyrolysis. High tensile strength PVA composites prepared. Highest dielectric constant of 8.2 achieved for composite PV6. Higher wave shielding up to 56.5 dB achieved in “E” band.

The impact of nanoparticle surface topography on the interfacial mechanical behavior and microstructure of polyvinyl alcohol composites

The interfacial mechanical strength between nanoparticle and matrix is one of the key factors affecting the mechanical properties of nanoparticulate-polymer composites. Based on the structural composition of a nanoscale iron particle/polyvinyl alcohol composite, this study employed molecular dynamics simulations to investigate the stress-response behavior and microstructural evolution of Fe/PVA/Fe interface models with different surface morphologies under both tensile and shear deformations. The results indicate that when the particle surfaces exhibit different rough structures, the interfacial tensile strength significantly increases with the absolute value of the interfacial binding energy. The order of tensile strength is Type-cube > Type-pyramid > Type-plane. Furthermore, during the shearing process, the protruding structures on the particle surfaces significantly hinder the deformation and unfolding of the matrix molecular chains. As the volume of the protruding structures increases, the interfacial shear strength decreases markedly. The research findings illuminate the mechanisms by which nanoparticle surface morphology at the microscopic molecular scale influences the mechanical properties of nanoparticle-polymer composite materials. These discoveries aid in selecting nanoparticle fillers that enhance the mechanical performance of polymer nanocomposites to a measurable extent.

Optimization of mass transfer-enhanced chlorine-resistant crosslinked PVA composite membranes for pervaporation desalination

Pervaporation (PV) is characterised by good hydrophilicity and antifouling properties. However, it is still unavoidable to need cleaning during long-term operation. Sodium hypochlorite (NaClO) is a commonly used purifying agent for organic pollutants, but it may cause damage to the polymer membrane. In this study, a grafting method was proposed to enhance the chlorine resistance and water permeability of membrane composite polyvinyl alcohol (PVA) pervaporation membrane. Modified PVA (SPVA) was prepared by grafting 5-sulfosalicylic acid (SSA) to improve the hydrophilicity of the membrane using the sulfonic acid group on SSA. SPVA-FA/PTFE composite membranes were prepared by using perfluoroglutaric acid (PFGA) as crosslinking agent to improve the chlorine resistance of the membranes by utilising the C-F chain contained therein. The water flux was 120.38 ± 1.72 kg/(m2·h), which was 84.2 % higher than that before grafting, when tested at 70 °C and 3.5 wt% NaCl. The chlorine resistance of SPVA-PFGA/PTFE composite membrane was tested in 2000 ppm (pH = 12) NaClO solution for 480 h, and the salt rejection remained above 99.93 %. When desalinating 20 wt% NaCl at 70 °C, the water flux of SPVA-PFGA/PTFE membrane is 51.95 ± 0.6 kg/(m2·h), which has the potential to treat high concentration brine.

Preclinical evaluation of the individualized approach for chronic non-healing wounds management

Chronic non‑healing wounds (CNHW) are very common and often incorrectly treated, the morbidity and associated costs of chronic wounds management highlight the need to implement wound prevention and treatment concepts. Objective — to evaluate the possibility of different metal nanooxide polymer nanofilms use for CNHW’ local treatment. Materials and methods. The study design is based on evaluation of various types of dressing materials considering their option for use in CNHW local treatment. Samples of biodegradable polymer films (with an optimal composition of gelatin, polyvinyl alcohol, lactic acid, glycerin and distilled water) saturated with nanoparticles of several oxides with expected antibacterial and pro‑regenerative feature — nZnO, nMgO in concentrations of 1%, 5%, and 10% were used in the study of antimicrobial action and substance release profiling. Quarterly ammonium antiseptic decamethoxin 0.02% was used for control. Results. Obtained data shows that polymer based biodegradable films incorporating optimal component composition (gelatin, polyvinyl alcohol, lactic acid and glycerin) enriched with 5% and 10% zinc nanooxide have potent antimicrobial activity against both gram‑positive and gram‑negative microorganisms, the most common causative agents of CNHW’s. The ion release capacity analysis showed that the Zinc impregnated wound‑healing biodegradable polymer film gradually releases the active substance in a time dependent manner, and the nano‑sized particles of nanoZinc oxide are released from the polymer composition faster than ordinary zinc oxide. Conclusions. Complex natural biodegradable polymer based nanofilms are composite materials impregnated with metal nanooxides showing high potential in local treatment of chronic non‑healing wounds. Polymer film with 5% nanoZnO showed up to the 58% higher antimicrobial activity, comparable or exceeding the one of quarterly ammonium compound decamethoxin. Furthermore, nanoZnO impregnated polymer films compared to standard ZnO impregnated polymer films showed up to 63.2% faster substance release profile with rapid and more unified curve.

Terahertz-based optoelectronic properties of ZnS quantum dot-polymer composites: For device applications

Terahertz (THz) technology integration with nanomaterials is receiving excellent attention for next-generation applications, including enhanced imaging and communication. The excellent optical properties in THz domain can lead to preparation of low-cost CMOS camera which can convert THz radiation into optical signal in very efficient manner. In the present study, we have studied the properties of Zinc Sulfide quantum dots (ZnS QDs) embedded with Polyvinyl Alcohol (PVA) composites films using THz Signal at room temperature. The optical characterizations such as refractive index, absorption coefficients and dielectric constants of these samples were measured in the 0.1–2.0 THz range. Additionally, optical impedance, surface roughness, and reflection coefficient in TE and TM mode between 0.1 and 2.0 THz range were determined for these samples based on surface roughness-based reflection and scattering properties. The surface roughness factor was used to measure the optical impedance of the ZnS QDs based polymer films. The measured values of the absorption coefficient at 266 nm are compared with THz radiation, and the refractive indices of these samples range from 1.75 to 2.0. Finally, these samples were subjected to UV light excitation (λexe = 266 nm) of 0.15 ns duration and 400 nm for the fluorescence and corresponding life time measurements. We observed two numbers of fluorescence lines in nanosecond based excited domain whereas 400 nm excitation-based fluorescence life time lies between 13.8–11.39 ns range along with shift in fluorescence lines between 538.7 to 560.7 nm, respectively.

Recent Advances in the Fabrication and Performance Optimization of Polyvinyl Alcohol Based Vascular Grafts.

Cardiovascular disease is one of the diseases with the highest morbidity and mortality rates worldwide, and coronary artery bypass grafting (CABG) is a fast and effective treatment. More researchers are investigating in artificial blood vessels due to the limitations of autologous blood vessels. Despite the availability of large-diameter vascular grafts (Ø>6mm) for clinical use, small-diameter vascular grafts (Ø<6mm) have been a challenge for researchers to overcome in recent years. Vascular grafts made of polyvinyl alcohol (PVA) and PVA-based composites have excellent biocompatibility and mechanical characteristics. In order to gain a clearer and more specific understanding of the progress in PVA vascular graft research, particularly regarding the preparation methods, principles, and functionality of PVA vascular graft, this article discusses the mechanical properties, biocompatibility, blood compatibility, and other properties of PVA vascular graft prepared or enhanced with different blends using various techniques that mimic natural blood vessels. The findings reveal the feasibility and promising potential of PVA or PVA-based composite materials as vascular grafts.

Structural, Optical, and Morphological Study of Manganese Substituted Cobalt Ferrite and Its Effect on the Magnetic and Dielectric Properties of PVA Composites

Nanopowders of Mn-substituted CoFe2O4 were prepared in different proportions using the sol-gel auto-combustion method and were structurally and morphologically studied. In another step, composites based on polyvinyl alcohol (PVA) with Mn-substituted CoFe2O4 fillers were prepared, and the effect of the Mn-substituted CoFe2O4 on the optical, magnetic, and dielectric properties was studied. X-ray analysis revealed the formation of polycrystalline Mn-substituted CoFe2O4. The results showed a decrease in the lattice constant with Mn2+ substituted and incorporated into the crystal structure of CoFe2O4. The Fourier confirmed the spinel structure of the Mn-substituted CoFe2O4 transform infrared spectrum where absorption bands appeared at 569–561 and 446–407 cm-1, which are attributed to tetrahedral and octahedral groups. The magnetic properties were affected when Mn ions were substituted with CoFe2O4, as shown by the results of VSM. It was observed that the saturation magnetization, remnant magnetization, and coercivity decreased with increasing Mn content. The dielectric constant and loss tangent of PVA/MnxCo1−xFe2O4 were also studied. The difference in the diameters of the substituted and host ions causes the dielectric constant to increase following the substitution of Mn ions.

Mechanical, Optical, and Thermal Properties of SnS2-Filled PVA Composites

The effects of tin disulfide (SnS2) addition on the mechanical, thermal, and optical characteristics of polyvinyl alcohol (PVA) were determined in this study. The solvent-casting approach was used to create composite films with varying SnS2 weight ratios. Mechanical testing revealed that the addition of SnS2 raised the tensile strength (TS) of the virgin PVA from 32.10 MPa to 47.50 MPa, while the elongation at break (EB) increased from 78.40% to 108.80%. Optical investigations revealed that PVA and SnS2 had intermolecular interactions. Furthermore, the contribution of SnS2 resulted in a drop in energy bandwidth from 5.310 eV to 4.821 eV. Thermal investigations revealed that PVA/SnS2 had greater stability than the virgin polymer. Given the data obtained, it was obtained that the addition of SnS2 simultaneously enhanced the mechanical, thermal, and optical properties of PVA.

Effects of Vancomycin/Tobramycin-Doped Ceramic Composite (Polyvinyl Alcohol Composite–Vancomycin/Tobramycin–Polymeric Dicalcium Phosphate Dihydrate) in a Rat Femur Model Implanted With Contaminated Porous Titanium Cylinders

BackgroundPeriprosthetic joint infection (PJI) remains common and problematic. We hypothesized that using a bioceramic that provided rapid release of the antibiotics (vancomycin [VAN] or VAN and tobramycin [VAN and TOB]) from a polyvinyl-alcohol-composite (PVA) combined with a delayed and sustained antibiotic release from polymeric-dicalcium-phosphate-dihydrate (PDCPD) ceramic would inhibit S. aureus-associated implant infections. MethodsA total of 50 male Sprague Dawley rats were randomly divided into 5 groups—I: negative control; II: bacteria only; III: bacteria + saline wash; IV: bacteria + PVA-VAN-PDCPD, and V: bacteria + PVA-VAN-TOB-PDCPD. A porous titanium (Ti) implant was press-fit into the rat knee. S. aureus-containing broth was added into the joint space creating a PJI. After 1 week, the joints from groups III to V were washed with saline and the fluid collected for bacterial quantification. This was followed by saline irrigation treatment (groups III to V) and application of the antibiotic-loaded PVA-PDCPD bioceramic (groups IV and V). On day 21, joint fluid was collected, and the implants harvested for bacterial quantification. ResultsNo bacteria were isolated from the negative control (group I). The positive control (group II) was positive on both days 7 and 21. Bacteria were still present on day 21 in the fluid and implant in group III. Groups (IV and V) showed a decrease in the bacterial burden in the fluid and implant on day 21. There were significant differences in bacteria levels in the collected wash fluid and on the implant at day 21 between the saline wash (group III) and treatment groups (IV and V). ConclusionsIn this animal model of acute periprosthetic infection, treatment with PVA-VAN-PDCPD and PVA-VAN/TOB-PDCPD reduced bacterial load in the infected joint and the infected Ti implant. Application of PVA-VAN-PDCPD and/or PVA-VAN/TOB-PDCPD after saline irrigation could be used as an addition to the treatment of PJI.