Vibration monitoring is critical in several disciplines, such as machine and civil engineering, structural health monitoring, biomedical diagnostics, and interactive technology. Mechanical vibrations can cause structural deterioration in engineering systems, or manifest as symptoms in neurodegenerative diseases. As an alternative approach to accelerometers for vibration sensing, carbon-based polymer composites with piezoresistive responses show great potential for detecting and monitoring vibrations. This study investigates the vibration sensing capabilities of polymer composites incorporating carbon black and carbon nanotubes embedded in polyurethane and polylactic acid matrices, and processed via additive manufacturing. Vibratory response tests were conducted on thin rectangular cantilever specimens using a custom-built vibrometer. In a typical free vibration test, a single air pulse is applied to induce oscillation, while the electrical resistance of the specimen is continuously recorded. The oscillatory changes in electrical resistance are correlated with the mechanical vibrations of the specimens, which are also independently measured by optical methods. The natural frequency and vibration amplitude are extracted from the electrical response of the material and validated with independent optical measurements of vibration. The measured natural frequencies are compared to vibratory analytical models. Carbon-based polymer composites demonstrated excellent capabilities to monitor vibratory stimuli and measure natural frequencies through their electrical responses, supporting their great potential for vibration-sensitive applications. These applications range from structural health monitoring to tremor detection in patients with neurodegenerative diseases. Additional advantages are offered by additive manufacturing in terms of fabrication simplicity and design flexibility.

To obtain composite materials using epoxy-functional siloxanes, direct amine addition to epoxy groups is thought to be a particularly useful approach for crosslinking epoxy, and they are used as the most popular curing agents.

In this study, we focused on an epoxy–siloxane amine composite obtained by the reaction between 1,3-Bis(3-glycidyloxypropyl)tetramethyldisiloxane (DS-PMO) and an aromatic amino compound, p-Phenylenediamine (PPDA). Two stages were involved in the preparation of the epoxy–siloxane amine composites. In the first stage, the hydrosilylation reaction between allyl glycidyl ether (AGE) and 1,1,3,3-tetramethyldisiloxane (TM-DS) was performed in the presence of a Karsted catalyst, resulting in the glycidoxypropyldisiloxane (GP-DS) intermediary compound. In the second stage, the GP-DS derivative was modified with PPDA to obtain the epoxy–siloxane amine composites (PPD-DS).

The polymers' structures were confirmed by FTIR, ¹H-NMR, and MS spectroscopy. The morphology and surface chemical compositions were highlighted using scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX). The samples were subjected to thermal investigations using thermogravimetric analysis (TGA) as well as advanced thermogravimetric analysis, namely TGA/FT-IR/MS. In addition, the optical properties and static contact angle of precursors and the synthesized sample were investigated. The results showed that modifying epoxy–siloxane with p-Phenylenediamine allows for the production of hybrid materials with very good thermal stability, and it can also be recommended to use the PPD-DS composite material for UV-based applications.

In this work, a prospective study on the current uses and applications of polyvinyl alcohol (PVA) nanofibrillar materials is presented. Polyvinyl alcohol is a synthetic polymer that has gained attention for its biodegradability and sustainable qualities under certain conditions. It has become a valuable material in various fields, including innovative food packaging, advanced hydrogen fuel cells, and sophisticated medical applications such as wound dressings and tissue engineering scaffolds. First, the theoretical background is studied in detail to understand the structure–property relationships that govern PVA performance, examining its essential properties intrinsically linked to its structural features, such as crystallinity, mechanical properties, and bio-sustainability. Then, the main processing parameters dictating nanofibrillar morphology and the factors and parameters that may control the morphological characteristics of PVA-based materials to favor the formation of nanofibers are focused on, with particular emphasis on the electrospinning (ES) and solution blow spinning (SBS) techniques. Finally, to give consistency on the practical feasibility of both approaches, PVA nanofibers were experimentally fabricated under the optimized ES and SBS conditions established herein. Morphological, structural, and thermal characterization of the resulting materials was carried out to elucidate the differences between the two processing techniques. Ultimately, this article discusses the future research directions to address the current challenges and prospective ways to fabricate PVA nanofibrous materials for potential biomedical applications.

Polymer structures are essential in biomedical applications, such as tissue engineering and regenerative medicine, due to their properties of biocompatibility and biodegradability. The use of polymer composites is particularly significant for various applications, as a combination of mechanical, chemical and biological properties can be achieved. The intended application determines the selection of the biopolymer materials. In addition, the method used to process the materials should produce scaffolds that deliver the required therapeutic effect. Electrospinning is a well-established technique for producing fibres from a spectrum of polymer feedstock with diameters ranging from micrometres to nanometres. Moreover, electrospun fibres may exhibit a variety of biomimetic surface features (such as porosity) and orientations. The present review is aimed at describing the synthetic and natural polymers commonly used in biomedical applications, with particular focus on composite polymers. The processing of polymer composites using various electrospinning techniques is also discussed, as well as the biomedical application of the electrospun polymer composites. Although polymer composites and electrospinning have seen significant growth in biomedicine, making them suitable candidates for Industry 4.0, recent advances have shown great potential in propelling them into Industry 5.0 applications. These advances include the fabrication of smart 3D multi-functional scaffolds with tailored mechanical and biological properties, and the inclusion of machine learning technologies.

Liquid crystalline epoxy resins containing mesogenic groups were cured under controlled temperature conditions to suppress the molecular mobility and promote crosslinking while maintaining an ordered alignment structure. The resulting alignment of polymer network chains in the cured materials was thoroughly characterized using polarized optical microscopy (POM) and X-ray diffraction (XRD). By varying the curing temperature, significant changes were observed in the domain size of the aligned liquid crystalline phases. These phases were identified as either nematic or smectic liquid crystal structures, which were found to be retained and fixed within the polymer network. The mechanical and thermal properties of the cured liquid crystalline epoxy thermosets were evaluated, and their relationship with the alignment structure of the network chains was discussed. In particular, fracture toughness was found to increase markedly with the enlargement of the liquid crystalline domains, indicating that the anisotropic order contributes to enhanced energy dissipation during the crack propagation.

Furthermore, the incorporation of cellulose nanofibers (CNFs) into the curing system led to an increased proportion of smectic liquid crystalline alignment. This enhancement is attributed to the hydroxyl groups present on the surface of the CNFs, which likely induced alignment of the liquid crystalline epoxy matrix through polar interactions.

Traditional passive wound dressings present significant limitations, including poor biocompatibility, inadequate mechanical strength, and uneven material distribution. This study addresses these challenges by enhancing hydrogel strength through UV-induced thiol-ene click chemistry, incorporating biocompatible polymers, chitosan (CS), hyaluronic acid (HA), and polyvinyl alcohol (PVA), and leveraging 3D printing for uniform porous scaffold architecture. Hydrogels composed of CS, HA, and PVA were prepared in various ratios. Chemical cross-linking was achieved using thiolated HA or PVA blended with allyl-modified CS, resulting in OAL-CS/PVA-SH/HA and OAL-CS/PVA/HA-SH formulations. The degree of cross-linking was evaluated through printability parameters (extrudability, uniformity, pore integrity) and physicochemical characterizations, including FTIR, XRD, water sorption, and hydrolytic degradation studies. FTIR analysis confirmed successful UV cross-linking via the disappearance of the alkene (CH₂=CH₂) peak at 1637 cm⁻¹. XRD patterns revealed that UV-cross-linked scaffolds exhibited reduced crystallinity, indicating a more amorphous structure—contributing to enhanced water absorption and permeability. Among all tested formulations, the OAL-CS/PVA-SH/3HA scaffold demonstrated the most favorable properties, including controlled degradation over 30 days, with minimal mass loss and exceptionally high water absorption (2412%), attributed to its amorphous network. Furthermore, 3D printing evaluations showed that this scaffold maintained a stable, uniform porous structure during multilayer deposition, supporting better cell distribution and facilitating uniform tissue formation. In conclusion, the OAL-CS/PVA-SH/3HA scaffold emerges as a promising candidate for tissue engineering, outperforming physically cross-linked variants in terms of mechanical stability, print fidelity, and biocompatibility.

Recent progress in nanoscience has enabled the development of nanostructured materials with applications in the diagnosis and treatment of diseases. Among these, silicon dioxide (SiO₂) nanoparticles combined with gold nanoparticles (AuNPs) have demonstrated significant promise in biomedical imaging and photothermal therapy due to their optical tunability and biocompatibility. In this study, SiO₂-Au nanocomplexes were synthesized and dispersed in aqueous polyvinyl alcohol (PVA) solutions to fabricate flexible films approximately 200 microns thick. The nanocomposite films were prepared with varying nanoparticle concentrations ranging from 1.50 to 4.5 mg/mL to investigate their optical and thermal behavior. Photopyroelectric (PPE) techniques were employed to determine key parameters such as optical absorption coefficient and thermal diffusivity, which are crucial for assessing their photothermal conversion capabilities. The results indicated that at specific SiO2-Au nanocomplex concentrations, the films exhibited high absorption coefficients in the visible spectrum, particularly at wavelengths of 520 nm and 660 nm. Their thermal diffusivities were recorded to determine their capacity for light-to-heat conversion. These findings highlight the potential of PVA films with SiO₂-Au nanocomplexes for use in minimally invasive photothermal therapies. Additionally, polyvinyl alcoholprovides biocompatibility, ease of processing, and mechanical flexibility, making this nanocomposite system a promising candidate for integration into biomedical devices and therapeutic platforms.

The development of high-performance elastomer nanocomposites increasingly depends on engineering the filler–matrix interphase rather than maximizing filler content. This study examines nitrile butadiene rubber (NBR) reinforced with 0.5–2.0 phr graphene oxide (GO) synthesized via a modified Hummers’ method, focusing on how hydrogen-bonded interfaces influence structural, mechanical, dielectric, and optical behavior. GO, rich in hydroxyl, carboxyl, and epoxide groups, was incorporated through a solution–coagulation process followed by sulfur vulcanization to promote uniform dispersion.
X-ray diffraction confirmed effective GO exfoliation, with maximum polymer chain ordering at 1 phr. FTIR spectra showed broadening/redshift of the nitrile band and GO-derived C–O–C and C–O absorptions, evidencing hydrogen bonding and dipole–dipole interactions without covalent grafting. Microscopy and AFM revealed optimal dispersion and a narrowed nanostructure size range (20–45 nm) at 1 phr. UV–Vis/Tauc analysis demonstrated a non-monotonic band gap trend (direct Eg: 3.01 → 3.13 → 3.11 eV), arising from competition between quantum confinement and π–π stacking.
Dielectric spectroscopy (10²–10⁶ Hz, 20–100 °C) indicated improved permittivity stability via Maxwell–Wagner–Sillars polarization, with 1 phr achieving the most balanced response. Mechanical testing showed gains in tensile strength, tear resistance, rebound elasticity, abrasion resistance, and solvent resistance, alongside enhanced rubber–metal adhesion and thermo-oxidative stability.
Across all analyses, 1 phr GO emerged as the optimal loading, offering a percolating yet well-dispersed interphase that maximizes property transfer while avoiding aggregation-driven losses. The results highlight interphase engineering as a scalable strategy for producing durable, dielectric-stable elastomers for sealing, oil-resistant, and industrial applications.

Efficient Thermal Energy Storage (TES) systems are vital for advancing energy efficiency and integrating renewable sources. Within this context, innovative composite coatings offer a promising avenue to enhance TES system effectiveness and longevity. This study focuses on developing and characterizing novel composite coatings, specifically tailored for TES applications, consisting of a sulfonated pentablock terpolymer (Nexar) matrix, known for its excellent water vapor permeability, filled with SAPO-34 zeolite filler, a microporous substance with high heat exchange capabilities at lower temperatures. A significant challenge for adsorbent coatings and composite materials lies in their susceptibility to aging, particularly when the polymeric matrix is crucial for maintaining structural and functional integrity. Prolonged exposure to adsorbates like water vapor can severely degrade the coating's performance. Therefore, assessing the composite's aging response is crucial for confirming its practical viability.

In this work, we subjected SAPO-34/Nexar composite coatings, with varying zeolite concentrations, to hydrothermal aging to verify their stability. The aging protocol involved hundreds of wet (30°C, 80% RH) and dry (40°C, 20% RH) cycles within a controlled climatic chamber. We evaluated the coatings' mechanical properties (including pull-off strength and scratch resistance) and adsorption/desorption capacity (by means of DVS analysis), both before aging and after specific aging durations. The mechanical properties of the coatings decrease with an increasing number of cycles: a decline that is most pronounced at lower zeolite concentrations. The 90 wt% zeolite composition offers superior mechanical stability over cycles, while exceeding this percentage leads to a degradation of properties due to the reduced amount of polymer binder. DVS analysis indicated only a minimal reduction (between 2.9% and 3.5%) in adsorption capacity. These findings highlight that a balanced composition is crucial for the practical viability of high-filler content SAPO-34/Nexar coatings in long-term TES applications.

Rapid population growth, expanding industries, and relentless economic development contribute significantly to water contamination which is a major obstacle to achieving sustainable quality water. The increasing presence of water contamination like heavy metals, salts and industrial effluents exacerbates the global water crisis, demanding advanced water filtration solutions. Therefore, the architectural evaluation for effective performance of nanofiltration (NF) membranes is of paramount importance. NF technology offers a promising avenue due to its ability to remove multivalent ions, organic and micro -pollutants efficiently while operating at relatively low pressure compared reverse osmosis (RO). This study focuses on the morphological structure, analysis of chemical composition, permeation and rejection of Polyethersulfone/coreshell-Fe₃O₄/ZnO membranes. The SEM images showed porous, interconnected tunnels and finger-like morphological structures of NF membranes. The water uptake, porosity and thickness contributed to the performance of the membranes. The contact angle of the membranes was improved significantly with the incremental addition of trimesoyl chloride. 0.50 wt % of PES/Fe₃O₄/ZnO was highly hydrophilic with a contact angle of 55.22˚. This membrane also offered maximum rejection of Na₂SO₄ (50.91 %)_, NaCl (52.64 %), and 80.39 % Pb(II) rejection . In addition, this study highlights that the synergistic effects of the pore-former, solvent evaporation time, metal oxides and monomers are crucial for effective performance of nanofiltration membranes.