Polymers

17 pages, 2302 KB

Open AccessArticle

Engineered GO-Based Hydrogels for Controlled Hyaluronic Acid Release in Knee Osteoarthritis Treatment

by Roya Binaymotlagh, Damiano Petrilli, Laura Chronopoulou, Giorgio Mandato, Francesca Sciandra, Andrea Brancaccio, Marisa Colone, Annarita Stringaro, Leonardo Giaccari, Francesco Amato, Andrea Giacomo Marrani, Silvia Franco, Roberta Angelini and Cleofe Palocci

Polymers 2026, 18(2), 152; https://doi.org/10.3390/polym18020152 - 6 Jan 2026

Abstract

Osteoarthritis (OA) is a prevalent chronic pain syndrome and a leading cause of disability worldwide, characterized by progressive deterioration of articular cartilage. This degradation leads to pain, swelling, inflammation, and eventual stiffness as the cartilage wears down, causing bone-on-bone friction. Current medical treatments [...] Read more.

Osteoarthritis (OA) is a prevalent chronic pain syndrome and a leading cause of disability worldwide, characterized by progressive deterioration of articular cartilage. This degradation leads to pain, swelling, inflammation, and eventual stiffness as the cartilage wears down, causing bone-on-bone friction. Current medical treatments primarily aim at pain relief; however, many interventions, especially invasive or surgical ones, carry risks of adverse outcomes. Consequently, intra-articular (IA) therapy, particularly hyaluronic acid (HA) injections, is widely adopted as a conservative treatment option. HA plays a crucial role in maintaining joint homeostasis by supporting proteoglycan synthesis and scaffolding, restoring optimal HA concentrations in synovial fluid, and providing chondroprotective and anti-inflammatory effects. In recent years, hydrogels composed of natural and synthetic materials have emerged as promising candidates for OA treatment. Our research focuses on the biosynthesis and characterization of novel hydrogel composites combining short peptide hydrogelators with aminated graphene oxide (a-GO) nanosheets functionalized with HA (a-GO-HA@Hgel). These a-GO-HA@Hgel nanocomposites are designed to facilitate the controlled release of HA into the extracellular matrix, aiming to promote cartilage regeneration and mitigate inflammation. The strategy is to exploit the oxygen-containing functional groups of GO nanosheets to enable covalent coupling or physical adsorption of HA molecules through various chemical approaches. The resulting a-GO-HA are incorporated within hydrogel matrices to achieve sustained and controlled HA release. We study the influence of a-GO-HA on the native hydrogel structure and its viscoelastic properties, which are critical for mimicking the mechanical environment of native cartilage tissue. Through this multidisciplinary approach combining advanced materials science and cellular biology, this work aims to develop innovative nanocomposite hydrogels capable of delivering HA in a controlled manner, enhancing cartilage repair and providing a potential therapeutic strategy for OA management. Full article

(This article belongs to the Special Issue Advances in Polymer Hydrogels for Biomedical Applications)

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16 pages, 2223 KB

Open AccessArticle

Influence of Connective Architectures of Inlaid Weft-Knitted Spacer Fabric on Compression, Impact Force Absorption, and Vibration Isolation

by Shu-Ning Yan, Yi-Lei Wang and Annie Yu

Polymers 2026, 18(2), 151; https://doi.org/10.3390/polym18020151 - 6 Jan 2026

Abstract

Spacer fabrics are a breathable material option for wearable cushioning, but the cushioning performance is still not comparable to that of traditional elastomeric cushioning materials. The polymer-based connective structure of spacer fabrics largely affects fabric properties, compression, and mechanical performance, and this is [...] Read more.

Spacer fabrics are a breathable material option for wearable cushioning, but the cushioning performance is still not comparable to that of traditional elastomeric cushioning materials. The polymer-based connective structure of spacer fabrics largely affects fabric properties, compression, and mechanical performance, and this is a research gap that calls for the development of spacer fabrics with enhanced cushioning functions. This study develops a new square-wave inlay pattern and investigates the effects of the inlay structure and spatial frequency of the spacer course, as well as the effects of the silicone inlay on compression, impact force absorption, and vibration isolation of the spacer fabric. Twelve samples are designed and evaluated. The results show that the square-wave inlaid spacer fabric has higher energy absorption during compression. The square-wave pattern with a shorter transition distance between the front and back tuck stitches could increase the inclination angle close to a right angle, and extra tuck stitches on the surface float could secure the square-wave structure to enhance the impact force absorption ability. The increment in the spatial frequency of spacer courses provides a less stiff fabric with lower impact force absorption but higher vibration isolation ability. This study shows the innovative development of spacer fabric for enhancing cushioning properties. Full article

(This article belongs to the Special Issue Polymer-Based Functional Fabrics for Advanced Applications)

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24 pages, 4055 KB

Open AccessArticle

Cadmium Removal from Synthetic Waste-Water Using TiO₂-Modified Polymeric Membrane Through Electrochemical Separation System

by Simona Căprărescu, Roxana Gabriela Zgârian, Grațiela Teodora Tihan, Alexandru Mihai Grumezescu, Eugenia Eftimie Totu, Daniel Costinel Petre and Cristina Modrogan

Polymers 2026, 18(2), 150; https://doi.org/10.3390/polym18020150 - 6 Jan 2026

Abstract

In this paper, a new polymeric membrane including polymers (cellulose acetate, polyethylene glycol 400), copolymer poly(4-vinylpyridine)-block-polystyrene, and TiO₂ nanoparticles were synthesized by the phase inversion method. In order to investigate the presence and the influence of the TiO₂ nanoparticles on the [...] Read more.

In this paper, a new polymeric membrane including polymers (cellulose acetate, polyethylene glycol 400), copolymer poly(4-vinylpyridine)-block-polystyrene, and TiO₂ nanoparticles were synthesized by the phase inversion method. In order to investigate the presence and the influence of the TiO₂ nanoparticles on the membrane matrix, a polymeric membrane without TiO₂ nanoparticles was prepared by the same preparation method. The structure of the polymeric membranes was characterized by several techniques, such as Fourier transform infrared spectroscopy and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, thermogravimetric analysis, and impedance spectroscopy. Also, the water contact angle, water retention, and porosity were determined. The results showed that the TiO₂ nanoparticles were incorporated into the pores and onto the surface of the polymeric membrane, which resulted in a more uniform structure. In addition, these polymeric membranes were tested for the removal of cadmium ions from synthetic waste-water using a laboratory-scale electrochemical separation system with a custom-built setup. The results showed that the polymeric membrane with TiO₂ nanoparticles showed a high cadmium ions removal rate (95.53%), compared to the polymeric membrane without TiO₂ nanoparticles (85.29%), after a 1.5 h electrochemical separation test. The final results indicated that the polymeric membranes prepared with TiO₂ nanoparticles had excellent thermal stability and exhibited the best ionic conductivity. The electrochemical separation system proved that the obtained polymeric membranes effectively remove cadmium from the synthetic waste-water. Full article

(This article belongs to the Special Issue Innovative Polymers and Technology for Membrane Fabrication)

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15 pages, 3639 KB

Open AccessArticle

Asymmetric Isoporous Membranes of 2-Vinylpyridine-Styrene Linear Diblock Copolymers: Fabrication and Evaluation in Water Treatment

by Maria Rikkou-Kalourkoti, Katerina Antoniou, Nicholas A. Pissarides, Georgios T. Papageorgiou and Costas S. Patrickios

Polymers 2026, 18(2), 149; https://doi.org/10.3390/polym18020149 - 6 Jan 2026

Abstract

Herein, we report the synthesis via controlled reversible addition-fragmentation chain transfer (RAFT) polymerization of amphiphilic 2-vinylpyridine-b-styrene (2VPy-b-Sty) diblock copolymers of high molar masses (range: 52,100–304,000 g mol⁻¹) and various compositions (range: 2VP content 11.6–59.2 mol%) and their [...] Read more.

Herein, we report the synthesis via controlled reversible addition-fragmentation chain transfer (RAFT) polymerization of amphiphilic 2-vinylpyridine-b-styrene (2VPy-b-Sty) diblock copolymers of high molar masses (range: 52,100–304,000 g mol⁻¹) and various compositions (range: 2VP content 11.6–59.2 mol%) and their use for the fabrication of nanoporous membranes. The successful synthesis of the amphiphilic diblock copolymers was confirmed through the characterization of their molar masses, molar mass distribution, and composition using GPC and ¹H-NMR spectroscopy, respectively. Subsequently, membranes of the diblock copolymers were fabricated following the “phase inversion” technique. The resulting membranes were characterized via scanning electron microscopy which revealed the presence of sphere percolation networks morphology for all diblock copolymers with M_n ranging from 120 to 300 kDa and 2VPy content between 10 and 15 mol% at the optimal conditions. Afterward, the developed membranes were evaluated in terms of their permeability towards water and in terms of their ability to retain two different microorganisms, namely, Enterococcus faecalis and Escherichia coli, that are known to be harmful to human health. The experimental water flux for a membrane with pore size around 60 nm was equal to 31,400 L h⁻¹ m² and expectedly decreased with the decrease in membrane pore diameter. The retention ability of membranes for Enterococcus faecalis and Escherichia coli was higher than 90%. In particular, the retention ability for Enterococcus faecalis was equal to 98.9% and for Escherichia coli was 91.4%. The toxicity of the produced membrane was also determined, and the measured value was relatively low, at 17%. Full article

(This article belongs to the Section Polymer Chemistry)

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18 pages, 2122 KB

Open AccessArticle

New Polycationic Arabinogalactan Derivatives with the CHPTAC System: Structure, Properties and Antioxidant Activity

by Maria V. Sereda, Yuriy N. Malyar, Valentina S. Borovkova and Alexander S. Kazachenko

Polymers 2026, 18(2), 148; https://doi.org/10.3390/polym18020148 - 6 Jan 2026

Abstract

Cationic arabinogalactan (AG) derivatives with a degree of substitution (0.02–0.19) containing quaternary ammonium groups were prepared by reaction of the etherification of (3-Chloro-2-hydroxypropyl)-trimethylammonium chloride (CHPTAC), catalyzed by an aqueous solution of sodium hydroxide. The effect of etherification was assessed by the degree of [...] Read more.

Cationic arabinogalactan (AG) derivatives with a degree of substitution (0.02–0.19) containing quaternary ammonium groups were prepared by reaction of the etherification of (3-Chloro-2-hydroxypropyl)-trimethylammonium chloride (CHPTAC), catalyzed by an aqueous solution of sodium hydroxide. The effect of etherification was assessed by the degree of substitution (DS). The DS values of the AG samples were controlled by the varied pH of the reaction mixture from 10 to 12 and the duration of the process quaternization (2, 18, 24, 30 and 72 h). In comparison, the quaternized samples of the AG were characterized by physicochemical research methods, such as elemental analysis, gel permeation chromatography (GPC), Fourier Transform Infrared (FTIR), and ¹H nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetric analysis (TGA). Furthermore, the improved antioxidant capacity of the quaternized AGs was evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay. It was found that the most favorable conditions for the quaternization process were pH = 12, duration and temperature of the process of 31.6 h and 50 °C, respectively. The esterification reaction was accompanied by hydrolysis side reactions at a longer process. Full article

(This article belongs to the Section Biobased and Biodegradable Polymers)

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18 pages, 4582 KB

Open AccessArticle

Comparative Evaluation of Polymer Screening and Oil Displacement Performance in Class III Reservoirs of the Daqing Oilfield

by Ming Yu, Yunwei He, Xin Jin, Tong Pei, Jinyun Wei, Fushan Li, Shuaishuai Zhao and Yanfu Pi

Polymers 2026, 18(2), 147; https://doi.org/10.3390/polym18020147 - 6 Jan 2026

Abstract

Class III reservoirs in the Daqing Oilfield are characterized by low permeability and strong heterogeneity, posing significant challenges to enhanced oil recovery (EOR). To improve the recovery efficiency of these reservoirs, the viscosifying ability, stability, shear resistance, and profile-control performance of fifteen polymer [...] Read more.

Class III reservoirs in the Daqing Oilfield are characterized by low permeability and strong heterogeneity, posing significant challenges to enhanced oil recovery (EOR). To improve the recovery efficiency of these reservoirs, the viscosifying ability, stability, shear resistance, and profile-control performance of fifteen polymer solutions were experimentally evaluated, and the two most compatible formulations were selected for the Daqing Class III reservoirs. Subsequently, a three-dimensional physical model equipped with real-time saturation monitoring was employed to compare the EOR performance of the selected polymers. The results indicate that a 1500 mg L⁻¹ polymer solution with a molecular weight (Mw) of 16 × 10⁶ Da and a 1200 mg L⁻¹ polymer solution with an Mw of 19 × 10⁶ Da exhibit the best compatibility with the target formation. After injecting the 1500 mg L⁻¹ (Mw = 16 × 10⁶ Da) polymer solution, the ultimate recovery reached 53.38%, with displacement efficiencies of 64.34% and 58.16% and sweep efficiencies of 92.26% and 80.35% in the high- and low-permeability layers, respectively. Injection of the 1200 mg L⁻¹ (Mw = 19 × 10⁶ Da) polymer solution yielded an overall recovery of 47.71%, corresponding to displacement efficiencies of 60.34% and 54.16% and sweep efficiencies of 88.52% and 76.38%. Consequently, the 1500 mg L⁻¹ (Mw = 16 × 10⁶ Da) polymer solution delivers the highest recovery increment in Class III reservoirs. These findings provide valuable guidance for the efficient polymer-flooding development of Class III reservoirs in Daqing and analogous formations worldwide. Full article

(This article belongs to the Special Issue Application of Polymers in Enhanced Oil Recovery)

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15 pages, 3005 KB

Open AccessArticle

Nitrogen-Doped Biochar Derived from Starch for Enzyme-Free Colorimetric Detection of Uric Acid in Human Body Fluids

by Feihua Ye, Fan Chen, Yunhong Zhang, Yunwei Huang, Shasha Liu, Jiangfei Cao and Yanni Wu

Polymers 2026, 18(1), 146; https://doi.org/10.3390/polym18010146 - 5 Jan 2026

Abstract

Uric acid (UA), a key end-product of human purine metabolism, serves as an important biomarker linked to multiple disorders. This study developed a novel enzyme-free colorimetric sensing platform based on starch-derived nitrogen-doped biochar (NC) for the highly sensitive and selective detection of UA [...] Read more.

Uric acid (UA), a key end-product of human purine metabolism, serves as an important biomarker linked to multiple disorders. This study developed a novel enzyme-free colorimetric sensing platform based on starch-derived nitrogen-doped biochar (NC) for the highly sensitive and selective detection of UA in human body fluids. The NC material with a high specific surface area and abundant nitrogen active sites was prepared via a two-step strategy involving hydrothermal synthesis followed by high-temperature pyrolysis, using starch and urea as raw materials. Under mild conditions, the NC effectively catalyzes dissolved oxygen to produce reactive oxygen species (·O₂⁻ and ¹O₂), which oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) to a blue-colored oxidation product (TMBox). The presence of UA reduces TMBox to colorless TMB, leading to a measurable decrease in absorbance at 652 nm and enabling quantitative UA detection. Key reaction conditions were systematically optimized. Material characterization and mechanistic investigations confirmed the catalytic performance of the NC. The method demonstrated a wide linear response from 10 to 500 μmol·L⁻¹, with a detection limit of 4.87 μmol·L⁻¹, and demonstrated outstanding selectivity, stability, and reproducibility. Practical application in human serum and urine samples yielded results consistent with clinical reference ranges, and spike-recovery rates ranged from 95.5% to 103.6%, indicating great potential for real-sample analysis. Full article

(This article belongs to the Section Biobased and Biodegradable Polymers)

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15 pages, 5010 KB

Open AccessArticle

Aluminum-Foil/Polyester Core-Spun Yarns Conductive Fabric Enabling High Electromagnetic Interference Shielding

by Yanyan Sun, Xiaoyu Han, Kun Zhao, Weili Zhao, Zhitong He, Zhengyang He, Yingtie Mo, Changliu Chu, Toshiaki Natsuki and Jun Natsuki

Polymers 2026, 18(1), 145; https://doi.org/10.3390/polym18010145 - 5 Jan 2026

Abstract

With the rapid advancement of modern electronic devices and wireless communication systems, electromagnetic pollution has become a prominent issue, prompting the development of high-performance electromagnetic interference (EMI) shielding materials. Although traditional metal shielding materials exhibit excellent conductivity, there are many limitations such as [...] Read more.

With the rapid advancement of modern electronic devices and wireless communication systems, electromagnetic pollution has become a prominent issue, prompting the development of high-performance electromagnetic interference (EMI) shielding materials. Although traditional metal shielding materials exhibit excellent conductivity, there are many limitations such as high weight, poor flexibility, susceptibility to corrosion, and high cost. To overcome these challenges, in this study, we design and fabricate core-spun yarns using polyester filaments as the core and an aluminum-foil-wrapped layer as the conductive outer component, and further weave them into three conductive fabrics with different structural parameters. Through systematic investigation of their surface morphology, air permeability, electrical properties, and EMI shielding performance, DT5W27 demonstrates optimal overall performance: electrical conductivity of 2722.64 S·m⁻¹, shielding effectiveness of 37.29 dB, and electromagnetic wave attenuation rate of 99.99%. Specifically, even after 100 bending, twisting cycles, and exposure to solutions with pH values ranging from 3 to 9, the fabric maintains high shielding performance. The fabrication process is facile and low cost, and these composites have good flexibility, outstanding EMI shielding performance, exceptional mechanical durability, and chemical stability. These advantages make them have broad application potential in protective clothing and lightweight shielding materials. Full article

(This article belongs to the Special Issue High-Performance Thermoplastic Polymer Composites: From Fabrication to Application)

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28 pages, 7160 KB

Open AccessArticle

Evaluation of the Seismic Behavior of Carbon-Grid-Reinforced Walls with Varying Anchorage and Axial Load Ratios

by Kyung-Min Kim, Sung-Woo Park, Bhum-Keun Song, Kyung-Jae Min and Seon-Hee Yoon

Polymers 2026, 18(1), 144; https://doi.org/10.3390/polym18010144 - 5 Jan 2026

Abstract

Fiber-reinforced polymers (FRPs) are being increasingly used to replace rebars as reinforcements for concrete. This study evaluated the seismic behavior of concrete walls reinforced with grid-type carbon FRP (CFRP; carbon grid) through quasi-static cyclic tests and compared the results with that of the [...] Read more.

Fiber-reinforced polymers (FRPs) are being increasingly used to replace rebars as reinforcements for concrete. This study evaluated the seismic behavior of concrete walls reinforced with grid-type carbon FRP (CFRP; carbon grid) through quasi-static cyclic tests and compared the results with that of the reinforced concrete (RC) wall. The experimental variables were the ratio of the carbon-grid anchorage length in the foundation to the wall length and the axial force ratio. Based on the results of the quasi-static cyclic tests, the ratio of the equivalent stiffness at the crushing of the compression-edge cover concrete to the initial stiffness of the carbon-grid-reinforced concrete specimens was 0.14 on average. This indicates that the specimens reached their maximum load due to the crushing of the compression-edge cover concrete after a significant reduction in stiffness due to cracking. The skeleton curve for the carbon-grid-reinforced concrete specimens was found to be bilinear, with reduced stiffness due to cracking and failure due to the crushing of the compression-edge cover concrete, making it definable and predictable. Additionally, in specimens with a high axial force or small ratio of the anchorage length in the foundation to the wall length, some of the longitudinal CFRP strands fractured at the same time as they reached the failure load. Moreover, the load at the crushing of the compression-edge cover concrete of the carbon-grid-reinforced concrete specimen increased by 1.10 times with the increase in the axial force ratio and decreased by 0.96 times with the decrease in the ratio of the anchorage length in the foundation to the wall length. It was found to be 0.73–0.80 times the flexural strength based on the assumption of plane sections remaining plane. In comparison with RC specimen, the cumulative absorbed energy of the carbon-grid-reinforced concrete specimen began to decrease after a story drift ratio of 1%, and the cumulative absorbed energy up to the target story drift ratio of 3.0% was found to be 0.60–0.62 times that of the RC specimen. Full article

(This article belongs to the Special Issue Polymer Composites in Construction Materials)

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17 pages, 3498 KB

Open AccessArticle

Impact of Thermomechanical Aging on Marginal Fit and Fracture Resistance of CAD/CAM Endocrowns Fabricated from Different Materials

by Bülent Kadir Tartuk and Gizem Akın Tartuk

Polymers 2026, 18(1), 143; https://doi.org/10.3390/polym18010143 - 5 Jan 2026

Abstract

The restoration of endodontically treated teeth remains a clinical challenge, particularly when substantial coronal tissue loss is present. Endocrowns fabricated using CAD/CAM technologies offer a conservative and esthetic alternative to conventional post-core systems; however, their long-term performance may be influenced by age-related mechanical [...] Read more.

The restoration of endodontically treated teeth remains a clinical challenge, particularly when substantial coronal tissue loss is present. Endocrowns fabricated using CAD/CAM technologies offer a conservative and esthetic alternative to conventional post-core systems; however, their long-term performance may be influenced by age-related mechanical and thermal stresses. This study evaluated the effect of thermomechanical aging on the marginal adaptation and fracture resistance of endocrowns fabricated from three CAD/CAM materials: zirconia-reinforced lithium silicate (ZLS), polyetherether ketone (PEEK), and 3D-printed resin. Sixty extracted human molars were endodontically treated and restored with endocrowns produced from these materials (n = 20 per group) and then subdivided into aged (n = 10) and control (n = 10) subgroups. Thermomechanical aging involved 5000 thermal cycles between 5 °C and 55 °C, and 75,000 mechanical loading cycles at 50 N. Marginal gaps were examined using scanning electron microscopy, and fracture resistance was tested under axial load at a crosshead speed of 0.5 mm/min. Data were analyzed using two-way ANOVA followed by Tukey’s post hoc test (α = 0.05). Thermomechanical aging significantly increased the marginal gaps in all materials (p < 0.05). The smallest marginal discrepancies were observed in the 3D-printed resin group, while the largest occurred in the ZLS after aging, likely due to dimensional changes during crystallization. Fracture resistance decreased in ZLS (−21.2%) and 3D resin (−20.9%) after aging (p < 0.05) but was not significantly affected in PEEK (−5.4%, p = 0.092). Thermomechanical aging adversely affects marginal adaptation across all materials, whereas its impact on strength is material-dependent. PEEK demonstrated the most stable mechanical performance and may represent a promising alternative for long-term endocrown restorations. Full article

(This article belongs to the Section Polymer Applications)

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23 pages, 4355 KB

Open AccessArticle

Impedance Spectroscopy Study of Solid Co(II/III) Redox Mediators Prepared with Poly(Ethylene Oxide), Succinonitrile, Cobalt Salts, and Lithium Perchlorate for Dye-Sensitized Solar Cells

by Ravindra Kumar Gupta, Ahamad Imran, Aslam Khan, Muhammad Ali Shar, Khalid M. Alotaibi, Idriss Bedja and Abdullah Saleh Aldwayyan

Polymers 2026, 18(1), 142; https://doi.org/10.3390/polym18010142 - 4 Jan 2026

Abstract

Countries like Saudi Arabia receive abundant sunshine with exceptionally high solar irradiance. High temperatures in desert regions and the sunray angle dependence of solar modules are some of the key challenges of conventional solar cells. Dye-sensitized solar cells present a compelling alternative with [...] Read more.

Countries like Saudi Arabia receive abundant sunshine with exceptionally high solar irradiance. High temperatures in desert regions and the sunray angle dependence of solar modules are some of the key challenges of conventional solar cells. Dye-sensitized solar cells present a compelling alternative with the simple cell design and use of non-toxic materials without angle dependence, but their performance hinges on the solid redox mediators used for dye regeneration. These mediators must have an electrical conductivity (σ_25°C) of more than 10⁻⁴ S cm⁻¹ with an activation energy of less than 0.3 eV for device application. Our work focused on novel solid Co(II/III) redox mediators using cobalt complexes and LiClO₄ in different matrices: pure PEO (an abbreviation for poly(ethylene oxide) with its redox mediator as M1), a [PEO–SN] blend (M2A and M2B with ethylene oxide to lithium ions molar ratio of 112.9 and 225.8, respectively), and pure SN (an abbreviation for succinonitrile with its redox mediator as M3). Impedance spectroscopy was the key technique, showing M1 and M2 behave like a mediator explainable with an (R₁–C)-type circuit, while M3 is explainable with an (R₁ − [R₂‖C])-type circuit. M3 achieved the highest value of σ_25°C with 2 × 10⁻³ S cm⁻¹, while M1 had the lowest σ_25°C, 3 × 10⁻⁵ S cm⁻¹. M2 achieved an optimal balance with σ_25°C of 4 × 10⁻⁴ S cm⁻¹ (M2A) and 1.5 × 10⁻⁴ S cm⁻¹ (M2B). M2 exhibited a remarkably low pseudo-activation energy of 0.042 eV and a Vogel–Tammann–Fulcher behavior ideal for consistent performance across temperatures. In contrast, M1 and M3 showed higher Arrhenius-type activation energies (>0.74 eV) in their solid states. These results correlated with those of the XRD, FT-IR spectroscopy, XPS, SEM, DSC, and TGA analyses. Ultimately, the [PEO–SN] blend emerges as a robust matrix, enabling the combination of high conductivity and low activation energy needed for a durable device in harsh environments. Full article

(This article belongs to the Special Issue Flexible, Highly Efficient Polymer Solar Cells)

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20 pages, 3125 KB

Open AccessArticle

Organocatalyzed Atom Transfer Radical (Co)Polymerization of Fluorinated and POSS-Containing Methacrylates: Synthesis and Properties of Linear and Star-Shaped (Co)Polymers

by Hleb Baravoi, Heorhi Belavusau, Aliaksei Vaitusionak, Valeriya Kukanova, Anastasia Frolova, Peter Timashev, Hongzhi Liu and Sergei Kostjuk

Polymers 2026, 18(1), 141; https://doi.org/10.3390/polym18010141 - 4 Jan 2026

Abstract

Hybrid fluorinated copolymers containing POSS moieties along with fluorinated homopolymers were synthesized via organocatalyzed atom transfer radical (co)polymerization (O-ATRP) of fluoroalkyl methacrylate (FMA) and a POSS-based monomer (IBSS) using perylene as a photocatalyst. Linear and four- and eight-armed star-shaped [...] Read more.

Hybrid fluorinated copolymers containing POSS moieties along with fluorinated homopolymers were synthesized via organocatalyzed atom transfer radical (co)polymerization (O-ATRP) of fluoroalkyl methacrylate (FMA) and a POSS-based monomer (IBSS) using perylene as a photocatalyst. Linear and four- and eight-armed star-shaped (co)polymers in a wide range of molecular weights with M_n(SEC) up to 53,100 g/mol for poly(FMA), 22,700 g/mol for poly(IBSS) and 87,300 g/mol for poly(FMA-co-IBSS) were successfully prepared. During polymerization, C–F activation was found to induce chain transfer and branching reactions, contributing to structural diversity. A mechanism for chain transfer to the polymer resulting in branching was proposed, applying density functional theory (DFT). Films based on the obtained (co)polymers showed tunable morphology, high thermal stability (up to 306 °C) and hydrophobicity, with water contact angles reaching 98°. Full article

(This article belongs to the Special Issue Recent Developments of Photopolymerization in Advanced Materials)

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16 pages, 2188 KB

Open AccessArticle

3D-Printed Poly(lactic acid)/Poly(ethylene glycol) Scaffolds with Shape-Memory Effect near Physiological Temperature

by Anastasia A. Fetisova, Abdullah bin Firoz, Alexandr S. Lozhkomoev, Elena I. Senkina, Egor E. Ryumin, Maria A. Surmeneva and Roman A. Surmenev

Polymers 2026, 18(1), 140; https://doi.org/10.3390/polym18010140 - 3 Jan 2026

Abstract

Biocompatible poly(lactic acid) (PLA) was plasticized with poly(ethylene glycol) (PEG) added at concentrations of 10, 15, and 20 wt.% relative to PLA, and then processed into gyroid triply periodic minimal surface (TPMS) scaffolds using fused filament fabrication (FFF) 3D printing. The influence of [...] Read more.

Biocompatible poly(lactic acid) (PLA) was plasticized with poly(ethylene glycol) (PEG) added at concentrations of 10, 15, and 20 wt.% relative to PLA, and then processed into gyroid triply periodic minimal surface (TPMS) scaffolds using fused filament fabrication (FFF) 3D printing. The influence of PEG concentration and gyroid structure (50% infill density) on thermal transitions, crystallinity, and low–temperature shape-memory performance was systematically investigated. The shape-memory effect (SME) of the PLA–based scaffolds was tailored through compositional control and structural design. Shape recovery under thermal activation at 40 °C and 50 °C was examined to reveal the correlation between composition and structure in governing low–temperature shape-memory behavior. The optimal composition (PLA/10 PEG, 50% gyroid infill) achieved shape recovery with a recovery ratio (R_r) of 97 ± 1% at 40 °C within 6 ± 1 min, demonstrating optimal shape-memory activation close to physiological temperature. Structural and morphological changes were characterized using ATR–FTIR, Raman spectroscopy, DSC, XRD, and SEM, providing comprehensive insight into the plasticization of the PLA matrix and its impact on structure–property relationships relevant to bone tissue engineering. Full article

(This article belongs to the Section Polymer Applications)

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22 pages, 3163 KB

Open AccessArticle

Dual-Band Electrochromic Poly(Amide-Imide)s with Redox-Stable N,N,N’,N’-Tetraphenyl-1,4-Phenylenediamine Segments

by Bo-Wei Huang and Sheng-Huei Hsiao

Polymers 2026, 18(1), 139; https://doi.org/10.3390/polym18010139 - 3 Jan 2026

Abstract

Two amide-preformed aromatic diamine monomers, N,N-bis(4-(3-aminobenzamido)phenyl)-N’,N’-bis(4-methoxyphenyl)-1,4-phenylenediamine (m-6) and N,N-bis(4-(4-aminobenzamido)phenyl)-N’,N’-bis(4-methoxyphenyl)-1,4-phenylenediamine (p-6), were synthesized and utilized to prepare two series of electroactive poly(amide-imide)s [...] Read more.

Two amide-preformed aromatic diamine monomers, N,N-bis(4-(3-aminobenzamido)phenyl)-N’,N’-bis(4-methoxyphenyl)-1,4-phenylenediamine (m-6) and N,N-bis(4-(4-aminobenzamido)phenyl)-N’,N’-bis(4-methoxyphenyl)-1,4-phenylenediamine (p-6), were synthesized and utilized to prepare two series of electroactive poly(amide-imide)s (PAIs) through a two-step polycondensation reaction with commercially available aromatic tetracarboxylic dianhydrides. The obtained polymers exhibited solubility in various polar organic solvents, and most of them could form transparent, flexible films via solution casting. Thermal analysis indicated glass transition temperatures (T_g) ranging from 250 °C to 277 °C, as measured by DSC, with no significant weight loss observed before 400 °C in TGA tests. Cyclic voltammograms (CV) of the polymer films on ITO-coated glass substrates revealed two reversible oxidation redox pairs between 0.67 and 1.04 V vs. Ag/AgCl in an electrolyte-containing acetonitrile solution. The PAI films showed stable redox activity with high optical contrast both in the visible and near-infrared regions, transitioning from colorless in the neutral state to green and blue in the oxidized states. Furthermore, the polymer films retained good electrochemical and electrochromic stability even after more than 100 cyclic switching operations. The PAIs displayed outstanding electrochromic performance, including high optical contrast (up to 95%), rapid response times (below 4.6 s for coloring and 5.7 s for bleaching), high coloration efficiency (up to 240 cm²/C), and low decay in optical contrast (less than 5% after 100 switching cycles for most PAIs). Full article

(This article belongs to the Section Smart and Functional Polymers)

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33 pages, 405 KB

Open AccessReview

Contemporary Use of Polymers in Dentistry: A Narrative Review

by Svetla Ivanova, Zlatina Tomova, Angelina Vlahova, Iliyana L. Stoeva, Elena Vasileva, Yordanka Uzunova, Magdalina Urumova, Desislav Tomov and Atanas Chonin

Polymers 2026, 18(1), 138; https://doi.org/10.3390/polym18010138 - 2 Jan 2026

Abstract

This narrative review examines contemporary applications of polymeric materials in dentistry from 2020 to 2025, spanning prosthodontics, restorative dentistry, orthodontics, endodontics, implantology, diagnostics, and emerging technologies. We searched PubMed, Scopus, Web of Science, and Embase for peer reviewed English language articles and synthesized [...] Read more.

This narrative review examines contemporary applications of polymeric materials in dentistry from 2020 to 2025, spanning prosthodontics, restorative dentistry, orthodontics, endodontics, implantology, diagnostics, and emerging technologies. We searched PubMed, Scopus, Web of Science, and Embase for peer reviewed English language articles and synthesized evidence on polymer classes, processing routes, mechanical and chemical behavior, and clinical performance. Approximately 116 articles were included. Polymers remain central to clinical practice: poly methyl methacrylate (PMMA) is still widely used for dentures, high performance systems such as polyether ether ketone (PEEK) are expanding framework and implant-related indications, and resin composites and adhesives continue to evolve through nanofillers and bioactive formulations aimed at improved durability and reduced secondary caries. Thermoplastic polyurethane and copolyester systems drive clear aligner therapy, while polymer-based obturation materials and fiber-reinforced posts support endodontic rehabilitation. Additive manufacturing and computer aided design computer aided manufacturing (CAD CAM) enable customized prostheses and surgical guides, and sustainability trends are accelerating interest in biodegradable or recyclable dental polymers. Across domains, evidence remains heterogeneous and clinical translation depends on balancing strength, esthetics, biocompatibility, aging behavior, and workflow constraints. Full article

(This article belongs to the Special Issue Polymers Strategies in Dental Therapy)

14 pages, 5134 KB

Open AccessArticle

Silicon Effect on Conductive Behavior in Rubber Recycled Composites

by Marc Marín-Genescà, Ramon Mujal Rosas, Jordi García Amorós, Lluis Massagues and Xavier Colom

Polymers 2026, 18(1), 137; https://doi.org/10.3390/polym18010137 - 2 Jan 2026

Abstract

In the present research, the structure and thermal–dielectric behavior of Styrene Butadiene Rubber (SBR) and of the SBR/EPDMd composite with SiO₂ with different compositions and concentrations of EPDMd are analyzed. In this sense, interesting behaviors are observed for the DC-AC regime of [...] Read more.

In the present research, the structure and thermal–dielectric behavior of Styrene Butadiene Rubber (SBR) and of the SBR/EPDMd composite with SiO₂ with different compositions and concentrations of EPDMd are analyzed. In this sense, interesting behaviors are observed for the DC-AC regime of the conductive behavior of the material; therefore, a very marked DC and AC regime is observed in the conductivities, showing a different dielectric behavior at low and high frequencies. On the other hand, peak relaxations due to polarization phenomena are observed in terms of the imaginary modulus. Conductively, SiO₂ does not produce significant or relevant changes, but it does produce changes in the permittivity and the electrical modulus, so it is concluded that the impact of the incorporation of SiO₂ in these compounds affects energy storage (permittivity and modulus) in these types of compounds. Compared with compounds without silica (insights—no SiO₂), it is observed that SiO₂ maintains a similar operating regime to the initial one (SBR and SBR + EPDMd + SiO₂) without SiO₂ dielectric changes occurring, so silica presence modifies the dielectric behavior, reducing polarization effects, as can be seen in the dielectric results. Conductively, SiO₂ produces more insulating compounds, that is, less conductive; this property can make it interesting as electrical insulation. Full article

(This article belongs to the Special Issue Advances in Functional Rubber and Elastomer Composites, 3rd Edition)

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3 pages, 134 KB

Open AccessEditorial

State of the Art and Perspectives on Polymer Science and Technology in China

by Sixun Zheng

Polymers 2026, 18(1), 136; https://doi.org/10.3390/polym18010136 - 2 Jan 2026

Abstract

In 2023, the Polymers journal launched a Special Issue to report research by Chinese scholars focusing on the physics and processing of polymers, the development of new materials, and the application of new technologies [...] Full article

(This article belongs to the Special Issue State of the Art and Perspectives of Polymer Science and Technology in China)

22 pages, 4387 KB

Open AccessArticle

The Optimal Amount of PAMAM G3 Dendrimer in Polyurethane Matrices Makes Them a Promising Tool for Controlled Drug Release

by Magdalena Zaręba, Magdalena Zuzanna Twardowska, Paweł Błoniarz, Jaromir B. Lechowicz, Jakub Czechowicz, Dawid Łysik, Magdalena Rzepna and Łukasz Stanisław Uram

Polymers 2026, 18(1), 135; https://doi.org/10.3390/polym18010135 - 1 Jan 2026

Abstract

Systemic anticancer therapy causes a number of side effects; therefore, local drug release devices may play an important role in this area. In this study, we developed polyurethane-dendrimer foams containing different amounts of third-generation poly (amidoamine) dendrimers (PAMAM G3) to evaluate their ability [...] Read more.

Systemic anticancer therapy causes a number of side effects; therefore, local drug release devices may play an important role in this area. In this study, we developed polyurethane-dendrimer foams containing different amounts of third-generation poly (amidoamine) dendrimers (PAMAM G3) to evaluate their ability to encapsulate and release the model anticancer drug doxorubicin (DOX), as well as their biocompatibility and effectiveness against normal and cancer cells in vitro. PU–PAMAM foams containing 10–50 wt% PAMAM G3 were prepared using glycerin-based polyether polyol and castor oil as co-components. Structural and rheological analyses revealed that foams containing up to 20 wt% PAMAM G3 exhibited a well-developed porous structure, while higher dendrimer loadings (≥30 wt%) led to irregular cell shapes, pore coalescence, and thinning of cell walls, and indicated a gradual loss of structural integrity. Rheological creep–recovery measurements confirmed the structural findings: moderate PAMAM G3 incorporation (≤20 wt%) increased both the instantaneous and delayed elastic modulus (E₁ ≈ 130–140 kPa; E₂ ≈ 80 kPa) and enhanced elastic recovery, reflecting improved cross-link density and foam stability. Higher dendrimer contents (30–50 wt%) caused a decline in these parameters and higher viscoelastic compliance, indicating a softer, less stable structure. The DOX loading capacity and encapsulation efficiency increased with PAMAM G3 content, reaching maximum values of 35% and 51% for 30–40 wt% PAMAM G3, respectively. However, the most sustained DOX release profiles were observed for matrices containing 20 wt% PAMAM G3. Analysis of cumulative release and kinetic modeling revealed a transition from diffusion-controlled release at low PAMAM contents to burst-dominated release at higher dendrimer loadings. Importantly, matrices containing 10–20 wt% PAMAM G3 also indicated selective anticancer action against squamous cell carcinoma (SCC-15) compared to non-cancerous human keratinocytes (HaCaT). Moreover, the DOX they released effectively destroyed cancer cells. Overall, PU–PAMAM foams containing 10–20 wt% PAMAM G3 provide the most balanced combination of structural stability, controlled drug release, and cytocompatibility. These materials therefore represent a promising platform as passive carriers in drug delivery systems (DDSs), such as local implants, anticancer patches, or bioactive wound dressings. Full article

(This article belongs to the Special Issue Advances in the Preparation, Properties and Application of Polyurethane, Cellulose and Their Composites (3rd Edition))

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16 pages, 3090 KB

Open AccessArticle

Experimental and Numerical Assessment of Flexural Behavior of CFRP–Strengthened Timber Beams

by Milot Muhaxheri, Enes Krasniqi, Naser Kabashi, Ylli Murati and Ridvan Mahmuti

Polymers 2026, 18(1), 134; https://doi.org/10.3390/polym18010134 - 1 Jan 2026

Abstract

Glued laminated timber (glulam) is increasingly adopted as a sustainable structural material; however, its performance under bending can be limited by brittle tensile failures and variability caused by natural defects. This study examines the flexural behavior of glulam beams strengthened with externally bonded [...] Read more.

Glued laminated timber (glulam) is increasingly adopted as a sustainable structural material; however, its performance under bending can be limited by brittle tensile failures and variability caused by natural defects. This study examines the flexural behavior of glulam beams strengthened with externally bonded carbon fiber reinforced polymer (CFRP) sheets. A four-point bending experimental program was carried out on glulam beams with varying CFRP bonded lengths, including unreinforced control beams. The results demonstrate that CFRP reinforcement enhanced load–carrying capacity by up to 48%, increased stiffness, and shifted failure modes from brittle tension–side ruptures to more favorable compression–controlled mechanisms. A nonlinear finite element (FE) model was developed using DIANA software 10.5 to simulate the structural response of both unreinforced and CFRP–strengthened beams. The numerical model accurately reproduced the experimental load–deflection behavior, stress redistribution, and failure trends, with deviations in ultimate load prediction generally within ±16% across all reinforcement configurations. The simulations further revealed the critical influence of CFRP bonded length on stress transfer efficiency and failure mode transition, mimicking experimental observations. By integrating experimental findings with numerical simulations and simplified analytical predictions, the study demonstrates that reinforcement length and bond activation govern the effectiveness of CFRP strengthening. The proposed combined methodology provides a reliable framework for evaluating and designing CFRP strengthened glulam beams. Full article

(This article belongs to the Special Issue High-Performance Polymer Materials and Fiber-Reinforced Composites for Engineering Applications)

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