Semi-interpenetrating Polymer Network Research Articles

Zwitterionic semi-IPN electrolyte with high ionic conductivity and high modulus achieving flexible 2.4 V aqueous supercapacitors

Polymer electrolytes (PEs) have the widespread interest for solid-state supercapacitors. As an ideal PEs, it is requested to possess high ionic conductivity, high electrolyte content, and excellent mechanical properties. Here, we present the zwitterionic semi-interpenetrating polymeric network electrolytes (ZSIPNEs) that enable achieving ultra-high ionic conductivity and excellent mechanical properties. ZSIPNEs are synthesis by interpenetrating various content of poly(sulfobetaine methacrylate) (pSBMA) into zwitterionic polymer (ZP) matrix, being simply prepared by 17 m NaClO4(aq) intake. At content of pSBMA of 0.1%, ZS-0.1 possesses the ultra-high ionic conductivity of 135.2 mScm−1 at 25 °C. In addition, ZS-0.1 shows excellent mechanical properties, including the compressive strength of 0.36 MPa, compressive strain of 74.5%, compressive modulus of 33.7 kPa, and toughness of 4.329 Jm−3. Furthermore, the electrochemical performances of electrolytes are studied using carbon-based supercapacitors which are assembled with 17 m NaClO4(aq) (C-aq), ZS-0 (C-ZPE), and ZS-0.1 (C-ZSIPNE), being evaluated by electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic charge/discharge. C-ZSIPNE shows the wide electrochemical window of 2.4 V and the superior electrochemical performance by delivering high energy density of 83.6Whkg−1, and high power density of 19.1kWkg−1. Under bending angles of 90°, the capacitance of C-ZSIPNE keeps at almost 100%, being potential application in flexible supercapacitors. 3 brief informative subheadingsZwitterionic polymer electrolyte, Semi-interpenetrating polymeric network, High performance supercapacitors BackgroundPolymer electrolytes (PEs) have the widespread interest for solid-state supercapacitors. As an ideal PEs, it is requested to possess high ionic conductivity, high electrolyte content, and excellent mechanical properties. MethodsThe ionic conductivity of PE was evaluated by electrochemical impedance spectroscopy. The mechanical properties of PE were evaluated by compressive strain-stress curve. The electrochemical properties of PE were evaluated by electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic charge/discharge. Significant FindingsZSIPNEs enable achieving ultra-high ionic conductivity of 135.2 mScm−1 and excellent mechanical properties (compressive modulus of 33.7 kPa). C-ZSIPNE shows the wide electrochemical window of 2.4 V and the superior electrochemical performance by delivering high energy density of 83.6Whkg−1, and high power density of 19.1kWkg−1. Under bending angles of 90°, the capacitance of C-ZSIPNE keeps at almost 100%, being potential application in flexible supercapacitors.

Three-Dimensional Printable Conductive Semi-Interpenetrating Polymer Network Hydrogel for Neural Tissue Applications.

Intrinsically conducting polymers (ICPs) are widely used to fabricate biomaterials; their application in neural tissue engineering, however, is severely limited because of their hydrophobicity and insufficient mechanical properties. For these reasons, soft conductive polymer hydrogels (CPHs) are recently developed, resulting in a water-based system with tissue-like mechanical, biological, and electrical properties. The strategy of incorporating ICPs as a conductive component into CPHs is recently explored by synthesizing the hydrogel around ICP chains, thus forming a semi-interpenetrating polymer network (semi-IPN). In this work, a novel conductive semi-IPN hydrogel is designed and synthesized. The hybrid hydrogel is based on a poly(N-isopropylacrylamide-co-N-isopropylmethacrylamide) hydrogel where polythiophene is introduced as an ICP to provide the system with good electrical properties. The fabrication of the hybrid hydrogel in an aqueous medium is made possible by modifying and synthesizing the monomers of polythiophene to ensure water solubility. The morphological, chemical, thermal, electrical, electrochemical, and mechanical properties of semi-IPNs were fully investigated. Additionally, the biological response of neural progenitor cells and mesenchymal stem cells in contact with the conductive semi-IPN was evaluated in terms of neural differentiation and proliferation. Lastly, the potential of the hydrogel solution as a 3D printing ink was evaluated through the 3D laser printing method. The presented results revealed that the proposed 3D printable conductive semi-IPN system is a good candidate as a scaffold for neural tissue applications.

Nafion-Based Proton-Exchange Membranes Built on Cross-Linked Semi-Interpenetrating Polymer Networks between Poly(acrylic acid) and Poly(vinyl alcohol).

We report semi-interpenetrating polymer network (semi-IPN) membranes prepared easily from a cross-linked network using poly(acrylic acid) (PAA) and poly(vinyl alcohol) (PVA) with interpenetrated Nafion for both proton-exchange membrane fuel cell (PEMFC) and proton-exchange membrane water electrolyzer (PEMWE) applications. Thermal esterification between PAA and PVA induced three-dimensional cross-linking to improve mechanical toughness and reduce hydrogen crossover, while the hydrophilic nature of the PAA-PVA-based cross-linked matrix still enhanced the water uptake (WU) and hence conductivity of the Nafion penetrant. The semi-IPN membrane (NPP-95) composed of Nafion, PAA, and PVA with a ratio of 95:2.5:2.5 showed a hexagonal cylindrical morphology and improved thermal, mechanical, and dimensional stability compared to a recast Nafion membrane (re-Nafion). The membrane was also highly effective at managing water due to its low WU and high conductivity. Furthermore, its hydrogen permeability was 49.6% lower than that of re-Nafion under the actual fuel cell operating conditions (at 100% RH and 80 °C). NPP-95 exhibited significantly improved conductivity and PEMFC performance compared to re-Nafion with a current density of 1561 mA/cm2 at a potential of 0.6 V and a peak power density of 1179 mW/cm2. Furthermore, in the PEMWE performances, NPP-95 displayed about a 1.5-fold higher current density of 4310 mA/cm2 at 2.0 V and much lower ohmic resistance than re-Nafion between 60 and 80 °C.

Anomalous bulk diffusion of methylene diphenyl diisocyanate in silicone elastomer

In this study, we investigate the anomalous diffusion of methylene diphenylmethane-4,4′-diisocyanate (MDI) into fumed silica filled poly(dimethylsiloxane) (PDMS) elastomer, which occurs in the industrial application of polyurethane vacuum casting. The absorbed MDI polymerizes with moisture to polyurea within the silicone medium, forming a sequential semi interpenetrating polymer network. This results in the formation of polyurea clusters near the exposed surface. Here we focus on the spatially resolved chemical characterization on the micrometer scale utilizing time-of-flight secondary ion mass spectrometry (ToF-SIMS), transmission electron microscopy (TEM), helium ion microscopy (HIM), atomic force microscopy (AFM), thermo-gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) as well as nuclear magnetic resonance spectroscopy (NMR). The concentration profile was determined experimentally using a customized method based on TGA. It was shown that the polyurea reaction of the MDI causes a time-dependency of both the surface concentration and the diffusion coefficient. Six analytical solutions to the diffusion equation obeying different time-dependent boundary conditions with different physical implications are proposed and used to model the measured concentration profiles. The parameterized models showed good predictive power for the measured absorption data and thus substantiated the conjectured molecular phenomena.

A hierarchically designed nanocomposite hydrogel with multisensory capabilities towards wearable devices for human-body motion and glucose concentration detection

Hydrogels have shown great potential as flexible/wearable sensors, for detection of a variety of external stimuli. However, reports of sensors capable of detecting both electrochemical and mechanical stimuli are virtually non-existent. The current study employs nanostructured hierarchy, as a unique strategy towards development of hybrid hydrogel nanocomposites, for sensing human-body motion and glucose level in sweat. The nanocomposites comprise of a semi-interpenetrating polymer network where the nanometric level of hierarchy enables high conductivity, while the microscopic level imparts favorable electrochemical and mechanical properties. The hydrogels exhibit superior mechanical strength (up to 7.7 MPa) and toughness (up to 7.48 MJ m−3), one of the highest reported till date, in addition to good electrical conductivity (up to 0.14 S m−1) and electrochemical behaviour. The hydrogel-based prototype sensors could efficiently be used for successful detection of a multitude of human-body motion as well as glucose level determination with extraordinary sensitivity and minimal hysteresis. Additionally, the facile synthesis method of the hybrid hydrogel nanocomposites allows for low-cost fabrication and easy scalability of robust multifunctional sensors.

A pH-sensitive semi-interpenetrating polymer network hydrogels constructed by konjac glucomannan and poly (γ-glutamic acid): Synthesis, characterization and swelling behavior

A novel pH-sensitive semi-interpenetrating polymer network (semi-IPN) hydrogel was prepared by using konjac glucomannan (KGM) and poly (γ-glutamic acid) (γ-PGA) with sodium trimetaphosphate (STMP) as the crosslinking agent. The structure of the semi-IPN hydrogels was characterized by FTIR spectra, thermogravimetric analysis (TGA), X-ray diffraction (XRD), rheological measurements, and scanning electron microscopy (SEM). The pH-sensitive effects were investigated by calculating the equilibrium swelling ratio (ESR) in buffer solutions (pH 2, 4, 6, and 8, respectively) at 37 °C. These results showed that the content of cross-linker and γ-PGA has a significant influence on the hydrogels' structure and swelling behavior. In vitro drug release behavior of semi-IPN hydrogels was investigated under simulated gastric and intestinal fluids using model drug Nicotinamide (NTM), and various models were applied to describe the drug release behaviors. The obtained results indicated that our synthesized semi-IPN hydrogel had the potential to be used as a suitable biomaterial carrier for functional components or drug delivery in the intestine.

Preparation and In Vitro Evaluation of Aspartic/Alginic Acid Based Semi-Interpenetrating Network Hydrogels for Controlled Release of Ibuprofen.

Different combinations of polymers, aspartic acid (ASP), alginic acid (AL), and monomer acrylic acid (AA) were crosslinked in the presence of an initiator ammonium peroxodisulfate (APS) and cross-linker ethylene glycol dimethacrylate (EGDMA) to develop aspartic acid/alginic acid-co-poly(acrylic acid) (ASP/ALPAA) (semi-interpenetrating polymer network (SIPN)) hydrogels by the free radical polymerization technique for the controlled delivery of ibuprofen (IBP). Various studies such as dynamic swelling studies, drug loading, in vitro drug release and sol−gel analysis were carried out for the hydrogels. Higher swelling was observed at higher pH 7.4 as compared to lower pH 1.2, due to the presence of carboxylic groups of polymers and the monomer. Hence, pH-dependent swelling was exhibited by the developed hydrogels which led to a pH-dependent drug release and vice versa. The structural properties of the hydrogels were assessed by FTIR, PXRD, TGA, DSC, and SEM which confirmed the fabrication and stability of the developed structure. FTIR analysis revealed the reaction of both polymers with the monomer during the polymerization process and confirmed the overlapping of the monomer on the backbone of the both polymers. The disappearance of high intense crystalline peaks and the encapsulation of the drug by the hydrogel network was confirmed by PXRD. TGA and DSC showed that the developed hydrogels were thermally more stable than their basic ingredients. Similarly, the surface morphology of the hydrogels was analyzed by SEM and showed a smooth surface with few pores. Conclusively, ASP/ALPAA hydrogels have the potential to deliver IBP for a long period of time in a controlled way.

Living fabrication of functional semi-interpenetrating polymeric materials

Cell-mediated living fabrication has great promise for generating materials with versatile, programmable functions. Here, we demonstrate the engineering of living materials consisting of semi-interpenetrating polymer networks (sIPN). The fabrication process is driven by the engineered bacteria encapsulated in a polymeric microcapsule, which serves as the initial scaffold. The bacteria grow and undergo programmed lysis in a density-dependent manner, releasing protein monomers decorated with reactive tags. Those protein monomers polymerize with each other to form the second polymeric component that is interlaced with the initial crosslinked polymeric scaffold. The formation of sIPN serves the dual purposes of enhancing the mechanical property of the living materials and anchoring effector proteins for diverse applications. The material is resilient to perturbations because of the continual assembly of the protein mesh from the monomers released by the engineered bacteria. We demonstrate the adoption of the platform to protect gut microbiota in animals from antibiotic-mediated perturbations. Our work lays the foundation for programming functional living materials for diverse applications.

(Invited) Semi-Interpenetrating Polymer Networks Based on N-Isopropylacrylamide and 2-Acrylamido-2-Methylpropane Sulfonic Acid for Hydrogel-Based Chemical Sensors

(Invited) Semi-Interpenetrating Polymer Networks Based on N-Isopropylacrylamide and 2-Acrylamido-2-Methylpropane Sulfonic Acid for Hydrogel-Based Chemical Sensors

Dynamic Semi IPNs with Duple Dynamic Linkers: Self-Healing, Reprocessing, Welding, and Shape Memory Behaviors.

Thermoset polymers show favorable material properties, while bringing about environmental pollution due to non-reprocessing and unrecyclable. Diels–Alder (DA) chemistry or reversible exchange boronic ester bonds have been employed to fabricate recycled polymers with covalent adaptable networks (CANs). Herein, a novel type of CANs with multiple dynamic linkers (DA chemistry and boronic ester bonds) was firstly constructed based on a linear copolymer of styrene and furfuryl methacrylate and boronic ester crosslinker. Thermoplastic polyurethane is introduced into the CANs to give a semi Interpenetrating Polymer Networks (semi IPNs) to enhance the properties of the CANs. We describe the synthesis and dynamic properties of semi IPNs. Because of the DA reaction and transesterification of boronic ester bonds, the topologies of semi IPNs can be altered, contributing to the reprocessing, self-healing, welding, and shape memory behaviors of the produced polymer. Through a microinjection technique, the cut samples of the semi IPNs can be reshaped and mechanical properties of the recycled samples can be well-restored after being remolded at 190 °C for 5 min.

Preparation of polyurethane/poly (2-hydroxyethyl methacrylate) semi-IPNs containing cellulose nanocrystals for biomedical applications

The purpose of this study was to prepare biocompatible and hydrophilic polyurethane (PU) nanocomposites by fabricating semi-interpenetrating polymer networks (semi-IPNs) using cross-linked poly (2-hydroxyethyl methacrylate) (PHEMA) in the presence of cellulose nanocrystals (CNCs) prepared from cellulose micro-fibers using the acid extraction method. CNCs had a mean length and diameter of 100 and 7 nm, respectively. A new acrylic-urethane cross-linker agent (MS) was used for crosslinking of PHEMA which was made by reaction of hexamethylene diisocyanate (HDI) and HEMA. The specifications of MS, CNCs, and semi-IPNs were examined via ζ-potential, NMR, FTIR, TEM, SEM, XRD, tensile, and an MTT assay. All the PU-based semi-IPNs were biodegradable, hydrophilic, and noncytotoxic, and also had suitable mechanical behavior. Hence, hydrophilic polyurethane bio-nanocomposites exhibiting better physicochemical characteristics and enhanced cell viability rates appear to be promising candidates for biomedical applications.

Ultralight and superelastic fibrous sponges with effective heat preservation and photo-thermal conversion for personal cold protection

Advanced warming materials integrating functions of reducing heat loss and providing extra heat for the body have attracted much attention. In this work, an ultralight and superelastic fibrous sponge serving as novel warmth retention materials was obtained by assembling the fibers contained zirconium carbide nanoparticles (ZrC NPs) into three-dimension (3D) configuration and creating the semi-interpenetrating polymer networks (semi-IPNs) within fibers via humidity-induced electrospinning and the thermal crosslinking technology. The resulting fibrous sponge (PCFS-12) exhibits high heat preservation ability (~25.2 mW m−1 K−1) and effective photo-thermal conversion performance that could improve the temperature of PCFS-12 to 70.3 °C under the sunlight irradiation. Moreover, the PCFS-12 showed a low density of 2.8 mg cm−3, low-temperature superelasticity with minor plastic deformation after 1000 compression, and good hydrophobic property (WCA = 132°). This work provides a novel approach to develop high-performance warmth retention materials for personal cold protection.

Poly(acrylic acid)/gum arabic/ZnO semi-IPN hydrogels: synthesis, characterization and their optimizations by response surface methodology

Synthesis of novel semi-interpenetrating poly(acrylic acid) (PAA)/gum arabic (AG)/ZnO hydrogels by in situ free radical polymerization was optimized using response surface methodology (RSM). The reaction variables were the molar ratio of the cross-linking agent (X1), the weight percentage of gum arabic (AG) (X2) as the reaction medium, and the amount of ZnO (X3), each of which was considered at five levels. The evaluated responses in RSM based on the central composite design (CCD) were the formation of samples (Y1), swelling ratio (Y2), conversion (Y3), and percentage of networking (Y4). Zinc oxide particles (ZnO) were prepared through a cost-effective and safe method based on the mixing of zinc acetate solution, ammonia solution, and sodium hydroxide into a microwave oven. The synthesized ZnO particles and prepared semi-interpenetrating polymer network (semi-IPNs) were evaluated by energy dispersive X-ray analyzer (EDX) and scanning electron microscopy (SEM), respectively. Synthesized samples based on RSM showed that hydrogels with less than 0.75 g of gum do not have suitable desirability. Also, the confirmation of the appropriate amount of cross-linking agent in hydrogels is between 10 and 16 (mol %), and more than this amount, the desirability of the responses decreases sharply. The results showed that increasing the amount of GA, as a biological macromolecule, significantly improves hydrogel formation, swelling rate, conversion, and networking of semi-IPNs which for the sample proposed by RSM were 1, 245%, 86%, and 94.5%, respectively.

Development and Characterization of Algae Based Semi-interpenetrating Polymer Network Composite

Spirulina Platensis (SP) reinforced semi-interpenetrating polymer networks (S-IPN) were developed using unsaturated polyester (USP) and polyurethane (PU). The concentrations of SP were varied in the polymer matrix. Characterization of the polymer matrix has been carried out using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Identified urethane linkages decreased with increase in SP content. Thermal stability, swelling behavior, water absorption, all increased with an increase in SP content. The biocomposites showed good chemical resistance.

Ultralight and Mechanically Robust Fibrous Sponges Tailored by Semi-Interpenetrating Polymer Networks for Warmth Retention.

People living in very cold climates urgently desire warmth retention equipment to remain healthy. However, creating materials that exhibit both effective warm retention and robust mechanical properties to maintain stable structures is extremely challenging. Herein, we report a facile and time-saving strategy for preparing ultralight, mechanically robust, and high-performance warmth retention materials via direct electrospinning and thermal crosslinking. Fluffy fibrous assemblies with stereoscopic fiber networks are fabricated with a humidity-induced electrospinning technique, followed by heating to create semi-interpenetrating polymer networks (semi-IPNs) within fibers to acquire fibrous sponges (FSs). The semi-IPN-based FSs (semi-IPN FSs) present integrated properties of high tensile stress (∼1 MPa), good fatigue resistance (∼0% plastic deformation after 1000 cyclic tensile or compressive tests), and nondestructive resilience in liquid nitrogen (-196 °C). Furthermore, the semi-IPN FSs exhibit a low volume density of ∼2.2 mg cm-3, effective heat preservation ability (low thermal conductivity ∼25.8 mW m-1 K-1), and desired waterproofness and breathability. The successful synthesis of semi-IPN FSs provides a novel attempt to develop high-performance materials with robust mechanical properties for numerous applications.

A Photopolymerized Semi-Interpenetrating Polymer Networks-Based Hydrogel Incorporated with Nanoparticle for Local Chemotherapy of Tumors.

To address the issue of local drug delivery in tumor treatment, a novel nanoparticle-hydrogel superstructure, namely semi-interpenetrating polymer networks (semi-IPNs) hydrogel composed of poly (ethylene glycol) diacrylate (PEGDA) and hyaluronic acid (HA) and incorporated with paclitaxel (PTX) loaded PLGA nanoparticles (PEGDA-HA/PLGA-PTX), was prepared by in situ UV photopolymerization for the use of local drug delivery. Using the gelation time, swelling rate and degradation rate as indicators, the optimal proportion of Irgacure 2959 initiator and the concentration of HA was screened and obtained for preparing hydrogels. Next, paclitaxel (PTX) loaded PLGA nanoparticles (PLGA-PTX NPs) were prepared by the emulsion solvent evaporation method. The mass ratio of the initiator was 1%, and the best concentration of HA was 5mg/mL in PEGDA-HA hydrogel. In vitro experiments showed that PLGA-PTX NPs had similar cytotoxicity to free PTX, and the cell uptake ratio on NCI-H460 cells was up to 96% by laser confocal microscopy and flow cytometry. The drug release of the PEGDA-HA/PLGA-PTX hydrogel local drug delivery system could last for 13days. In vivo experiments proved that PEGDAHA/PLGA-PTX hydrogel could effectively inhibit the tumor growth without causing toxic effects in mice. This study demonstrated that the PEGDA-HA/PLGA-PTX hydrogel is a promising local drug delivery system in future clinical applications for tumor therapy. A photopolymerized semi-interpenetrating polymer networks-based hydrogel incorporated with paclitaxel-loaded nanoparticles was fabricated by in situ UV photopolymerization, providing a promised nanoplatform for local chemotherapy of tumors.

Injectable Fibrin/Polyethylene Oxide Semi-IPN Hydrogel for a Segmental Meniscal Defect Regeneration

Background: Meniscal deficiency from meniscectomy is a common situation in clinical practices. Regeneration of the deficient meniscal portion, however, is still not feasible. Purpose: To develop an injectable hydrogel system consisting of fibrin (Fb) and polyethylene oxide (PEO) and to estimate its clinical potential for treating a segmental defect of the meniscus in a rabbit meniscal defect model. Study Design: Controlled laboratory study. Methods: The Fb/PEO hydrogel was fabricated by extruding 100 mg·mL-1 of fibrinogen solution and 2,500 U·mL-1 of thrombin solution containing 100 mg·mL-1 of PEO through a dual-syringe system. The hydrogels were characterized by rheological analysis and biodegradation tests. The meniscal defects of New Zealand White male rabbits were generated by removing 60% of the medial meniscus from the anterior side. The removed portion included the central portion. The Fb/PEO hydrogel was injected into the meniscal defect of the experimental knee through the joint space between the femoral condyle and tibial plateau at the anterior knee without a skin incision. The entire medial menisci from both knees of each rabbit were collected and photographed before placement in formalin for histological processing. Hematoxylin and eosin, safranin O, and immunohistochemical staining for type II collagen was performed. The biomechanical property of the regenerated meniscus was evaluated using a universal tensile machine. Results: The Fb/PEO hydrogel was fabricated by an in situ gelation process, and the hydrogel displayed a semi-interpenetrating polymer network structure. We demonstrated that the mechanical properties of Fb-based hydrogels increased in a PEO-dependent manner. Furthermore, the addition of PEO delayed the biodegradation of the hydrogel. Our in vivo data demonstrated that, as compared with Fb hydrogel, Fb/PEO hydrogel injection into the meniscectomy model showed improved tissue regeneration. The regenerated meniscal tissue by Fb/PEO hydrogel showed enhanced tissue quality, which was supported by the histological and biomechanical properties. Conclusion: The Fb/PEO hydrogel had an effective tissue-regenerative ability through injection into the in vivo rabbit meniscal defect model. Clinical Relevance: This injectable hydrogel system can promote meniscal repair and be readily utilized in clinical application.

Graft Semi-Interpenetrating Polymer Network Phase Change Materials for Thermal Energy Storage

Graft semi-interpenetrating polymer networks (IPNs) out of poly(ethylene glycol), PEG8000-based polyurethane, and acrylic copolymers were synthesized for phase change applications. The chemical structure of the IPN samples was checked with Fourier transform infrared spectroscopy. Thermal properties of the IPNs were studied using differential scanning calorimetry and thermogravimetric analysis. A scanning electron microscope was used to study the surface morphology of the IPN samples. Moreover, polarized optical microscopy and X-ray diffraction were utilized to examine the crystallization properties of the IPNs. The cycling stability of the IPNs was studied as well. Overall, graft-IPN samples show high thermal and cycling stability with excellent shape solidity and no change in crystallization properties compared to the pristine PEG8000. The results confirm the enormous potential of IPNs in a wide variety of phase change applications.

Preparation and evaluation of a UV-curing hydrophilic semi-IPN coating for medical guidewires

Guidewires have crucial roles in intravascular, critical care, and urological applications. In recent years, the demand for guidewires with lower friction surfaces has arisen for medical applications. Among various surface lubrication strategies for guidewires, the most promising is the use of a hydrophilic coating. However, obtaining a hydrophilic coating on guidewires with strong adhesion remains difficult owing to the surface energy difference between the substrate and hydrophilic coating. Herein, we present a UV-curing semi-interpenetrating polymer network coating for medical thermoplastic polyurethane (TPU)-sheathed nitinol guidewires. A polyurethane acrylate (PUA) was synthesized and cured as a transition layer on the TPU substrate to provide strong adhesion. Then, polyvinyl pyrrolidone (PVP) and polyethylene glycol diacrylate (PEGDA) permeated into the PUA layer and cured to form the composite coating. The PUA–PEGDA–PVP coating exhibited excellent lubricity and satisfactory adhesion force. The surface coefficient of friction decreased to approximately 0.02 after modification with the coating, and the coating was stable during long-term soaking in water and repeated friction. In vitro toxicity tests revealed that the coating had good biocompatibility. Thus, our PUA–PEGDA–PVP coating has the potential for application as super-lubricity guidewires and other medical devices.

Robust and Highly Ion-Conducting Gel Polymer Electrolytes with Semi-Interpenetrating Polymer Network Structure

Here we report gel polymer electrolytes (GPEs) formed by the film casting of the solution containing poly(ethylene glycol) methyl ether methacrylate (PEGMA) and trimethylolpropane ethoxylate triacrylate (ETPTA) with poly(vinylidene fluoride-co-hexafluoropropylene (PVDF-HFP), followed by the thermal radical polymerization and liquid electrolyte absorption. The resulting GPEs show a semi-interpenetrating polymer network (SIPN) structure that provides film robustness which is investigated by morphological, structural, and electrochemical studies. Particularly, the GPE prepared by the composition of 98 mol% PEGMA and 2 mol% ETPTA in the presence of 40 wt% of PVDF-HFP (relative to total amount of PEGMA and ETPTA) manifests large ionic conductivity (1.46 × 10−3 S cm−1) and tensile strength (6.28 MPa at elongation at break of 156%) at a room temperature due to large uptake of the liquid electrolyte (up to 267%) and SIPN structure. We also verify that the GPE is electrochemically stable up to 4.7 V (vs. Li/L+), suggesting it holds the great promise of a polymer electrolyte membrane for energy storages such as rechargeable batteries or supercapacitors.