Interpenetrating Polymer Networks Research Articles

Photonic Aptasensor Based on the Smart Cholesteric Liquid Crystal Network Structure for Cylindrospermopsin Detection.

Solid-state cholesteric liquid crystals (CLCsolid) with one-dimensional photonic structure offer a promising platform for constructing chemical and biological optical sensors, owing to their facile fabrication, signal readout, and sensitive and selective responsiveness to target analytes. In this study, we designed a CLCsolid photonic structure intertwined with an interpenetrating polymeric network (IPN) immobilized with a cylindrospermopsin aptamer (CY9) for the selective detection of the cylindrospermopsin toxin (CYT) in water. Upon exposure to CYT, it induced a blue shift in the color of the IPNCY9 biosensor chip. This shift occurred because the CY9 aptamer selectively bound to the CYT, reducing the polarity of the IPN hydrogel, leading to water release and shrinkage of the photonic structure. The IPNCY9 biosensor chips demonstrated the ability to detect CYT within a linear range of 4.2-120 nM, with a limit of detection of 2.55 nM. This innovative biosensor chip not only provides a new strategy for designing targeted toxin biosensors by immobilizing different receptors but also exhibits significant potential for use in portable kits for remote areas.

Occlusal parameters and wear of artificial teeth in complete dentures with lingualized versus bilateral balanced occlusion: a randomized clinical trial

ObjectiveThis study aimed to assess the occlusal contact area (OCA), occlusal contact number (OCN), bite force, and artificial tooth wear in complete dentures with lingualized and bilateral balanced occlusion.MethodsEdentulous participants who fulfilled the inclusion criteria were divided into the three groups as follows: group I, dentures with lingualized occlusion using interpenetrating polymer network artificial teeth; group II, dentures with lingualized occlusion using double cross-linked artificial teeth; and group III, dentures with bilateral balanced occlusion using anatomical micro-hybrid resin teeth. The silicone techniques were used to assess the OCA and OCN of the mandibular dentures and the Dental Prescale II was used to evaluate the bite force at the 2-week, 3-month, and 12-month follow-up visits. Occlusal contact analyzer software was used to assess the maxillary and mandibular posterior tooth wear at the 12-month follow-up visit. All data was analyzed using the SPSS software.ResultsThe OCA of group III was significantly higher than that of groups I and II at the 2-week follow-up visit, whereas group I was considerably higher than groups II and III at the 3-month and 12-month follow-up visits. The OCN of the three groups exhibited significant differences at all three follow-up visits. Groups I and II had significantly lower bite force than Group III at the three follow-up visits. At the 12-month follow-up visit, groups I and II had significantly higher wear than Group III.ConclusionsAs the duration of use increases, the occlusal contact area of complete dentures increases, regardless of the occlusal schemes. The bite force of lingualized occlusion is typically lower than that of bilateral balanced occlusion. The wear locations of artificial teeth differ between the two types of occlusal schemes. (Retrospectively registered: The Chinese Clinical Trial Registry, No. ChiCTR2300073420(11/07/2023))

Toughening Healable Supramolecular Double Polymer Networks Based on Hydrogen Bonding and Metal Coordination.

Double polymer networks (DNs) consist of two interpenetrating polymer networks and can offer properties that are not merely a sum of the parts. Here, we report an elastic DN made from two supramolecular polymers (SMPs) that consist of the same poly(n-butyl acrylate) (BA) backbone. The two polymers feature different non-covalent binding motifs, which form dynamic, reversible cross-links. The polymers were prepared by reversible addition-fragmentation chain-transfer polymerization of n-butyl acrylate and either the self-complementary hydrogen-bonding motif 2-ureido-4[1H]pyrimidinone, or the 2,6-bis(1'-methylbenzimidazolyl)pyridine ligand, which forms complexes with metal ions. The supramolecular DN made by these components combines features of the single networks, including high thermal stability and resistance to creep. The DN further exhibits excellent healability and displays a higher extensibility and a higher toughness than its constituents. The mechanical characteristics of the DN can be further enhanced by selectively pre-stretching one of the networks, which is readily possible due to the reversible formation of the supramolecular cross-links and their orthogonal stimuli-responsiveness.

Interpenetrating Polymer Network Hydrogels with Tunable Viscoelasticity and Proteolytic Cleavability to Direct Stem Cells In Vitro.

The dynamic nature of cellular microenvironments, regulated by the viscoelasticity and enzymatic cleavage of the extracellular matrix, remains challenging to emulate in engineered synthetic biomaterials. To address this, a novel platform of cell-instructive hydrogels is introduced, composed of two concurrently forming interpenetrating polymer networks (IPNs). These IPNs consist of the same basic building blocks - four-armed poly(ethylene glycol) and the sulfated glycosaminoglycan (sGAG) heparin - are cross-linked through either chemical or physical interactions, allowing for precise and selective tuning of the hydrogel's stiffness, viscoelasticity, and proteolytic cleavability. The studies of the individual and combined effects of these parameters on stem cell behavior revealed that human mesenchymal stem cells exhibited increased spreading and Yes-associated protein transcriptional activity in more viscoelastic and cleavable sGAG-IPN hydrogels. Furthermore, human induced pluripotent stem cell (iPSC) cysts displayed enhanced lumen formation, growth, and pluripotency maintenance when cultured in sGAG-IPN hydrogels with higher viscoelasticity. Inhibition studies emphasized the pivotal roles of actin dynamics and matrix metalloproteinase activity in iPSC cyst morphology, which varied with the viscoelastic properties of the hydrogels. Thus, the introduced sGAG-IPN hydrogel platform offers a powerful methodology for exogenous stem cell fate control.

Characterization and Performance Enhancement of Bio-Based Polyurethane-Modified Cement Mortar Utilizing Polyglycerol Polyester Polyol.

The increasing focus on sustainable construction is driving the industry toward materials that combine functionality with environmental benefits. A viable approach to address this demand is the use of bio-based additives to improve traditional cementitious composites. This study introduces a novel approach to developing a polymer-modified construction material by incorporating varied amounts (0, 1, 2, 3, and 6%) of bio-based polyurethane (PU), derived from polyglycerol polyester polyol, into cementitious mortar. The resulting PU-modified cementitious mortar (PUMC) was evaluated for its mechanical, physicochemical, and microstructural properties. Results show that the incorporation of 2% PU by cement weight significantly enhanced compressive strength by 58.2%, flexural strength by 37.0%, and initial flow performance by 20.0% after 28 days, while a 6% PU incorporation provided the best abrasion resistance. These improvements were attributed to a uniform particle and pore size distribution and the formation of a uniform interpenetrating polymer network (IPN), as confirmed by BET-BJH and SEM-EDX analyses. Additionally, FTIR and TGA analyses revealed that the metal-ligand coordination between Ca2+ ions in the cement mortar and PU ligand groups strengthened the interfacial connectivity through noncovalent bonding, further enhancing the material properties. This research highlights the potential of bio-based PU as an eco-friendly additive that significantly improves the performance of cementitious mortars, making it a promising option for industrial flooring applications.

Damping and acoustic properties of nanosilica filled poly(styrene-acrylate) interpenetrating polymer networks (IPNs): Effect of nanocomposite preparation method

Research on noise pollution reduction has focused on utilizing damping coatings and polymer nanocomposites to enhance sound absorption. Nanosilica/poly(styrene-acrylate) nanocomposites as a water-based coating were prepared through in-situ emulsion polymerization and direct mixing methods at varying concentrations of 1, 2, and 3 wt% of nanosilica. Fourier transform infrared (FTIR) spectroscopy revealed that the inclusion of surfactant-containing micelles and a more extended synthesis period in the in-situ synthesis technique enhanced the interaction between silica nanoparticles and polymer chains. Dynamic light scattering (DLS) analysis showed a unimodal distribution and an acceptable range of polydispersity index (PDI) for neat and nanocomposite latexes. The addition of silica nanoparticles enhanced the stability of latex particles, especially evident in the direct mixing method. The field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) images confirmed the better dispersion of nanoparticles within the polymer matrix in the in-situ method. The addition of nanosilica resulted in a significant increase in pseudoplastic behavior and viscosity, notably in the in-situ synthesis. In both the in-situ synthesis and direct mixing techniques, the addition of 1 wt% of nanosilica resulted in an increase in the damping factor of nanocomposite films to about 2. However, when the nanosilica content was further increased to 3 wt%, the damping factor decreased. Acoustic tests demonstrated improved sound absorption with silica nanoparticles, yielding noise reduction coefficient (NRC) values of 0.49 and 0.46 for in-situ synthesis and direct mixing. The direct mixing method notably enhanced tensile properties at all nanoparticle content levels. Dried nanocomposite films exhibited superior UV-blocking capabilities compared to neat polymer films.

Fluoride Ions Sequestration From Contaminated Water Using PVA‐Agar‐Based Green Anion‐Exchanger

AbstractThe current work is focused on the designing of a green interpenetrating polymer network (IPN) PA@polyAAm:AN using polyvinyl alcohol‐agar hybrid backbone and its subsequent conversion into an anion‐exchanger PA@polyAAm:AN‐AE through reduction of nitrile group in presence of LiAlH4. Further, the reduced form of IPN was quaternized using methyl iodide so that anion to anion exchange could take place between F− and I− anions. The primary objective of synthesizing an anion‐exchanger was to eliminate F− ions from contaminated water through the utilization of a prepared device. During the optimization of different experimental parameters for getting the optimal anion‐exchange capacity (AEC), the favorable conditions found were: pH, 9.0; contact period, 120 min; adsorbent dosage, 30 mg and initial F− ion concentration, 8.0 mg L−1. The pseudo‐second order kinetic model best described the F− ions adsorption kinetics, with a 0.97 R2 value. The rate constant (KF) was found to be 2.3, which further supported the validity of the Freundlich isotherm. Thus, the current study has remarkable potential with a 79.99% adsorption capacity for eliminating F− ions. Moreover, the ecofriendly anion‐exchanger prepared was found effective in the removal of F− ions from aqueous medium up to four cycles during reusability analysis.

Viscous solvent effect on fracture of predamaged double-network gels examined by pre-notch and post-notch crack tests

Double network (DN) gels, composed of two interpenetrating polymer networks with contrasting properties, garnered considerable attention since their invention due to large resistances to crack initiation and propagation. This study systematically investigates the effect of viscous solvent on the fracture behavior of DN gels through pre-notch and post-notch crack tests conducted on both water-swollen and ethylene glycol (EG)-swollen DN gels. Fracture energy analysis reveals that the chain dynamics changed by viscous solvent EG would remarkably reduce the two individual fracture energy contributions Γbulk and Γtip, originating from the energy dissipation in the bulk and in the crack tip vicinity, respectively. Furthermore, we observed that chain dynamics influence crack propagation behaviors and the molecular orientation of network strands ahead of crack tips in DN gels. Examination of the retardation patterns ahead of propagating crack tips allows for the analysis of the molecular orientation of network strands. Unusual butterfly-like retardation patterns were observed for the EG-swollen DN gels, in stark contrast to the conventional damage zone patterns seen in water-swollen DN gels. This suggests that the slowed chain dynamics induced by the viscous solvent EG lead to significant viscoelastic mechanical responses ahead of crack tips, which governs the stress/strain fields at the crack tip. This study offers valuable insights into the underlying toughening mechanism of DN gels, particularly regarding the effect of polymer chain dynamics. The experimental analysis, integrating findings on fracture energy contributions, crack propagation behaviors, and retardation observations from both pre-notch and post-notch crack tests, could be applied to characterize other soft materials with diverse toughening mechanisms, thereby aiding in the design and application of future soft materials.

Photo/thermo-sensitive chitosan and gelatin-based interpenetrating polymer network for mimicking muscle tissue extracellular matrix

The dynamic interplay between extracellular matrix (ECM), its 3D architecture and resident cells plays a pivotal role in cell behavior influencing essential processes like proliferation, migration, and differentiation. Matrix-based 3D culture systems have emerged as valuable tools to model organ and tissue interactions in vitro. A 3D matrix analog must possess high biocompatibility and fully reproduce the characteristics of the native tissue in terms of mechanical properties. In this regard, interpenetrating polymer networks (IPNs) are particularly attractive because of the high tunability of their physicochemical properties. In this study, a chitosan (Ch) and modified gelatin (GelMA) IPN with a sol-gel transition triggered by two external physical stimuli, UV light and temperature, was designed to mimic the muscle tissue ECM in terms of mechanical stiffness. The system was deeply characterized demonstrating to support not only the growth and viability of muscle cells embedded within the hydrogel, but also cell differentiation toward muscle phenotype.

Interpenetrated Polymer Network Systems (PEG/PNIPAAm) Using Gamma Irradiation: Biological Evaluation for Potential Biomedical Applications

The potential antimicrobial and antibiofouling properties of previously synthesized PEG/NiPAAm interpenetrated polymer networks (IPNs) were investigated against three of the most common bacteria (E. coli, S. aureus, and S. epidermidis). The main goal was to evaluate the material’s biocompatibility and determine its potential use as an antifouling component in medical devices. This was intended to provide an alternative option that avoids drug usage as the primary treatment, thus contributing to the fight against antimicrobial resistance (AMR). Additionally, characterization and mechanical testing of the IPN were carried out to determine its resistance to manipulation processes in medical/surgical procedures. IPNs with different NiPAAm ratios exhibited excellent cytocompatibility with BALB/3T3 murine fibroblast cells, with cell viability values of between 90 and 98%. In addition, the results regarding the adsorption of albumin as a model protein showed a nearly constant adsorption percentage of almost zero. Furthermore, the bacterial inhibition tests yielded promising results, demonstrating effective pathogen growth inhibition after 48 h. These findings suggest the material’s suitability for use in biomedical applications.

Modified Release Interpenetrating Polymeric Network Hydrogel Beads of Montelukast Sodium Via Box Behnken Design

Background: Interpenetrating Polymeric Networks (IPN) are cross-linked polymeric alloys developed when two or more cross-linked polymers inter-penetratingly entangle. Interpenetrating polymeric networks possess several benefits including stability, biocompatibility, biodegradability, high swelling ability, and modified release efficiency. Aim: The aim of this study is to design stable, control-released montelukast sodium-loaded IPN hydrogel beads as a promising approach toward drug delivery. Objective: The goal of the present work was to develop Chitosan (swellable polymer) and glutaraldehyde (cross-linker) based modified (controlled) released montelukast sodium IPN hydrogel beads. Methods: The montelukast sodium IPN hydrogel beads were prepared via the precipitation method, and the final batch of IPN hydrogel beads was based on particle size, percent entrapment efficiency, area of swelling, and cumulative percent drug release using an overlay plot in Box-Behnken design. Compatibility studies (DSC, FT-IR) and microscopical observation (SEM) confirmed the compatibility and sphericity of the formulations. Results: The optimized (comprising 2.01% chitosan and 0.48% glutaraldehyde) IPN hydrogel beads having satisfactory particle size (817.76±54.49 μm), good entrapment efficiency (71.36±3.04%), and area of swelling (27.00±1.68 mm2) showed swelling and pH-dependent controlled montelukast release (92.96±1.05%) after 12 h with longer duration of action. Conclusion: The prepared montelukast sodium IPN hydrogel beads could be a potent control-released drug delivery vehicle.

Synthesis and Characterization of Shungite Modified Poly-N-Ninylpyrrolidone-Agarose Composites for Medical Application.

A systematic investigation was conducted to synthesize hybrid composite materials that use synthetic poly-N-vinylpyrrolidone and natural (agar-agar) macromolecules with plasticizers (PEG-400) and mineral filler shungite by means of electron irradiation. The XRD and SEM data showed that the structure of the resulting hybrid composites is an interpenetrating network with distributed particles of mineral component. It has been established that the mechanical properties of hybrid composites are determined mainly by the structural organization of the interpenetrating polymer network formed under electron irradiation of the initial synthetic and natural polymer mixture in the presence of plasticizers, as well as by the conditions for intercalation of polymer segments into the mineral matrix and vice versa. It has been revealed that the degree of swelling of hybrid composites strongly depends on the concentration of a low-molecular plasticizer in the polymeric interpenetrating network, which easily impregnates into the matrix of shungite. Successfully obtained [PVP-AA-PEG] hydrogels with shungite can be applied in regenerative medicine as wound healing dressings.

PH-RESPONSIVE INTERPENETRATING POLYMER NETWORK HYDROGEL MICROBEADS OF POLYACRYLAMIDE-G-GUM KONDAGOGU AND SODIUM ALGINATE FOR GASTROPROTECTIVE DRUG DELIVERY: IN VITRO-IN VIVO CHARACTERIZATIONS

The present work aims to design interpenetrating polymer network (IPN) mediated hydrogel microbeads of hydrolyzed polyacrylamide-g-gum kondagogu (H-pAAm-g-GK) and sodium alginate (SA) for pH-sensitive gastroprotective drug delivery of diclofenac sodium (DS). In brief, the pAAm-g-GK was prepared using microwave irradiation, followed by conversion into a pH-sensitive polymer (H-pAAm-g-GK) using alkaline hydrolysis. Then, DS-loaded IPN microbeads were made utilizing an ionotropic gelation method using Ca+2 ions and glutaraldehyde (GA) as a crosslinking agent. After this, different characterizations, such as FT-IR, DSC, PXRD, swelling analysis, drug entrapment, drug release study, in vivo anti-inflammatory activity, etc., were performed. The amorphous state of DS in the microbeads was validated by thermograms and diffractograms, whereas SEM analysis confirmed the spherical shape of the obtained DS-loaded H-pAAm-g-GK@SA mediated microbeads. The pulsatile swelling analysis assured the H-pAAm-g-GK@SA mediated microbeads showed significantly increased swelling as the pH switched from 1.2 to 7.4. Additionally, the microbeads exhibit a 15% DS release in a pH 1.2 buffer medium, while a substantial 94% of the drug was released in a pH 7.4 buffer. It assured the DS release was drastically augmented as the pH of the surrounding medium was switched from acidic to alkaline. Principally, the COOH- groups of hydrogels offer ionization at higher pH levels, wherein the osmotic pressure within the microbeads rises, resulting in more swelling and higher drug release. Finally, the in vivo anti-inflammatory activity assured pH-sensitive sustained release of DS. In conclusion, the H-pAAm-g-GK@SA mediated pH-sensitive IPN hydrogel microbeads show potential in the design of gastroprotective oral delivery systems for DS. In the future, H-pAAm-g-GK can be used for the design of pH-sensitive IPN hydrogel microbeads for targeted delivery.

Hydrogels with Independently Controlled Adhesion Ligand Mobility and Viscoelasticity Increase Cell Adhesion and Spreading.

A primary objective in designing hydrogels for cell culture is recreating the cell-matrix interactions found within human tissues. Identifying the most important biomaterial features for these interactions is challenging because it is difficult to independently adjust variables such as matrix stiffness, stress relaxation, the mobility of adhesion ligands and the ability of these ligands to support cellular forces. In this work we designed a hydrogel platform consisting of interpenetrating polymer networks of covalently crosslinked poly(ethylene glycol) (PEG) and self-assembled peptide amphiphiles (PA). We can tailor the storage modulus of the hydrogel by altering the concentration and composition of each network, and we can tune the stress relaxation half-life through the non-covalent bonding in the PA network. Ligand mobility can be adjusted independently of the matrix mechanical properties by attaching the RGD cell adhesion ligand to either the covalent PEG network, the dynamic PA network, or both networks at once. Interestingly, our findings show that endothelial cell adhesion formation and spreading is maximized in soft, viscoelastic gels in which RGD adhesion ligands are present on both the covalent PEG and non-covalent PA networks. The dynamic nature of cell adhesion domains, coupled with their ability to exert substantial forces on the matrix, suggests that having different presentations of RGD ligands which are either mobile or are capable of withstanding significant forces are needed mimic different aspects of complex cell-matrix adhesions. By demonstrating how different presentations of RGD ligands affect cell behavior independently of viscoelastic properties, these results contribute to the rational design of hydrogels that facilitate desired cell-matrix interactions, with the potential of improving in vitro models and regenerative therapies.

Synthesis and characterization of epoxy resin‐polydicyclopentadiene interpenetrating polymer networks by UV‐initiated simultaneously frontal polymerization

AbstractBy combination of UV curing and frontal polymerization, interpenetrating polymer networks (IPNs) based on diglycidyl ether of bisphenol‐A (DGEBA) epoxy resin and polydicyclopentadiene (PDCPD) were prepared by UV‐induced simultaneously frontal polymerization in this paper. Compared with the net DGEBA cured polymer, the tensile strength, elongation at break and impact strength of the IPNs were simultaneously improved. The maximum tensile strength and elongation at break of the IPNs reached 100 MPa and 4.64%, respectively, and the maximum impact strength reached 7.34KJ/m2 with an improvement of 115.2% over that of the net DGEBA cured polymer. Thermogravimetric analysis (TGA) results revealed that the IPNs could enhance the thermal stability. Data of the differential scanning calorimetry (DSC) and TGA testing shows that the IPN shows a single glass transition temperature (Tg) which is between the Tg of DGEBA and DCPD, indicating homogeneous phase and highly cross‐linked IPN formed. Morphologies and molecular structure of the IPNs polymer were observed by scanning electron microscope (SEM) and characterized by Fourier transform infrared spectroscopy (FTIR), respectively, whose results also proved the formation of ideal IPNs structures.

Enhancement on the thermal and tribological behaviors of polyurethane/epoxy-based interpenetrating network composites by orientationally aligned CNF/MXene/WPU aerogels

Tribological behaviour of polyurethane/epoxy interpenetrating polymer network (PU/EP IPN) as friction materials was investigated. This was a combination of the good flexibility of PU and high hardness of EP to realize polymer synergistic effect of interpenetrating network structure, aiming to broaden and develop the application of polymer-based composites in friction engineering materials. A novel CNF/MXene/WPU aerogel (CMW) was prepared by employing flexible NCO-terminated waterborne polyurethane prepolymer (WPU) as the supporting skeleton of aerogel, and synchronously combining the reinforcing-phase carbon nanofibers (CNF) and lubricating-phase MXene. Subsequently, the prepared ultralight porous yet mechanically robust CMW aerogels were encapsulated with IPN by vacuum impregnation. As expected, the addition of aerogel imparted IPN matrix with enhanced thermal and tribological properties due to the thermal dispersion and enhancement effects conferred on the matrix by the highly aligned and ordered three-dimensional interconnected structure of aerogel. Meanwhile, CMW reinforced IPN composites were explored for the formation of a high-quality transfer film on the contact surface during friction. The transfer film prevented direct contact between the friction couples, which facilitated the improvement of wear resistance of composites, thus giving this material great potential for tribological applications.

Fabrication of plasticized interpenetrating polymer network (IPN) leatherette derived from bacterial cellulose and silicon dioxide using a novel 2-in-1 thickening process

Fabrication of plasticized interpenetrating polymer network (IPN) leatherette derived from bacterial cellulose and silicon dioxide using a novel 2-in-1 thickening process

Influence of Rheological Modifications on Primary Network Chemical and Structural Cure Kinetics for an Interpenetrating Polymer Network Resin.

The development of non-contact in situ techniques for monitoring cure kinetics has the potential to greatly improve both resin formulation and processing. We have recently shown that low-frequency Raman spectroscopy is a viable method for assessing resin structural cure kinetics and complements the traditional chemical conversion determined from the fingerprint region of the spectrum. In this work, we further evaluate the relationship between structural and chemical conversion by investigating two chemically identical yet rheologically different interpenetrating polymer network resin formulations. Rheological analysis demonstrates a relationship between structural conversion and storage modulus, which is not observed in the chemical conversion data. We show that one can produce master cure kinetics curves with comparable kinetic constants using both the chemical and structural conversion methodologies. Parametric analysis of the structural conversion, chemical conversion, and photorheological conversion was combined with a semi-empirical model for the storage shear modulus as a function of the extent of cure.

The effects of 1D multi‐wall carbon nanotubes and 2D graphene nanoplatelets on curing behavior of epoxy/vinyl ester interpenetrating polymer network nanocomposites

AbstractThis study meticulously investigated the effect of two carbon allotrope nanofillers, two‐dimensional graphene nanoplatelets (GnPs) and one‐dimensional multi‐wall carbon nanotubes (MWCNTs) individually, at various loadings on the kinetics of curing of the epoxy (EP)/vinyl ester (VE) based interpenetrating polymer network (IPN) system, with a mass ratio of 1:1. The IPN system is including a liquid epoxy resin based on bisphenol A which has been cured by methyltetrahydrophthalic anhydride (MTHPA) in the presence of 1‐methyl imidazole (Mi) as an accelerator and a vinyl ester resin based on bisphenol A which has been cured by methyl ethyl ketone peroxide (MEKP). The curing behavior of all prepared nanocomposites under non‐isothermal conditions was studied using DSC at four heating rates. Two different isoconversional approaches were applied to evaluate the reaction kinetics, that is, the Friedman and the advanced Vyazovkin methods. The obtained activation energy curves for all samples revealed a complex curing behavior involving three stages: early IPN stage, IPN growth stage, and late IPN stage. Then, the activation energy values for each reaction step were determined based on the Friedman method. The presence of GnPs showed no catalytic effect on the reaction of VE with MEKP. In contrast, incorporating MWCNT nanoparticles considerably decreases the activation energy values of the reaction of ring opening of epoxides with MTHPA‐Mi and the reaction of esterification of the hydroxyl groups of VE with MTHPA.Highlights MWCNTs reduce activation energy in curing reactions for EP/MTHPA‐Mi and VE/MTHPA. GnPs do not catalyze VE/MEKP reaction unlike MWCNTs. Combining MWCNTs and GnPs enhances properties of IPN nanocomposites. Curing process includes early, growth, and late IPN stages impacting activation energy. SEM analysis reveals better dispersion of GnPs in IPN nanocomposites with MWCNTs.

A comprehensive investigation of cholesteric liquid crystal interpenetrating polymer networks for metal ion sensor technology

This study outlines the fabrication process of a photonic polymer cholesteric liquid crystal (PCLC) engineered for dynamic response to external stimuli. The methodological framework includes the precise templating of PCLC onto an interpenetrating polymer network (IPN) following selective UV crosslinking and the careful removal of nonreactive mesogens. The sensor component of the PCLC film is composed of poly(acrylic acid) hydrogel. A key aspect of the process involves the formation of micro-holes through acetone treatment to enhance sensitivity. Additionally, functionalization with potassium hydroxide (KOH) improves the detection of calcium ions (Ca2+) by disrupting hydrogen bonds and facilitating the formation of potassium carboxylate salt. Combining the inherent properties of PCLC with the hydrogel’s responsiveness to metal ions results in a sophisticated sensor designed to detect Ca2+ ions through the modulation of PCLC pitch, creating distinct transmission bands. The manuscript provides a detailed quantitative analysis of stimulus-induced changes in PCLC wavelength, using measured spectra to refine and optimize process conditions. The resulting PCLC sensor demonstrates exceptional sensitivity (9.30 nm/mM) within the 1–15 mM Ca2+ ion concentration range, along with excellent specificity. This cost-effective, user-friendly, and colorimetric sensing modality holds significant promise for various applications in analytical chemistry.