ABSTRACT Microfluidic devices have been widely commercialized in recent years, especially in the field of in vitro diagnostics (IVD), these microfluidic devices are sometimes also referred to as “cartridges.” Used microfluidic devices contain sensitive personal information (e.g., genetic information), as well as the intellectual property (IP) of the microfluidic device manufacturer. For IVD application scenarios like home testing, field & resource‐limited area testing, the used cartridges may not get proper medical waste treatment. To avoid personal information leakage or the counterfeit/reuse of the microfluidic device, the microfluidic devices need to be property destructed after use. Although very limited discussions have been published on the destruction (disposal) of microfluidic devices, the self‐destructing methods of microfluidics can be adopted from integrated circuit (IC) or micro‐electromechanical systems (MEMS) fields. This perspective discusses various possible approaches to self‐destructing microfluidics, where devices are designed to self‐destruct after use, enabling the safe disposal of the processed fluid sample, the destruction of the device structure, or both. We believe this study could provide some useful insight for future studies on self‐destructing microfluidics in the context of the wide application of microfluidics in IVD and other fields.
ABSTRACT Electronic cigarettes (e‐cigarettes) have acquired more popularity in recent years, mainly because they are supposed to be less harmful than regular cigarettes. The thermal stability of sucralose (Suc) as sweetener in e‐cigarettes is important. This study aimed to synthesize sucrose loaded cyclodextrin‐metal–organic frameworks (CD‐MOFs) from potassium hydroxide, crystallized with β‐cyclodextrin (β‐CD) and γ‐CD, and their complex thermal stability properties were further evaluated. The basic β‐CD MOFs reaches high sucrose payloads of 92.54 wt%, corresponding to a molar ratio of 8:1 between sucrose and β‐CD. Thermal stability analysis indicates a substantial improvement, with the Suc‐β‐CD‐MOF complexes displaying an onset decomposition temperature of 197°C, representing a 125°C increase relative to that of free sucrose. In comparison to Suc‐β‐CD‐MOF, sucrose coated with β‐CD‐MOF maintained 73.4% at 80°C for 12 h, with the release rate reduced by about 26.6%. These findings demonstrate the potential of β‐CD‐MOF as effective carriers for sucrose thermal stability enhancement.
ABSTRACT The ongoing miniaturization, multifunctionalization, and integration of modern electronic devices lead to more and more heat generated. Therefore, developing thermal interface materials (TIMs) with high thermal conductivity (TC) is of great significance in effective thermal management. Polymers are selected for thermally conductive composites owing to their excellent properties, including stability and electrical insulation. However, achieving their high TC often requires adding a large amount of heat fillers to the polymer matrix, which inevitably increases costs. Thus, it remains a key challenge to develop polymer composites that simultaneously possess high TC and low cost. It is an effective approach to solve this problem by adding low‐cost mineral fillers. In this study, inexpensive and widely used calcium carbonate fillers were incorporated to fabricate low‐cost polyethylene/calcium carbonate/boron nitride (PE/CaCO 3 /BN) TIMs. The PE/CaCO 3 /BN composite (40/30/30, volume ratio) has a TC of 3.53 W/(m·K) and a tensile strength of 12.11 ± 2.30 MPa. Furthermore, the PE/CaCO 3 /BN composite also has good thermal stability; its TC decreases to 3.17 ± 0.09 W/(m·K) after 50 hot‐cold cycles, which is a reduction of 10.11% compared with that of the as‐prepared counterpart. This study offers an effective strategy to fabricate high thermally conductive composites at a low cost.
ABSTRACT Transparent glass fiber‐reinforced polymer composites (tGFRPs) are promising for photovoltaic and architectural applications, but surface contamination, poor self‐cleaning capability, and limited durability hinder their practical use. In this study, highly transparent PETG‐based tGFRP laminates were fabricated through hot‐pressing optimization, yielding a maximum transmittance of 80.9% and a haze of 11.6%. Two transparent organic–inorganic hybrid hydrophobic coatings with different organosilane compositions were then prepared via a sol–gel process. Both coatings formed dense surface layers, reduced surface roughness, and improved optical performance, with transmittance increasing to 81.8% and 83.1% and haze decreasing to 10.9% and 10.1%, respectively. Meanwhile, the coatings transformed the laminate surface from hydrophilic to hydrophobic, with water contact angles of 110.3° and 129.7° and sliding angles of 12.3° and 8.5°, respectively. The octyl‐containing coating showed better self‐cleaning and anti‐fouling performance, whereas the methyl‐functional coating exhibited superior mechanical and chemical durability. In addition, tGFRP showed damage self‐reporting capability through transparency attenuation during tensile loading, and the local transparency variation correlated well with the DIC strain distribution. These findings provide a feasible strategy for developing multifunctional transparent composites with combined surface functionality and damage self‐reporting capability.
ABSTRACT For ultra‐high‐voltage thick‐section epoxy insulation, reducing curing exotherm without compromising comprehensive performance remains a major challenge. This challenge is closely associated with the molecular architecture developed during chain extension and the cross‐linked network formed during subsequent curing. Herein, two commonly used chain‐extension catalysts, triethylbenzylammonium chloride (TEBAC) and triphenylphosphine (PPh 3 ), were systematically investigated to clarify their roles throughout the chain‐extension and curing process. TEBAC promotes the further reaction of secondary hydroxyl groups, producing a moderately branched molecular architecture while maintaining a low epoxy value of 0.30 eq/100 g. During subsequent curing, TEBAC exhibits a lower apparent activation energy and lower curing‐temperature range than PPh 3 , favoring a higher degree of curing under identical conditions. Consequently, the mEP/TEBAC system exhibits substantially improved overall performance compared with the commercial epoxy resin, with impact strength, glass transition temperature, and volume resistivity increased from 13.97 to 29.82 kJ m −2 , 111.6°C to 130.4°C, and 0.55 × 10 17 to 1.08 × 10 17 Ω cm, respectively. These results demonstrate that chain‐extension catalysts can influence not only the molecular architecture formed during chain extension but also the subsequent curing behavior, establishing a direct link between catalyst selection, molecular structure, curing process, and final properties.
ABSTRACT A hybrid manufacturing strategy for protective equipment applications is presented, combining fused deposition modeling (FDM) of polyethylene terephthalate glycol (PETG) with vacuum bag‐assisted UV‐curing of glass fiber‐reinforced, PLA‐like photopolymer over‐molds. X‐ray diffraction confirmed FDM‐induced crystallinity increase in PETG from 23.1% to 28.7%, enhancing substrate rigidity. Flexural modulus increased 38.8% (31.4 ± 0.8 MPa to 42.9 ± 1.9 MPa) with glass fiber reinforcement, though strength decreased from 89.6 ± 4.5 MPa to 65.1 ± 5.9 MPa due to modulus mismatch. Interlaminar shear strength (5.77 ± 1.76 MPa) revealed the PETG/photopolymer interface as the critical weakness, with predominant adhesive failure. This tool‐less, digitally‐driven approach enables rapid customization of geometrically complex composite structures while eliminating energy‐intensive metal molds, establishing a scalable pathway for small‐batch protective component manufacturing.
ABSTRACT The sustainable development of polycarbonates from greenhouse gases, like carbon dioxide (CO 2 ), is of significant interest; however, achieving a high molecular weight polymer, with improved thermal properties and degradability remains challenging. This study reports the one‐pot ring‐opening polymerization of L‐lactide (LLA), propylene oxide (PO), and CO 2 to synthesize a degradable terpolymer by incorporating ester segments into a poly(propylene carbonate) (PPC) backbone using a novel ternary salophen‐cobalt catalyst. The study systematically investigates the influence of reaction parameters on molecular weight ( M w ), selectivity, monomer conversion, and PPC/PLA molar ratio. The resulting terpolymer achieves a high M w of 139 kDa, under mild reaction conditions (60°C, 25 bar), and an improved glass transition temperature ( T g ) of 46°C, notably higher than standard PPC (≤ 35°C). Degradation studies demonstrate the polymer's susceptibility to thermal, alkaline, and enzymatic hydrolysis, with up to a 36.6% reduction in M w over 4 weeks. Furthermore, the study provides insight into the roles of each component within the ternary catalytic system, suggesting a synergistic function enabling a one‐pot terpolymerisation of monomers with varying ring strains within a single catalytic framework.
ABSTRACT Polyvinyl butyral (PVB) films are promising encapsulation materials for photovoltaic (PV) modules because of their mechanical properties and electrical insulation. However, achieving favorable flexibility and volume resistivity remains an important consideration in the formulation of PVB films. Focusing on regulating these two properties, this study investigates the effects of molecular structure and plasticizer formulations on PVB performance. As acetoxy content increased from 2% to 12%, the glass transition temperature of the PVB resin decreased from 70.7°C to 64.4°C, while film flexibility and volume resistivity both showed favorable trends. Regarding plasticizer formulations, increasing plasticizer content generally reduces volume resistivity while significantly improving flexibility. For the triethylene glycol bis(2‐ethylhexanoate) (3G8) system, PVB films maintain volume resistivity above 1.0 × 10 16 Ω·mm when plasticizer content is below 17.0%. The plasticizer type critically influences performance. At equivalent content, the system exhibits decreasing volume resistivity from dioctyl phthalate (DOP) to dioctyl sebacate (DOS), diisononyl phthalate (DINP), and triethylene glycol bis(2‐ethylhexanoate) (3G8), while the flexibility follows the reverse sequence. Consistently, the through‐cracked tensile (TCT) tests show that enhanced plasticization improves interlayer flexibility but reduces the adhesion‐related load‐bearing and crack‐bridging capability of PVB/glass laminates. These findings highlight the inherent trade‐offs in plasticizer formulations for optimizing both properties.
ABSTRACT Cable accessories are weak points in high‐voltage systems, imposing stringent requirements on insulation materials. In this work, EPDM was modified with polypropylene (PP) of different molecular structures and contents to clarify structure–property relationships. Among random‐copolymer PP (R‐PP), block‐copolymer PP (B‐PP), and homopolymer PP (H‐PP) compared at the same content, H‐PP exhibited the highest crystallinity and showed superior electrical performance, particularly at elevated temperatures. Meanwhile, H‐PP also enhanced tensile strength, elastic modulus, and thermal conductivity while retaining a high elongation at break. Increasing the H‐PP content from 0 to 15 wt% further increased the crystallinity from approximately 0.3% to 6.1%, with only minor changes in crosslinking density. As a result, the AC breakdown strength, volume resistivity, tensile strength, and thermal conductivity were progressively improved, while the relative permittivity and dielectric loss remained comparatively stable. However, high H‐PP contents markedly increased the elastic modulus and reduced the elongation at break, revealing a trade‐off between reinforcement and mechanical compliance. Among the investigated formulations, 5 wt% H‐PP provided the most balanced combination of electrical performance, mechanical strength, and deformability. These results demonstrate that optimizing PP structure and content provides an effective approach for improving the comprehensive properties of EPDM for cable accessory insulation.
ABSTRACT Heat exchangers in the petrochemical industry face severe corrosion risks. In this study, a graphene‐reinforced epoxy (Gr‐EP) nanocomposite coating was prepared by incorporating 0.3 wt% of vapor‐phase synthesized graphene into an epoxy matrix along with two‐dimensional fillers (graphite, mica, and talcum powder) and functional pigments (chromium oxide green and red micaceous iron oxide). The Gr‐EP coating exhibited visibly fewer internal defects, improved adhesion, and better mechanical properties than both the epoxy coating without graphene and the commercial epoxy primer. Electrochemical tests revealed that the Gr‐EP coating exhibited a low‐frequency impedance modulus of 2.90 × 10 9 Ω·cm 2 . Moreover, the Gr‐EP coating remained intact without blistering or rusting after 6000 h of salt spray testing. The excellent anticorrosion performance is attributed to a synergistic physicochemical mechanism involving the physical barrier effect of the two‐dimensional nanomaterials and the passivation effect of the active fillers. In addition, owing to the high thermal conductivity and effective integration of the graphene nanosheets, the Gr‐EP coating also showed improved thermal properties. This work provides a promising and practical route toward durable corrosion protection for heat exchangers.
ABSTRACT In this study, wood‐based composites were prepared from waste pine and epoxy resin for use in water resistant applications. Wood‐based composites are produced using waste pine powder in varying weight percentages (10–50 wt.%) within epoxy resin. The study determined that adding waste pine to composites increased compression strength by 103.96% to 582.02% compared to pure resin. However, it was determined that when the percentage of waste pine exceeded 20%, the compression strength of the samples decreased by 24.76%–70.09% compared to the compression strength value of the composite with 20% waste pine added. Furthermore, while the contact angle value of pure resin was 81.33°, the contact angle of wood‐based composite samples was shown to be in the range of 83.88°–103.70°. The contact angles of the composites with 40% and 50% waste pine added were 98.49° and 103.70°, respectively. Composites having these contact angles (angles > 90°) also exhibited higher water resistance as their surfaces were not easily wetted by water. In summary, through the synthesis of these composites employing epoxy resin and waste pine powder in varying proportions, they exhibit considerable viability for application in water repellant applications in high humidity surroundings owing to their mechanical and hydrophobic characteristics.
ABSTRACT The interfacial structure between nanofillers and polymer matrices plays a critical role in determining the overall performance of polymer nanocomposites. In this study, we explored how varying the grafting density of flexible poly(oxyethylene/oxypropylene)‐2‐propylamine (MPOEA) chains on cellulose nanofibers (CNFs) influences the mechanical and thermal properties of CNF‐reinforced Acrylonitrile–butadiene–styrene (ABS) composites. The grafted MPOEA chains formed interfacial layers around the CNFs, with higher grafting densities yielding more interactive interphases. As a result, compared with the unmodified CNF/ABS composite, the optimized composite (J‐100%) exhibited an approximately 26‐fold increase in tensile toughness, from 0.90 ± 0.24 to 23.62 ± 7.47 MJ m −3 , while maintaining a Young's modulus of 1.52 ± 0.30 GPa, which remained comparable to that of neat ABS (1.41 ± 0.03 GPa). Thermomechanical analysis indicated that the addition of CNFs reduced the thermal expansion of the composites, and although this effect diminished at higher grafting densities, the coefficient of thermal expansion (CTE) values remained lower than that of neat ABS, ranging from (133.9 ± 0.3) × 10 −6 K −1 for J‐0% to (157.2 ± 4.4) × 10 −6 K −1 for J‐100%, compared with (169.5 ± 7.7) × 10 −6 K −1 for neat ABS.
ABSTRACT Herein, two diamine monomers 2‐amino‐3′,6′‐bis(4‐amino‐3‐hydroxyphenoxy)spiro[isoindoline‐1,9′‐xanthen]‐3‐one (ABAHS) and 9,9′‐bis(3‐amino‐4‐hydroxyphenyl)fluorene (BAHPF) were copolymerized with 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA) to prepare copolyimide (CPI) precursors and corresponding copolymerized thermally rearranged (CTR) membranes. Two rigid skeletons (ABAHS spiro heterocycle and BAHPF fluorene Cardo moiety) were synergistically introduced to tailor chain stacking. ABAHS ether groups offer superior film‐forming and mechanical strength, and intermolecular hydrogen bonds from phenolic hydroxyls and polar heteroatoms adjust chain packing density. The as‐fabricated CPI precursors exhibit prominent thermal stability with glass transition temperatures ranging from 348°C to 359°C. The precursor with an ABAHS/BAHPF molar ratio of 9:1 achieves optimal mechanical properties, with a tensile strength of 123 MPa and an elongation at break of 3.0%. After thermal rearrangement, the gas permeability of CTR membranes is drastically enhanced. The CTR‐5:5 membrane shows permeability coefficients of 72, 1408, 425 and 1537 Barrer for N 2 , H 2 , O 2 and CO 2 respectively. In contrast, the CTR‐9:1 membrane with high ABAHS content retains nitrogen polar sites and forms well‐defined molecular‐sieving channels with favorable CO 2 affinity. It delivers ideal H 2 /N 2 and CO 2 /N 2 selectivities of 27.60 and 26.16, both exceeding the 2008 Robeson upper bound, and its O 2 /N 2 selectivity reaches 7.80 above the 2015 upper bound.
ABSTRACT Bipolar plates are multifunctional components of proton exchange membrane fuel cells, responsible for electron transfer, gas distribution, water management, and structural support. Compression molding dominates the manufacture of composite bipolar plates. Mold pressure and temperature govern plate properties, dimensional accuracy, durability, and safety. This study combines Finite Element Method and experiments to account for simultaneous mold deformation and heat conduction and quantifies how mold thickness affects pressure and temperature fields. A thick mold plus preheat strategy is proposed. Increasing mold thickness improves molding quality, but thicker molds develop marked temperature gradients that create regional property variations. A mold with a thickness of 40 mm reduces pressure non‐uniformity by 21.5%, while experimental and predicted values deviate < 5%. However, this change introduces a 4°C–10°C temperature difference of the mold forming surface. Consequently, mold preheating is mandatory. Under the tested material system and processing window, the optimized process yields composite bipolar plates with 143 S cm −1 electrical conductivity, 4.3 mΩ cm 2 contact resistance at 2 MPa, 1.9 × 10 −7 cm 3 cm −2 s −1 helium permeability, and 80.06 MPa flexural strength. These measured properties meet the Department of Energy standards and fuel cell requirements.
ABSTRACT Ethylene‐vinyl acetate (EVA) is widely used but suffers from high flammability, poor thermal stability, and low hardness. It is often blended with polyethylene (PE) and flame retardants to improve performance, yet this often causes poor synergy and uneven filler distribution. In this study, vinyl acetate (VA) is grafted onto PE via melt grafting to obtain PE‐g‐VA, which combines the mechanical strength of PE with the polar dispersion of VA. When compounded with aluminum hydroxide (AH), PE‐g‐VA/AH achieves a limiting oxygen index of 32.1% and a UL‐94 V‐0 rating without melt dripping. Compared with EVA/PE/AH, PE‐g‐VA/AH shows 37.2% higher tensile strength and reductions of 33.3% (PHRR), 26.7% (THR), 36.9% (PSPR), and 60.7% (TSP). These improvements arise from the VA side chains, which enhance AH dispersion and char layer integrity. This work provides a feasible matrix‐modification strategy for high‐performance flame‐retardant composites.
ABSTRACT Organic solvent nanofiltration (OSN) has emerged as an energy‐efficient alternative to conventional separation processes for molecular‐level separations under mild operating conditions. Among the various membrane materials investigated, polyimides (PIs) have attracted significant attention because of their excellent thermal stability, mechanical robustness, and chemical resistance. However, conventional PI membranes often suffer from solvent‐induced swelling and structural instability, limiting their long‐term industrial applicability. To overcome these challenges, extensive research has focused on advanced crosslinking strategies, sustainable fabrication methods, and emerging data‐driven membrane design approaches. Chemical modifications such as diamine crosslinking, metal‐ion coordination, and synergistic multistep crosslinking have significantly enhanced solvent resistance and separation performance, achieving solute rejection values exceeding 99% in harsh solvents including DMF. Simultaneously, sustainable fabrication approaches involving green solvents and bio‐derived materials are gaining increasing importance. In parallel, artificial intelligence (AI) and machine learning techniques are being integrated into membrane research for predictive modeling, optimization, and virtual screening of membrane performance. This review critically discusses recent advances in PI‐based OSN membranes, emphasizing crosslinking chemistry, sustainable fabrication, and AI‐assisted membrane design while highlighting current challenges and future industrial prospects.
ABSTRACT The catalytic hydration of ethylene oxide (EO) to monoethylene glycol (MEG) is an industrially important process, but conventional ion‐exchange resin (IER) catalysts suffer from limited thermal stability and undesirable swelling. In this study, multiwalled carbon nanotubes (CNTs) are incorporated into a pyrrolidinium‐functionalized styrene‐divinylbenzene resin via in situ suspension polymerization to address these challenges. Comprehensive characterization confirms the effective CNT dispersion and strong interactions with the polymer matrix. The resulting CNT‐reinforced IER exhibits improved thermal stability, enhanced anti‐swelling capacity, and a notably lower exchange capacity loss compared with conventional IERs. In a fixed‐bed reactor for EO hydration, the bicarbonate‐form of CNT‐reinforced IER catalyst achieves over 97% EO conversion and 98% MEG selectivity under optimized conditions (90°C, 2.25 h −1 and a water‐to‐EO molar ratio of 11.20) and maintains stable performance over 2500 h. These results demonstrate that CNT reinforcement, combined with the pyrrolidinium functionality, provides a durable and highly selective catalyst for industrial EO hydration.
ABSTRACT This study systematically investigated the effects of micro‐scale expandable graphite (EG) on the bonding performance and impact toughness of an epoxy adhesive. The significant influence of EG content on adhesive properties was demonstrated by tensile shear tests, pendulum impact tests, scanning electron microscopy, metallographic microscopy, and finite element analysis using a representative volume element (RVE). The results indicated that EG particles synergistically enhanced both properties; however, the overall performance was highly dependent on the EG content. The addition of 0.1 wt.% EG improved the impact toughness by 105.8% and increased the tensile shear strength by 14.4%. At 0.5 wt.% EG, the tensile shear strength increased by 65.0%, while the impact toughness improved by 14.0%. However, when the EG content was further increased to 0.8, 1.0, and 2.0 wt.%, the excess particles tended to agglomerate and form isolated domains, leading to a decline in modification effectiveness. Considering the overall mechanical performance and processing feasibility, 0.1 wt.% EG was recommended as the optimal content. By correlating the failure morphologies of the bonded specimens, impact fracture micrographs, and RVE simulation results, this study elucidated the synchronous enhancement mechanism, linking the improved properties to interfacial pinning as well as crack deflection, bifurcation, and jumping.
ABSTRACT This study reports the development of a biodegradable hydrogel, synthesized from gelatin and dialdehyde gum tragacanth (Gel/DGT), for the effective removal of polycyclic aromatic hydrocarbons (PAHs) from contaminated water. The hydrogel was prepared by crosslinking dialdehyde gum tragacanth (DGT), obtained via periodate oxidation of gum tragacanth, with gelatin through covalent Schiff‐base linkages (–C═N–). The resulting Gel/DGT hydrogel exhibited robust mechanical strength, high swelling capacity (400% at pH 7 and 25°C), and significant biodegradability (94.67% within 30 days). Its rough surface morphology, high surface area, and abundant functional groups facilitated efficient adsorption of PAHs, achieving removal efficiencies of 97.5% for phenanthrene (Phen), 70.0% for acenaphthene (Ace), and 58.0% for naphthalene (Nap). Adsorption data best conformed to the Freundlich isotherm model ( R 2 > 0.98), with a maximum adsorption capacity of 500 mg/g for Phen. These findings demonstrate the Gel/DGT hydrogel as a sustainable, high‐capacity adsorbent for mitigating persistent organic pollutants in aqueous systems, offering advantages over conventional remediation methods.
ABSTRACT This work develops a series of flexible thermal ablation‐resistant epoxy‐modified polydimethylsiloxane (EDA@PDMS) composites with integrated mechanical and thermal protection performance through multiscale design strategy. EDA@PDMS was prepared by epoxy ring‐opening and hydrosilylation reactions. Then, 10 phr silicon dioxide and 6 phr carbon fibers were added to simultaneously enhance the mechanical strength and ablation resistance of EDA@PDMS‐c. Results showed that the tensile strength of EDA@PDMS‐c reached 2.31 MPa, which is 41.7% higher than that of PDMS‐c. Under 4 MW/m 2 for 30 s, the linear ablation rate (LAR) and mass ablation rate (MAR) of EDA@PDMS‐c reached 0.0515 mm/s and 0.0357 g/s, which were 32.1% and 18.5% lower than those of PDMS‐c, respectively. Additionally, a peak back‐face temperature of 89.4°C was monitored during the ablation process, indicating excellent thermal insulation performance. The above improvement was ascribed to the combined effects of the intrigue molecular structure design through CSi synergistic mechanism and reinforcing fillers. The research proposed a strategy for fabricating high‐performance flexible ablation composites that can be potentially used for thermal protection purposes in the areas of fire protection and aerospace among others.
