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We demonstrate an eco-friendly, simple, and cost-effective method for manufacturing reduced graphene oxide (GO) induced with electron-beam irradiation, and we investigate the feasibility of the electron-beam-induced reduced GO (ERGO) as a hole-transporting interfacial layer in polymer solar cells (PSCs). In addition, the chemical composition, conductivity, work-function, and morphology of ERGOs with various absorbed doses were systematically investigated. The analytical results revealed that the reduced GO (RGO) was successfully prepared using electron-beam irradiation, and the electrical conductivity of ERGO was increased (up to 18.3 S/cm) with increasing the amount of absorbed dose. The PSCs with the ERGO as a hole-transporting interfacial layer exhibited comparable cell performance (3.52 ± 0.08% of power conversion efficiency) to that of the conventional PSCs with the poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), and they had better stability than the PEDOT:PSS-based PSCs. From the results, we confirmed that electron-beam irradiation is an effective approach to prepare the RGO, and the ERGO was preferable to the PEDOT:PSS for high-performance and stable PSCs. [ABSTRACT FROM AUTHOR]

To study the effect of cross-linking density of silicone encapsulant on gas permeability, a light-emitting diode (LED) package was produced with two kinds of silicone, methyl-group (silicone A) and phenyl-group (silicone B), and a sulfur compound gas permeability test of the fabricated packages was performed. We found that the main penetration route of sulfur compound gas into the Ag-plated layer in an LED package could be directly observed by inserting Ag wire in an encapsulant. The persistency rate of radiant flux increased as the curing time of the silicone encapsulant became longer. When electron beam is irradiated on an LED package, the persistency of radiant flux is also increased. [ABSTRACT FROM PUBLISHER]

To investigate the influence of electron beam irradiation on the properties of poly(ϵ-caprolactone) (PCL), PCL films prepared by solvent casting were irradiated with high-energy electron beams. The irradiated PCL films were investigated in terms of degree of cross-linking, mechanical properties, thermal properties, and biodegradability. The degree of cross-linking of the irradiated PCL films was found to be dependent on the absorption dose. The tensile strength of the irradiated PCL films increased with increasing absorption dose, while their elongation-at-break was reduced. The dynamic mechanical analysis results revealed that the irradiated PCL films had a higher glass transition temperature and a wider rubbery state plateau. The melting and thermal decomposition temperatures of the irradiated PCL films gradually decreased with increasing absorption dose. The results of the enzymatic degradation test revealed that the irradiated PCL films were more slowly degraded than the nonirradiated PCL film. These changes in the properties of the PCL film after irradiation could result from the occurrence of cross-linking and chain scission during electron beam irradiation. [ABSTRACT FROM AUTHOR]

Abstract: The electron beam-induced crosslinking of poly(butylene adipate-co-terephthalate) (PBAT)/polyhedral oligomeric silsesquioxane (POSS) nanocomposites was investigated in this study. PBAT/POSS nanocomposites prepared by a solution blending with various compositions were crosslinked by electron beam irradiation at various absorbed doses ranging from 20 to 200kGy and their properties were characterized in terms of their degree of crosslinking, morphology, thermal and mechanical properties, and biodegradability. The results of the degree of crosslinking measurements revealed that PBAT/POSS nanocomposites were more effectively crosslinked than the pure PBAT and that the degree of crosslinking was dependent on the absorbed dose and POSS content. From the results of the FE-SEM and EDX analyses, the POSS was found to be uniformly dispersed in the PBAT matrix. Based on the results of the UTM, DMA, and TMA, the crosslinked PBAT/POSS nanocomposites exhibited much higher thermal and mechanical properties compared to those of the pure PBAT. [Copyright &y& Elsevier]

Abstract: Crosslinked poly(ε-caprolactone)/polyhedral oligomeric silsesquioxane (PCL/POSS) nanocomposite films prepared by a solution casting were crosslinked by electron beam irradiation under various conditions. The results of the crosslinking degree measurement revealed that the crosslinking degree of the PCL/POSS nanocomposites reached to 74%, which depended on the POSS content and the absorbed dose. The results of the FE–SEM and EDX analyses revealed that the POSS was homogeneously dispersed in the PCL matrix. In comparison to the virgin PCL with a tensile strength of 20MPa, the tensile strength of the crosslinked PCL/POSS nanocomposites increased to 25.8MPa with an increasing POSS content and absorbed dose to 100kGy, whereas their elongation-at-break was considerably reduced. The results of the dynamic mechanical analysis revealed that the crosslinked PCL/POSS nanocomposites had a higher heat resistance than the virgin PCL. Based on the results of the enzymatic degradation test, the biodegradability of the crosslinked PCL/POSS nanocomposites was significantly reduced in comparison to that of the virgin PCL. [Copyright &y& Elsevier]

Abstract: Biodegradable poly(butylene adipate-co-terephthalate) (PBAT) was crosslinked by electron beam irradiation and their properties were investigated in this research. PBAT films prepared by a solution casting method were crosslinked by electron beam under various absorbed doses ranging 20–200kGy and their properties were characterized by using a crosslinking degree measurement, a thermogravimetric analyzer (TGA), universal testing machine (UTM), dynamic mechanical analyzer (DMA), and thermal mechanical analyzer (TMA). The results of the crosslinking degree measurement revealed that the PBAT could be crosslinked by electron beam irradiation and its crosslinking degree was dependant on the absorbed dose. In addition, the results of the UTM, DMA, TMA, and TGA analyses revealed that the thermal and mechanical properties of the crosslinked PBS was much improved in comparison to those of the control PBAT. [Copyright &y& Elsevier]

Abstract: In this study, poly(lactic acid) (PLA)/poly(ethylene glycol)-functionalized polyhedral oligomeric silsesquioxane (PEG-POSS) nanocomposites with or without triallyl isocyanurate (TAIC) were investigated by melt blending and electron beam irradiation to enhance the flexibility of PLA. Based on the results of the crosslinking degree measurements, the PLA/PEG-POSS nanocomposites were crosslinked by electron beam irradiation in the presence of triallyl isocyanurate (TAIC) and their crosslinking degree reached up to 80% based on the absorbed dose and their compositions. From the results of the FE-SEM and EDX Si-mapping, the crosslinked PLA/PEG-POSS nanocomposites were homogenous without a micro-phase separation or radiation-induced morphological change. Based on the results of the tensile test, the PLA/PEG-POSS nanocomposites containing 15wt% PEG-POSS exhibited the highest flexibility, and their tensile strength showed a maximum value of 44.5MPa after electron beam irradiation at an absorbed dose of 100kGy in the presence of TAIC, which is comparable to non-biodegradable polypropylene. The results of the dynamic mechanical analysis revealed that the crosslinked PLA/PEG-POSS nanocomposites exhibited a higher thermal resistance above their melting temperature in comparison to that of the neat PLA, although their glass transition temperature was lower than that of the neat PLA. The enzymatic biodegradation test revealed that the PLA/PEG-POSS nanocomposites were biodegradable even though their biodegradability was deteriorated in comparison to that of the neat PLA. [Copyright &y& Elsevier]

[Display omitted] • Crosslinked PP- g -PVP/PEGDA was prepared by EB-induced graft polymerization in water solvent. • Addition of PEGDA crosslinker increased grafting degree by up to three times relative to that without PEGDA. • A VP-to-PEGDA weight ratio of 10:1 is suitable for efficient grafting with a smaller effect on the tensile properties of pristine PP. • Iodine-complexed PP- g -PVP/PEGDA-I exhibited excellent water absorptivity. • Antibacterial activity of PP- g -PVP/PEGDA-I depends on grafting degree and can be easily controlled. In this study, we developed an efficient method to prepare a crosslinked poly(vinyl pyrrolidone)/poly(ethylene glycol) diacrylate) (PVP/PEGDA) copolymer-grafted non-woven polypropylene (PP) sheet for which water can be used as a green solvent while providing a large amount of grafting functional groups on the PP matrix without diminishing mechanical properties. It was demonstrated that subsequent iodine complexation of the PP- g -PVP/PEGDA produces a strong antibacterial activity desirable for wound dressings. Efficient functionalization of hydrophobic non-woven PP sheet was achieved using electron beam (EB)-induced graft polymerization of vinyl pyrrolidone (VP) with the addition of hydrophilic crosslinker (PEGDA), resulting in the PP- g -PVP/PEGDA. In this preparation method, the grafting degree was remarkably increased up to 3-fold, even in the water solvent, and was found to be controlled by the concentration of VP and PEGDA. To impart antibacterial activity, the PP- g -PVP/PEGDA subsequently underwent iodine complexation, yielding PP- g -PVP/PEGDA-I. Structural analysis and water absorptivity studies confirmed that excellent water-absorbing PVP/PEGDA-I complexes were successfully introduced in the non-woven PP sheet without significant change in the porous structure of the PP sheet. Moreover, the PP- g -PVP/PEGDA-I exhibited strong antibacterial activities against Gram-negative E. coli , Gram-positive S. aureus , and MRSA bacterial species in a time-killing assay, and the activities showed high dependence on the grafting degree. This finding demonstrates that the PP- g -PVP/PEGDA-I can effectively and immediately inactivate external bacteria upon invasion. This green and efficient strategy is thus promising to produce PVP-I complex-based wound dressings with rapid antibacterial activity. [ABSTRACT FROM AUTHOR]

In this research, we report an initiator-free and room-temperature 2.5 MeV electron beam (EB)-induced gelation strategy to in-situ create polyvinylpyrrolidone-based gel polymer electrolytes (PVP-GPEs) in a fully-assembled lithium ion battery (LIB). A radiation-sensitive liquid precursor consisting of 1-vinyl-2-pyrrolidone (VP), poly (ethylene glycol) diacrylate (PD), and LiClO 4 liquid electrolyte (LE) was effectively converted to freestanding PVP-GPEs even at an absorbed dose of 2 kGy (Irradiation time of 6 s). The formed GPE at the absorbed dose of 2 kGy exhibited good thermal stability and mechanical integrity while providing good electrochemical oxidative stability (up to 4.7 V) and ion conductivity (2.03 × 10−3 S/cm at 25 °C). Moreover, the LiCoO 2 /PVP-GPE/graphite coin cell in-situ prepared at the absorbed dose of 2 kGy showed comparable retention capacity to that of an LE-based coin cell after 50 cycles. The findings of this study suggest that the proposed in-situ quick EB-induced gelation strategy (without use of an initiator and thermal treatment) could be a scalable way to allow high-throughput production of reasonably performing and safe LIBs. • PVP-GPE based LIB is developed by in-situ EB-induced gelation in a fully-assembled battery. • Free-standing PVP- GPE was formed even in a short time of 6–24 s without an initiator. • PVP-GPEs showed better thermal stability and comparable good ionic conductivity to a LE. • PVP-GPEs exhibit similar cycling performance compared to LE. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electron beam (EB)-induced in-situ formation of PVCEA GPEs in the LIBs is developed. • The EB-based in-situ formation can be carried out in a short time without an initiator or thermal treatment. • The GPEs prepared in a nonwoven fabric exhibit comparable ionic conductivity to that of a LE. • Intimate integrity between the GPE and electrodes is achieved. • The GPE-based LIB shows comparable cycling performance to a LE-based LIB. Several in-situ preparation methods of gel polymer electrolytes (GPEs) to develop long-lasting and safe lithium ion batteries (LIBs) recently have been reported. However, the reported in-situ methods still have technical gaps for practical industrial uses in terms of processing time, integrity with the current production line, and scalability. Here, we report an in-situ method to prepare crosslinked poly(vinylene carbonate- co -cyanoethyl acrylate) (PVCEA) GPEs using 10 MeV electron beam (EB) irradiation in a fully-assembled metallic housing LIB that can be processed in a short time without any initiator or thermal treatment. The successful in-situ formation of PVCEA GPEs was achieved at absorbed doses above 16 kGy (irradiation time of 56 s), leading to intimately integrated GPEs with the electrodes, while ensuring stable charge and discharge performance. The prepared PVCEA GPE exhibited a higher transference number (t Li+ = ca. 0.53) and a wider electrochemical operation window (up to 5.0 V) than those of a liquid electrolyte (LE), while providing good ionic conductivity (1.17 mS/cm at 20 °C). Furthermore, the PVCEA GPE-based LIB prepared at an optimized dose of 16 kGy showed comparable retention capacity of 83 % at 0.5C to the conventional LE-based LIB after 300 cycles at 25 °C, and more importantly, better cycling durability at elevated temperature of 60 °C in comparison to the LE-based LIB. This study suggests that the combination of radiation-sensitive precursor formulation and high-energy EB with high penetration ability can provide a promising solution for industrial production of high-performing and safe LIBs. [ABSTRACT FROM AUTHOR]

In this study, we demonstrated that the enhanced performance of poly(acrylic acid) binder-based silicon/graphite composite anode (c-PAA-Si/C) can be achieved by a quick, scalable, and solid-state electron beam irradiation-induced crosslinking in the presence of methylenebisacrylamide (MBA) as a water-soluble crosslinker. The result from analysis of an irradiated PAA binder film revealed that the PAA was completely crosslinked by the electron beam irradiation at the absorbed dose of 30 kGy in the presence of 10 wt% MBA, thereby leading to the much reduced swelling degree and improved tensile strength. Likewise, the c-PAA-Si/C-30 anode (irradiated at absorbed dose of 30 kGy) possessed higher hardness than the non-irradiated PAA-Si/C-0 probably due to the effective formation of the crosslinked structure. Moreover, based on the coin-type half cell performance and cycle stability test, the c-PAA-Si/C-30 anode-based cell exhibited the better retention capacity at 100 cycles than that of the PAA-Si/C-0-based one. The EIS and FE-SEM results showed that this better cycling performance could be ascribed to the crosslinked structure-induced structural stability. • PAA-based Si/C anode was crosslinked by e-beam irradiation in the presence of MBA. • The hardness of the crosslinked Si/C anode was greater improved than non-irradiated one. • The crosslinked anode-based cell exhibited the enhanced capacity retention as well. • This solid-state room temperature crosslinking enables the longer-lasting Si anode. [ABSTRACT FROM AUTHOR]

Abstract: A rapid, facile, and eco-friendly electron beam (EB)-based method for the reduction of graphene oxide (GO) is demonstrated in this research. GO prepared by the well-known modified Hummer׳s method was dispersed in an ethanol/water solution, and then reduced by EB irradiation. The analytical results revealed that reduced GO (RGO) was successfully prepared by the EB irradiation of GO suspensions, and the chemical structure, thermal stability, and dispersibility of the resulting RGO depended on the absorbed dose. Noticeably, the prepared RGO exhibited an electrical conductivity of 1.50×10−2 S/cm even at 50kGy (5min), which further increased up to 4.50S/cm with an increase in the absorbed dose to 200kGy (20min). These results indicate that this fast and eco-friendly EB irradiation-induced reduction method can strongly support the mass production of RGO for practical applications. [Copyright &y& Elsevier]

In this research, we demonstrate that a solution-processable reduced graphene oxide/poly (N -vinylpyrrolidone) nanocomposite (rGO/PVP) can be easily obtained by a scalable and cost-effective electron beam-based method; and further, that it functioned well as a hole-transport layer (HTL) in perovskite solar cells (PeSCs). The rGO/PVP composites were produced by electron-beam irradiation-induced reduction of GO/PVP mixtures in ethanol/distilled water (50 v/v %), without any heat or reducing agents. The prepared rGO/PVP showed dispersion stability of six months, even in an aqueous alcoholic solvent of 5 mg/mL. Its solution-processed thin film demonstrated a uniform, smooth surface, and full-cover morphology, a good conductivity of ~0.2 S/cm, and a high work function of 5.15 eV. As a result, the solution-processed rGO/PVP as HTL for the PeSCs outweighed the conventional graphene nanoflakes (GNFs), producing higher device efficiency. Worthy of note, the rGO/PVP-based PeSCs showed better power conversion efficiency (PCE) and device stability than the reference poly (3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS)-based counterpart. This finding demonstrates that the rGO/PVP composite, which is easily producible via cost-effective and large-scale affordable electron beam technology, could provide a promising solution-processable GNFs-based HTL for long-lasting high-performance PeSCs. Image 1 [ABSTRACT FROM AUTHOR]