美国原子能委员会

As part of efforts to minimize the harmful effects of toxic solvents associated with the production of polymeric nanoparticles, polycaprolactone (PCL) nanoparticles were synthesized using three different methods: emulsification solvent evaporation/extraction, spontaneous emulsification solvent diffusion, and nanoprecipitation. In this study, and for the first time, Menthol/Camphor and Menthol/Camphor/Thymol—both green eutectic solvents—were successfully used to dissolve PCL and facilitate nanoparticle synthesis. Various formulation parameters, including temperature, polymer number average molecular weight and concentration, emulsifier type, solvent composition, internal-to-external phase ratio, and the addition of an extraction phase, were systematically evaluated for their impact on nanoparticle characteristics such as morphology, zeta potential, size, and size distribution. Furthermore, the effect of incorporating PCL nanoparticles into a hydrogel network was investigated. Selected formulations of PCL nanoparticles, with their diverse properties and concentrations, were embedded in a PVP/Chitosan/Poloxamer 407 hydrogel crosslinked via gamma irradiation. The successful incorporation of nanoparticles was confirmed through DSC and FTIR analyses. This study demonstrated that PCL nanoparticles enhance the structural integrity of the hydrogel, increase its hydrophobicity, and reduce the minimum gamma irradiation dose required for hydrogel formation. The resulting hydrogels exhibited a high gel fraction with favorable swelling behavior across different temperatures and pH conditions.

Computational design of cross-conjugated macrocycles offers a valuable strategy for developing photosensitizers with tunable long-wavelength and near-infrared optical properties; however, the geometric constraints governing their successful synthesis remain poorly understood. Here, density functional tight binding (DFTB) and time-dependent DFTB (TD-DFTB) calculations were employed to evaluate the conformational characteristics, frontier electronic structures, and predicted optical properties of ortho-phenylene- and peri-naphthylene-modified cross-conjugated macrocycles and selected derivatives. Guided by this computational assessment, direct and stepwise condensations of 1,3-diiminoisoindoline with o-phenylenediamine and naphthalene-1,8-diamine were investigated experimentally. Rather than affording isolable macrocycles, both ortho-phenylene-directed routes converged to the benzimidazole derivative III, obtained in 57% yield by direct condensation, whereas the peri-naphthylene route furnished the perimidine-type heterocycle VI in 65% yield, which, to the best of our knowledge, has not previously been reported.Although nuclear magnetic resonance (NMR), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), and high-resolution mass spectrometry (HRMS) initially left structural ambiguity, single-crystal X-ray diffraction unambiguously established III and VI as the major products. HRMS detected trace formation of the targeted macrocycles. The observed outcome is consistent with preferential local [1+1] annulation promoted by the constrained ortho/peri-geometry. Photophysical and reactive oxygen species (ROS) studies of the isolated bulk materials revealed weak long-wavelength responses influenced by the trace higher-order species. Among the parent designs, the asymmetric [3+1] macrocycle emerged as the most promising candidate within the present computational screening set for long-wavelength optical response. It exhibited the narrowest calculated highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) gap and predicted electronic transitions extending toward 800 nm. Collectively, the computational and experimental findings reveal a geometry-directed alteration of the reaction pathway that restricts diiminoisoindoline macrocyclization and provides a rational basis for developing future synthetic strategies toward constrained cross-conjugated macrocycles.

Silicon substrates were plasma treated before being coated by plasma-polymerized hexamethyldisilazane (pp-HMDSN) thin films. The pretreatments included oxygen (O2), SF6 and argon (Ar) plasmas. The effect of these pretreatments on the properties of deposited thin films was studied, including film thickness, morphology and photoluminescence (PL). The deposition of pp-HMDSN thin films was performed using plasma enhanced chemical vapor deposition (PECVD). It was found that the substrate pretreatment induces an increase of film thickness, and the morphology of the deposited thin film follows that of the treated substrate, while the intensity of PL increases due to change of nanostructure accompanied with roughness and thin film thickness increase.

Proton exchange membranes (PEMs) enable clean energy generation in fuel cells by producing only water as a by-product. They significantly reduce greenhouse gas emissions and support the transition to a sustainable, hydrogen-based energy system. In this study, Gamma radiation was used to graft acrylonitrile (AN) and sodium styrene sulfonate (SSS) onto ETFE backbone to create a proton exchange membrane. The grafting yield was 20–50