Bulky cellulosic network structures (BRC) with densities between 60 and 130 g/l were investigated as a sustainable alternative to fossil-based foams for impact liners in bicycle helmets. The mechanical properties of BRC foams were characterized across a wide range of strain rates and incorporated into a validated finite element model of a hardshell helmet. Virtual impact tests simulating both consumer information and certification scenarios were conducted to compare BRC-lined helmets against conventional expanded polystyrene (EPS) designs.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
December 2024
In this work, a battery layup consisting of a poorly flammable ionic liquid electrolyte and a poly(vinylidene fluoride--hexafluoropropylene) (PVdF-HFP) thermoplastic has been developed along with composite anode and cathode electrodes. The developed gel electrolyte exhibits feasible ionic conductivity of about 1 mS/cm at 30 °C. State-of-the-art active electrode materials, i.
View Article and Find Full Text PDFACS Appl Mater Interfaces
June 2024
Polymer coating to substrates alters surface chemistry and imparts bulk material functionalities with a minute thickness, even in nanoscale. Specific surface modification of a substate usually requires an active substrate that, e.g.
View Article and Find Full Text PDFCotton ovule cultures are a promising platform for exploring biofabrication of fibers with tailored properties. When the ovules' growth medium is supplemented with chemically synthesized cellulose precursors, it results in their integration into the developing fibers, thereby tailoring their end properties. Here, we report the feeding of synthetic glucosyl phosphate derivative, 6-deoxy-6-fluoro-glucose-1-phosphate (6F-Glc-1P) to cotton ovules growing , demonstrating the metabolic incorporation of 6F-Glc into the fibers with enhanced mechanical properties and moisture-retention capacity while emphasizing the role of molecular hierarchical architecture in defining functional characteristics and mechanical properties.
View Article and Find Full Text PDFGradient macroporous polymers were produced by polymerization of emulsion templates comprising a continuous monomer phase and an internal aqueous template phase. To produce macroporous polymers with gradient composition, pore size, and foam density, we varied the template formulation, droplet size, and internal phase ratio of emulsion templates continuously and stacked those prior to polymerization. Using the outlined approach, it is possible to vary one property along the resulting macroporous polymer while retaining the other properties.
View Article and Find Full Text PDFCarbons form critical components in biogas purification and energy storage systems and are used to modify polymer matrices. The environmental impact of producing carbons has driven research interest in biomass-derived carbons, although these have yield, processing, and resource competition limitations. Naturally formed fungal filaments are investigated, which are abundantly available as food- and biotechnology-industry by-products and wastes as cost-effective and sustainable templates for carbon networks.
View Article and Find Full Text PDFJ Colloid Interface Sci
June 2022
A tubular co-flow reactor to produce macroporous polymer beads by polymerization of medium and high internal phase emulsion (M/HIPE) templates was developed. This reactor allows for improved production rates compared to tubing based microfluidic devices. Water-in-oil (W/O) M/HIPEs, containing methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) monomers in the continuous phase, were injected into a re-circulating carrier phase.
View Article and Find Full Text PDFA solid epoxy resin formulation containing 2.5 wt % carbon nanotubes is 3D printed into self-standing parts, which after thermal curing result in CNTs/epoxy nanocomposites with mechanical properties attractive for heavy-duty applications.
View Article and Find Full Text PDFNonaqueous foams were successfully produced by mechanically beating air into liquid epoxy resin, surfactant, and silica particle mixtures and used as templates to produce macroporous polymers. The air bubbles introduced into the epoxy formulations served as templates for the pores of the cured epoxy foams. The addition of silica particles into the resin mixture resulted in an increased viscosity of the formulation, thus enhancing the stability of the liquid epoxy froths, which could then be thermally cured at 60 °C.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2015
Closed cell elastomeric polydimethylsiloxane (PDMS) based polymerized medium internal phase emulsions (polyMIPEs) containing an aqueous solution of sodium hydrogen carbonate (NaHCO3) have been produced. Via thermal decomposition of NaHCO3, carbon dioxide was released into the polyMIPE structure to act as a blowing agent. When placed into an atmosphere with reduced pressure, these macroporous elastomers expanded to many times their original size, with a maximum expansion of 30 times.
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