Abstract: A delignified wood material is formed by removing substantially all of the lignin from natural wood. The resulting delignified wood retains cellulose-based lumina of the natural wood, with nanofibers of the cellulose microfibrils being substantially aligned along a common direction. The unique microstructure and composition of the delignified wood can provide advantageous thermal insulation and mechanical properties, among other advantages described herein. The thermal and mechanical properties of the delignified wood material can be tailored by pressing or densifying the delignified wood, with increased densification yielding improved strength and thermal conductivity. The chemical composition of the delignified wood also offers unique optical properties that enable passive cooling under solar illumination.

Abstract: A battery cell that include sulfide cathodes are described with examples being suitable for operation at elevated temperatures. Also described are methods of making and using these battery cells.

Abstract: A piece of natural fibrous plant material, such as wood or bamboo, can be infiltrated with a chemical solution and subsequently subjected to a temperature of at least 80° C. to produce a softened piece of fibrous plant material having modified lignin therein. The content of modified lignin in the softened piece can be at least 90% of the content of native lignin in the natural fibrous plant material. The modified lignin retained in the softened piece can have shorter macromolecular chains than that of the native lignin. The softened piece can be subjected to densification, for example, to yield a high-strength structural material, or to subsequent drying, for example, to yield a flexible or anisotropically-clastic material. The processing of the natural fibrous plant material can avoid, or at least reduce, the production of black liquor or other waste liquids.

Abstract: A structure can comprise one or multi-element compound (MEC) nanoparticles. Each MEC nanoparticle can have a plurality of sites comprising one or more elements. Each site can form a compound bond with at least one other site of the MEC nanoparticle. One or more of the compound bonds can comprise a covalent bond, an ionic bond, or a metallic bond. Each MEC nanoparticle can be formed of at least three different elements. For example, one or more MEC nanoparticles can be a multi-element oxide nanoparticle, a multi-element carbide nanoparticle, a multi-element intermetallic nanoparticle, or any other type of compound nanoparticle.

Abstract: An ion-conducting structure comprises a metal-fibril complex formed by one or more elementary nanofibrils. Each elementary nanofibril can be composed of a plurality of cellulose molecular chains with functional groups. Each elementary nanofibril can also have a plurality of metal ions. Each metal ion can act as a coordination center between the functional groups of adjacent cellulose molecular chains so as to form a respective ion transport channel between the cellulose molecular chains. The metal-fibril complex can comprise a plurality of second ions. Each second ion can be disposed within one of the ion transport channels so as to be intercalated between the corresponding cellulose molecular chains. In some embodiments, the metal-fibril complex is formed as a solid-state structure.

Abstract: A formation of multielement nanoparticles is disclosed that includes at least three elements. Each of the at least three elements is uniformly distributed within the multielement nanoparticles forming nanoparticles having a homogeneous mixing structure. At least five elements may form a high-entropy nanoparticle structure. A method for manufacturing a formation of multielement nanoparticles includes providing a precursor material composed of the at least three component elements in multielement nanoparticles; heating the precursor material to a temperature and a time; and quenching the precursor to a temperature at a cooling rate to result in a formation of multielement nanoparticles containing at least three elements and the heating and the quenching representing a multielement nanoparticle thermal shock formation process. A corresponding system for manufacturing the formation of multielement nanoparticles and a method of using the multielement nanoparticles are also disclosed.

Abstract: A battery cells that include sulfide cathodes are described with examples being suitable for operation at elevated temperatures. Also described are methods of making and using these battery cells.

Abstract: The disclosure provides an electrolyte comprising a plurality of chitosan molecular chains crosslinked with zinc cations. The disclosure also provides an electrochemical device comprising: an anode; a cathode; and an electrolyte positioned between the anode and the cathode, wherein the electrolyte comprises a plurality of chitosan molecular chains crosslinked with zinc cations. In one embodiment, the device is a zinc ion battery, and the cathode comprises a zinc host material selected from the group consisting of (i) metal oxides, metal sulfides, metal phosphates, and metal selenides wherein the metal is one or more of manganese, vanadium, zinc, lithium, cobalt, iron, molybdenum, titanium, niobium, bismuth and tungsten, (ii) poly(benzoquinonyl sulfide), (iii) lead titanate, (iv) Prussian blue compounds, (v) electrically conductive polymers, and (vi) mixtures thereof, and the anode comprises a material selected from metallic zinc and zinc alloys.

Abstract: Solar thermal devices are formed from a block of wood, where the natural cell lumens of the wood form an interconnected network that transports fluid or material therein. The block of wood can be modified to increase absorption of solar radiation. Combining the solar absorption effects with the natural transport network can be used for various applications. In some embodiments, heating of the modified block of wood by insolation can be used to evaporate a fluid, for example, evaporating water for extraction, distillation, or desalination. In other embodiments, heating of the modified block of wood by insolation can be used to change transport properties of a material to allow it to be transported in the interconnected network, for example, heating crude oil to adsorb the oil within the block of wood.

Abstract: A solid lignocellulosic bioplastic can be formed from a biomass comprising an intertwined structure of lignin, hemicellulose, and cellulose. The lignin in the biomass can be dissolved such that the cellulose is fibrillated. After the lignin dissolution and cellulose fibrillation, the lignin can be regenerated in situ. The regenerated lignin can be deposited on and can form hydrogen bonds between the fibrillated cellulose, so as to form a slurry of lignin-cellulose solids in solution. The slurry can then be dried to form the bioplastic. In some embodiments, the lignin is dissolved by immersing the biomass in a first chemical. The lignin can then be regenerated in situ by addition of a second chemical to the first chemical.

Abstract: The disclosure provides an ion exchange membrane with ion-conducting nanochannels formed by crosslinking chitosan molecular chains to form a unique threefold helical conformation and nanochannels that facilitate ion transport. The crosslinking promotes ion conductivity, suppresses swelling in water, inhibits fuel permeation, and enhances mechanical strength. The ion exchange membrane is stable in harsh alkaline environments. The ion exchange membrane can be used in a direct methanol fuel cell that displays an exceptional power density of 305 mW cm?2.

Abstract: In some embodiments, a material comprises a contiguous block of chemically-modified wood infiltrated with an index-matching polymer. The contiguous block has a first section that is substantially transparent to light and a second section that is translucent or opaque. The first section can have a lower lignin content than the second section. Alternatively, the first section can have a chromophore state altered from that of the wood in its natural state, and the lignin in the second section can retain a chromophore state of the wood in its natural state. In some embodiments, a material comprises a section of wood chemically-modified such that chromophores of lignin within the wood in its natural state are altered or removed, and the section retains at least 70% of the lignin of the wood in its natural state. Methods for forming such materials are also disclosed.

Abstract: An inverted battery device has a pair of electrodes, first and second volumes, and an electrical conductor. One of the pair of electrodes is configured as an anode and the other is configured as a cathode. A first electrolyte solution and the anode are disposed in the first volume, while a second electrolyte solution and the cathode are disposed in the second volume. The electrical conductor extends between the first and second volumes to couple the pair of electrodes to each other such that electrons travel between the pair of electrodes. The device is constructed to produce ions rather than electrons such that an ionic current can be generated in a separate system, such as a biological system or other ionic system, when coupled between the anode and cathode.

Abstract: Naturally-occurring cellulose-based material, such as wood, bamboo, grass, or reed, can be subjected to one or more chemical treatments to remove at least some lignin therefrom. The resulting partially-delignified material can be partially dried or fully dried and then rehydrated to yield a moldable cellulose-based material. The moldable material can be formed from a substantially flat planar configuration into a non-planar three-dimensional configuration. Once formed into a desired configuration, the moldable material can be fully dried to set its shape, thereby forming a rigid molded piece. In some embodiments, the molded piece can be used as a structural material, for example, to form a load-bearing structure or part of a composite load-bearing structure.

Abstract: An evaporative device has a piece of at least partially-delignified plant material. The at least partially-delignified plant material has a modified microstructure including a plurality of vessels, a plurality of fibers, and a plurality of engineered micropores. Each vessel can define a first lumen having a maximum cross-sectional dimension of at least 100 ?m. Each fiber can define a second lumen having a maximum cross-sectional dimension less than or equal to 20 ?m. The engineered micropores can extend through walls of the vessels or fibers so as to fluidically interconnect the first and second lumina. In some embodiments, the plant material is reed or bamboo.

Abstract: A system for in situ repair of a metal pipe has a pipe repair head, an actuation assembly, an electrical power supply, and a controller. The pipe repair head can have an arm extending along a radiation direction of the pipe and a Joule heating element coupled to a distal end portion of the arm. The actuation assembly can move the pipe repair head along the axial and/or circumferential directions of the metal pipe. The controller controls the actuation assembly to position the pipe repair head with respect to a surface portion of the inner circumferential wall. The controller can then control the electrical power supply to apply a current pulse to the Joule heating element so as to generate a temperature of at least 1000° C. proximal to the surface portion, thereby sintering a metal powder in a slurry on the surface portion to form a metal repair layer.

Abstract: A super strong and tough densified wood structure is formed by subjecting a cellulose-based natural wood material to a chemical treatment that partially removes lignin therefrom. The treated wood retains lumina of the natural wood, with cellulose nanofibers of cell walls being aligned. The treated wood is then pressed in a direction crossing the direction in which the lumina extend, such that the lumina collapse and any residual fluid within the wood is removed. As a result, the cell walls become entangled and hydrogen bonds are formed between adjacent cellulose nanofibers, thereby improving the strength and toughness of the wood among other mechanical properties. By further modifying, manipulating, or machining the densified wood, it can be adapted to various applications.

Abstract: A piece of natural plant material is subjected to one or more chemical treatments to remove substantially all lignin therefrom, thereby allowing the extraction of delignified, cellulose-based fibers. For example, the natural plant material can be a grass, such as bamboo or gladiolus. Subsequent drying of the extracted fiber densifies the structure, yielding improved mechanical properties. In some embodiments, the extracted fibers can be used, either alone or in combination with other materials, as a structural material. For example, the extracted fibers can be embedded within, infiltrated with, coated by, or otherwise combined with a polymer or concrete to form a composite material.

Abstract: One or more reactants are flowed into thermal contact with a heating element in a reactor for a first time period. During a first part of a heating cycle, the one or more reactants are provided with a first temperature by heating with the heating element, such that one or more thermochemical reactions is initiated. The one or more thermochemical reactions includes pyrolysis, thermolysis, synthesis, hydrogenation, dehydrogenation, hydrogenolysis, or any combination thereof. The first heating element operates by Joule heating and has a porous construction that allows gas to flow therethrough. During a second part of the heating cycle, the one or more reactants are provided with a second temperature less than the first temperature, for example, by de-energizing the heating element. A duration of the first time period is equal to or greater than a duration of the heating cycle, which is less than five seconds.

Abstract: Solar thermal devices are formed from a block of wood, where the natural cell lumens of the wood form an interconnected network that transports fluid or material therein. The block of wood can be modified to increase absorption of solar radiation. Combining the solar absorption effects with the natural transport network can be used for various applications. In some embodiments, heating of the modified block of wood by insolation can be used to evaporate a fluid, for example, evaporating water for extraction, distillation, or desalination. In other embodiments, heating of the modified block of wood by insolation can be used to change transport properties of a material to allow it to be transported in the interconnected network, for example, heating crude oil to adsorb the oil within the block of wood.