Hydrothermal Reaction Of Glucose Research Articles

Effect size of carbon micro-nanoparticles on cyclic stability and thermal performance of Na2SO4⋅10H2O–Na2HPO4⋅12H2O phase change materials

In this paper, carbon particles with micro- and nano-particle size were synthesized through a hydrothermal reaction of glucose, namely C-1(123.1 nm), C-2(229.2 nm), C-3(335.1 nm), C-4(456.2 nm) and C-5(534.0 nm) with distinct sizes. We utilized five size carbon particles as individual fillers into the EHS matrix materials to prepare composite eutectic phase change materials (C/EHS PCMs) by melt blending technique. The impact of carbon particle size on the dispersion stability and thermal properties of Na2SO4⋅10H2O–Na2HPO4⋅12H2O (EHS) phase change materials was investigated. Scanning electron microscopy (SEM) and dynamic light scattering (DLS) analysis were done to analyze the diameters of carbon particles. The cryogenic-scanning electron microscopy (Cryo-SEM) analysis indicated that the carbon particles resulted in modification in the morphology of the EHS. The results of in situ X-ray diffraction (XRD) and Fourier-transformed infrared (FTIR) analysis showed only simple physical mixing between carbon particles and EHS. It is shown that adding 0.2 wt.% C-2 can decrease the supercooling degree of EHS to 1.5[Formula: see text]C. The cyclic stability of C/EHS varies significantly depending on the size of carbon particles. The thermal conductivity of EHS increased by 42.1%, 39.9%, 14.4%, 19.5%, and 18.8% with the addition of C-1, C-2, C-3, C-4, and C-5, respectively, at a mass fraction of 0.2%. The results of differential scanning calorimetry reveal that the incorporation of C-1, C-2, C-3, and C-4 into EHS leads to an enhancement of latent heat. The latent heat capacity of EHS with 0.2 wt.% C-2 is 243.4 J⋅g[Formula: see text], and after undergoing 500 cycles of solid-liquid phase transition, the latent heat remained above 200 J⋅g[Formula: see text]. Through the comprehensive analysis, the C-2/EHS composite phase change material holds significant potential for advancing building insulation and solar energy storage technologies.

Creation of hollow silica-fiberglass soft ceramics for thermal insulation

Hollow-structured materials show promise in thermal insulation because the shells encapsulating gaseous voids can interrupt heat transport pathways. Here, we present two low-cost routes to fabricate hollow silica nanoshells, via gas-phase and liquid-phase methods. The gas-phase synthesis method generates hollow shells by a droplet surface precipitation mechanism in a flame aerosol reactor. The liquid-phase synthesis route forms hollow shells by removal of a carbon template, which is produced by hydrothermal reaction of glucose. Both approaches (gas- and liquid-phase) provide hollow silica with amorphous structure, low thermal conductivity (0.023 and 0.026 W m−1 K−1), small particle size (442 and 383 nm), thin shell (35 and 36 nm), and low density (0.015 and 0.033 g cm−3). We employed high shear mechanical mixing to fabricate hollow silica-fiberglass composite ceramics. The resulting three-dimensional network provides the ceramics with robust mechanical elasticity and fire-retardancy while maintaining low thermal conductivity, dramatically outperforming an analogous material using commercial silica gel in place of the hollow nanoshells. Our findings provide two practical routes to synthesize hollow silica, either of which can be used to manufacture a class of hollow shell-fiber nanocomposite soft ceramics for energy-saving applications.

Fabrication of nitrogen doped and hierarchically porous carbon flowers for CO2 adsorption

Porous carbon with specifically designed structure as CO2 adsorbent is a very attractive and interesting research topic. In this study, we presented the synthesis and CO2 adsorption of flower shaped porous carbons. Flower-like hydrochar derived from the hydrothermal reaction of glucose, cobalt sulfate, and hexamethylenetetramine was used as the precursor, which was converted to carbon flower during CO2 activation. The flowers had hierarchically macro-meso-microporous structure. Interspaces and voids were formed by assembly of the petals, and the petals were distributed with pores of different scales. The formation mechanism of, and influences of various synthesis parameters on the flower shape were studied and analyzed. The carbon flowers exhibited surface area of 422−691 m2/g, and very high nitrogen content of 9.31–11.91 wt%. CO2 adsorption performances of the carbon flowers were also studied. Influences of the textural properties and doped nitrogen on the adsorption performances were investigated. The experiment results demonstrated that nitrogen doping showed positive effects on CO2 uptake at 1 bar, and had strong influence on the CO2/N2 selectivity.

Porous carbon nanospheres aerogel based molecularly imprinted polymer for efficient phenol adsorption and removal from wastewater

By adopting porous carbon nanospheres gel (PCNS-gel) carrier, the corresponding 3D monolithic surface molecularly imprinted polymer adsorbent ([email protected]) possesses unique advantages of excellent stability and efficient renewability besides its outstanding selectivity towards target phenol molecules. Carrier PCNS-gel is fabricated through the hydrothermal reaction of glucose, borax, and polyvinyl alcohol mixture. Based on the PCNS-gel, the functional adsorbent [email protected] is obtained via surface molecular imprinting technology, with phenol as template molecule and methacrylic acid as functional monomer. Owing to the surface imprinted layer, [email protected] performances a good adsorption capacity of 64.02 mg g−1 towards phenol. In addition, [email protected] has good selectivity towards phenol in the quaternary mixture solution of phenol, hydroquinone, p-nitrophenol, and p-tert-butylphenol with relative selectivity factors of 3.04, 16.50, and 3.93, respectively. More importantly, thanks to the 3D monolithic PCNS-gel carrier, the [email protected] adsorbent exhibits exceptional separation and recovery efficiency as well as outstanding stability and durability. The adsorption capacity only decreases by 10% after 10 repeated adsorption–desorption cycles. The adsorption capacity of [email protected] towards phenol in alkaline wastewater with complex composition is 58.4 mg g−1. The prepared novel 3D monolithic [email protected] adsorbent shows a promising application prospect for the deep and selective adsorption removal of phenol from wastewater.

Derivation of carbonaceous nanoparticles from glucose-modified nickel-titanium oxide nanoparticles grown on Nitinol fiber for solid phase microextraction of several polycyclic aromatic hydrocarbons in water samples

A facile strategy was developed for the fabrication of new nanoparticles-templated carbonaceous coating on a Nitinol (NiTi) fiber substrate. The NiTi fiber was first electrochemically anodized for the growth of nickel-titanium oxide nanoparticles (NiTiONPs). Thereafter, NiTiONPs were used as supporting templates for the derivation of carbonaceous nanoparticles (CNPs) via the hydrothermal reaction of glucose followed by carbonization in nitrogen atmosphere. The adsorption performance of the NiTi@NiTiONPs and the NiTi@NiTiO@CNPs fibers was evaluated using typical aromatic compounds as model analytes coupled to high-performance liquid chromatography with UV detection. The results clearly indicated that the NiTiO@CNPs coating exhibited higher extraction capability for polycyclic aromatic hydrocarbons (PAHs) than UV filters. For this purpose, several parameters of SPME with the NiTi@NiTiO@CNPs fiber were examined for the enrichment of PAHs in water. Under the obtained conditions, the calibration curves were linear over the concentration ranges of 0.05–200 μg·L–1 with correlation coefficients above 0.999. Limits of detection were between 0.012 μg·L–1 and 0.15 μg·L–1. Relative standard deviations (RSDs) of the intra-day and the inter-day analyses with the single fiber varied from 3.03% to 5.34% and from 3.31% to 5.82%, respectively. Moreover, RSDs for the fiber-to-fiber reproducibility with five fibers fabricated in different batches were between 4.89% and 7.10%. Finally, the applicability of the proposed method was validated via determination of target PAHs in real water samples with the relative recoveries of 82.6%–114%. Notably, the superior extraction performance of the fabricated fiber was still maintained even after more than 250 extraction/desorption cycles due to strong adhesion of the CNPs coating to NiTiONPs.

The surface carboxyl group of carbonaceous microspheres effects on the synthesis and structure of SiOC ceramics

In this study, C/SiOC and C/SiO2 composites were prepared by using carbonaceous microspheres with different surface functional groups. Carbonaceous microspheres based on hydrothermal reaction of glucose contains hydroxyl group, while the surface carboxyl group increases after NaOH etching. The hydroxyl group increases the oxygen-enriched structural units of SiOC ceramics, and the C spheres are closely enwrapped in SiOC matrix after pyrolysis at 900 °C. However, the interfacial reaction of surface carboxyl with Si–OH results in the formation of cristobalite SiO2, and C spheres are not only encased inside the SiOC matrix, but also dispersed outside of SiOC ceramics. After removal of C via calcination at 500 °C for 5 h, C/SiOC and C/SiO2 composites are transformed into amorphous SiO2 and cristobalite SiO2, respectively. The thermogravimetric analysis indicates the oxidation resistance of SiOC is superior to that of C and SiO2.

Effect of glucose concentrations on wear resistance of Al/APC composites prepared by hydrothermal carbonized deposition on chips

In this study, a novel method termed hydrothermal carbonized deposition on chips (HTCDC) is proposed to prepare aluminum alloy-amorphous carbon (Al/APC) composites. The influences of glucose concentration in hydrothermally reaction on the microstructure and wear resistance of the Al/APC composites were thoroughly studied. Amorphous carbon was deposited by HTCDC onto Al⿿20Si chips as a supporter. The Al/APC composites were prepared by hot extrusion from the chips. The results indicated that a uniform carbon film was successfully synthesized on the surface of the chips, improving the wear resistance of the Al/APC composites. With increasing concentration of glucose solution, the size and the number of delamination on the wear surface and the coefficient of friction decreased, and the wear rate decreased at first and then increased. In addition, the dehydration and carbonization processes in the hydrothermal reaction of glucose were analyzed. A schematic model of the wear surface of the Al/APC composites was established and the wear mechanisms were discussed.

Nitrogen and Sulfur Co-Doped Graphene-Like Carbon from Industrial Dye Wastewater for Use as a High-Performance Supercapacitor Electrode.

Nitrogen and sulfur co‐doped graphene‐like carbon (N,S‐GLC) is successfully prepared in a one‐step hydrothermal reaction of glucose with industrial dye wastewater followed by chemical activation. The nitrogen and sulfur are sourced entirely from the industrial wastewater. The process not only provides an alternative way of treating industry wastewater, but also offers a green route for recovering energy from the waste in the form of chemicals. The resultant N,S‐GLC shows a good degree of graphitization, a high specific surface area (1734 m2 g−1), and moderate heteroatom doping (N: 2.1 at%, S: 0.7 at%). The N,S‐GLC electrode displays high specific capacitance of 275 F g−1 at a current density of 0.5 A g−1 with a retention of 65.4% at 20 A g−1 in 6 m KOH. Moreover, the assembled symmetrical supercapacitor cell shows a capacitance of 38 F g−1 at a current density of 0.5 A g−1, which is equivalent to an energy density of 6.4 Wh kg−1 at a power density of 275.0 W kg−1. This approach provides an alternative and sustainable way of fabricating heteroatom‐doped graphene‐like carbon materials for use in high‐performance supercapacitors.

Sandwich structure of carbon-coated silicon/carbon nanofiber anodes for lithium-ion batteries

Abstract For electrospun silicon/carbon nanofiber composites, the surface precipitation of silicon nanoparticles can cause poor cycle stability. To solve this, a carbon-coated silicon/carbon nanofiber (Si/C@C) composite with a ‘sandwich’ structure is constructed by hydrothermal reaction of glucose and an electrospun silicon/carbon nanofiber, followed by high-temperature carbonization. The effects of the thickness of the carbon coating layer and calcining temperature on the electrochemical performance are studied. The results showed that carbon is uniformly and continuously coated on the surface of the composite fibers, which avoid direct exposure of precipitated silicon on the surface of the nanofibers to the electrolyte, reduce the occurrence of side reactions and is conducive to the stable formation of SEI films. At the same time, the carbon shell inhibit the volume expansion of silicon to a certain extent and improve the conductivity of the composites. Consequently, the obtained Si/C@C exhibit good rate performance and cycle stability. With the optimised carbon coating thickness and calcination temperature, the obtained electrodes deliver a reversible capacity of 1120 and 683 mA h g-1 at a current density of 0.1 and 2 A g-1 respectively, and a specific capacity of 602 mAh∙g-1 at a current density of 1 A g-1 after 100 cycles, a capacity retention rate of 80%. The facilely synthesised Si/C@C composite shows potential applications in high-capacity silicon-based anode materials.

Cataluminescence sensing of carbon disulfide based on CeO2 hierarchical hollow microspheres.

Material morphology-dependent cataluminescence (CTL) sensing characteristic and application are presented in this work. Hierarchical hollow microspheres CeO2 were synthesized via the hydrothermal reaction of glucose and N,N-dimethyl-formamide (Glu-DMF). SEM, XRD, TEM, HRTEM and BET were used to characterize the prepared CeO2 materials. Compared with CeO2 cubics (CeO2 Cubs), CeO2 hierarchical hollow microspheres (CeO2 HMs) show an enhanced CTL response to carbon disulfide. The response and recovery times of CeO2 HMs-based CTL sensor towards carbon disulfide are about 8 s and 20 s, respectively. CeO2 HMs exhibits a linear CTL response to carbon disulfide in the concentration range of 0.50~10 μg•mL-1 with an excellent sensitivity and selectivity. These results suggest that CeO2 HMs will be a highly promising CTL sensing material for the detection and monitoring carbon disulfide. Graphical abstract CeO2 hierarchical hollow microspheres (CeO2 HMs) were synthesized via the hydrothermal reaction of glucose and N, N-dimethyl-formamide (Glu-DMF). Meanwhile, the prepared CeO2 HMs shows commendable CTL response towards carbon disulfide. Due to the excellent analytical performance of designed CeO2 HMs-based sensor for carbon disulfide, it has potential application value in various locations.

3-15.アルカリ条件下でのグルコースとグリシンの水熱反応((4)水熱I,Session 3 バイオマス等)

3-15.アルカリ条件下でのグルコースとグリシンの水熱反応((4)水熱I,Session 3 バイオマス等)

Spherical Core–Shell Titanium (Oxy)nitride@Nitrided Carbon Composites as Catalysts for the Oxygen Reduction Reaction: Synthesis and Electrocatalytic Performance

AbstractAiming at the development of highly active and stable platinum‐free catalysts for the oxygen reduction reaction (ORR) in polymer electrolyte fuel cells (PEFCs), we explored the potential of a new composite material, where the core–shell structure should result in a combination of high ORR activity and improved electric conductivity. TiOxNy@CnNm composite nanoparticles were prepared by covering uniform carbon spheres of about 300 nm in size, synthesized through the hydrothermal reaction of glucose, with a homogeneous titania shell made by sol‐gel processing. The core–shell particles were then subjected to nitridation in ammonia vapor at different temperatures (550 °C–150 °C). The influence of the nitridation temperature on the structure and phase composition of the resulting composite particles was evaluated by a variety of techniques, including electron microscopy (SEM, TEM), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), elemental analysis, thermogravimetric (TG) analysis, and N2 sorption measurements, the electrochemical properties and the ORR performance of the materials were determined by rotating ring disk electrode (RRDE) measurements. Trends in the evolution of the structural/chemical properties and electrochemical/electrocatalytic properties as well as correlations between them are discussed; an optimized mesoporosity of the titanium (oxy)nitride shell was identified as the key criterion for the catalyst's ORR performance.

Mobility of black pigments for electrophoretic display depending on the characteristics of carbon sphere

A carbon sphere can be used as a black pigment in an electrophoretic display, substituting the convectional carbon black. The carbon sphere is synthesized through a hydrothermal reaction of glucose or fructose, and its characteristics are strongly dependent on the reaction parameters. The size of the produced carbon sphere simply increases with the reaction time, while the surface state related to the outermost functional group is not linearly changed. Since the electrophoretic motion of the carbon sphere is determined by the surface zeta potential of the black pigment, the impact of both size and surface chemistry on the surface zeta potential should be investigated. In this study, the changes in the size and surface state of carbon sphere according to the reaction time are examined, and their influences on the surface zeta potential before and after the polymerization step are clarified. It is confirmed that the surface zeta potential and the electrophoretic motion of black pigment under the electric field are obviously affected by the surface chemistry as well as the size of the carbon sphere. The results suggest that the accurate control of the size and surface state of the carbon sphere during the hydrothermal reaction is important to improve the performance of the electrophoretic display.

Hydrothermal synthesis and characterization of carbon nanospheres: a mechanistic insight

SEM and PL for CNS synthesized for 4 h by hydrothermal reaction of glucose.

Production of lactic acid from glucose by alkaline hydrothermal reaction

In this paper, alkaline hydrothermal conversion of glucose, a model compound of carbohydrate biomass, into lactic acid was discussed. Results showed that both NaOH and Ca(OH)2, can promote the formation of lactic acid in a hydrothermal reaction of glucose. In the case of the addition of NaOH, lactic acid was obtained with a yield of 27% based on a starting carbon mass of glucose at 300 °C for 60 s with a NaOH concentration of 2.5 M. In the case of the addition of Ca(OH)2, the highest yield of lactic acid is 20%, which occurred at 300 °C for 60 s with a Ca(OH)2 concentration of 0.32 M. The formation mechanisms of lactic acid from glucose were also discussed according to intermediate products identified, to examine if lactic acid is also formed via the aldose having one and two carbon atoms besides via the aldose having three carbon atoms. Result showed that lactic acid may be generated via formaldehyde, glycolaldehyde besides via the aldose having three carbon atoms in hydrothermal reaction which all formed by the reverse aldol condensation of hexoses.

Selective Adsorption of Glucose-Derived Carbon Precursor on Amino-Functionalized Porous Silica for Fabrication of Hollow Carbon Spheres with Porous Walls

Coating of polysuccharide (PS) generated by hydrothermal treatment of glucose on Stober's silica particles was examined. Uniform surface coverage of PS was achieved when the silica particles, the surfaces of which had been modified with amino groups, were mixed during the hydrothermal reaction of glucose. On the other hand, bare silica could not be coated with PS upon addition to the hydrothermal reaction solution; instead, this produced spherical PS particles with diameters of a few tens of nanometers beside silica particles. The significant effect of surface amino-functionalization of silica particles on the coverage of PS is attributable to induction of an electrostatic attraction between the positively charged amino-functionalized silica surface and negatively charged PS. When silica (core)−porous silica (shell) spheres were used instead of Stober's silica, efficient filling of the pores of the silica shell with PS could also be achieved by amino-functionalization of the surface of the porous silica s...

Hydrothermal Reaction of Glucose and Glycine as Model Compounds of Biomass

Glucose and glycine as biomass model compounds were reacted in hot-compressed water between 150 and 350°C. The product distribution as gas, char, oil and aqueous products was examined based on the reaction temperature. The Maillard products, melanoidin, were decomposed over 200°C to produce the char, gas, ammonia and decomposed products in aqueous solution. The char was formed in the low reaction temperature-range from 150 to 200°C, while the oil was formed over 250°C. The overall reaction scheme was proposed as follows.

3-9.グルコースとグリシンの水熱反応におけるC/N比の影響((2)水熱/バイオマスニッポン,Session 3 バイオマス等)

3-9.グルコースとグリシンの水熱反応におけるC/N比の影響((2)水熱/バイオマスニッポン,Session 3 バイオマス等)