Large-area freestanding graphene papers (GPs) are fabricated by electrospray deposition integrated with a continuous roll-to-roll process. Upon mechanical compaction and thermal annealing, GPs can achieve conductivity of as high 1238.3–1434 W m−1 K−1. The super-thermally conductive display an outstanding heat-spread ability more efficient in removing hot spots than Cu Al foils. As service to our authors readers, this journal provides supporting information supplied the authors. Such...

The liquid−solid phase change enthalpy, crystallization, and thermal conductivity of graphene/1-octadecanol (stearyl alcohol) composite, a nanostructured material, was investigated as function graphene content. (κ) the nanocomposite increased by nearly 2.5-fold (∼140% increase) upon ∼4% (by weight) addition while drop in heat fusion (i.e., storage capacity) only ∼15.4%. enhancement properties 1-octadecanol obtained with is markedly superior to effect other nanofillers such silver nanowires...

The 3ω method has been proven to be very useful for determining the thermal conductivity of thin films and their substrates. Several simplifications are often used in based on experimentally measured signal. These simplifications, however, have limited range applicability. In this work, we present a detailed analysis mathematical modeling applied different experimental conditions. Effects considered include finite substrate thickness, anisotropic nature film conductivity, film-substrate...

Lack of a bandgap limits the utilization graphene in nanoelectronic and nanophotonic devices. It is shown that tunable up to ≈0.2 eV can be engineered by controlled adsorption water molecules surface. The effect reversible, energy gap reduces ≈0.029 as humidity brought down zero.

Atmospheric water harvesting (AWH) has received tremendous interest because of population growth, limited freshwater resources, and pollution. However, key challenges remain in developing efficient, flexible, lightweight AWH materials with scalability. Here, we demonstrated a radiative cooling fabric for via its hierarchically structured cellulose network hybrid sorption–dewing mechanisms. With 8.3% solar absorption ∼0.9 infrared (IR) emissivity, the material can drop up to 7.5 °C below...

This paper investigates the change in contact angle of droplets fluid containing dispersed nanoparticles (nanofluid) functionalized with thioglycolic acid molecules as a function concentration and size nanoparticles, quality composition substrate material. Bismuth telluride an average ranging from 2.5 to 10.4 nm groups were grown by microemulsion method water. Experimental measurements nanofluid cast on smooth glass silicon substrates show that depends strongly nanoparticle concentration....

This work investigates the effect of size and concentration nanoparticles on effective gas–liquid surface tension aqueous solutions bismuth telluride functionalized with thioglycolic acid. The is obtained by solving Laplace–Young equation under experimentally measured boundary conditions droplet parameters. results demonstrate that depends as well nanoparticle size. Solutions containing 2.5 10.4 nm diameters have been tested. For both, a minimum exists within range tested mass...

We demonstrate epoxy-silver nanoparticle composites with high thermal conductivity κ enabled by self-constructed nanostructured networks (SCNN) forming during the curing process at relatively low temperatures (150 °C). The formation mechanism involves agglomeration of polyvinylpyrrolidone (PVP) coated nanoparticles, PVP removal, and sintering nanoparticles suppressed induced their small diameters (20–80 nm). Sintering SCNN are supported differential scanning calorimetry electron microscopy...

Highly oriented [1 1 0] Bi2Te3 films were obtained by pulsed electrodeposition. The structure, composition, and morphology of these characterized. thermoelectric figure merit (zT), both parallel perpendicular to the substrate surface, determined measuring Seebeck coefficient, electrical conductivity, thermal conductivity in each direction. At 300 K, in-plane out-of-plane merits (5.6 ± 1.2)·10(-2) (10.4 2.6)·10(-2), respectively.

Antimony telluride has a low thermoelectric figure of merit (ZT < ∼0.3) because Seebeck coefficient α arising from high degenerate hole concentrations generated by antimony antisite defects. Here, we mitigate this key problem suppressing defect formation using subatomic percent sulfur doping. The resultant 10-25% higher in bulk nanocrystalline leads to ZT ∼ 0.95 at 423 K, which is superior the best non-nanostructured alloys. Density functional theory calculations indicate that increases...

Thermal conductivity reduction is observed in P3HT nanowires inside porous alumina, upon size confinement due to a change crystal orientation.

The relative role of the residual strain and dimensional scaling on heat transport in nanostructures is investigated by molecular dynamics simulations a model Lennard-Jones solid. It observed that tensile (compressive) strains lead to reduction (enhancement) lattice thermal conductivity. A nonhydrostatic induces conductivity anisotropy material. This effect due variation with stiffness tensor anharmonicity, therefore phonon group velocity mean free path. anharmonicity appears be dominant....

Branched core/shell bismuth telluride/bismuth sulfide nanorod heterostructures are prepared by using a biomimetic surfactant, L-glutathionic acid. Trigonal nanocrystals of telluride encapsulated nanoscopic shells orthorhombic sulfide. Crystallographic twinning causes shell branching. Such heteronanostructures attractive for thermoelectric power generation and cooling applications.

This investigation introduces the asymptotic contact angle as a criterion to quantify surface wettability of nanofluids and determines variation solid tensions with nanofluid concentration nanoparticle size. The angle, which is only function gas-liquid-solid physical properties, independent droplet size for ideal surfaces can be obtained by equating normal component interfacial force on an axisymmetric that spherical droplet. technique illustrated series bismuth telluride where measured...

We demonstrate a microprobe technique that can simultaneously measure thermal conductivity κ and Seebeck coefficient α of thin films. In this technique, an alternative current joule-heated V-shaped microwire serves as heater, thermometer voltage electrode, locally heats the film when contacted with surface. The is extracted from resistance measured between probe unheated regions by modeling heat transfer in probe, sample their contact area, calibrations standard reference samples....

Dilute isovalent sulfur doping simultaneously increases electrical conductivity and Seebeck coefficient in Bi2Te2Se nanoplates, bulk pellets made from them. This unusual trend at high electron concentrations is underpinned by multifold effective mass attributable to sulfur-induced band topology effects, providing a new way for accessing thermoelectric figure-of-merit topological-insulator-based nanomaterials through doping. As service our authors readers, this journal provides supporting...

The thermal conductivity of films is measured using a scanning hot probe method and the calibration contact parameters investigated.

We report the first experimental results on temperature dependent in-plane and cross-plane thermal conductivities of a symmetrically strained Si/Ge superlattice Ge quantum-dot measured by two-wire 3 omega method. The conductivity values are highly anisotropic significantly reduced compared to bulk structures. can be explained using heat transport models based Boltzmann equation with partially diffusive scattering phonons at interfaces.