A rechargeable molecular solar thermal system below 0 °C

Abstract

The optimal temperature is crucial for a broad range of applications, from chemical transformations, electronics, human comfort, to energy production and the whole planet. Photochemical molecular thermal energy storage systems...

Efficient and Robust Molecular Solar Thermal Fabric for Personal Thermal Management

“…This is because the π–π stacking and van der Waals interactions are disrupted by the stronger stereospecific blockade and polarity of the Z form. [ 7c,9,11,13 ] The optically controlled crystallization enables efficient energy utilization in ambient environment, even under super‐low temperature conditions.…”

“…[11] The other reagents were purchased from Sinopharm Chemical Reagent Co., Ltd. (China). 1 H and 13 C NMR spectra were obtained at 600 and 100 MHz, respectively, at room temperature using a Bruker Avance 400 MHz NMR spectrometer equipped with a z-gradient coil. Highresolution mass spectra were recorded on a Vanquish UHPLC system combined with a Q Exactive Plus mass spectrometer (Thermo Fisher Scientific).…”

Photoliquefiable Azobenzene Surfactants toward Solar Thermal Fuels that Upgrade Photon Energy Storage via Molecular Design

“…The resulted cis‐ AZO‐1 after 30 min UV light irradiation gets a much lower half‐life of 1.05 h than that in solution (Figure S8, Supporting Information), owing to the intermolecular interactions in tightly packed solid that energetically favor the formation of trans ‐azobenzene in dark. [ 42,43 ] Interestingly, the half‐life of cis ‐AZO‐2 in condensed state is kind of equal to that in solution (Figure S9, Supporting Information).…”

“…While, upon Vis light or heat stimuli, the reversible cisto-trans isomerization discharges the stored energy out as heat (∆H iso ) (Figure 1a). This leads to a closed-system with merits of photon-to-heat energy conversion in high efficiency [1] and advantage of the photoinduced solid-liquid phase change, arylazopyrazoles gain superiority in gravimetric energy density thanks to their relative low molecular weight, [16,[31][32][33] and recently via delicate design the heteroarene with selected ortho-substituents gains the light penetration depth over 1400 µm for solid samples, which provides a new type of solar thermal fuels with easy phase change property and high energy density. [34] In contrast, azobenzene compounds exhibit a contradiction between gravimetric energy density and photoinduced phase change.…”

“…As compared to the medium/high‐grade heat being harnessed to generate power from industrial process, [ 15 ] the collection of environmental low‐grade heat is way more difficult. Phase change, especially melting, would be an ideal way for storing heat energy, but with several limitations in the practical use, including: 1) energy charging (∆ H m ) and discharging (∆ H c ) normally occur at same temperature ( T m = T c ), disfavoring the energy storage; 2) controllable phase transitions at ambient condition are difficult [ 16 ] (Figure 1b). Therefore, to collect the environmental low‐grade heat, the development of phase change materials (PCMs) with controllable energy charging and discharging abilities at ambient condition becomes necessary.…”