Bioinspired Temperature Regulation in Interfacial Evaporation

Abstract

Human skin shows self‐adaptive temperature regulation through both enhanced heat dissipation in high temperature environments and depressed heat dissipation in cold environments. Inspired by such thermal regulation processes, an interfacial material system with self‐adaptive temperature regulation in the solar‐driven interfacial evaporation system, which can exhibit automatic temperature oscillation to enable pyroelectricity generation while producing water vapor, is reported. The bioinspired interface system is designed with the combination of a thermochromism‐based temperature regulator consisting of tungsten‐doped vanadium dioxide nanoparticles and a polymeric pyroelectric thin film of polyvinylidene fluoride. Under the simulated solar illumination with power density of 1.1 kW m−2, the bioinspired interfacial evaporation system achieves a self‐adaptive temperature oscillation with the maximum temperature difference of ≈7 °C and this system can simultaneously generate water vapor as well as electricity with an evaporation efficiency of 71.43% and a maximum output electrical power density of 104 µW m−2, respectively. The study demonstrates a design of thermal management at the interface of solar‐driven evaporation system to exhibit a self‐adaptive temperature oscillation and offers an alternative approach for the multifunctional harvesting of solar energy.

Advances in Solar‐Driven Hygroscopic Water Harvesting

“…Based on these characteristics, the sequential solar‐driven hygroscopic water harvesting technology based on the interfacial heating is expected to be used for freshwater production, particularly for areas that lack direct access to clean water. Additionally, due to the high photothermal conversion efficiency, interfacial heating is promising to be widely used in other fields, such as solar desalination, [ 101,108,124,138–144 ] wastewater treatment, [ 66,76,98,99,104,112,113,116,118,122,145–152 ] high‐salinity brine treatment, [ 153 ] power generation, [ 154–156 ] synergistic solar electricity‐water generation, [ 157 ] etc.…”

Hydrophilic 3D Interconnected Network of Bacterial Nanocellulose/Black Titania Photothermal Foams as an Efficient Interfacial Solar Evaporator

“…The mass difference with and without BNC/BT PTFs under ∼1000 W m –2 was assessed, and the rate per unit area was calculated for each sample. The power required for the evaporation of water ( Q e ) was measured using eq where m is the mass of evaporated water per unit area, t is the time, and h LV is the enthalpy of vaporization of water from a hydrogel system, obtained directly from a differential scanning calorimetry (DSC) thermogram of the corresponding hydrogel sample, , acquired on a PerkinElmer DSC 8000 instrument at a heating rate of 10 °C min –1 under a nitrogen flow.…”

“…Effective thermal management by reducing the radiation and convection loss to the atmosphere as well as the downward conduction loss to the bulk water is the central research goal in the fabrication of an efficacious solar vapor generator for the maximum utilization of solar energy. , Consequently, diverse designs were proposed, including three-dimensional morphologies capable of recycling the incident radiation within the porous blackbody channels, ,, use of thermal insulating materials to prevent the downward conduction loss, etc. Generally, most of the nanoenabled photothermal materials often require a lightweight support like polymers to make them porous, flexible, floatable, and/or easily moldable. , Furthermore, bringing down the energy demand for water evaporation by virtue of a water–polymer interaction in polymeric hydrogels containing hydrophilic functional groups is another modernistic and revolutionary approach to achieve augmented evaporation rate. − Thus, hydrophilic polymers like poly­(vinyl alcohol) (PVA), chitosan, etc., were already proven to have the potential to outperform most conventional hydrophobic polymers like poly­(vinylidene fluoride) (PVDF), ,,, polystyrene (PS), polypyrrole (PPy), polyurethane (PU), etc. Zhao and co-workers reasoned the reduction in water evaporation enthalpy by water activation through the formation of intermediate water by a water–polymer (PVA) interaction. , …”

Self-Healing Hydrophilic Porous Photothermal Membranes for Durable and Highly Efficient Solar-Driven Interfacial Water Evaporation

“…4 Recently, solar-driven interfacial water evaporation, which minimizes thermal dissipation and applies most of the heat to the liquid-vapor phase transition by concentrating heat at the water-air interface, has been developed to improve the evaporation efficiency of water. [5][6][7][8][9][10][11][12][13][14][15][16][17] Generally, most of the reported solar-driven interfacial evaporators comprise three parts [18][19] (Scheme 1a1): 1) a photothermal layer with broadband light absorption and high photothermal conversion, 2) a floatable supporting layer with a low thermal conductivity, and 3) a hydrophilic water channel either on the outside or in the middle of the supporting layer that ensures a continuous water supply to the photothermal layer. Although many highefficiency solar-driven interfacial evaporators have been developed, in practical applications, the photothermal layer or water channel can be damaged by scratching or corrosion, thereby deteriorating the water evaporation efficiency (Scheme 1a2).…”