To address the surface icing problems of wind turbine blades and power transmission lines, a renewable flexible photothermal-electrothermal superhydrophobic coating was developed using spraying methods. Firstly, durable flexible sandpaper was employed as the micro-scale rough layer. Secondly, a silicone-based adhesive was used to fix the electrothermal layer between the micro-scale rough layer and a flexible silicone substrate. Finally, a photothermal superhydrophobic material was sprayed to complete the coating preparation. The results show that the coating had a contact angle of 152.78° and a sliding angle of 2.03°, with a light absorption rate as high as 96.6%. At a light intensity of 1 kW/m2, the coating surface temperature rises to 70.1 ℃ within 750 s, and a 3.0 mm thick ice layer is completely removed within 1 577 s. At an applied voltage of 6 V, the equilibrium temperature of the coating reaches 76.6 ℃, achieving complete removal of the 3.0 mm thick ice layer in 678 s. The coating demonstrates excellent stability, deformation resistance, and renewability. It can effectively inhibit surface icing and reduce ice accumulation, providing technical support for anti-icing and deicing applications in power systems.

Solar desalination has been extensively researched as a promising way to address freshwater shortages. However, developing a salt resistant solar evaporator that can be easily extended and manufactured is still a challenge in practical applications. In this work, a 3D hydrogel-based salt resistant self-floating solar-driven interfacial evaporator with efficient water-lifting capacity was proposed using the prepared hydrogel with carbon black (CB) nanoparticles and extruded polystyrene (XPS) board as raw materials. The experimental results implied that the developed evaporator had the highest evaporation rate and evaporation efficiency at 0.05 g CB loading, which were 1.70 kg m- 2h- 1 and 92.8 % at a light intensity of 1 kW m- 2. Moreover, the evaporator also displayed prominent salt resistance in the evaporation of brine with high salinity and outstanding stability after 10 cycles. Significantly, the outdoor experiment demonstrated that 1 m2 evaporator can generate 5923.5 g freshwater per day, which was enough to meet the daily requirement of two adults for drinking water. In addition, the physical fields of the hydrogel with CB nanoparticles of the evaporator at evaporation equilibrium were simulated to analyze its long-term and high-performance operation capability. All in all, the 3D hydrogel-based salt resistant self-floating solar-driven interfacial evaporator with efficient water-lifting capacity presented an enormous application prospect in the field of solar desalination.

Flow visualization is essential for a comprehensive understanding of complex fluid dynamics. Planar laserinduced fluorescence (PLIF) has emerged as one of the most promising techniques for multi-dimensional imaging acquisition, offering high spatial and temporal resolutions. However, PLIF images frequently suffer from impulse and speckle noise under low-density, low-pressure conditions, thereby affecting the quality of visualization. This study proposes a novel hybrid algorithm that integrates order-statistic and non-local means filters with residue feedback. The algorithm enhances image quality and eliminates noise effectively by incorporating recursive processes guided by the structural similarity index (SSIM) and anisotropic diffusion. The efficacy of the method is confirmed through evaluation using peak signal-to-noise ratio (PSNR) and SSIM on images with varying noise levels. The algorithm demonstrates computational efficiency and shows promise for denoising PLIF images.

Globally, billions of people are suffering from freshwater shortage, which has been exacerbated by heavy metal pollution. Therefore, variable removal strategies are proposed to handle this problem. However, these methods are usually accompanied by high cost, unsatisfied efficiency and environmental unfriendliness. In this work, the lactic acid bacteria (LAB) as a kind of probiotic were employed to adsorb Cu2+, and the produced copper-bearing bacterial sludge after biosorption was calcined to prepare C-CuxO composite as a photothermal conversion material. Moreover, a solar evaporator was developed by incorporating C-CuxO composite, where an extruded polystyrene foam was used as heat insolation layer and an aerogel was utilized as evaporation layer. The developed solar evaporator with C-CuxO composite had a high light absorbance of 94.2 %, low thermal conductivity of 0.031 W m-1 K-1 and good hydrophilicity, whose evaporation rate and evaporation efficiency reached up to 1.65 kg m -2h- 1 and 87.7 %, respectively. Besides, it also possessed good salt-tolerance, stability and desalination properties, as well as the water desalted by it achieved the standard of drinking water from the World Health Organization (WHO). Consequently, preparing C-CuxO composite from biosorption product of LAB is viable, and the solar evaporator with C-CuxO composite possessed spacious application prospect in heavy metal control, solar thermal utilization and desalination.

Superhydrophobic material with photothermal conversion property is considered as a promising candidate in practical application because of its double abilities: both superhydrophobic anti-icing and photothermal deicing. Therefore, in this work, we employed a polyurethane (PU) foam with three-dimensional porous grid structure as the skeleton and carbon nanotubes (CNTs) as the photothermal conversion materials to construct a hierarchical coating with photothermal superhydrophobic property by spraying CNTs/SiO2 and modification of polydimethylsiloxane (PDMS), where a dual-size micro/nano structure was formed by adsorbing and fixing these CNTs-entangled SiO2 nanoparticles into PU foam to enhance the superhydrophobicity and light absorption capacity of coating. In this case, the water contact angle of the hierarchical coating reached up to 157.0 degrees, accompanied by a rolling angle of 3.2 degrees, while the water droplet hitting its wall can fully rebound within 27 ms. Importantly, the formation of hierarchical structure and the incorporation of CNTs contributed to an enhancement of light absorbance to 97.1 %, which was able to warm the coating surface up to 101.9 degrees C at 1 kW m- 2 after 300 s illumination. Noteworthily, the surface temperature of the coating can be raised to 62.5 degrees C within 15 min to achieve deicing under a low ambient temperature of-20 degrees C. In addition, a remarkable stability and wear resistance were maintained after 10 freeze-thaw cycles and 20 friction cycles. Consequently, it can be concluded that the developed hierarchical coating with exceptional superhydrophobicity and excellent photothermal conversion performance was expected to be a potential substitute for anti-icing and deicing.

The flow phenomenon of liquid with bubbles is widespread in various industrial fields, which determines the mass transfer characteristics of the equipment. In this work, the dynamic behaviour of bubbles emerging from micro-capillary orifice in a flow channel was studied by a visualization experiment, while the effects of gas flow rate and liquid flow rate on these processes of bubble growth, departure, and inrush were explored. The experimental results showed that one bubble formation cycle can be divided into three stages: Waiting, departure, and inrush, as well as the dynamic behaviour of bubble emerging from micro-capillary orifice in a flow channel, were significantly affected by gas flow rate and liquid flow rate. At a higher gas flow rate, the growth time and the departure time were shorter, as well as the departure volume of the leading bubble and the inrush volume of the trailing bubble were smaller, while the transverse longitudinal ratio fluctuated more violently, and the swing amplitude of the bubble centroid was greater. With an increasing liquid flow rate, the growth time, the departure time, and the inrush time shortened, while the departure volume of the leading bubble decreased and the fluctuation of the bubble centroid weakened. These findings are conducive to improving the performance of the equipment by optimizing the design of the aerator to regulate the dynamic behaviour of bubbles.

Thermal storage technology based on phase change material (PCM) holds significant potential for temperature regulation and energy storage application. However, solid–liquid PCMs are often limited by leakage issues during phase changes and are not sufficiently functional to meet the demands of diverse applications. Fortunately, it has been recognized that many polymer materials can effectively address these problems in the field of phase-change energy storage. These polymers exhibit exceptional performances and provide versatile options for energy storage applications. Due to the wide range of available polymers, different structures and properties are be utilized in various ways for energy storage purposes. This review focuses on three key aspects of polymer utilization in phase change energy storage: (1) Polymers as direct thermal storage materials, serving as PCMs themselves; (2) strategies for the development of shape-stable PCMs based on polymers, including vacuum impregnation, direct blending, chemical grafting, electrospinning, microencapsulation, and the homogeneous-to-heterogeneous-strategy; and (3) polymer-enhanced multifunctional PCMs, which can exhibit additional properties such as flexibility, hydrophobicity, and photo-thermal conversion. The objective of this review is to expand the application of polymers in the field of phase change energy storage and to provide more research ideas for the development of novel, high-performance multifunctional shape-stable PCMs with excellent performances.

Superhydrophobic material is widely utilized as one of excellent candidates for anti-icing. Unfortunately, the undesirable mechanical property and unprecise preparation method have significantly hindered its further application. In this work, a flexible superhydrophobic microarray was developed using photolithography technology, where its maximal water contact angle reached 151.1 & PLUSMN; 0.9 by optimizing its microcolumn spacing and height. Moreover, carbon black nanoparticles were introduced into the flexible superhydrophobic microarray to endow it with outstanding photothermal conversion performance. As a result, when the flexible photothermal superhydrophobic microarray was used in the fields of anti-icing and deicing, the time for a water droplet on it to be completely frozen was delayed by 87 %, as well as it took 43.1 % and 28.5 % less time for an ice pellet and an ice sheet on it to be removed, respectively. In addition, the flexible photothermal superhydrophobic microarray was in possession of prominent stability. In conclusion, by the combination of passive anti-icing and active deicing, this work presented a novel way to broaden the application of photolithography technology and provided a competent candidate for anti-icing and deicing.

Solar desalination has been extensively investigated as a promising candidate for solving freshwater shortage but developing an expandable evaporator with excellent salt resistance and evaporation performance is still a challenge in practical application. In this work, inspired by the color effect between abandoned tea and rusty iron nails, a ferric tannate/gallate with full-spectrum absorption and low cost characteristics was prepared as a high-performance photothermal conversion material and further employed to develop an expandable ferric tannate/ gallate polyurethane sponge evaporator for efficient solar desalination accompanied by outstanding salt resis-tance in NaCl solution with high salinity. The results showed that the developed evaporator had an evaporation rate of 1.76 kg m- 2 h-1 with a corresponding evaporation efficiency of 89.7 % at 1 kW m- 2 illumination. Moreover, this evaporator possessed splendid recyclability and superior salt tolerance in 20 wt% NaCl solution due to its hydrophilicity and sufficient transport channels for salt and water. It was also proved by outdoor experiment that the system with 1 m2 evaporator was able to provide more than 7.5 kg freshwater per day for satisfying individual daily survival demand. This work demonstrated that an easy-to-implement and practical expandable ferric tannate/gallate polyurethane sponge evaporator exhibited enormous potential in the field of solar desalination.

Microalgae-based nutrients recovery from liquid anaerobic digestate of swine manure has been a hotspot in recent decades. Nevertheless, in consideration of the high NH4+-N content and poor light penetrability exhibited by the original liquid digestate, uneconomical pretreatment on liquid digestate including centrifugation and dilution are indispensable before microalgae cells inoculation. Herein, aiming at eliminating the energy-intensive and freshwater-consuming pretreatment on liquid digestate and enhancing microalgae growth, the dialysis bag which permits nutrients transferring across its wall surface whereas retains almost all matters characterized by impeding light transmission within the raw liquid digestate was integrated into a column photobioreactor (DB-PBR). Consequently, light availability of microalgae cells in DB-PBR was elevated remarkably and thus contributed to a 357.58% improvement on microalgae biomass concentration in DB-PBR than the conventional PBR under 80 mu mol m (2) s (1). Likewise, superior nutrients removal efficiencies from liquid digestate were obtained in DB-PBR (NH4+-N: 74.84%, TP: 63.75%) over the conventional PBR (NH4+-N: 30.27%, TP: 16.86%). Furthermore, higher microalgae biomass concentration (1.87 g L-1) and nutrients removal efficiencies (NH4+-N: 95.12%, TP: 76.87%) were achieved in the DB-PBR by increasing the light intensity to 140 mu mol m(-2) s(.)(-1) More importantly, the DB-PBR may provide a simple and greener solution to purify other kinds of wastewater.

Solar water evaporation is universally considered as an effective method to alleviate the freshwater shortage worldwide. A series of three-dimensional, salt-resistant evaporators have been brought out to improve the evaporation performance. However, little attention was paid to the collection of salt from seawater and high salinity brine. In this work, a carbon black polyvinyl alcohol (PVA) sponge was prepared to harvest light using a physical adsorption method to load carbon black on the PVA sponge. The experimental results showed that optimal light absorption (97.8%) and evaporation rate (1.60 kg m-2 h-1) were achieved when the carbon black PVA sponge was produced at a carbon black concentration of 1 g L-1. Moreover, we stacked PVA sponges beneath the carbon black PVA sponge to construct a non-photothermal evaporation area. It was seen that the evaporator with an eight-layer PVA sponge had an excellent evaporation rate as high as 2.35 kg m-2 h-1. In addition, the salt-collecting paper, all-black printed by a laser printer, was inserted between the stacked PVA sponges for salt collection, and the eight-layer PVA sponge evaporator with the salt-collecting paper at the fourth floor was tested in a 2 h desalination experiment. The outcome indicated that a square meter of this evaporator can produce about 7.03 L of freshwater and 206 g of salt per day from 10 wt % NaCl solution. As a result, the solar evaporator developed in this work is capable of collecting salt and maintaining a high evaporation rate, which is of great competence in the fields of freshwater production and salt collection.

The global printed circuit board (PCB) industry produces millions of tons of wastewater containing Cu2+ every year, which exacerbates the shortage of freshwater. As one of low cost, eco-friendly and effective materials, the chitosan-based adsorbent has been widely used for the disposition of PCB industrial sewage. Unfortunately, little attention is paid to the reutilization of waste adsorbent. In this work, we synthesized a carbon-based material containing copper oxide (CMCC) by calcining a chitosan porous adsorption material (CPAM) with Cu2+ as the after-use adsorbent. Then, by loading the CMCC as the photothermal conversion material, a flexible porous cellulose polyacrylamide hydrogel (PCPH) was fabricated, whose light absorbance was 97.4%. Moreover, the PCPH achieved a prominent evaporation rate of 1.80 kg m(-2) h(-1) under the light intensity of 1.0 kW m(-2). In addition, the PCPH possessed superb stability and the desalinated seawater successfully reached the criterion of drinking water from the World Health Organization (WHO). The results revealed that the PCPH with CMCC for solar water evaporation is a possible solution to the reuse of waste adsorbent from PCB industry and the competent remission of freshwater shortage.

With an increasingly prominent lack of clean water resources, solar water evaporation as a convenient desalination technique has been favored in arid areas, but the serious pollution of offshore oil put forward the higher requirements to desalinate seawater polluted by oil. In this work, a modified composite structure (MCS) with photothermal conversion and water-oil separation properties was developed by modifying polyurethane sponges (PUS) with different hydrophobicity, where its evaporation structure (ES) had excellent light absorbing ability (spectral absorption of 98.1%) and underwater super-oleophobicity (underwater oil contact angel of 151.7 degrees) by loading carbon black (CB) and hydrophilic modification, as well as its oil-absorption structure (OS) can absorb 1 mL oil within 10 s for achieving water-oil separation through hydrophobic modification. The experimental results revealed that the evaporation rate of the evaporator with the MCS reached 2.03 kg m(-2) h(-1) under 1 sun when its height exposed to air was 3 cm. Consequently, the MCS possessed highly efficient evaporation performance and can effectively desalinate seawater polluted by oil to prevent secondary pollution caused by oil evaporation, which had good practical value and promotion prospects in seawater desalination.

Superhydrophobic material is widely accepted as an excellent candidate for anti-icing application. Unfortunately, the undesirable mechanical property and unprecise preparation method have greatly hindered its further development. In this work, a flexible superhydrophobic microarray was designed and prepared using photolithography, where its maximal water contact angle (WCA) reached 151.1±0.9° by the optimization of its column spacing and height. Besides, carbon black particles were added to endow the flexible superhydrophobic microarray with outstanding photothermal conversion performance. As a result, when the flexible photothermal superhydrophobic microarray was used in the fields of anti-icing and deicing, the time for a water droplet to be completely frozen was delayed by 87%, and it took 43.1% and 28.5% less time for an ice pellet and an ice sheet to be removed, respectively. Moreover, the flexible photothermal superhydrophobic microarray was in possession of prominent stability. In combination of passive anti-icing and active deicing, this work presented a novel way to broaden the application of photolithography and provided a competent candidate in anti-icing and deicing fields.

本文以藻液作为连续相,空气作为分散相,采用对称与非对称两种结构的T型微通道,对其内部气泡的破裂行为进行可视化研究,探求了不同结构下微通道内气泡在藻液中的破裂行为及其变化规律.实验结果表明:在对称T型微通道内,气泡在藻液中的运动行为可分为两种,即完全阻塞破裂和不破裂;在对称T型微通道内,气泡的破裂周期主要受气液流量的影响,而在非对称T型微通道内,破裂后生成子气泡的体积分配比主要受母气泡长度和藻液流量的影响.

In this work, we in situ synthesized C-CuO composite by a facile solid phase grinding for efficient photo-thermal conversion. Moreover, surface morphology, hydrophilicity property, light absorption characteristic, and evaporation performance were investigated on C-CuO membrane. It can be seen that C-CuO composite was well dispersed on the membrane, prompting light harvesting and intentionally encouraging water evaporation. The surface hydrophilicity assisted valid water flow by the membrane toward the heat localization zone and smooth steam escape. At a calcination temperature of 250 degrees C and a mass ratio of 1:1 regarding the preparation of C-CuO composite, surface temperature of C-CuO membrane reached to the maximum value around 87.4 degrees C, noticeably stimulating the conversion of water to vapor. Further, the evaporation system with 0.015 g C-CuO composite loading possessed top-quality evaporation performance with superior recyclability, which mirrored to 92.6% evaporation efficiency and 1.34 kg m(-2) hours(-1) evaporation rate after 30 minutes exposure to light, respectively. Our work suggested that in situ synthesized C-CuO composite was regarded as a potential alternative for clean water production by solar-driven interfacial evaporation.

In recent years, solar steam generation technology has received widespread attention in seawater desalination, but existence of some problems, namely difficulty in salt cleaning and high expense, limited it further development. Herein, in this work, a carbon black gauze membrane (CBGM), with low cost and easy to clean properties, was developed by stacking macroporous membrane to construct 3D optical absorption holes, which were favorable to an enhancement of light absorption. The 4-layer CBGM evaporation device displayed an improved solar steam generation performance, which was corresponded to the evaporation rate of 1.60 kg m(-2)h(-1) and the evaporation efficiency of 96.0% under 1 kW m(-2), respectively. Likewise, the 4-layer CBGM evaporation device exhibited superior recyclability, long life and excellent desalination performance, as well as was able to effectively produce potable freshwater from seawater. Consequently, the CBGM was regarded as a promising alternative for high efficiency solar-driven seawater desalination. (c) 2020 Elsevier Ltd. All rights reserved. Superscript/Subscript Available

High-efficiency photo-thermal conversion is an attractive approach for solar thermal energy to alleviate energy crisis. In this work, MWCNT-H2O nanofluids were prepared and its photo-thermal conversion properties were characterized. Moreover, an optical fiber as internal light source was introduced into direct absorption solar collector (DASC), in which the photo-thermal conversion performance of the stored MWCNT-H2O nanofluids was systematically explored. The experimental results showed that the photo-thermal conversion performance of MWCNT-H2O nanofluids was improved by introducing optical fiber as internal light source into the DASC and a maximum photo-thermal conversion efficiency of 65.4% was acquired at the MWCNTs concentration of 0.010 wt % and the optical fiber location of 15 mm. This study indicated that the MWCNT-H2O nanofluids applied in the DASC with optical fiber was a potential candidate for solar thermal energy.

The development of high-efficient working fluids with excellent photo-thermal conversion and heat storage properties is an important factor to solar thermal utilization. In this work, magnetic phase change microcapsules (MPCMs) were prepared via in situ polymerization, where melamine-formaldehyde (MF) resin and octadecane containing oleic acid-coated magnetic nanoparticles (OA-MNs) were used as the shell and core, respectively. The microstructure, magnetic and thermal properties of MPCMs were investigated, and the photo-thermal conversion and heat storage properties of slurries prepared by dispersing MPCMs into multi-walled carbon nanotubes (MWCNTs) nanofluids were explored. The encapsulation efficiency of MPCMs with superparamagnetic nature achieved 63.51%, while the thermal conductivity of MPCMs was slightly increased with regard to phase change microcapsules (PCMs) and the thermal stability of octadecane was enhanced after being encapsulated. Moreover, the slurry with 0.01 wt% MWCNTs and 15 wt% MPCMs had the optimal photo-thermal conversion properties and thermal storage capacity. Beyond that, the recycled MPCMs represented excellent recyclability. Our research demonstrated that the MWCNTs-dispersed MPCMs slurry is one of ideal working fluids with excellent photo-thermal conversion and heat storage characteristics for direct absorption solar collector.

A highly efficient knitting aryl network polymers (KAPs)-embedded copper foam (CF)-based thermal energy storage material was synthesized by using PPh3 and benzene as monomers via a biomimetic synthesis protocol.