Photothermal Conversion Effect Research Articles

In Situ Photoactivated Antibacterial and Antioxidant Composite Materials to Promote Bone Repair.

Trauma and tumor removal usually cause bone defects; in addition, the related postoperative infection also shall be carefully considered clinically. In this study, polylactic acid (PLLA) composite fibers containing Cerium oxide (CeO2) are first prepared by electrospinning technology. Then, the PLLA/CeO2@PDA/Ag composite materials are successfully prepared by reducing silver ion (Ag+) to nano-silver (AgNPs) coating in situ and binding AgNPs to the materials surface by mussel structure liked polydopamine (PDA). In the materials, Ag+ can be slowly released in simulated body fluids. Based on the photothermal performance of AgNPs, the photothermal conversion efficiency of the materials is 21%, under NIR 808nm illumination. The effective photothermal conversion can help materials fighting with E. coli and S. aureus in 3 h, with an antibacterial rate of 100%. Additionally, the sustained Ag+ release contributes to the antibacterial in long term. Meanwhile, the materials can mimic the bio-behavior of superoxide dismutase and catalase in decreasing the singlet oxygen level and removing the excess reactive oxygen species. Furthermore, the materials are beneficial for cell proliferation and osteogenic differentiation in vitro. In this study, a promising bone-regenerated material with high photothermal conversion efficiency and antibacterial and anti-oxidation properties, is successfully constructed.

A photothermal colorimetric dual-signal sensor for Staphylococcus aureus in food based on CuS nanoparticles

Staphylococcus aureus (S. aureus) is a common foodborne pathogenic organism, and rapid detection with high sensitivity and targeted killing are essential for controlling its spread. Therefore, a sandwich structure of magnetic bead-target bacteria-copper sulfide was constructed in this paper. The photothermal conversion function and peroxidase (POD) activity of CuS NPs were utilized to establish a dual sensing platform for temperature and color rendering, that is, after capturing target bacteria, light was converted to heat signal by infrared irradiation. Moreover, the specific detection of S. aureus was realized by detecting the temperature change of the complex and the oxidation of TMB by nano-enzymes of residual CuS in the supernatant to form oxTMB blue product, which formed the change of UV (ultraviolet) − Visible spectroscopy. Based on the high specificity binding and strong signal amplification of the method, the linear range of the photothermal specific probe combined with MBs-S. aureus-CuS was 10–106 CFU/mL, and the detection limit was 1.407 CFU/mL. The linear range of the color specific probe was 10–106 CFU/mL, R2 = 0.9853, and the detection limit was 1.15 CFU/mL. The photothermal efficiency of MBs-S. aureus-CuS system can reach 62.84 %, which has excellent photothermal conversion effect, and the temperature rises to about 70 °C within 7 min, which can directly kill bacteria in the detection. In addition, the portable infrared thermal imager is applied to realize the real-time field detection of S. aureus. The study was significant, because exploratory experiments were conducted to conceive a proof-of-concept based on multiple bacterial sensors that could easily be adapted to a variety of fields where bacteria pose a threat.

Photo‐Responsive TiO2‐Gold Nanoparticle‐Polymer Nanohybrid Exhibits Photothermal, Thermo‐Release, and Photocatalytic Effects

The development of multi‐responsive nanohybrid systems that combine photothermia, thermo‐responsive effects and photocatalysis is a challenging topic in the research of multifunctional materials with a large field of applications. Here, we report the first example of a three‐components light‐responsive nanosystem consisting of titania, gold nanoparticles and poly‐N‐isopropylacrylamide (TiO2‐Au‐PNM). The hybrid nanostructure exhibited photothermal conversion effect upon green‐light excitation and capacity to entrap methylene blue and curcumin selected as cargo models. The formation of the nanohybrid―cargo adducts, the photothermal‐controlled cargo release triggered by green‐light irradiation (532 nm) and mediated by lower critical solution temperature (LCST), as well as the photocatalytic effect prompted by UV‐light excitation (300 nm) were demonstrated by spectroscopic techniques. The mechanism involved in the interaction of the polymeric component with the cargos was investigated by molecular modelling calculations.

Visible light-driven self-heating photocatalytic decarboxylation of fatty acid over α-Fe2O3

Here we report a temperature-dependent strategy that achieves high-efficiency photocatalytic decarboxylation of long-chain fatty acids to Cn-1 n-alkanes, e.g., producing ∼0.5 M of n-heptadecane from stearic acid in a single operation with ∼91% selectivity, far beyond no more than mM limit capacities of conventional photocatalysis. Through the use of high boiling-point n-alkane solvents for getting the best self-heating based on the photothermal conversion effect of α-Fe2O3, i.e., high temperatures, which force the standing C-chain at low temperatures down onto the α-Fe2O3 surface for energy-storing, allowing photo-induced hole-electron pairs to readily approach and react with the more strained C-COO- bonds. And the consumption of photogenerated electrons shifts from the conventional PCET of the photo-Koble reaction into a step-wise pathway to form more favorable carbanion intermediate that reacting with H+ into RH is accelerated with lifting temperature. Our work offers a practical approach to upgrade photocatalytic decarboxylation by a convenient photo-to-heat route.

Synthesis of Prussian blue analogue nanoboxes with enhanced photothermal and catalytic performance

Recently, Prussian blue analogues (PBA) were widely studied in energy and electrochemistry field. However, the strategy of preparation for PBA nanoboxes with enhanced photothermal conversion effect is rarely discussed due to the lower absorption in near infrared region (NIR) of PBAs. Herein, a novel CuMnFe nanobox was prepared for the first time by a simple S etching method. After S etching, the as-prepared CuMnFe nanobox possessed outstanding photothermal conversion performance and amazing catalytic activity due to introduction of S element. Various optimization experiments were also performed to investigate the preparation of CuMnFe nanobox. The mechanism of the enhanced performance was also discussed. This work will pave a way to enhance the performance of PBAs and expand their application from traditional energy chemistry to the field of biomedicine.

Eight-Electron Copper Nanoclusters for Photothermal Conversion.

Owing to distinct physicochemical properties in comparison to gold and silver counterparts, atomically precise copper nanoclusters are attracting embryonic interest in material science. The introduction of copper cluster nanomaterials in more interesting fields is currently urgent and desired. Reported in this work are novel copper nanoclusters of [XCu54Cl12(tBuS)20(NO3)12] (X=S or none, tBuSH=2-methyl-2-propanethiol), which exhibit high performance in photothermal conversion. The clusters have been prepared in one pot and characterized by combinatorial techniques including ultraviolet-visible spectroscopy (UV-vis), electrospray ionization mass spectrometry (ESI-MS), and X-ray photoelectron spectroscopy (XPS). The molecular structure of the clusters, as revealed by single crystal X-ray diffraction analysis (SCXRD), shows the concentric three-shell Russian doll arrangement of X@Cu14@Cl12@Cu40. Interestingly, the [SCu54Cl12(tBuS)20(NO3)12] cluster contains 8 free valence electrons in its structure, making it the first eight-electron copper nanocluster stabilized by thiolates. More impressively, the clusters possess an effective photothermal conversion (temperature increases by 71 °C within ~50 s, λex=445 nm, 0.5 W cm-2) in a wide wavelength range (either blue or near-infrared). The photothermal conversion can be even driven under irradiation of simulated sunlight (3 sun), endowing the clusters with great potency in solar energy utilization.

Preparation and characteristic of palmitic acid/flower-shaped CuS composite phase change material for effective heat storage and photothermal conversion

Designing and synthesizing the excellent heat storage and photothermal integrated composite phase change materials (PCMs) is an effective strategy for solar energy utilization. This work focuses on two kinds of CuS (cuboidal and 3D flower-shaped) with different morphology were designed as substrates and photothermal materials, and PA/F–CuS and PA/C–CuS composite PCMs have been prepared by melt-blending and vacuum impregnation method. Through SEM and pore structure characterization as well as leakage testing, it is proved that 3D layered flower-shaped CuS not only exposes the large specific surface area and rich adsorption sites, but also 2D thin layers can perform multiple reflections to improve the utilization rate of solar energy. The flower-shaped CuS is more suitable for the supporting material. Noteworthy, the latent heat of PA/F–CuS can reach 226.3 J/g, and the thermal conductivity is 0.3447 W/(m·K). Furthermore, compared with pure PA, the photothermal property of PA/F–CuS increased by 49.22–84.59%, and the photothermal conversion efficiency can reach 70.3%. This work provides an innovative idea for the design and manufacture of composite PCMs related to medium and low temperature solar energy storage, and has broad application potential in the field of thermal energy storage such as solar energy utilization and building insulation materials.

Acceptor-donor-acceptor type organic photothermal agents with enhanced NIR absorption and photothermal conversion effect for cancer photothermal therapy

Numerous photothermal agents (PTAs) require high-intensity and long-duration laser excitation for photothermal therapy (PTT), resulting in light damage to healthy skin and tissue as well as limiting their biomedical applications. Integrating desirable near-infrared (NIR) absorption and high photothermal conversion efficiency (PCE) into a single small-molecule PTA is an important prerequisite for realizing efficient PTT, but is a serious challenge. Herein, through molecular engineering strategy, an acceptor-donor-acceptor (A-D-A) type PTA (ADA3) was readily developed for 808 nm laser-driving photothermal imaging and PTT of tumor. Theoretical calculations and experiment results show molecular engineering strategy is significant in regulating the structure and energy gap of PTAs, so as to effectively induce a narrow band gap for NIR absorption and further optimize photothermal properties. ADA3 possesses molar extinction coefficient of 3.1 × 104 M−1 cm−1 at 808 nm, followed being assembled into nanoparticles, ADA3-NPs show high PCE of 80.3%. In vivo experiments indicate that ADA3-NPs have excellent antitumor capability under one-time, low-intensity and short-duration (808 nm, 330 mW/cm2, 3 min) laser irradiation. Therefore, this work definitely exemplifies the enormous potential of molecular engineering strategy and provides an effective method for developing small-molecule PTAs.

Radical-Induced Photochromic Silver(I) Metal-Organic Frameworks: Alternative Topology, Dynamic Photoluminescence and Efficient Photothermal Conversion Modulated by Anionic Guests.

Photogenerated radicals are an indispensable member of the state-of-the-art photochromic material family, as they can effectively modulate the photoluminescence and photothermal conversion performance of radical-induced photochromic complexes. Herein, two novel radical-induced photochromic metal‒organic frameworks (MOFs), [Ag(TEPE)](AC)⋅7/4H2O⋅5/4EtOH (1) and [Ag(TEPE)](NC)⋅3H2O⋅EtOH (2), are reported. Distinctly different topological networks can be obtained by judiciously introducing alternative π-conjugated anionic guests, including a new topological structure (named as sfm) first reported in this work, describing as 4,4,4,4-c net. EPR data and UV-Vis spectra prove the radical-induced photochromic mechanism. Dynamic photochromism exhibits tunability in a wide CIE color space, with a linear segment from yellow to red for 1, while a curved coordinate line for 2, resulting in colorful emission from blue to orange. Moreover, photogenerated TEPE* radicals effectively activate the near-infrared (NIR) photothermal conversion effect of MOFs. Under 1 W cm-2 808 nm laser irradiation, the surface temperatures of photoproducts 1* and 2* can reach ~160 ℃ and ~120 ℃, respectively, with competitive NIR photothermal conversion efficiencies η = 51.8% (1*) and 36.2% (2*). This work develops a feasible electrostatic compensation strategy to accurately introduce photoactive anionic guests into MOFs to construct multifunctional radical-induced photothermal conversion materials with tunable photoluminescence behavior.

Nanoarchitectonics of Bimetallic Cu-/Co-Doped Nitrogen-Carbon Nanozyme-Functionalized Hydrogel with NIR-Responsive Phototherapy for Synergistic Mitigation of Drug-Resistant Bacterial Infections.

Superbug infections and transmission have become major challenges in the contemporary medical field. The development of novel antibacterial strategies to efficiently treat bacterial infections and conquer the problem of antimicrobial resistance (AMR) is extremely important. In this paper, a bimetallic CuCo-doped nitrogen-carbon nanozyme-functionalized hydrogel (CuCo/NC-HG) has been successfully constructed. It exhibits photoresponsive-enhanced enzymatic effects under near-infrared (NIR) irradiation (808 nm) with strong peroxidase (POD)-like and oxidase (OXD)-like activities. Upon NIR irradiation, CuCo/NC-HG possesses photodynamic activity for producing singlet oxygen(1O2), and it also has a high photothermal conversion effect, which not only facilitates the elimination of bacteria but also improves the efficiency of reactive oxygen species (ROS) production and accelerates the consumption of GSH. CuCo/NC-HG shows a lower hemolytic rate and better cytocompatibility than CuCo/NC and possesses a positive charge and macroporous skeleton for restricting negatively charged bacteria in the range of ROS destruction, strengthening the antibacterial efficiency. Comparatively, CuCo/NC and CuCo/NC-HG have stronger bactericidal ability against methicillin-resistant Staphylococcus aureus (MRSA) and ampicillin-resistant Escherichia coli (AmprE. coli) through destroying the cell membranes with a negligible occurrence of AMR. More importantly, CuCo/NC-HG plus NIR irradiation can exhibit satisfactory bactericidal performance in the absence of H2O2, avoiding the toxicity from high-concentration H2O2. In vivo evaluation has been conducted using a mouse wound infection model and histological analyses, and the results show that CuCo/NC-HG upon NIR irradiation can efficiently suppress bacterial infections and promote wound healing, without causing inflammation and tissue adhesions.

Radical‐Induced Photochromic Silver(I) Metal‐Organic Frameworks: Alternative Topology, Dynamic Photoluminescence and Efficient Photothermal Conversion Modulated by Anionic Guests

Photogenerated radicals are an indispensable member of the state‐of‐the‐art photochromic material family, as they can effectively modulate the photoluminescence and photothermal conversion performance of radical‐induced photochromic complexes. Herein, two novel radical‐induced photochromic metal‒organic frameworks (MOFs), [Ag(TEPE)](AC)⋅7/4H2O⋅5/4EtOH (1) and [Ag(TEPE)](NC)⋅3H2O⋅EtOH (2), are reported. Distinctly different topological networks can be obtained by judiciously introducing alternative π–conjugated anionic guests, including a new topological structure (named as sfm) first reported in this work, describing as 4,4,4,4‐c net. EPR data and UV‐Vis spectra prove the radical‐induced photochromic mechanism. Dynamic photochromism exhibits tunability in a wide CIE color space, with a linear segment from yellow to red for 1, while a curved coordinate line for 2, resulting in colorful emission from blue to orange. Moreover, photogenerated TEPE* radicals effectively activate the near‐infrared (NIR) photothermal conversion effect of MOFs. Under 1 W cm‐2 808 nm laser irradiation, the surface temperatures of photoproducts 1* and 2* can reach ~160 ℃ and ~120 ℃, respectively, with competitive NIR photothermal conversion efficiencies η = 51.8% (1*) and 36.2% (2*). This work develops a feasible electrostatic compensation strategy to accurately introduce photoactive anionic guests into MOFs to construct multifunctional radical‐induced photothermal conversion materials with tunable photoluminescence behavior.

NIR photoresponsive shape memory polyurethanes composite with self-healing and anti-corrosion properties

The self-healing ability of organic coatings is crucial for restoring protective functions and achieving long-lasting corrosion protection in the case of coating defects. This article prepares a shape memory-assisted self-healing polyurethane composite with the dual response of light and heat (SMPUx-Uy@CS). The shape memory performance of the material is controlled by adjusting the addition ratio of polyether glycol with different molecular weights. The introduction of reversible quadruple hydrogen bonds (UPy) further enhances the microphase separation of the system, endowing the material with excellent mechanical properties and self-healing ability. Carbon nanospheres (CS) are added to produce a photothermal conversion effect under near-infrared (NIR) irradiation. On the one hand, it can achieve precise repair, and on the other hand, it can improve corrosion resistance. When PTMG-1000:PTMG-250 = 4:1, SMPU3-U30@CS-0.5 with 30% UPy and 0.5 wt% CS has the best comprehensive performance, with a tensile strength of 8.42 MPa and an elongation at a break of 194.91%. The surface scratches of the composite coating can be healed after 60 s under 3 W/cm2 NIR irradiation. Magnesium alloy with SMPU3-U30@CS-0.5 coating has a corrosion potential of −1.34 V and corrosion current density of 5.37 × 10−9 A cm−2, and the damaged coating recovers well in corrosion resistance after 300 s of NIR irradiation. Thanks to the maze effect and hydrophobic performance, the addition of CS is beneficial for improving the anti-corrosion performance of the coating. The experimental results indicate that the repair efficiency of NIR is much higher than that of thermal repair, making it more green, environmentally friendly, and sustainable. This article provides a straightforward, green synthesis strategy for constructing self-healing coatings with efficient corrosion resistance.

Photothermal Properties and Solar Water Evaporation Performance of Lignin-Based Polyurethane Foam Composites.

Solar interfacial evaporation is the most promising route for desalination because it is highly efficient, affordable and offers green energy. Polyurethane foam (PUF) is an ideal substrate material for efficient solar water evaporation because of its low thermal conductivity, affordability, and high efficiency for continuous water transport. However, PUF exhibits poor mechanical properties after water absorption and expansion, and lacks the photothermal conversion effect. In this study, biorefinery lignin with efficient photothermal properties was introduced to prepare functional lignin-based PUF (LPUF), and the relationship between the molecular structure of fractioned lignin and the solar water evaporation performance was systematically investigated. The addition of lignin effectively enhanced the mechanical properties of LPUF after water absorption and swelling, and imparted the foam with a photothermal conversion effect. The water evaporation rate of LPUF was as high as 2.58 kg m-2 h-1 and could be further improved to more than 3.0 kg m-2 h-1 after loading polyaniline (PANI) on the surface of LPUF. LPUF-PANI exerted an excellent purification effect on dye wastewater with outstanding long-term stability, providing a potential solution for ecofriendly and sustainable economic production of fresh water. This study broadens the effective utilization of LPUF bulk materials in the fields of energy and environment.

Easy but Efficient: Facile Approach to Molecule with Theoretically Justified Donor-Acceptor Structure for Effective Photothermal Conversion and Intravenous Photothermal Therapy.

To accelerate the pace in the field of photothermal therapy (PTT), it is urged to develop easily accessible photothermal agents (PTAs) showing high photothermal conversion efficiency (PCE). As a proof-of-concept, hereby a conventional strategy is presented to prepare donor-acceptor (D-A) structured PTAs through cycloaddition-retroelectrocyclization (CA-RE) reaction, and the resultant PTAs give high PCE upon near-infrared (NIR) irradiation. By joint experimental-theoretical study, these PTAs exhibit prominent D-A structure with strong intramolecular charge transfer (ICT) characteristics and significantly twisting between D and A units which account for the high PCEs. Among them, the DMA-TCNQ exhibits the strongest absorption in NIR range as well as the highest PCE of 91.3% upon irradiation by 760-nm LED lamp (1.2W cm-2 ). In vitro and in vivo experimental results revealed that DMA-TCNQ exhibits low dark toxicity and high phototoxicity after IR irradiation along with nude mice tumor inhibition up to 81.0% through intravenous therapy. The findings demonstrate CA-RE reaction as a convenient approach to obtain twisted D-A structured PTAs for effective PTT and probably promote the progress of cancer therapies.

Highly efficient photocatalytic decarboxylation of fatty acids to alkanes enabled by photothermal conversion effect

Heating is the most straightforward means to achieve rapid, high-flux production of thermal catalytic reactions, but photocatalysis rarely uses it mainly because their intrinsic driving force depends on the photogenerated carriers separation , which has always been treated as little dependent of temperature and sometimes even with negative dependence. Here we report a temperature-dependent strategy of in-situ thermal-assisted photocatalytic decarboxylation of bioderived long-chain fatty acids into Cn–1n-alkanes over Sb2S3 photocatalyst. Under concentrated simulated sunlight illumination without external heating, this reaction system is readily self-heated to boiling (254 °C) of n-tetradecane solvent only by the photothermal conversion effect of Sb2S3. The heat from the incident light enables the standing C-chain at low temperature down onto the surface of Sb2S3 resulted in the CCOO− bonds with more strain, which makes it easier for light-induced hvb+/ecb− to approach and react with the energy-storing CCOO− bonds, thereby resulting in an increase in n-alkane single output concentrations exceeding five orders of magnitude. Our study demonstrated the vast majority of incident light energy could be harnessed in a heat form to enhance the efficiency of photocatalytic decarboxylation.

Design and application of polyurethane-polydopamine/Ag double-shell microcapsules for enhanced photothermal conversion and incremental energy storage

Solar energy is a clean and renewable source of energy. However, its intermittent nature hampers its utilization efficiency. Although phase change microcapsules store and release energy using latent heat, they rely on temperature differences, which limits their effectiveness in absorbing and utilizing solar energy as heat. This study employed a two-step method to synthesize a novel double-shell phase change microcapsule to enhance the conversion and step-by-step storage of solar energy. The double shell was constructed using polyurethane (PU) and polydopamine/silver (PDA/Ag), while octadecane and paraffin (P/O) served as the core materials. The synthesized microcapsules displayed a unique double-shell structure, and a consistent spherical shape, and demonstrated a remarkable latent heat storage capacity surpassing 150 J/g. The coating exhibited outstanding photothermal conversion performance, attributed to the synergistic photothermal conversion effect of PDA and Ag in the first shell. The gradual energy transfer within microcapsules was achieved by integrating polyethylene glycol into the PU layer and utilizing two different PCMs as the core materials. Furthermore, the antimicrobial of the treated textiles against S. aureus and E. coli were 99.99% and 99.56%, respectively. The double-layer design of the P/O@PU@PDA/AgNPs provides leakproofness and shape stability, making them ideal for photothermal energy storage applications.

Synergistic quorum sensing inhibition and mild-temperature photothermal therapy of integrated nanoplatform for implant-associated biofilm infections

In current clinical practice, the presence of biofilms poses a significant challenge in the effective elimination of bacterial infections because of the physical and chemical barriers formed by biofilms, which offer persistent protection to bacteria. Here, we developed hollow mesoporous polydopamine (hMP) nanoparticles (NPs) loaded with luteolin (Lu) as a quorum sensing inhibitor, which were further coated with hyaluronic acid (HA) shells to create hMP-Lu@HA NPs. We observed that upon reaching the infection site, the HA shells underwent initial degradation by the hyaluronidase enzyme present in the bacterial infection's microenvironment to expose the hMP-Lu NPs. Subsequently, Lu was released in response to the acidic conditions characteristic of bacterial infections, which effectively hindered and dispersed the biofilm. Moreover, when subjected to near-infrared irradiation, the robust photothermal conversion effect of hMP NPs accelerated the release of Lu and disrupted the integrity of the biofilms by localized heating. This dual action enhanced the eradication of the biofilm infection. Importantly, hMP-Lu@HA NPs also promoted tissue regeneration and healing at the implantation site, concurrently addressing biofilm infection. Taken together, this nanosystem, combined with mild-temperature photothermal therapy and quorum sensing inhibition strategy, holds significant potential for applications in the treatment of implantation-associated infections.

Heat transfer behavior of graphene-based photothermal conversion materials prepared with tube array-porous network composite structure

In order to solve the problems of low energy utilization and poor structural stability of photothermal conversion materials, a graphene-based photothermal conversion material was prepared, which was structurally integrated with a light-absorbing upper layer and a heat insulating base. During the preparation process, a tightly arranged nanotube array upper layer was constructed on the basis of graphene films by microimprinting technology, and a porous aerogel base was molded by a fixed-point titration and multiple-foaming method. The results show that the light trap constructed from graphene hollow nanotubes can significantly increase the number of light reflections and reduce light reflectivity. Meanwhile, the length of the nanotubes is directly proportional to the light-absorbing capacity of the material, which can increase the light-absorbing rate to more than 98% under the embossing conditions of 85 kN and 8h. In addition, the porous aerogel insulation base can effectively improve the photothermal conversion effect, and a photothermal conversion efficiency of 87% and a water evaporation rate of 1.3 kg/(m2 h) can be achieved at a base thickness of 6 mm.

A facile strategy for improving the hydrophobicity and photo-thermal conversion capability of biochar and its application in the absorption of hazardous chemicals and viscous oil

Biochar is considered as a promising adsorbent due to its unique porous structure, large surface area and lightweight nature. In this study, pomelo peel was used as raw material, and graphene oxide was introduced as a functional material. High-temperature carbonization was employed to achieve simultaneous carbonization of pomelo peel and thermal reduction of graphene oxide, resulting in the preparation of a porous sponge-like biochar with high hydrophobicity, thermal stability and photothermal conversion capability. This biochar was successfully applied to the efficient separation of various oil–water mixtures, demonstrating excellent cyclic adsorption stability. Furthermore, by harnessing its photothermal conversion effect, efficient absorption of viscous oil product was achieved. This study proposes a facile biochar preparation strategy that can expand its application in the field of oil spill emergency treatment and promote the utilization of agricultural waste.

Robust superhydrophobic coating with carbon nanotubes and silica nanoparticles in the matrix of fluorinated polyurethane

After years of research, superhydrophobic coatings have made great progress, but the complex preparation process and poor durability are still key issues that limit their practical application. Herein, we developed a room temperature cured durable superhydrophobic coating through a simple spraying method. The main polymer matrix used in this study was fluorinated polyurethane (FPU), which exhibited high hardness (5H), strong adhesion to the substrate (grade 1, GB/T 9286), and excellent hydrophobicity with a contact angle of approx. 108 ° Silica nanoparticles were found to be highly effective in enhancing the surface hydrophobicity of FPU. Nevertheless, these particles can be easily removed from the surface by even a simple touch with a finger. For enhanced durability, we incorporated carbon nanotubes (CNTs) with intertwining structures. Additionally, polydimethylsiloxane (PDMS) was utilized to facilitate the interaction between the inorganic fillers and the organic FPU matrix, owing to its inorganic Si-O skeleton and organic side chains. The so-optimised composite coating was covered with micro-/nano- particles and the hydrophobicity was enhanced greatly (contact angle of ∼165 ° and sliding angle of 5.5 °). The contact angle of the coating remained higher than 150 ° even after undergoing a range of tests. These tests included immersing in corrosive solutions for 60 h, gravel impacting for 100 cycles, water jetting for 1200 s, and abrading against sandpaper for 1000 cycles. The good chemical and mechanical durability was due to the high compactness, high hardness (4H pencil hardness), and high adherence (grade 1, GB/T 9286) of the coating. Moreover, due to the photothermal conversion effect of carbon nanotubes, the coating possessed excellent photothermal performance and showed good application prospects in anti icing / deicing.