Excellent Photothermal Performance Research Articles

FeOOH Quantum Dots Assembled MXene-Decorated 3D Photothermal Evaporator for Synergy Application in Solar Evaporation and Fenton Degradation.

Solar-driven water evaporation is considered as the sustainable approach to alleviate freshwater resource crisis through direct use of solar energy. However, it is still challenging to achieve the multifunctional solar evaporators equipped with both high evaporation and purification performance to handle practical complex wastewater. Here, a simple and cost-effective multifunctional 3D solar evaporator is prepared by alternately decorating the commercial sponge with FeOOH quantum dots (FQDs) supported MXene sheets composites and chitosan hydrogel coatings for enabling the solar water evaporation and organic wastewater photodegradation simultaneously. MXene composites allow the solar evaporator with excellent photothermal conversion performance, the hydrophilic chitosan hydrogel coated interconnecting skeleton structures of sponge serve as the mass transfer and water transport channels. The Fenton-catalytic FQDs anchored on the MXene sheets surface accept the photo-generated electrons of MXene sheets to induce the organic pollutant photo-Fenton degradation reaction under sunlight irradiation. The resulting evaporator possesses both excellent water evaporation rate of 2.54kg m-2h-1 and high degradation efficiency (99.24% for methylene blue), coupled with durable salt-resisting performance during long-term seawater desalination (20 wt.% NaCl). This work provides a simple and feasible strategy for designing multifunctional solar evaporators to meet the potential application scenarios in practice.

Superhydrophobic, Multifunctional, and Mechanically Durable Carbon Aerogel Composites for High-Performance Underwater Piezoresistive Sensing.

Carbon aerogel piezoresistive sensors (CAPSs), owing to their good thermal stability, self-constructed conductive network, and fast response to pressure, have attracted extensive attention in the field of flexible and wearable electronics in recent years. However, it is still a great challenge for CAPSs to monitor subtle deformations and achieve high-performance underwater piezoresistive sensing. Herein, a superhydrophobic and electrically conductive carbon aerogel composite (CAC) was fabricated by the combination of fluorination of carbon aerogels and decoration of fluorinated halloysite nanotubes (HNTs). Due to the exceptional light absorption and excellent photothermal conversion performance, CAC has a fast and accurate response to temperature with a high-temperature coefficient of resistance (TCR) of -1.06%/°C. The resistance of CAC exhibits a linear response toward compressive strain up to 80% with a high gauge factor of -1.24. Significantly, the CAC sensor can effectively detect tiny deformations, thanks to its excellent waterproof performance, and it enables stable output of sensing signals in an underwater environment. This work provides new insights into the development of superhydrophobic, multifunctional, and mechanically durable piezoresistive sensors with potential applications in underwater flexible electronics.

Planar Chiral Charge-Transfer Cyclophanes: Convenient Synthesis, Circularly Polarized Light-Responsive Photothermal Conversion and Supramolecular Chiral Assembly.

We report herein a series of macrocycles in which the densely π-stacked charge-transfer (CT) donor/acceptor with naphthalenediimides (NDIs) or perylene diimide (PDI) as acceptor moiety pairing various donor moieties are locked by covalent bond. The X-ray crystallography of C8BDT-NDI reveals a short intramolecular π-stacking distance around 3.4 Å and the existence of intermolecular donor/acceptor π-stacking (3.7 Å). The intramolecular CT is highly dependent on the electron-donating ability of donor moiety and replacing carbazole (C8KZ) with benzo[1,2-b:4,5-b']dithiophene (C8BDT) or dihydroindolo[3,2-b]indole (C8DN) redshift CT absorption into NIR region. Notably, both C8BDT-NDI and C8DN-NDI demonstrate excellent photothermal performance, which is a result of the active non-radiative pathways. Interestingly, the different molecular symmetry between donor and acceptor moiety in cyclophanes endow C8BDT-NDI and C8DN-NDI with intrinsic planar chirality. The enantiomeric C8BDT-NDI shows chiral selectivity for incident light, i.e., when irradiated by left-circularly polarized light, (R)-C8BDT-NDI is more sensitive and a higher maximum stable temperature is achieved. While, enantiomeric C8DN-NDI pack with different orientations forming M- and P-handedness helix, respectively, demonstrating molecular planar chirality being transferred and amplified through molecular assembly. These results provide insight into the intramolecular charge transfer in enforced D/A π-stacks in which CT interactions and planar chirality would be engineered through structural control.

Synergistic Antimicrobial Packaging Film with Photothermal-Controlled Biocatalytic Capability for Tangerine Preservation

The nanomaterials-functionalized composite packaging film with antimicrobial performance has attracted more and more research interests. However, designing the multi-mode synergistic composite film for efficient and intelligent antibacterial is still a challenge. In this work, a Fe-MoOx functionalized chitosan composite film (CS/FM) was designed by doping the Fe-MoOx into chitosan film. CS/FM film inherited excellent photothermal performance and photothermal-enhanced oxidase-like activity of Fe-MoOx, which endow CS/FM film with superior antimicrobial ability. The optimal composite film (CS/FM0.2) able to killed ≥98.87% of S. aureus and ≥98.26% of E. coli, and could significantly inhibit the growth of P. expansum and P. italicum. Besides, CS/FM0.2 film also showed good water vapor permeability (0.71 × 10−10 g m−1 s−1 Pa−1) and tensile strength (58.16 MPa). Low hemolysis rate (≤ 4.91%), high cell viability (≥ 90.32%), and the normal body organs after being treated with Fe-MoOx verified the biosafety of CS/FM film. The tangerine preservation results indicated that CS/FM0.2 film could extend the shelf life of tangerine by at least 9 days and prevent the loss of tangerine nutrients. Our work boosted the development of designing composite packaging film with multi-mode synergistic antimicrobial effect via nanomaterials functionalized for food preservation.

Study on the preparation of photothermal catalyst for toluene degradation from spent batteries

This work produced a novel photothermal catalyst TiO2-CeO2@S-AZMB for toluene degradation, based on waste zinc-manganese batteries. Using a direct ball milling technique, the catalyst was created by mixing nanoscale TiO2 and CeO2 with active metals extracted from wasted batteries. The catalyst demonstrated excellent photothermal catalytic performance at a material addition ratio of 3:6:1, with S-AZMB, TiO2, and CeO2 at that ratio. At this point, the reaction temperature was 110 °C, the light intensity in the reaction system was 32 mW/cm2, and the toluene elimination efficiency was high. Toluene elimination effectiveness could be as high as 94.34 %. The catalyst greatly lowered the initiation temperature of catalytic combustion in addition to increasing thermocatalysis and photocatalysis efficiency through the photothermal synergistic effect. A novel theoretical foundation for the recycling of used batteries and the advancement of photothermal catalytic technology was also provided by the investigation of the photo-absorption properties and photothermal conversion mechanism of the catalysts.

Dual-emission carbon dots-based biosensor for polarity/targeting bimodal recognition and mild photothermal therapy of tumor

It is essential to develop a multifunctional nanoplatform for biosensing, tumor diagnosis and treatment simultaneously. Herein, dual-emission fluorescent carbon dots (HA-CDs) were fabricated via a one-pot solvothermal method using spinach powder as carbon source and hyaluronic acid (HA) as targeting agent. The obtained HA-CDs exhibited outstanding optical properties, good targeted tumor and excellent photothermal conversion performance. Interestingly, HA-CDs can sensitively perceive the changes in polar environments attributed to the inherent ratiometric fluorescence characteristics, and combined with the intrinsic targeting tumor ability achieved tumor cell recognition. More importantly, the HA-CDs possess good photothermal conversion efficiency of 21.2 % to be beneficial for photothermal therapy of tumors. The survival rate of HeLa cells incubated with HA-CDs dramatically decreased to 14 % after 660 nm laser irradiation, revealing the significant tumor inhibition of HA-CDs in vitro. Notably, through individual intraperitoneal and intratumoral injection, it was found that HA-CDs demonstrated a similar tumor suppressed effect on 4T1 tumor-bearing mice exposed to laser irradiation, fully uncovering that HA-CDs can efficiently accumulate at tumor site by intraperitoneal injection. Besides, the histopathological analysis of major organs ex vivo revealed a good biosafety profile. Collectively, this strategy of designed HA-CDs provides a new multifunctional nanoplatform for potential clinical application.

A NIR-II Organic Dendrimer with Superb Photothermal Performance Based on Electron-Donor Iteration for Photothermal Immunotherapy.

Organic photothermal materials have attracted extensive attention due to their designable molecular structure, tunable excited-state properties, and excellent biocompatibility, however, the development of near-infrared II (NIR-II) absorbingorganic photothermal materials with high photothermal conversion efficiency (PTCE) and molar extinction coefficient (ɛ) remains challenging. Herein, a novel "electron-donor iteration" strategy is proposed to construct organic photothermal dendrimers (CR-DPA-T, CR-(DPA)2-T and CR-(DPA)3-T) with donor-π-acceptor-π-donor (D-π-A-π-D) features and diradical characteristics. Owing to the enhanced D-A effect and intramolecular motions, their absorption and photothermal capacity increase as the generation grows. Surprisingly, an excellent photothermal performance (ɛ1064 ×PTCE1064) with a superb value of 2.85×104 in the NIR-II region is achieved for CR-(DPA)3-T nanoparticles (CR-(DPA)3-T NPs) compared to most reported counterparts. Besides, CR-(DPA)3-T NPs exhibit superior antitumor efficacy by the synergistic effect of photothermal therapy (PTT)and immunotherapy, efficiently inhibiting the growth of both primary and distant tumors. To the best knowledge, organic photothermal dendrimer is for the first time reported, and a universal donor engineering strategy is offered to develop NIR-II-absorbing organic photothermal materials for photothermal immunotherapy.

Planar Chiral Charge‐Transfer Cyclophanes: Convenient Synthesis, Circularly Polarized Light‐Responsive Photothermal Conversion and Supramolecular Chiral Assembly

We report herein a series of macrocycles in which the densely π‐stacked charge‐transfer (CT) donor/acceptor with naphthalenediimides (NDIs) or perylene diimide (PDI) as acceptor moiety pairing various donor moieties are locked by covalent bond. The X‐ray crystallography of C8BDT‐NDI reveals a short intramolecular π‐stacking distance around 3.4 Å and the existence of intermolecular donor/acceptor π‐stacking (3.7 Å). The intramolecular CT is highly dependent on the electron‐donating ability of donor moiety and replacing carbazole (C8KZ) with benzo[1,2‐b:4,5‐b']dithiophene (C8BDT) or dihydroindolo[3,2‐b]indole (C8DN) redshift CT absorption into NIR region. Notably, both C8BDT‐NDI and C8DN‐NDI demonstrate excellent photothermal performance, which is a result of the active non‐radiative pathways. Interestingly, the different molecular symmetry between donor and acceptor moiety endows C8BDT‐NDI and C8DN‐NDI with intrinsic planar chirality. The enantiomeric C8BDT‐NDI shows chiral selectivity for incident light, i.e., when irradiated by left‐circularly polarized light, (R)‐C8BDT‐NDI is more sensitive and a higher maximum stable temperature is achieved. While, enantiomeric C8DN‐NDI pack with different orientations forming M‐ and P‐handedness helix, respectively, demonstrating molecular planar chirality being transferred and amplified through molecular assembly. These results provide insight into the intramolecular charge transfer in enforced D/A π‐stacks in which CT interactions and planar chirality would be engineered through structural control.

Bifunctional Photothermal Evaporator Based on an MXene/Fe-MOF Collaborative Effect toward Efficient Solar Steam Generation and Simultaneous VOC Removal.

Solar-driven interfacial water evaporation has become one of the most promising approaches to effectively harvesting freshwater, yet the fabrication of high-performance and multifunctional solar interfacial evaporators (SIEs) still remains a huge challenge to date. In this study, a multifunctional MXene and Fe-MOF@cellulose acetate/polyvinylpyrrolidone (MXM@CP) SIE was prepared via a facile "electrospinning and suction filtration deposition" coupling strategy. Thanks to the incorporation of MXene, MXM@CP displayed excellent photothermal conversion performance. Together with the fast water transport channel provided by the porous cellulose acetate electrospinning substrate, a remarkable solar-driven water evaporation property was achieved for MXM@CP, showing a higher water evaporation rate of 1.1 kg m-2 h-1 under one sun irradiation. Moreover, the resultant composite film also exhibited excellent Fenton catalytic activity to effectively degrade volatile organic compounds (VOCs) due to the synergistic effect of the MXene and Fe-based MOF (Fe-MOF). Particularly, a relatively higher degradation rate of 82.8% was acquired for the resulting evaporator toward the benzene contaminant. These results provide new insights into the construction of high-performance and multifunctional SIEs toward clean freshwater collection from the VOC-contaminated water system.

Fabrication of Low-Cost Porous Carbon Polypropylene Composite Sheets with High Photothermal Conversion Performance for Solar Steam Generation.

The development of absorber materials with strong light absorption properties and low-cost fabrication processes is highly significant for the application of photothermal conversion technology. In this work, a mixed powder consisting of NaCl, polypropylene (PP), and scale-like carbon flakes was ultrasonically pressed into sheets, and the NaCl was then removed by salt dissolution to obtain porous carbon polypropylene composite sheets (P-CPCS). This process is simple, green, and suitable for the low-cost, large-area fabrication of P-CPCS. P-CPCS has a well-distributed porous structure containing internal and external connected water paths. Under the dual effects of the carbon flakes and porous structure, P-CPCS shows excellent photothermal conversion performance in a broad wavelength range. P-CPCS-40 achieves a high temperature of 128 °C and a rapid heating rate of 12.4 °C/s under laser irradiation (808 nm wavelength, 1.2 W/cm2 power). When utilized for solar steam generation under 1 sun irradiation, P-CPCS-40 achieves 98.2% evaporation efficiency and a 1.81 kg m-2 h-1 evaporation rate. This performance means that P-CPCS-40 outperforms most other previously reported absorbers in terms of evaporation efficiency. The combination of carbon flakes, which provide a photothermal effect, and a porous polymer structure, which provides light-capturing properties, opens up a new strategy for desalination, sewage treatment, and other related fields.

Tumor Microenvironment-Responsive Biodegradable Nanomedicine for Self-Enhanced Synergistic Chemo-, Photothermal, and Chemodynamic Therapy.

The nanoscale multidrug codelivery system for synergistic therapy is an effective strategy for tumor treatment. However, the low drug delivery efficiency and poor therapeutic effects limit its application. Here, based on the coordination effect of Artemisinin (Art), quercetin (Qc), and Fe3+, we had constructed a safe and efficient carrier-free hyaluronic acid (HA)-modified Art-Fe-Qc nanoparticles (AFQ@HA NPs) for enhanced chemotherapy/photothermal therapy (PTT)-chemodynamic therapy (CDT) synergistic therapy, which achieved an ultrahigh drug loading efficiency and a multifunction anticancer strategy. The results showed that high drug loading was achieved based on drug coordination self-assembly, with Art and Qc contents of 38.6 and 42.7%, respectively. At the same time, based on the Qc-Fe coordination molecular network, the system had excellent photothermal conversion performance with an efficiency of 57.3% and could effectively inhibit the expression of HSP70, achieving enhanced PTT. Further, under the stimulation of excessive H2O2 and glutathione (GSH) in the tumor microenvironment, the AFQ@HA NPs were continuously degraded, while releasing Art and Fe3+/Fe2+ to achieve iron ion-enhanced CDT. The results of in vitro and in vivo experiments showed that AFQ@HA NPs could achieve chemotherapy-PTT-CDT synergistic therapy in response to tumor microenvironment by passively targeting and actively targeting tumor cells with CD44, demonstrating its excellent targeted antitumor effects.

Nanofiber aerogel with layered array with structure coupled photothermal/magnetothermal effect for continuous seawater desalination

The solar evaporation is susceptible to intermittent solar irradiation as well as salt crystallization deposition on the surface severely limits the evaporation efficiency. In this work, subject to inspiration of the transpiration, groove array structure and antifouling performance of banana leaves, a multifunctional photothermal/ magnetothermal coupled three-dimensional(3D) aerogel evaporator with layer-by-layer array structure was prepared by blow-spun technology which can achieve mass produced. The unique super hydrophilic vertical array structure has multi-scale high-efficiency water transport channels and the SnSe-Fe3O4 evaporation layer realizes super hydrophobic self-cleaning and excellent photothermal and magnetothermal conversion performance, which can achieve all-weather seawater desalination. The vertical array structures facilitate the reflection and refraction of light and promote the seawater convection and salt crystals absorption coupling. It could improve the photothermal conversion efficiency and salt resistance of the evaporator. Which resulted in an evaporation rate of 2.53 kg m−2h−1 under 1 sun, with solar energy conversion efficiency of 105 % and the evaporation rate is about 4.54 kg m−2h−1 at a magnetic field. Furthermore, it could purify organic pollutants in industrial wastewater and use waste heat to generate electricity. This evaporator provides a new economical and environmentally friendly solution for seawater desalination and sewage treatment.

Photothermal effect enhanced antibacterial activity of CuAl-layered double hydroxides

CuAl-layered double hydroxides (CuAl-LDH) with Cu/Al atomic ratios of 2:1 and 3:1 are prepared by a facile coprecipitation method. The as-prepared CuAl-LDH have hexagonal crystalline structure and possess photothermal responsive ability. Upon 808 nm near-infrared laser irradiation for 10 min, CuAl-LDH-3 with a Cu/Al atomic ratio of 3:1 demonstrated rapid temperature elevation of 53 °C. Moreover, the dissolution rate of copper ions from CuAl-LDH increases with the increase of Cu/Al atomic ratio, and can be further promoted by irradiation. CuAl-LDHs are noncytotoxic to human umbilical vein endothelial cells and demonstrate excellent photothermal antibacterial performance against Gram-positive bacteria Staphylococcus aureus (S. aureus) and Gram-negative bacteria Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae), respectively. CuAl-LDH-3 displays the better antibacterial capacity attributed to the synergistic effects of the photothermal effect induced release of high concentration copper ions and the generation of reactive oxygen species (ROS). This work offers novel LDH-based antibacterial materials with photothermal and enzymatic effects.

Fabrication of boron nitride/copper oxide@multi-walled carbon nanotubes composites for enhancing heat transfer and photothermal conversion of phase change materials

To realize the efficient storage and conversion of solar energy by phase change materials (PCMs), low photothermal conversion efficiency and poor heat transfer performance remain great challenges. Herein, polyethylene glycol (PEG)-based composite PCMs with excellent photothermal conversion performance and exceptional thermal management capability were obtained by using boron nitride/copper oxide@multi-walled carbon nanotubes (BN/CuO@MWCNTs) as the thermal conductive and photothermal conversion enhancement fillers. The results indicate that owing to the bridging effect, the introduction of CuO and MWCNTs on the BN surface can construct additional heat transfer paths, resulting in a high thermal conductivity of up to 2.35 W/(m·K) for the as-prepared PEG/BN/CuO@MWCNTs composite, which is about 9-folds enhancement than pristine PEG. Simultaneously, the supercooling degree of PEG in PEG/BN/CuO@MWCNTs is effectively suppressed due to the synergistic nucleation effect of BN, CuO and MWCNTs. Additionally, the PEG/BN/CuO@MWCNTs composites not only exhibit a high latent-heat capacity of 154.5 J/g and a high photothermal conversion efficiency of 92.2 %, but also show favorable shape stability and durable reliability. This work offers a workable solution for the synergistic enhancement of photothermal conversion and thermal management, which can effectively promote the practical application in solar energy conversion and storage.

Facile synthesis of Ti3C2Tx MXene nanosheets using aryl diazonium tetrafluoroborate for multiple applications

The development of an HF-free and environmentally benign method for etching the middle aluminum layer (Al) from the Ti3AlC2-MAX phase is a challenging task in titanium carbide (Ti3C2Tx) MXene synthesis. Herein, we designed a diazonium salt-based ultrasonic method to prepare MXene. We have explored 4-carboxy benzene diazonium tetrafluoroborate (4-CBDF) as a delaminating agent, which can dissolve the Al layer directly from the MAX phase. 4-carboxy benzene diazonium (4-CBD+) ion promotes the intercalation as well as exfoliation simultaneously during the etching of the MAX phase and directly results in Ti3C2Txnanosheets without undergoing any additional delamination process. Synthesized MXene nanosheets show excellent photothermal performance with a conversion efficiency of 59 %. This MXene-coated GC electrode exhibits the highest capacitance of 1133 F/g at a current density 1 A/g, which maintains a retention capacitance of 91% even after 10,000 GCD cycles. The present method provides a fundamental insight into the development of MXene-based next-generation photothermal materials and supercapacitors.

A morphologically transformable hypoxia-induced radical anion for tumor-specific photothermal therapy

Tumor microenvironment activatable therapeutic agents and their effective tumor accumulation are significant for selective tumor treatment. Herein, we provide an unadulterated nanomaterial combining the above advantages. We synthesize a perylene diimide (PDI) molecule substituted by glutamic acid (Glu), which can self-assemble into small spherical nanoparticles (PDI-SG) in aqueous solution. PDI-SG can not only be transformed into nanofibers at low pH conditions but also be reduced to PDI radical anion (PDI·‒), which exhibits strong near-infrared absorption and excellent photothermal performance. More importantly, PDI-SG can also be reduced to PDI·‒ in hypoxic tumors to ablate the tumors and minimize the damage to normal tissues. The morphological transformation from small nanoparticles to nanofibers makes for better tumor accumulation and retention. This work sheds light on the design of tumor microenvironment activatable therapeutics with precise structures for high-performance tumor therapy.

Optically selective catalyst design with minimized thermal emission for facilitating photothermal catalysis

Converting solar energy into fuels is pursued as an attractive route to reduce dependence on fossil fuel. In this context, photothermal catalysis is a very promising approach through converting photons into heat to drive catalytic reactions. There are mainly three key factors that govern the photothermal catalysis performance: maximized solar absorption, minimized thermal emission and excellent catalytic property of catalyst. However, the previous research has focused on improving solar absorption and catalytic performance of catalyst, largely neglected the optimization of thermal emission. Here, we demonstrate an optically selective catalyst based Ti3C2Tx Janus design, that enables minimized thermal emission, maximized solar absorption and good catalytic activity simultaneously, thereby achieving excellent photothermal catalytic performance. When applied to Sabatier reaction and reverse water-gas shift (RWGS) as demonstrations, we obtain an approximately 300% increase in catalytic yield through reducing the thermal emission of catalyst by ~70% under the same irradiation intensity. It is worth noting that the CO2 methanation yield reaches 3317.2 mmol gRu−1 h−1 at light power of 2 W cm−2, setting a performance record among catalysts without active supports. We expect that this design opens up a new pathway for the development of high-performance photothermal catalysts.

Plant transpiration inspired biomass-derived solar evaporator for highly efficient solar vapor generation

The interface solar evaporation is an energy-saving and environmentally friendly method for seawater desalination and sewage purification. In this work, a biomimetic solar evaporator (ppy@AZL) inspired by plant transpiration was designed to achieve high efficient vapor generation. The ppy@AZL evaporator was made of zizania latifolia as raw material, has a cellulose skeleton with high water transport after alkalization and was decorated with photothermal polypyrrole to form bionic branches and leaves, and has excellent photothermal conversion performance. The evaporation performance and potential application of ppy@AZL evaporator in seawater desalination and sewage treatment were studied. The results indicated that the average evaporation rate of the ppy@AZL in simulated seawater (3.5 wt%) under the irradiation of one sun (1 kW m−2) was 2.239 kg m−2 h−1, and the photothermal conversion efficiency was 93.4 % in this work. In addition, the ppy@AZL evaporator has excellent evaporation rate of 2.668 kg m−2 h−1 in 9 h outdoor continuous evaporation experiment of simulated seawater (3.5 wt%), and can continuously and stably generate vapor. Therefore, this study provided a new solar evaporator with low-cost, simple preparation, better salt resistance, and high evaporation performance for seawater desalination and sewage treatment.

3D-printed multifunctional biomass hydrogel device for controlled photothermal distribution and molecular release

Photothermal therapy based on photothermal conversion has received increasing attention due to its non-invasiveness and low side effects. In this study, a 3D-printed biomass photothermal therapy device was prepared for accurate control of photothermal conversion and molecular release. The prepared black phosphorus nanosheets (BPNSs) showed excellent photothermal performance and antibacterial activity. A temperature-regulated sol-gel reversible system was prepared with konjac glucomannan (KGM), tara gum (TG), BPNSs, and manganese dioxide (MnO2) nanoparticles. The sol-gel transition was attributed to the change of interactions of hydrogen bond, and molecular entanglement. Photothermal conversion films with accurate multi-layer and array structures were prepared by 3D printing using the biomass sol-gel conversion system. The photothermal conversion efficiency was regulated by the concentration of BPNSs and MnO2. Under infrared radiation (808 nm, 1 W/cm2) for 5 min, the temperatures of hydrogel films with a MnO2 concentration of 0, 0.5, and 1 % were raised from 25 to 29.3, 61.8, and 90.8 °C, respectively. The accurate temperature distribution induced the controlled release of small active molecules such as epigallocatechin gallate (EGCG) loaded in hydrogels, which was resulted from the changes in the hydrogel structure and the decrease in adsorption energy between polysaccharide and EGCG at high temperatures. This study provides a biomass 3D-printed multifunctional photothermal therapy device and more understanding of the molecular release during photothermal conversion.

Silk Fabrics Modified with Photothermal Phase Change Microcapsules for Personal Thermal Management.

With the development of technology, personal heat management has become a focus of attention. Phase change fabrics, as intelligent materials, are expected to be widely used in multiple fields, bringing comfortable, intelligent and convenient living experience. In this study, miniature phase change microcapsules (MPCM) with n-octadecane as core and poly(methyl methacrylate) as shell were successfully prepared. Using the in-situ reduction property of polydopamine, gold nanoparticles were deposited on the surface of the microcapsules, which retained the heat storage function and imparted photothermal and antibacterial properties. The MPCM with photothermal conversion function was modified on the surface of silk fabric using aqueous polyurethane after verified by comprehensive material characterisation techniques. Under the near infrared light of 808 nm wavelength and 0.134 W/cm² irradiation intensity, the MPCM@PDA@Au modified silk fabrics showed excellent photothermal conversion performance, which could be increased from 25°C to 60°C in 50s. After the light source was cut off, the fabrics showed good heat release ability, with melting enthalpy and crystallisation enthalpy reaching 41.58 J/g and 43.3 J/g, respectively, which were not changed after repeated cycles. After the light source is cut off, the fabric has good heat release ability, and the enthalpy of melting and crystallisation reaches 41.58 J/g and 43.3 J/g, respectively, and the photothermal efficiency remains unchanged after many cycles of use, which proves that it has excellent durability and stability. The antimicrobial test shows that the fabric has significant antibacterial effect on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). MPCM@PDA@Au silk fabrics bring new possibilities for the future of personal thermal management and antimicrobial protection in the field of medical health, outdoor sports and other areas of broad application prospects, heralding the birth of a series of innovative applications and solutions.