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The rapid development of infrared surveillance technologies has attracted great attention for scientists to design advanced functional materials with prominent infrared stealth and thermal camouflage effectiveness. In the current study, a sandwich‐like functional composite based on a crosslinked polyimide aerogel, a meso‐erythritol (mE)‐based phase‐change composite, and an MXene film has been developed to achieve long‐term thermal camouflage at elevated temperatures. In this composite system, the lower aerogel layer can act as a barrier to insulate heat transfer through its layer‐stacking structure under ultralow directional thermal conduction. The introduction of the middle phase‐change composite layer ensures that the composite system obtains a dynamical temperature‐regulation capability through sensible and latent heat absorption of mE as a phase change material, while the upper MXene layer provides a very low emissivity surface for the system. As a result, the developed composite achieves a significant reduction in the thermal radiation temperature of a high‐temperature target. Moreover, the MXene film exhibits good electromagnetic interference shielding effectiveness, making the sandwich‐like composite obtain a thermal camouflage capability in various complicated scenarios. This work provides a promising approach for the design of advanced functional materials to realize long‐term infrared stealth and thermal camouflage of high‐temperature targets in security protection and counter‐surveillance. [ABSTRACT FROM AUTHOR]

Sugar alcohols are a type of organic solid-liquid phase-change materials with high latent heat-storage capacity and low cost and have been considered as a promising candidate for low-to-medium temperature thermal energy storage. Nevertheless, sugar alcohols show inherent defects, such as low thermal conductivity, high supercooling, low thermal reliability, and easy exudation and leakage in their melting state. To overcome these inherent defects, four strategies have been summarized in this review to optimize their comprehensive performance, which include nanoadditives, porous impregnation, encapsulation technology, and molecular structure design. Combining sugar alcohols with nanoadditives was determined as the simplest and most effective way to improve the thermal response of sugar alcohols. Porous materials could enhance the thermal stability of sugar alcohols and depress their supercooling. Microencapsulation technology was determined to be an effective way to prevent the leakage of sugar alcohols during their phase transitions. The molecular structure design provided an effective method to decrease the phase-change temperatures of sugar alcohols. After the optimization by different strategies, sugar alcohols exhibit great application potential in low-to-medium temperature waste heat recovery, solar cookers, and thermoelectric power generation for industrial waste heat and solar energy storage. This review presents better understanding of designing and fabricating sugar alcohol-based composites for efficient thermal energy storage, conversion, and utilization. The future research and development direction of sugar alcohols are also prospected for designing sugar alcohol-based composites with a high latent heat capacity, a low supercooling degree, enhanced thermal conductance, and multiple functions for efficient utilization. [Display omitted] • Physical and chemical characteristics of sugar alcohol-based PCMs are summarized. • The thermal response of sugar alcohols can be improved by introducing nanoadditives. • Porous materials can effectively depress the supercooling of sugar alcohols. • Microencapsulation can prevent sugar alcohols from leaking and flowing. • Challenges and prospects in the development of sugar alcohols are analyzed. [ABSTRACT FROM AUTHOR]

A novel double-layered hydrogel based on the polyacrylamide matrix, pen ink, and phase-change microcapsules was developed to construct a hydrogel-based evaporator for efficient and continuous seawater desalination. The n -eicosane (core)@crystalline TiO 2 (shell) phase-change microcapsules were fabricated through interfacial polycondensation, and the resulting phase-change microcapsules obtained a considerably high latent-heat capacity of 187 J·g−1. The upper layer of the hydrogel exhibits a high solar absorptivity of over 90 % due to the introduction of pen ink as a solar absorber, which helps the hydrogel-based evaporator to gain an excellent photothermal energy conversion capability. A high evaporation efficiency of 93.89 % was obtained for the developed hydrogel-based evaporator along with a high evaporation rate of 1.85 kg·m−2·h−1 under one-sun illumination. The phase-change microcapsules dispersed in the lower layer of the hydrogel can act as a latent heat-storage unit to store a great quantity of photothermal energy through melting phase change by the phase change material core. This imparts a consecutive evaporation capability to the developed hydrogel-based evaporator. As a result, its water production was increased by 11 % under 50-min one-sun illumination and 50-min non-illumination. [Display omitted] • We developed a new double-layered hydrogel based on polyacrylamide, phase-change microcapsules, and pen ink. • The hydrogel was used to fabricate a solar-driven evaporator for continuous and efficient desalination. • Pen ink and phase-change microcapsules enhance the solar energy utilization efficiency of the evaporator. • The hydrogel-based evaporator exhibits an improved yield in clean water under intermittent solar illumination. [ABSTRACT FROM AUTHOR]

Microencapsulating phase-change materials (PCMs) into CaCO 3 shell is considered as an effective way to resolve the leakage problem of the microcapsule system and enhance its heat transfer. Herein, we designed and fabricated a type of phase-change microcapsule system based on an n -docosane core and CaCO 3 /Fe 3 O 4 composite shell using a nonaqueous emulsion-templated self-assembly technology for enhancing solar photothermal energy absorption, conversion and storage performance. The type and addition amount of templating agent and the mass ratio of PCM core to wall material play key roles in the formation of microcapsules with a controllable spherical or rhombohedral morphology and a perfect core-shell microstructure. The resultant phase-change microcapsules show a satisfactory latent heat-storage capacity of around 140 J/g, high encapsulation ratio of over 59%, high thermal conductivity of 0.795 W m−1 K−1, excellent leakage prevention capability and good thermal cycle stability when synthesized under the optimum synthetic condition. More importantly, the phase-change microcapsules exhibit a significant enhancement in solar photothermal conversion and storage performance due to the presence of Fe 3 O 4 nanoparticles in their shell, and their photothermal conversion efficiency was improved by 47.9% compared to the corresponding microcapsules without Fe 3 O 4. In conclusion, the phase-change microcapsules developed in this work show considerable potential in high-efficient solar energy utilization. [Display omitted] • We design a phase-change microcapsule system for high-efficient solar energy utilization. • This system is constructed with an n-docosane core and CaCO3/Fe3O4 composite shell. • The system achieves an enhancement in solar photothermal energy-conversion efficiency. • The system exhibits a high latent-heat capacity for solar photothermal energy storage. • The study provides a new approach for development of high-performance microencapsulated PCMs. [ABSTRACT FROM AUTHOR]

[Display omitted] • We design a fluorescent sensing system for enhancing the determination of tetracycline. • The sensing system is based on molecularly imprinted phase-change microcapsules and CQDs. • The system exhibits a high thermal storage capacity for thermal management applications. • The system achieves an enhancement in specific identification through in situ thermal regulation. • The study provides an innovative strategy for high-efficienct detection of hazardous substances. Aiming at enhancing the detection efficiency and identification accuracy of tetracycline under a high-temperature condition, this study focuses on an innovative fluorescent sensing system (MIP@CQD-PCM) based on molecularly imprinted phase-change microcapsules along with the carbon quantum dots (CQDs) embedded in their shell. This system was fabricated by microencapsulating n -eicosane as a phase change material (PCM) core within a CQDs-embedded SiO 2 shell, followed by coating a tetracycline-templated molecularly imprinted polymer (MIP) layer onto the surface of the SiO 2 shell. The specific recognition sites to tetracycline molecules were finally achieved by removal of tetracycline template from the MIP layer. Comprehensive characterizations and investigations on the structure and performance of the fluorescent sensing system were given to confirm its successful fabrication in accordance to our design strategy. The resultant MIP@CQD-PCM exhibits a satisfactory thermal storage capacity and phase-change cycle stability for temperature regulation and thermal management applications under a phase-change enthalpy of over 162 J/g. Most of all, a typical fluorescence-quenching effect was obtained from the combination of the CQDs embedded in the SiO 2 shell and the tetracycline molecules adsorbed in the MIP layer. This makes the MIP@CQD-PCM achieve an enhanced capability for the fluorescence identification of tetracycline in a high-temperature environment through the in situ thermal management of its PCM core. The MIP@CQD-PCM also displays high selectivity and good reusability for tetracycline detection in industrial applications. This work provides a promising strategy for the design and development of fluorescent sensing systems with high recognition efficiency and identification accuracy in the detection of hazardous substances. [ABSTRACT FROM AUTHOR]

Hybrid terahertz (THz) metamaterial resonators have exhibited superior reconfigurable resonant response enabled by active materials, such as liquid crystals, graphene, and semiconductors. However, the tunable range of constitutive parameters of materials is still limited, which leads to the low modulation depth of THz devices. Unlike other phase change materials, vanadium dioxide (VO 2) exhibits an insulator-to-metal transition characteristic and the conductivity can be increased by 4–5 orders of magnitude under external stimulus including electric fields, optical, and thermal pumps. Here, we propose an active tunable THz resonator based on a hybrid VO 2 metasurface for thermal control. The simulated results show that by external thermal stimulation, we realize the tuning between the single and double resonant modes. The resonant peak at high frequency disappears while the low frequency peak is enhanced with the increasing temperature. The simulated surface electric fields confirm the physical mechanism of the excellent tunable performance that the L-shaped and cross resonances play a dominant role at the low and high temperature, respectively, due to the VO 2 phase transition. Such a hybrid VO 2 metasurface resonator with tunable characteristics will greatly promote the practical application of THz functional devices, such as modulators, sensors and filters. [ABSTRACT FROM AUTHOR]

This paper reported the design and fabrication of microencapsualed n -eicosane with a poly(methyl methacrylate- co -methacrylic acid) shell as a novel type of pH -responsive microencapsulated PCM for multipurpose applications such as thermal energy storage and controlled chemical release by an emulsion-templated in-situ polymerization technology. The spherical morphology and core-shell microstructure of the resultant pH -responsive microcapsules were confirmed and their chemical structure and elemental compositions were identified. Furthermore, their phase change behaviors and thermal energy-storage performance were investigated extensively. The pH -responsive microcapsules not only obtained excellent thermal regulation and thermal management capabilities due to a high phase change enthalpy over 177 J/g and good phase change reversibility, but also presented a well-defined pH -responsive controlled-release behavior by association and dissociation of hydrogen bonding interaction induced by different pH conditions and electrostatic repulsion. The dye release experimental results indicated that a maximum release amount of Rhodamine B could be achieved for the dye-loaded microcapsules at mildly acidic pH 5.05. In the light of highly efficient pH -stimuli responsiveness and excellent thermal regulation capability, the pH -responsive microcapsules developed by this study exhibit a great potential for pH -stimuli responsive controlled release applications of temperature/heat-sensitive drugs or chemicals when performing the thermal energy storage and thermal regulation. [ABSTRACT FROM AUTHOR]

Abstract In this study, a novel type of dual-responsive microencapsulated phase change material (PCM) was fabricated by encapsulating n -eicosane into a brookite TiO 2 shell through emulsion-templated interfacial polycondensation, followed by impregnation of ZnO. The resulting microcapsules are expected not only to generate a thermal response by phase transitions of the PCM core but also to gain a photocatalytic response capability originated from the ZnO-doped TiO 2 shell. The dual-responsive microcapsules were found to show a perfect core-shell microstructure as well as a regular morphology, and their chemical compositions and microstructure were determined by various spectroscopy and microscopy characterizations. The thermally responsive behaviors and phase change performance of the dual-responsive microcapsules were confirmed by differential scanning calorimetry and their photocatalytic response was identified by an antibacterial experiment. An applied research was carried out by incorporation of the dual-responsive microcapsules into the gypsum matrix, and the resulting gypsum/microcapsule composites not only presented a diverse range of superior thermal performance including prominent thermal regulation and thermal management capabilities, high thermal reliability, good operation durability and highly stable shape/form, but also showed an enhanced antibacterial function. This type of dual-responsive microcapsules exhibits a great potential for solar thermal energy-storage, energy-saving, healthcare and medical applications. Graphical abstract fx1 Highlights • We design a new dual-responsive microencapsulated PCM with a ZnO-doped TiO 2 shell. • Doping of ZnO endows the TiO 2 shell with enhanced photocatalytic effectiveness. • The microcapsules show an effective thermal response through phase transitions. • The microcapsules achieve a higher phase change enthalpy than others reported. • Thermal regulation and antibacterial capabilities can be obtained for gypsum/microcapsule composites. [ABSTRACT FROM AUTHOR]

Abstract In this work, we designed and fabricated three types of n -eicosane/TiO 2 -based microcapsules with different morphologies through an emulsion-templated interfacial polycondensation route, followed by the structure-inducing formation of TiO 2 shell. As we expected, the resultant microcapsules achieved the tubular, octahedral and spherical morphologies as well as a well-defined core-shell microstructure under the structure-directing control with different crystallization promoters. X -ray diffraction confirmed that the tubular microcapsules obtained a crystalline TiO 2 (B) shell, whereas a brookite TiO 2 shell was formed for the octahedral and spherical microcapsules. According to the thermal analysis under the isothermal and nonisothermal conditions, the tubular microcapsules showed the fastest thermal response due to their specific internal nanostructures, and the spherical microcapsules presented the largest amounts of charged and discharged heat because of their highest effective encapsulation ratio of n -eicosane core. These three types of microcapsules achieved a good energy storage capability in an order of the spherical microcapsules > the octahedral microcapsules > the tubular microcapsules, and all of them presented a diverse range of superior performance including excellent temperature-regulating and photocatalytic capabilities, good thermal reliability and durability, good shape stability and prominent heat charging/discharging performance when used for thermal energy harvesting and temperature regulation. Highlights • The microcapsules consisting of n -eicosane core and TiO 2 shell were designed in different shapes. • The microcapsules show interesting tubular, octahedral and spherical morphologies as expected. • These microcapsules present excellent thermal regulation and thermal management capabilities. • The tubular microcapsules exhibit a faster thermal response to ambient temperature than the other two. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • We reported an innovative combination of superhydrophobic surface and thermal energy-storage material. • This idea was realized by microencapsulating PCM with a flower-like ZnO/SiO 2 shell. • This material exhibits a good heat-storage and thermal regulation capability. • This material reveals a self-cleaning behavior due to its ZnO nanostructure. • This work opens a door in design of PCMs for multifunctional applications. Abstract We reported an innovative design for a novel type of superhydrophobic thermal energy-storage material by microencapsulation of phase change material (PCM) with a nanostructured ZnO/SiO 2 shell. This hierarchical microcapsule system was constructed through emulsion-templated interfacial polycondensation of silica precursor and structure-induced growth of ZnO crystals. The chemical composition and structural characterizations identified the successful fabrication of this hierarchical microcapsule system in accordance with our design idea and also confirmed the formation of a well-defined core-shell structure as well as a flower-like ZnO surface. Thermal analysis indicated that the resultant microcapsules not only could perform latent-heat storage and release by phase changes with the associated enthalpies over 139 J/g, but also demonstrated a high phase change reliability and long-term durability. The optimum heat charging and discharging conditions of the microcapsules were also determined by nonisothermal and isothermal differential scanning calorimetric analyses. Infrared thermographic analysis proved that the resultant microcapsules had the capability of conducting thermal regulation and thermal management. Most of all, a superhydrophobic surface was achieved by a combination of the nanostructured surface and low-surface-energy coating, thus leading to a large water contact angle of 159.7°. Owing to a smart combination of PCM and superhydrophobic feature, the hierarchical microcapsule system developed by this study is expected to have a great potential in multifunctional applications for thermal energy storage, thermal regulation and management, self-cleaning and antifouling coatings, anticorrosion, liquid transportation, and many more. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) have been widely applied for thermal energy storage and thermoregulation. This paper reported a smart design and construction of nanoflake-like MnO 2 /SiO 2 hierarchical microcapsules containing n -docosane PCM for in-situ thermal management of supercapacitors. The microcapsules based on an n -docosane core and SiO 2 shell were first synthesized through interfacial polycondensation, and then a mesoporous nanoflake-like MnO 2 layer was fabricated onto the surface of SiO 2 shell through template-directed self-assembly. The chemical compositions of the resultant microcapsules were confirmed by energy dispersive X -ray, X -ray photoelectron and Fourier -transform infrared spectroscopy, and their nanoflake-like hierarchical morphology and well-defined core–shell structure were identified by scanning and transmission electron microscopy. The mesoporous architecture of nanoflake-like MnO 2 outer layer was determined by nitrogen adsorption–desorption isotherm. The obtained microcapsules exhibited high phase-change enthalpies, high encapsulation efficiency, good phase-change and anti-osmosis performance and an effective thermoregulation capability. Most of all, these microcapsules demonstrated a higher specific capacitance than traditional MnO 2 /SiO 2 solid particles at operation temperatures higher than 45 °C due to in-situ thermal management by the n -docosane core. They not only achieved a high specific capacitance of 312.2F/g at 45 °C with a current density of 1.0 A/g due to the mesoporous architecture of MnO 2 layer, but also presented a superior long-term cycling stability with high capacitance retention of 94.7% after 1000 charging/discharging cycles. With the above-mentioned superiorities, the microcapsules developed by this work will be a good candidate as an electrode material for supercapacitors. This study opens a new pathway for the development and applications of microencapsulated PCMs in the thermoregulatory electrode system of supercapacitors and Li-ions battery cells. [ABSTRACT FROM AUTHOR]

A novel form-stable phase change material (FSPCM), namely, diethylene glycol hexadecyl ether-grafted graphene oxide (E 2 C 16 - g -GO), was fabricated by an esterification reaction. As E 2 C 16 was modified with GO for the first time, the optimal E 2 C 16 and GO reactant ratio and reaction time were determined to be 6:1 and 6 h, respectively. The successful synthesis and chemical structure of E 2 C 16 - g -GO were confirmed by various spectroscopy and microscopy techniques. The thermal properties and stability of E 2 C 16 - g -GO were characterized by DSC and TGA. The melting and crystallization points of E 2 C 16 - g -GO are 43.3 °C and 29.4 °C, respectively. The latent heats of melting and crystallization are 70 and 72 J/g, respectively. The degradation temperature of E 2 C 16 - g -GO is approximately 20 °C higher than that of E 2 C 16 , indicating that it has good thermal stability. Furthermore, E 2 C 16 - g -GO exhibits good shape-stability and excellent thermal reliability and structural stability, indicating that it is a promising FSPCM for energy storage applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel microcapsule system was constructed for sensitive detection of H 2 O 2 at high temperature. • The microcapsules were based on PCM core, electroactive layer, and surface-immobilized catalase. • The microcapsules show a high latent heat capacity for thermal regulation of H 2 O 2 biosensor. • The biosensor exhibits an enhanced ability for H 2 O 2 determination due to in-situ thermal management. • The biosensor finds great potential for detecting the H 2 O 2 level over a broad working temperature range. To address the deterioration in electrochemical biosensing detection of hydrogen peroxide (H 2 O 2) caused by enzymatic inactivation in high-temperature environments, we have developed a novel type of catalase-immobilized electroactive phase-change microcapsules based on a phase change material (PCM) core, an SiO 2 shell, and a poly(3,4 -ethylenedioxythiophene)/Au nanocomposite layer with the surface-immobilized catalase. The microcapsules not only show a well-defined core–shell microstructure with the desired chemical compositions, but also present a high latent heat capacity of over 130 J/g for thermal regulation. An electrochemical biosensor was established using the microcapsule-modified working electrode to obtain a high electrochemical response to H 2 O 2 through combining the highly electroactive layer with covalently bonded catalase. The developed biosensor achieved an enhanced electrochemical biosensing response to H 2 O 2 through regulating the microenvironmental temperature surrounding the working electrode by the latent heat release of its PCM core to prevent enzymatic inactivation at high temperature. Compared to conventional H 2 O 2 biosensors without thermal management by PCMs, the developed biosensor exhibits a higher sensitivity of 42.85 µA·mM−1·cm−2 and a lower detection limit of 3.56 µM at a high working temperature of 50 °C. The developed biosensor has found practical applications for sensitive detection and accurate determination of H 2 O 2 level in real food and biological samples over a wide temperature range. [ABSTRACT FROM AUTHOR]

[Display omitted] • We developed a novel solar-driven interfacial evaporator for continuous and efficient desalination. • The developed evaporator is based on the MXene-decorated magnetic phase-change microcapsules. • The microcapsules show high latent-heat capacity and high solar photothermal conversion efficiency. • The evaporator achieves an increase in evaporation mass under intermittent solar illumination. • This study offers an effective solution for salt acumination problem in seawater desalination. Solar-driven interfacial evaporators provide a powerful means for rapid wastewater purification and seawater desalination. However, there is still an immense challenge in interfacial evaporators with efficient energy utilization and long-term evaporation stability due to intermittent solar illumination and salt accumulation. To address these issues, we developed a novel type of interfacial evaporator based on the microencapsulated n -tetracosane and n -eicosane as twin phase-change material (PCM) cores with a SiO 2 /Fe 3 O 4 composite shell along with a surface-coated polypyrrole layer and surface-decorated MXene nanosheets. The resultant microcapsules act as both a solar absorber and a latent-heat storage material for sustainable evaporation of seawater. Benefiting from a rational combination of PCMs and solar absorbers, the evaporator based on the microcapsules achieved a high light absorption efficiency of 95.4 % together with evaporation rates of 2.04 and 4.11 kg·m−2·h−1 under 1.0-sun and 2.0-sun illumination, respectively. Owing to the photothermal energy released by the PCM cores, the developed evaporator exhibits a consecutive and stable evaporation behavior even without solar illumination. Compared to conventional evaporators without a PCM, there is an increase by 0.45 kg·m−2 in the yield of the distilled water obtained from the developed evaporator under 2.0-sun illumination and then in the dark environment. Based on magnetic Fe 3 O 4 nanoparticles in the silica-matrix shell, the separability of the microcapsules from the accumulated salt crystals was improved through simple washing and magnetic separation. Through an innovative integration of magnetic phase-change microcapsules and solar absorbers, this study will provide a new idea and promising approach for the sustainable evaporation system design based on solar energy utilization for applications of seawater desalination and wastewater treatment. [ABSTRACT FROM AUTHOR]

Electrochemical energy-storage devices usually suffer from performance deterioration at high operating temperatures due to exothermic redox reactions during the cyclic charge–discharge process. Aiming at addressing this crucial issue, we have developed a novel type of thermoregulatory electrode material based on the hierarchically nanostructured Co(OH) 2 /MXene/SiO 2 / n -docosane phase-change composite for enhancing electrochemical energy-storage performance of supercapacitors through in-situ thermal management. The resultant composite shows a regular spherical morphology and a layer-by-layer core-shell microstructure for the phase-change microcapsules anchored on MXene nanosheets, together with a well-defined nanostructured Co(OH) 2 layer deposited on the surfaces of the microcapsules and nanosheets. Through a multilevel integration of phase change material (PCM) and electroactive materials in an electrode material, the microenvironmental temperature surrounding the working electrode can be regulated effectively, buffering the heat impact to supercapacitors at high temperature. The phase-change composite achieved a satisfactory latent heat capacity of over 130 J/g together with good thermal cycling stability for long-term use in thermal management of supercapacitors. Compared to conventional electrode material without a PCM, the thermoregulatory electrode material developed in the current work exhibits an increase in specific capacitance by 6.6% at 45 °C and in capacitance retention by 10.8% after 3000 charge-discharge cycles at 45 °C, suggesting better electrochemical energy storage performance and higher charge-discharge cycling stability at high operating temperature thanks to its in-situ thermal management effectiveness. This study provides a promising approach to developing high-performance electrode materials for supercapacitor application over a broad temperature range. [Display omitted] F0B7 A thermoregulatory electrode composite was developed for thermal management of supercapacitors. F0B7 The composite is based on the nanostructural Co(OH) 2 /MXene-decorated phase-change microcapsules. F0B7 The composite exhibits a high latent heat capacity for in-situ thermal management of supercapacitors. F0B7 The composite shows enhanced supercapacitor performance due to thermal buffer at high temperature. F0B7 The composite finds great potential for supercapacitor application over a broad temperature range. [ABSTRACT FROM AUTHOR]

[Display omitted] • We developed a new type of phase-change composites for solar-driven seawater desalination. • The composites are based on polyimide/MXene hybrid aerogel and PEG phase change material. • The composites show high latent-heat capacity and high solar photothermal conversion efficiency. • The composites exhibit a seawater evaporation rate of 1.24 kg·m−2·h−1 under one sun illumination. • The composites have great potential for the application in sustainable seawater desalination. Aiming to explore a high-efficient seawater desalination technique based on solar photothermal energy as the cleanest and most abundant renewable energy source, we developed a novel type of phase-change composites based on a polyimide (PI)/MXene hybrid aerogel as a supporting material and polyethylene glycol (PEG) as a phase change material. The introduction of Ti 3 C 2 T x MXene nanosheets as a high-efficient sunlight absorber not only significantly enhanced solar photothermal energy-conversion efficiency up to 87.28% for the aerogel/PEG composites, but also improved the volume capacity of the hybrid aerogels. This resulted in an extremely high PEG loading rate of up to 97.68 wt% and a high enthalpy efficiency of up to 95.16%. The hybrid aerogel/PEG composites also exhibit an outstanding thermal energy-storage capability under a high latent heat capacity of over 170 J·g−1, high thermal cycle stability, good leakage-resistant performance, excellent thermal impact resistance, and good shape/form stability to deal with the use in seawater desalination. More importantly, the hybrid aerogel/PEG composites show a high seawater evaporation mass of 6.07 kg·m−2, a high evaporation rate of 1.24 kg·m−2·h−1 under one-sun illumination, and a high evaporation efficiency of 50.6% when used in a solar-driven evaporation device. The PI/MXene hybrid aerogel/PEG composites developed by this work exhibit a great potential for application in sustainable seawater desalination. [ABSTRACT FROM AUTHOR]

Enzyme-based biosensors are sensitive to temperature due to their strong temperature dependency of catalytic activity. Aiming at enhancing biosensing detection for glucose assay over a wide range of applicable temperatures, we designed a thermal self-regulatory intelligent biosensor through an innovative integration of phase change material (PCM) and bioelectrocatalytic substances. An electroactive phase-change microcapsule system was firstly fabricated by microencapsulating n -docosane as a PCM core in the SiO 2 shell, followed by depositing polydopamine along with carbon nanotubes as an electroactive layer on the surface of SiO 2 shell. The resultant microcapsules showed a regularly spherical morphology and well-defined core-shell microstructure. They also exhibited a satisfactory latent heat capacity of around 137 J/g for implementing temperature regulation with a good working stability. An electrochemical biosensing system was constructed with the resultant electroactive microcapsules together with glucose oxidase as a redox enzyme, achieving a thermal self-regulation capability to enhance the biosensing detection of glucose under in-situ thermal management at higher temperatures. With a high sensitivity of 5.95 μA⋅mM−1⋅cm−2 and a lower detection limit of 13.11 μM at 60 °C, the intelligent biosensor developed by this study demonstrated a superior determination capability and better detection performance toward glucose than conventional biosensors in a high temperature region thanks to effective regulation of microenvironment temperature in the electrode system. This study provides a promising strategy for the development of thermal self-regulatory smart biosensors with an enhanced identification ability to detect various chemical substances over a wide range of applicable temperatures. [Display omitted] • We design an intelligent biosensor with enhanced ability to detect glucose at high temperatures. • The biosensor was based on bioelectrocatalytic phase-change microcapsules. • The biosensor exhibits a thermal self-regulatory capability to buffer thermal swings. • The biosensor shows good detection performance in glucose assay under thermal management. • This study offers a promising strategy for development of intelligent biosensors. [ABSTRACT FROM AUTHOR]

[Display omitted] • We fabricated a type of phase-change microcapsules with surface-constructed Ni(OH) 2 nanoflowers. • The resultant microcapsules show a well-defined layer-by-layer core-shell microstructure. • The microcapsules achieve a significant enhancement in heat transfer and thermal response. • The microcapsules exhibit a satisfactory latent-heat capacity and stable thermal energy-storage process. • This study offers a new design of phase-change microcapsules with fast thermal response. A phase-change microcapsule system based on an n -docosane core and SiO 2 /nanostructural Ni(OH) 2 layer-by-layer shell was designed with the aim to enhance the heat transfer and thermal response capability of phase-change microcapsules. This system was fabricated through emulsion-templated interfacial polycondensation to form a SiO 2 / n -docosane microcapsule system, followed by anchoring Ni(OH) 2 nanoflowers on the surface of the SiO 2 shell via structure-directed interfacial precipitation. The resultant microcapsule system achieved a satisfactory latent heat-storage capacity of around 130 J/g with high energy-storage efficiency over 99%. Compared to conventional SiO 2 / n -docosane phase-change microcapsules, this microcapsule system not only presents high thermal conductivity, rapid heat transfer rate, good leakage prevention capability, high heat charging-discharging stability, but also exhibits a good phase-change reversibility and resilience ability to perform repetitious solid-liquid phase transformations. The combination of traditional phase-change microcapsules with a nanostructural Ni(OH) 2 outer layer results in a significant enhancement in heat transfer, which makes the system a fast thermal response ability to satisfy a variety of applications where fast and stable thermal energy storage/release is required. Through constructing the Ni(OH) 2 nanoflowers on the surface of conventional phase-change microcapsules, this study offers a promising strategy for the design and fabrication of high-performance phase-change microcapsules with fast thermal response. [ABSTRACT FROM AUTHOR]

Intermittent sunlight irradiation severely limits the performance of solar evaporators for electricity output and freshwater production. To address this issue, a hierarchical‐structured three‐dimentional (3D) solar evaporator to simultaneously enhance output voltage and freshwater production by integrating a paraffin‐type phase change material (PCM) with a circular concave‐shaped 3D supporter covered with a carbon‐black‐nanoparticles‐modified poly(ethylene terephthalate) fabric (PMCB) is developed. In this developed 3D solar evaporator, the 3D‐printed supporter can trap sunlight to improve solar energy absorption, and the PMCB obtained from hydrophilic and hydrophobic modification can adequately absorb sunlight for electricity generation and water evaporation, resulting in a maximum output voltage of 3.51 V and a high evaporation rate of 4.0 kg m−2 h−1 under natural sunlight illumination. Owing to the introduction of the PCM, the 3D solar evaporator obtains a decrease in the time required for charging a capacitor by 57.9% and an increase in freshwater production by 29.9% compared to the counterpart without a PCM. Through rationally utilizing the solar photothermal energy stored by the PCM and innovatively integrating the PCM and PMCB in a hierarchical‐structured 3D supporter, the developed 3D solar evaporator exhibits great application potential for simultaneous electricity generation and freshwater supply under intermittent solar irradiation. [ABSTRACT FROM AUTHOR]

• We designed the thermochromic phase-change microcapsules with a sandwich shell structure. • A thermochromic layer was well isolated by the silica base shell and polymeric outer shell. • This system exhibits a highly reversible and durable thermochromic response capability. • This system has a high latent heat-storage capacity with real-time indication by color. • This study offers a new insight for design of thermochromic heat-storage systems. We reported a design of novel thermochromic phase-change microcapsules (TCMs) with a sandwich-structured shell for reversible and durable indication of thermal energy storage and management in real-time. Two types of TCMs with red and blue color indicators were successfully constructed by fabricating a silica base shell onto the n -docosane core, followed by formation of a thermochromic indication layer and a polymeric protective layer, and their multilayered configuration and well-defined core-shell structure were confirmed by microstructural investigation and chemical composition analysis. These two types of TCMs not only showed an outstanding latent heat-storage/release capability with a high capacity over 150 J/g, but also exhibited a good shape stability, high thermal stability and excellent phase-change reversibility and durability. The optimum operation conditions for thermal energy charge/discharge were also determined by nonisothermal and isothermal differential scanning calorimetric analyses. Most of all, the two types of TCMs presented an entirely reversible thermochromic behavior individually with high-contrast red and blue color indications for the phase-change state of n -docosane core. Both of them exhibited high reversibility and long cycle life in thermochromic indication, which meets the design requirements for durable indication of latent heat storage and thermal management in real-time. In the light of an innovative configuration of sandwich-structured shell and a smart combination of latent heat-storage and thermochromic functions, the TCMs designed by this study has a great potential for applications in smart fibers and textiles, wearable electric devices, energy-saving buildings, temperature-sensitive medical system, safety clothing, smart windows, aerospace engineering and many more. [ABSTRACT FROM AUTHOR]

Traditional micro- or nanoencapsulation of phase change materials (PCMs) generally results in high supercooling and slow thermal response. Hereby, we designed and synthesized two types of meso-silica/ n -eicosane phase-change nanocomposites in the forms of uniform nanospheres and core-shell structured nanocapsules through self-templating strategy. The meso-silica/ n -eicosane nanospheres have a disordered worm-like mesopore nanostructure, whereas the meso-silica/ n -eicosane nanocapsules show a 3D cubic cage-like mesoporous structure for the core and a solid silica layer for the shell. These two types of phase-change nanocomposites achieved superior thermal performance including a good thermal storage capability, high thermal stability, good shape stability and satisfactory phase-change reliability. Most of all, owing to the formation of specific hierarchical nanostructures, both of them achieved a significant enhancement in thermal conductivity and effective depression in supercooling. Compared to the conventional silica/ n -eicosane microcapsules, these two types of phase-change nanocomposites exhibited a shorter heat-charging period due to good thermal conduction by their interconnecting mesopores silica matrix, but a longer heat-discharging period because of the internal narrow mesopores resulting in crystallization confinement of encapsulated n -eicosane. With low supercooling and rapid thermal response, the phase-change nanocomposites developed by this work exhibit a great potential for hi-tech applications in fast temperature regulation and precise thermal management. • We designed two types of phase-change nanocomposites for supercooling depression and heat transfer enhancement. • The phase-change nanocapsules were constructed with the meso-silica/ n -eicosane core and silica shell. • The phase-change nanospheres were fabricated by loading n -eicosane into mesoporous silica matrix. • Both of them exhibited a low supercooling degree and rapid thermal response. • A satisfactory latent heat-storage capability, high thermal reliability and good shape stability were also achieved. [ABSTRACT FROM AUTHOR]

A nanoflaky nickel-hydroxide-decorated phase-change microcapsule system [designated as Ni(OH) 2 -SiO 2 -MEPCM] was designed as a smart electrode material for supercapacitor application. This system was constructed through microencapsulating n -docosane core into a silica shell via emulsion-templated interfacial polycondensation, followed by fabricating a nanoflaky Ni(OH) 2 layer on the surface of silica shell through structure-directed interfacial precipitation. Such a combination of phase-change microcapsules and electrochemically active material makes the Ni(OH) 2 -SiO 2 -MEPCM synchronously implement thermal self-regulation and electrochemical energy storage. The Ni(OH) 2 -SiO 2 -MEPCM shows a perfect core-shell structured morphology and well-defined nanoflaky surface microstructure. The Ni(OH) 2 -SiO 2 -MEPCM not only possesses a good temperature regulation capability with a latent-heat capacity of around 140 J/g but also exhibits an excellent thermal cycle stability and good high-temperature shape stability. Most importantly, compared to traditional electrode materials, the Ni(OH) 2 -SiO 2 -MEPCM can perform effective thermal self-regulation to regulate the micro-ambient temperature by its n -docosane core when used as an electrode material for supercapacitors, leading to improved electrochemical performance and good long-term cycle stability with capacitance retention of 86.2% after 3000 charge-discharge cycles at a high ambient temperature of 50 °C. All of these features indicate that the Ni(OH) 2 -SiO 2 -MEPCM developed by this work has great potential as a smart electrode material for electrochemical energy-storage applications. [Display omitted] • A nanoflaky Ni(OH)2-decorated phase-change microcapsule system was constructed. • The system can serve as a self-thermoregulatory electrode material for supercapacitors. • The electrode material has an effective temperature regulation and thermal management capability. • The electrode material exhibits the enhanced electrochemical performance and cycle stability. • The study offers a new design of smart electrode materials for supercapacitor applications. [ABSTRACT FROM AUTHOR]

We have developed a novel type of solar-driven interfacial evaporation and electricity generation integrating system based on the modified carbon black (MCB)-decorated magnetic phase-change composites (MCB-MPCC) for continuous seawater desalination and clean electric power generation under intermittent solar illumination. In this system, MCB-MPCC acts as not only a solar absorber but also a hydrovoltaic functional coating. MCB-MPCC was fabricated through encapsulating n -docosane as a phase change material (PCM) in a SiO 2 /Fe 3 O 4 composite shell through emulsion-templated interfacial polycondensation, followed by coating a polydopamine layer and surface-depositing MCB nanoparticles. Owing to the introduction of a PCM core, the resultant MCB-MPCC obtained a high latent heat capacity of over 145 J g−1 for consecutive seawater evaporation under intermittent solar illumination. Moreover, the surface-decorated MCB nanoparticles contribute to superior sunlight absorptivity and good wettability of MCB-MPCC, promoting a high evaporation rate of 2.67 kg m−2 h−1 for the MCB-MPCC-based evaporator under one-sun illumination along with excellent salt resistance. Meanwhile, the developed system achieved a stable output voltage of 0.43 V and output current of 10.05 μA under one-sun illumination, and the generated electric power could be stored by a commercial capacitor to provide a power supply for lightening an LED lamp. [Display omitted] • We developed a novel solar-driven interfacial evaporation and electricity generation integrating system. • The system is based on the carbon black-decorated magnetic phase-change composites. • The composites show a high latent-heat capacity and high solar photothermal conversion efficiency. • Water evaporation and electric power generation can be synchronously performed under solar irradiation. • The study offers a new strategy for sustainable seawater desalination and clean electric power generation. [ABSTRACT FROM AUTHOR]

Phase-change materials can store and release tremendous amounts of latent heat energy in a single storage unit, and they have become a promising candidate for building comfort temperature regulation with a significant energy-saving effect. In this study, we developed a novel type of size-tunable phase-change microcapsules for high-efficient thermal management and temperature regulation in buildings. The phase-change microcapsules were based on an n -eicosane core and a CaCO 3 shell and fabricated using an emulsion-templated self-assembly interfacial precipitation method. Their sizes were controlled through regulating the surfactant concentration, resulting in a desired capsule size as well as a well-defined core-shell microstructure and a regular spherical morphology. When the mass ratio of sodium dodecyl sulfate to sulfobetaine varied from 3/2 to 1/1 in the mixed surfactant system, the resultant phase-change microcapsules exhibited a tunable diameter from 740 nm to 1.54 µm together with a significant increase in latent-heat capacity from 100 to 131.5 J/g. The application investigation of the obtained microcapsules in building thermal regulation was performed through incorporating microcapsule samples into cement, employing the resultant cement composites as building envelopes for a model house. The cement composites presented a good ability to regulate the indoor temperature of the model house thanks to the thermal energy storage and latent heat release of the phase-change microcapsules. The model house coated with the cement composites on the roof exhibited a maximum indoor temperature of 47 °C after subjected to the simulated sunlight radiation for 4 h, leading to a decrease in indoor temperature by 5 °C compared to the model house with pure cement. With a rational combination of the phase-change microcapsules and cement, this study provides a promising approach to passive and efficient comfort temperature regulation for green energy-saving building applications. [Display omitted] • We developed the size-tunable phase-change microcapsules with an n -eicosane core and a CaCO 3 shell. • The microcapsules show a well-defined core-shell microstructure and a regular spherical morphology. • The microcapsules reveal a good thermal regulation ability under a latent-heat capacity of over 130 J/g. • The cement composites with the microcapsules can implement building comfort temperature regulation. • The cement composites exhibit great potential for applications in energy-saving buildings. [ABSTRACT FROM AUTHOR]

Infrared stealth technology plays a vital role in development of defense industry and new military equipment. The current study focused on a novel type of flexible and foldable composite films based on polyimide (PI)/phosphorene (PR) hybrid aerogel and phase change material (PCM) for infrared stealth and thermal camouflage applications. The composite films were successfully obtained by fabricating a PI/PR hybrid aerogel through prepolymerizaton, film casting, freeze-drying, and thermal imidization, followed by vacuum impregnation of polyethylene glycol (PEG) as a PCM into the aerogel framework. The combination of PI and PR nanoflakes endows the hybrid aerogel with an effective enhancement in mechanical properties, near infrared absorption, and infrared photothermal conversion. The resultant composite films not only present prominent tensile and fatigue-resistant performance but also exhibit a good thermal regulation capability with a high latent-heat capacity of over 150 J/g. More importantly, the composite films demonstrate good infrared stealth and thermal camouflage performance on the high-temperature targets through effective thermal buffer and insulation. With ultralight, flexible, foldable, shape-tunable, and thermal self-regulatory characteristics, the PI/PR aerogel/PEG composite films developed by this work exhibit great application potential in infrared stealth and thermal camouflage for new military equipment. [Display omitted] • A flexible and foldable composite film was designed for infrared stealth and thermal camouflage. • The film was based on the polyimide/phosphorene hybrid aerogel and phase change material. • The introduction of phosphorene enhances infrared absorption and photothermal conservation. • The film exhibit a good thermal regulation ability to buffer thermal swings. • The film shows great potential for stealth and camouflage applications in new military equipment. [ABSTRACT FROM AUTHOR]

Electromagnetic (EM) and infrared (IR) stealth play an important role in the development of military technology and the defense industry. This study focused on developing a new type of multifunctional composite film based on polyimide (PI)/graphene/Fe3O4 hybrid aerogel and polyethylene glycol (PEG) as a phase change material (PCM) for EM and IR bi-stealth applications. The composite films were successfully fabricated by constructing a series of PI-based hybrid aerogels containing different contents of graphene nanosheets and Fe3O4 nanoparticles through prepolymerizaton, film casting, freeze-drying, and thermal imidization, followed by loading molten PEG through vacuum impregnation. The construction of PI/graphene/Fe3O4 hybrid aerogel films provides a robust, flexible, and microwave-absorption-functionalized support material for PEG. The resultant multifunctional composite films not only exhibit high microwave absorption effectiveness across a broad frequency range, but also show a good ability to implement thermal management and temperature regulation under a high latent-heat capacity of over 158 J/g. Most of all, the multifunctional composite films present a wideband absorption capability at 7.0–16.5 GHz and a minimum reflection loss of −38.5 dB. This results in excellent EM and IR bi-stealth performance through the effective wideband microwave absorption of graphene/Fe3O4 component and the thermal buffer of PEG. This study offers a new strategy for the design and development of high-performance and lightweight EM–IR bi-stealth materials to meet the requirement of stealth and camouflage applications in military equipment and defense engineering. [ABSTRACT FROM AUTHOR]

Phase change material is a high thermal storage substance, which can reduce temperature-related diseases of asphalt pavement when mixed with asphalt mixture. In this paper, NiTi alloy phase change heat-storage asphalt mixture (NiTi APCHAM) are prepared by using equal volume parts to replace fine asphalt aggregates partially with the NiTi alloy phase change energy-storage particles (NiTi APCEP). As the temperature increases, the specific heat capacity of NiTi APCHAM will increase first and then decrease due to the heat-storage effect of NiTi APCEP. The thermal conductivity coefficient of NiTi APCHAM shows a linear increasing trend with the increase in the substitution rate of NiTi APCEP. Adding NiTi APCEP in asphalt mixture can reduce its daily maximum temperature. Increasing admixture of NiTi APCEP in asphalt mixture can help to improve the phase change heat-storage thermoregulation capacity of the mixture. However, at a 6 wt% substitution rate of NiTi APCEP, the latent heat thermoregulation efficiency of NiTi APCEP reaches to maximum. With the increase in the content of NiTi APCEP, the Marshall stability of asphalt mixture gradually increases, and flexural-tensile strain at low temperature decreases gradually. By contrast, the water stability of the asphalt mixture is unaffected by the addition of NiTi APCEP. • NiTi alloy phase change heat-storage asphalt mixture were prepared. • Adding NiTi APCEP in asphalt mixture can reduce its daily maximum temperature. • The optimal substitution rate of NiTi APCEP was recommended in this paper. [ABSTRACT FROM AUTHOR]

A novel type of MXene-decorated and sodium alginate (SA)-coated phase-change microcapsules (hereafter named "MXene/SA/SiO 2 -MEPCM") was designed as a bifunctional solar absorber for the interfacial evaporator to realize sustainable seawater desalination. The MXene/SA/SiO 2 -MEPCM was fabricated by encapsulating n -docosane as a phase change material (PCM) in the SiO 2 shell, followed by depositing a SA layer and decorating MXene nanosheets. An innovative integration of SA and MXene nanosheets enables the microcapsules to achieve a high light absorption capability of over 97 % together with good wettability, promoting a high evaporation rate of 2.11 kg·m−2·h−1 under one-sun illumination. The MXene/SA/SiO 2 -MEPCM exhibits a high latent heat capacity of over 150 J·g−1 for consecutive and high-efficient evaporation under intermittent solar illumination. Compared to the evaporator without a PCM core, the MXene/SA/SiO 2 -MEPCM-based evaporator achieved an increase in evaporation mass by 1.4 kg·m−2 through 5-cycle consecutive evaporation processes under solar illumination and natural cooling. Furthermore, its total water production was increased by 1.01 kg·m−2 under natural solar illumination for 7.5 h on a semi-cloudy day. The MXene/SA/SiO 2 -MEPCM also exhibits good recyclability for long-term use in solar-driven seawater desalination thanks to the good structural stability of its shell and highly stable reversible phase transitions of its PCM core. [Display omitted] • We developed a novel solar-driven evaporator for consecutive and high-efficient seawater desalination. • The developed evaporator is based on MXene/sodium alginate-decorated phase-change microcapsules. • The microcapsules show a high latent-heat capacity and high solar photothermal conversion efficiency. • The evaporator exhibits a high yield of condensate water under intermittent solar illumination. • The study offers an effective solution for salt acumination problem in seawater desalination. [ABSTRACT FROM AUTHOR]

Renewable energy or low grade energy utilizations need high performance of phase change heat exchangers. Suspending micromembrane cylinder in tube (called modulated heat transfer tube) increases the void fractions or vapor qualities near the tube wall to significantly enhance heat transfer. The R123 condensation heat transfer with horizontal position was investigated. The results for the bare tube and modulated heat transfer tube were tested case by case. It is found that the modulated heat transfer tube significantly enhance the condensation heat transfer, with the heat transfer enhancement factors (EF) covering the range of 1.118-2.124. The comprehensive performance evaluation criteria (PEC) had the range of 0.71-1.66, with most of runs behaving PEC larger than 1.0. For the two-phase outlet conditions, the EF values are increased with increases in the vapor mass fluxes, Gx, where G is the mass flux and x is the inlet vapor mass quality. The EF values are inversely related to Gx for the subcooled liquid outlet cases. The enhanced heat transfer mechanisms are analyzed with the observed images together with the discussion of pressure and velocity distributions. [ABSTRACT FROM AUTHOR]

Aiming at improving the utilization efficiency of solar photothermal energy, this study focuses on a novel phase-change microcapsule system based on an n -docosane core and a carbon-nanotubes (CNTs)/polydopamine (PDA)/silica hierarchical shell. The system was fabricated by encapsulating n -docosane in a silica shell and then depositing a PDA layer on the shell surface, followed by conglutinating CNTs onto the PDA layer. The resultant microcapsule system shows a regular spherical morphology together with desired core-shell hierarchical microstructure and chemical compositions. The presence of CNTs/PDA coating layer can impart an efficient solar light-to-heat energy conversion capability to the microcapsule system through photon capture and sunlight absorption. The microcapsule system not only shows a good latent heat-storage capability with satisfactory phase-change enthalpies of over 130 J/g but also exhibits an optimal photothermal conversion efficiency of 90.1%. The microcapsule system also exhibits good leakage-prevention performance, high thermal cycle stability, excellent thermal impact resistance, and good shape/form stability to deal with a wide range of solar photothermal energy applications. Through integrating CNTs and PDA into a phase-change microcapsule system, this work provides a promising approach for the development of PCMs-based functional materials with enhanced solar light-to-heat energy conversion and storage performance for efficient utilization of solar energy. [Display omitted] • We developed new PCM-based microcapsules for high-efficient solar light-to-heat conversion. • The microcapsules were based on the n -docosane core and CNTs/PDA/SiO 2 hierarchical shell. • The microcapsules have an eligible latent-heat capacity of over 130 J/g for thermal energy storage. • The microcapsules show a high photothermal conversion efficiency of 90.1% for solar energy harvest. • The microcapsules exhibit great potential for efficient utilization of solar energy. [ABSTRACT FROM AUTHOR]

[Display omitted] • This study focuses on an ingenious integration of biosensors and phase change materials. • We designed a smart biosensor for enhancing detection effectiveness in a high temperature region. • The biosensor was constructed with bioelectrocatalytic phase-change microcapsules. • The biosensor shows a thermal self-regulatory ability to buffer thermal swings. • The biosensor exhibits good performance for detection of catechol under in-situ thermal management. Conventional enzyme-based biosensors are highly sensitive to operation temperature due to a strong temperature dependency of biocatalytic activity. Aiming to enhance the biosensing detection of hazardous substances at high ambient temperatures, we focused on the design and construction of a thermal self-regulatory smart biosensor through an innovative combination of phase change material (PCM) and bioelectrocatalytic material. A bioelectrocatalytic phase-change microcapsule system was first fabricated by microencapsulating n -eicosane as a PCM core in the TiO 2 shell and then depositing polypyrrole (PPy) as an electroactive coating layer on the surface of TiO 2 shell, followed by immobilizing horseradish peroxidase on the surface of PPy coating layer through physical adsorption. The resultant microcapsules exhibit a regular spherical morphology and layer-by-layer core–shell microstructure with the desired chemical compositions. The microcapsules not only exhibit a good thermal management ability to perform effective temperature regulation under a latent-heat capacity of approximately 115 J/g, but also reveal high thermal impact resistance and good thermal cycle stability for the long-term thermal management application in biosensors. A working electrode was modified with the microcapsules obtained above and then used to construct an electrochemical biosensing system imparted with a thermal self-regulation capability. With a high sensitivity of 5.571 µA·L·µmol−1·cm−2 and a low detection limit of 5.384 µmol/L at 55 °C, the resultant smart biosensor exhibits a better determination ability to detect catechol as a model hazardous substance at high operation temperatures than conventional biosensors thanks to the in-situ thermal management derived from its n -eicosane core. This study provides a new approach for development of thermal self-regulatory smart biosensors with an enhanced identification capability to detect hazardous substances over a wide range of temperatures. [ABSTRACT FROM AUTHOR]

In the process cementing of deep water, cement particles react with water to produce a lot of hydration heat, which can lead to decomposition of natural gas hydrate. We synthesized a kind of micro-capsule thermal control material with paraffin wax as the base material and calcium carbonate as the skeleton support material. At first, the chemical structure and chemical element composition of thermal control material were obtained by FTIR and EDS, respectively. Secondly, the phase change properties of MPCM-1 were measured by using DSC. As a result, it was shown that phase change temperature and phase change enthalpy of thermal control material is 31.11 °C and 88.59 J/g, respectively. Simultaneously, the thermal stability of IPCM-1 was obtained by using a synchronous thermal analyzer. Then, the micro-encapsulated thermal control material is introduced into the cement slurry system, and the hydration heat and maximum hydration temperature rise of the cement slurry were investigated by a self-made hydration heat test device. As a result, compared with cement slurry CB, the hydration heat released to the environment by cement slurry CS 12.0% decreased by 44.16% (at 48 h), and the maximum hydration temperature of cement slurry CS12.0% is reduced by 25.4 °C. Besides, compared with cement slurry CB, the compressive strength of cement slurry CS 12.0% increased by 5.9% (24 h) and 9.8% (48 h). The thermal control material was added into the cement slurry, and a low hydration heat cement slurry system was successfully prepared. • Microcapsule thermal control material of inorganic wall material was synthesized. • Microcapsule thermal control material can control the hydration heat and temperature rise of cement slurry. • A low hydration heat cement slurry successfully prepared by applying microcapsule thermal control material. [ABSTRACT FROM AUTHOR]

• A self-thermoregulatory electrode system was designed for supercapacitors. • The system was constructed by phosphorene-decorated phase-change microcapsules. • The system has an excellent thermal regulation and management capability. • The system exhibits the improved supercapacitor performance and cycle stability. • This work provides a novel strategy for design of high-performance electrode materials. Phosphorene is a promising candidate for the pseudocapacitive electrode material, because it offers a huge number of ion-accessible sites for multiphase active materials. A high working temperature is bound to deteriorate the electrochemical behavior of supercapacitors due to exothermic redox reactions during the charge–discharge process. To address this problem in supercapacitors, a self-thermoregulatory electrode material is designed and constructed to enhance the electrical energy-storage performance of supercapacitors for use in a wider temperature range. This electrode material is fabricated by microencapsulating n -docosane phase-change material (PCM) with a SiO 2 inner shell and then coating a polyaniline/phosphorene hybrid outer layer as an electrochemical active material. A well-defined core-shell microstructure and expected components of the resultant electrode material are confirmed by morphological observations and structural characterizations. In this electrode material, while the polyaniline/phosphorene hybrid layer performs charge storage/release behaviors according to the faradic mechanism, the PCM core can effectively regulate the microenvironmental temperature for the electrode system in situ through phase transitions, thus improving the rate capability and specific capacitance of the electrode system. Furthermore, the hybridization of polyaniline and phosphorene contributes to the enhancement of capacitive behavior and charge–discharge cycle stability by offering more ion-accessible site in the polyaniline active material. In view of a unique combination of phosphorene and PCM, the novel electrode material developed by this work exhibits a potential application for high-performance supercapacitors suitable for use at high working temperatures. Image, graphical abstract [ABSTRACT FROM AUTHOR]

During the cementing process of natural gas hydrate (NGH) layer, the hydration heat of cement slurry can easily cause decomposition of NGH which leads to cementing risk. A thermal control material of phase change micro-capsule (PCM-1) with paraffin as the core material and urea-formaldehyde resin as the wall material was successfully synthesized, and then a low hydration heat cement slurry was prepared by using PCM-1. The basic performances of PCM-1 were characterized by using DSC, FTIR, SEM and TG, and the results show that the performances meet designed requirements. Then, the PCM-1 was introduced into cement slurry system, and the hydration heat (Q) and hydration temperature rise (T r) were measured by using the self-developed semi-adiabatic test equipment. As a result, it was confirmed that the Q and the T r decrease with the increase of PCM-1 content. The T r of cement slurry CP 15% was 25.4 °C, lower than that of cement slurry CB. Meanwhile, compared with cement slurry CB, at 24 and 48 h hydration heat of cement slurry CP 15% were decreased by 7.68 × 104 and 7.28 × 104 J, respectively. Therefore, the decomposition of NGH was avoided attribute to the smaller Q of cement slurry, and the cementing operation risk in deep water was reduced. • The heat evaluation of cement slurry system was investigated by using a self-developed semi-adiabatic test equipment. • A high performance thermal control material PCM-1 was synthesized successfully. • PCM-1 can effectively control the early hydration heat and temperature rise of cement slurry. • A low hydration heat cement slurry system successfully prepared by applying PCM-1. [ABSTRACT FROM AUTHOR]