Conjugated Microporous Polymer Aerogels Encapsulated within Hydroxyapatite Nanowires Exhibit Good Thermal Insulation and Flame-Retardant Properties.

Aerogels have been widely studied in the field of thermal insulation. Herein, we reported a kind of conjugated micropolymer (CMP) aerogel synthesized by 1,3,5-triethynylbenzene and 2-amino-3,5-dibromopyridine. To enhance the flame-retardant property, we composited hydroxyapatite (HAP) nanowires with a CMP aerogel. Transmission electron microscopy (TEM) analysis revealed that HAP nanowires were encapsulated within nanosized CMP tubes. In addition, the thermal conductivity of HAP2-NCMP aerogel was 0.0251 W m-1 K-1, which possesses good thermal insulation property. In the micro-combustion calorimeter (MCC) test, compared with pure NCMP, the peak heat release rate (pHRR) of HAP2-NCMP decreased from 39.3 to 30.82 W g-1, approximately 21.6% lower. Furthermore, with the increased addition of hydroxyapatite in the HAP-NCMP composite, the pHRR of HAP3-NCMP decreased by about 37.4%. Besides, NCMP possesses good mechanical properties, with a compressive strength of 117.3 kPa at a strain level of 60%. These findings suggest promising application potential for HAP-NCMP in energy-saving and flame-retardant applications.

Recent advances and perspectives in solar photothermal conversion and storage systems: A review.

Developing high-efficiency solar photothermal conversion and storage (SPCS) technology is significant in solving the imbalance between the supply and demand of solar energy utilization in time and space. Aiming at the current research status in the field of SPCS, this review thoroughly examines the phase change materials and substrates in SPCS systems. It elucidates the design principles and methods of SPCS integrated composites. Comparatively, it analyzes the parameters of various types of SPCS composites in terms of photothermal conversion, thermal conductivity, energy density, and cycling stability. Additionally, the review discusses the trade-offs between each parameter to achieve the most optimal effect of SPCS. By sorting out the current status of the application of SPCS technology in solar thermal/photovoltaic, aerospace, buildings, textile, and other industries, this analysis clarifies the requirements for various latent heat, phase change temperature, and other properties under different environmental conditions. Through a comprehensive discussion of SPCS technology, this paper accurately captures the development trend of efficiently and comprehensively utilizing solar energy by analyzing existing scientific problems. It identifies bottlenecks in SPCS technology and suggests future development directions that need focused attention. The insights gained from this analysis may provide a theoretical basis for designing strategies, enhancing performance, and promoting the application of SPCS.

Janus membranes derived from multi-shelled hollow spheres coated electrospun PVA membranes as phase change composites for photothermal conversion.

The development and preparation of multifunctional photothermal conversion materials has far-reaching significance for the utilization of solar energy resources in response to the energy crisis. Herein, we propose a Janus membrane for interfacial solar evaporation and phase change energy storage. The membranes were fabricated via combining the PVA film with multi-shelled hollow spheres (MHS). The membranes have asymmetric wettability, that is, one side is hydrophilic and the other side is hydrophobic. The as-resulted membranes obtain outstanding light absorption without further processing. According to these two advantages, the membranes were applied to solar evaporation. The evaporation rate of the membrane is 1.41 kg*m-2h-1 and the evaporation efficiency is 92.4 % under 1sun irradiation. Moreover, the membrane prepared by impregnating 1-Hexadecanamine (HDA) into MHS possesses excellent tensile strength (2.21 MPa) and photothermal conversion ability. The light-to-thermal conversion efficiency can reach 81.9 % under 1sun irradiation. Therefore, the membranes have broad application prospects in the field of photothermal conversion.

Multishell Copper Oxide Hollow Spheres Incorporated with Fatty Amines for High Light-To-Thermal Conversion.

Composite phase change materials (PCMs) are of great importance for the storage and conversion of energy. In this study, a multishell metal oxide hollow microsphere (CuOHS) was prepared by the hydrothermal method, and a new composite PCM (CuOHS@PCMs) for energy storage and conversion purposes was developed by effectively absorbing fatty amines [namely, tetradecylamine (TDA), hexadecylamine (HDA), and octadecylamine (ODA)] PCMs into the CuOHS via the abundant micropores located on the surface of the microsphere. The incorporation of uncontaminated phase alteration substances with CuOHS yields superior light absorption and leak prevention traits. The three CuOHS@PCMs, specifically CuOHS@TDA, CuOHS@HDA, and CuOHS@ODA, possess considerable latent heats of 198.8, 192.6, and 196.0 J·g-1, respectively, and exhibit desirable thermal properties even after completing 50 and 100 thermal cycles. Moreover, under illumination, the photothermal conversion efficiencies of the three variations of CuOHS@PCMs were 84.0, 81.4, and 78.0%. This CuOHS@PCMs, which are based on CuOHS, have considerable potential in the fields of photothermal conversion, solar energy harvesting, and storage.

Highly Electrical Conductive PEDOT:PSS/SWCNT Flexible Thermoelectric Films Fabricated by a High-Velocity Non-solvent Turbulent Secondary Doping Approach.

Materials based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) can be potentially employed as flexible thermoelectric generators (TEGs) to capture waste heat and generate electrical energy. Among various methods, secondary doping is an effective way to modulate its thermoelectric (TE) performance. Different from conventional measures such as dropping, soaking, and steam fumigation, strong shear is integrated with the doping process and termed high-velocity non-solvent turbulent secondary doping (HNTD). We systematically investigate the transformation of PEDOT:PSS during this procedure and the formation mechanism of its highly conductive pathway. It is illustrated that PEDOT:PSS experiences PSS swelling, the phase separation of PEDOT from PSS, the removal of isolated PSS, and the evolution of PEDOT to a linear conformation. These evolutions contribute to the substantial elevation of electrical conductivity (σ). Furthermore, by employing continuous single-walled carbon nanotube (SWCNT) networks as structural units, highly conductive flexible PEDOT:PSS/SWCNT TE thin films could be prepared without sacrificing the Seebeck coefficient (S). Additionally, the effect of HNTD and direct addition method on TE properties of composite films is also compared. Finally, the PEDOT:PSS composite film with 40 wt % SWCNTs by the HNTD method exhibits the maximized power factor (PF) of 501.31 ± 19.23 µW m-1 K-2 with σ of 4717.8 ± 41.51 S cm-1 and S of 32.6 ± 0.13 µV K-1 at room temperature. It is worth mentioning that the σ value 4717.8 ± 41.51 S cm-1 is the highest among the composites based on commercial carbon fillers and organic semiconductors. Finally, a 6-leg TEGs prototype is assembled and illustrates an output power of 4.416 µW under a temperature difference (ΔT) of 58 K. It is thought that such a strategy may provide some guidelines for manufacturing PEDOT:PSS-based functional materials.

Mechanically robust conjugated microporous polymer membranes prepared using polyvinylpyrrolidone (PVP) electrospun nanofibers as a template for efficient PM capture.

Air pollution has become a challenging environmental problem worldwide due to rapid industrial development and excessive emissions of vehicle exhaust. Herein, we report a preparation of conjugated microporous polymer membranes (CMPM) with a hierarchical porous structure by electrospun polyvinylpyrrolidone (PVP) nanofibers as a template for effective removal of PM from airborne and vehicle exhaust. CMP membranes have hierarchical holes, where the macropores are from electrospun nanofiber membranes and the mesopores are from polymer synthesis. Taking advantage of its inherent physicochemical and thermal stability and hierarchical hole characteristics, the CMPM-based filter can work continuously for up to 36 h and still maintains a high removal efficiency (>99.56%), and also has a high filtration efficiency in the treatment of vehicle exhausts, with 95.18% for PM0.3, 98% for PM0.5 and >99% for PM2.5-10.0. The superior mechanical properties of CMPM allow the filter to be cleaned and reused. After three cycles, the filtration effectiveness of CMPM is still 94.83% for respirable particulate matter. Under high humidity (RH ≥ 95%) conditions, the CMPM-based filter showed higher than 95.37% filtration of PM0.3-10, and the oil adsorption rate could be maintained at 284% at high speed, proving the great potential of CMPM to clean air in complex situations.

ZnO nanorods loading with fatty amine as composite PCMs device for efficient light-to-thermal and electro-to-thermal conversion.

Phase change materials (PCMs) with ideal light-to-thermal conversion efficiency play an important role in solar energy storage and conversion. Hence, we report the fabrication of a novel composite PCMs (CPCMs) device based on ZnO nanorods deposited indium tin oxide (ITO) glass loading with fatty amines. ZnO nanorods were deposited on the ITO glass using a three-electrode electrodeposition method, and 1-Hexadecylamine (HDA) was loaded on the ITO glass via spin-coating, followed by spraying polypyrrole (ppy) on the surface of CPCM device to improve thermal conductivity and solar absorption. The as-prepared CPCM device exhibits excellent light-to-thermal conversion efficiency, achieving a high conversion efficiency of 90.2% obtained at 1sun owing to its high light absorption (80%), enhanced thermal conductivity (improved by 57.8%), and the unique vertical aligned nanorods structure which could significantly decrease tortuosity, thereby reducing thermal route and lowering thermal response time. Furthermore, the electro-to-thermal conversion efficiency of the CPCMs device has also been investigated and the results show that it can reach up to 69.8% under a low voltage of 5 V, indicating that the CPCM device has a high potential in the field of electro-to-thermal conversion. Based on the benefits listed above, the CPCM device may serve an ideal platform for a wide range of solar energy storage and conversion applications.

Holey Ti3C2 nanosheets based membranes for efficient separation and removal of microplastics from water.

The accumulation of non-degradable microplastics (MPs) originated from the mass production and huge consumption of plastics of modern industry in the water environment has resulted in severe pollution problems globally. Herein, we report for the first time the preparation of holey Ti3C2Tx (h-Ti3C2Tx) membranes obtained by etching Co3O4 nanoparticles embedded on Ti3C2Tx nanosheets followed by simple vacuum filtration using polymeric membranes as supporting matrix for efficient removal of MPs from wastewater. The h-Ti3C2Tx nanosheets exhibit a planar porous structure which present nano-holes with an average hole-size of 25 nm in diameter, which facilitated the construction of membranes with better water flux for the separation of MPs. Using fluorescent PS (FP) microspheres of different diameters as microplastic models, the obtained h-Ti3C2Tx membranes exhibited extremely high MPs removal performance (up to 99.3% under our conditions). Moreover, a large water flux of 196.7 L h-1 m-2 k Pa-1 can be obtained, which can compete or be larger than that of most of the membranes composed of untreated two-dimension nanomaterials. Due to the physicochemical stability, tremendous large water reflux, and the high MPs removal efficiency of h-Ti3C2Tx membranes, there may be a great potential for practical applications in the separation and removal of various contaminants such as MPs or suspended solids from water.

Retinal development in mandarinfish Siniperca chuatsi and morphological analysis of the photoreceptor layer.

We describe the process of retinal development in mandarinfish Siniperca chuatsi from larvae to young fish. The developmental characteristics of the retinal structure and related cells were identified. Siniperca chuatsi were found to exhibit an altricial mode of retinal development that required considerable time to be completed after hatching. The retina was classed as a pure cone type during the early developmental stage. In the subsequent developmental stages, however, double cones gradually occupied the majority of the cone cells, while rod cells represented the majority of the photoreceptor cells. The outer segment (OS) of the rod cells were significantly longer compared with other morphological features, the OS of the two kinds of cone cells were significantly elongated and the diameters of the inner segment (IS) and OS of the double cone cells were significantly narrower in the later developmental stages. Combined with the scattered arrangement of cone cells at the different stages, the retina was found to have sacrificed a considerable part of visual acuity in the developmental process. The distribution of cone cells was observed to have gradually become regionalised during development. The findings of the present study also indicated that S. chuatsi have a high photosensitivity under dim light conditions as a result of specialised structures of the OS of photoreceptor cells and an increased number of rod cells. The loose arrangement of the cone mosaic presumably resulted in a poor imaging quality and, to some extent, the regionalisation of the cone-cell distribution compensated for the above shortcomings, which would enhance the ability of S. chuatsi to perceive targets in important directions for effective predation behaviour.