Search Results (11)

Organic phase-change materials (PCMs) offer great promise in addressing challenges in thermal energy storage and heat management, but their applications are greatly limited by low energy density and a rigid phase transition temperature. Herein, by introducing carbon dots (CDs) with abundant oxygen-related groups, we develop a novel kind of erythritol (ET)-based composite PCMs (CD-ETs) featuring an enhanced latent heat storage capacity and a reduced degree of supercooling compared to pure ETs. The optimally formulated CD-ETs increase the latent heat storage capacity from 377.3 to 410.2 J·g⁻¹ and the heat release capacity from 209.0 to 240.2 J·g⁻¹ compared to the pristine ETs. Moreover, the subcooled degree of CD-ETs is more than 30 °C lower than that of pristine ETs. By successively encapsulating CD-ETs and CD-containing polyethylene glycol (PEG) with a low melting point in a reduced graphene oxide-modified melamine sponge, the resultant shape-stabilized system not only prevents leakage of molten PCMs but also allows for a wide response temperature window and promotes the heat transfer ability of melted PEG in close contact with solid CD-ETs. Stepped melting and crystallization guarantee phase changes in high-melting-point ETs via solar heating, Joule heating or a combination thereof. Specifically, the melting enthalpy of this system is as high as 306.5 J·g⁻¹, and its cold crystallization enthalpy reaches 196.5 J·g⁻¹, surpassing numerous organic PCMs. This work provides a facile and efficient strategy for the design of ideal thermal energy storage materials to meet the needs of application scenarios in a cost-effective manner. Full article

As a technology for water landscape performance that considers landscape, ecological, and social effects, nature-based solutions play a crucial role in enhancing the functionality of integrated ecosystem services on the micro-scale. This study conducted a systematic investigation into the landscape performance of the “Clear as a Drain” composite sponge facility at Handan Garden Expo Park. The following conclusions were drawn: (1) In terms of ecological restoration support services, the “Clear as a Drain” artificial wetland exhibited diverse habitat types, a rich variety of plant species specific to the site’s region, and high plant diversity indices for shrubs (1.776) and herbaceous aquatic plants (3.352). Reclaimed water reused in the artificial terraced wetland promoted plant growth and diversity while contributing to site self-rehabilitation; plants also significantly contributed to carbon fixation, oxygen release, and carbon emission reduction. (2) Regarding ecological restoration regulation services, the artificial wetland effectively purified reclaimed water with substantial improvements observed in incoming water quality during spring, summer, and autumn—particularly notable purification effects were observed during the summer months. Pollutant reduction rates for COD, BOD₅ ammonia nitrogen, TP, and TN reached 75.8%, 72.1%, 93.8%, 96.7%, and 90.3%, respectively; different independent subsystems within the wetland demonstrated distinct advantages in pollutant removal; park plants displayed strong air purification capabilities; annual energy savings from park plants could fully cover daily energy consumption for nearby residents. This case could serve as guidance for scientific management and design parameter optimization of other composite sponge facilities. Full article

Wastewater treatment from oil, oil products and organic mixtures is a very relevant topic that can be successfully utilized to solve problems of severe environmental pollution, such as oil spills, industrial oily wastewater discharges and water treatment in the water treatment process. In this work, we have developed new superhydrophobic magnetic polyurethane (PU) sponges, functionalized with reduced graphene oxide (RGO), MgFe₂O₄ nanoparticles, and silicone oil AS 100 (SO), as a selective and reusable sorbent for the purification and separation of wastewater from oil and organic solvents. The surface morphology and wettability of the sponge surface were characterized by scanning electron microscopy (SEM) and a contact angle analysis system, respectively. The results showed that the obtained PU sponge PU/RGO/MgFe₂O₄/SO had excellent mechanical and water-repellent properties, good reusability (lasted more than 20 cycles), as well as fast (immersion time 20 s) and excellent absorption capacity (16.61–44.86 g/g), and additional good magnetic properties, which made it easy to separate the sponge from the water with a magnet. The presence of RGO in the composition of the nanomaterial improves the separating and cleaning properties of the materials and also leads to an increase in the absorption capacity of oil and various organic solvents. The synthesized PU sponge has great potential for practical applications due to its facile fabrication and excellent oil–water separation properties. Full article

Large-area craniofacial defects remain a challenge for orthopaedists, hastening the need to develop a facile and safe tissue engineering strategy; osteoconductive material and a combination of optimal growth factors and microenvironment should be considered. Faced with the unmet need, we propose that abundant cytokines and chemokines can be secreted from the bone defect, provoking the infiltration of endogenous stem cells to assist bone regeneration. We can provide a potent mRNA medicine cocktail to promptly initiate the formation of bone templates, osteogenesis, and subsequent bone matrix deposition via endochondral ossification, which may retard rapid fibroblast infiltration and prevent the formation of atrophic non-union. We explored the mutual interaction of BMP2 and TGFβ3 mRNA, both potent chondrogenic factors, on inducing endochondral ossification; examined the influence of in vitro the transcribed polyA tail length on mRNA stability; prepared mRNA nanomedicine using a PEGylated polyaspartamide block copolymer loaded in a gelatin sponge and grafted in a critical-sized calvarial defect; and evaluated bone regeneration using histological and μCT examination. The BMP2 and TGFβ3 composite mRNA nanomedicine resulted in over 10-fold new bone volume (BV) regeneration in 8 weeks than the BMP2 mRNA nanomedicine administration alone, demonstrating that the TGFβ3 mRNA nanomedicine synergistically enhances the bone’s formation capability, which is induced by BMP2 mRNA nanomedicine. Our data demonstrated that mRNA-medicine-mediated endochondral ossification provides an alternative cell-free tissue engineering methodology for guiding craniofacial defect healing. Full article

Serious damage caused by oily wastewater makes the development of efficient superhydrophobic and superoleophilic materials for oil/water separation processes critical and urgent. Herein, durable superhydrophobic nanometer-scale TiO₂ grains with low-surface-energy substance composite-modified materials were fabricated by using a cost-effective and facile synthesis method for the gravity-driven separation of oil/water mixtures under harsh conditions. Different substrates, such as sawdust, wheat straw, cotton, sponge and fabric, were applied for superhydrophobic surface preparation, and various low-surface-energy reagents could interact with deposited TiO₂ nanoparticles, including cetylamine, dodecanethiol, stearic acid and HDTMS. The resultant materials showed superhydrophobic properties with a water contact angle (WCA) higher than 150.8°. The separation of various oil/water mixtures with high efficiency and purity was acquired by using the as-prepared sponge. More importantly, the coated sponge exhibited good resistance to various harsh environmental solutions. Moreover, its superhydrophobicity also remained even after 12 months of storage in air or 10 cycles of abrasion. The durable superhydrophobic coating prepared in this work could be practically used for the highly efficient separation of oil/water mixtures under various harsh conditions. Full article

Photothermally assisted superhydrophobic materials play an important role in a variety of applications, such as oil purification, waste oil collection, and solar desalination, due to their facile fabrication, low-cost, flexibility, and tunable thermal conversion. However, the current widely used superhydrophobic sponges with photothermal properties are usually impaired by a high loading content of photothermal agents (e.g., gold or silver nanoparticles, carbon nanotubes), low photothermal efficiency, and require harmful processes for modification. Here, a one-pot, simple composite consisting of two-dimensional (2D) selenium (Se) nanosheets (NSs) and commercially used melamine sponge (MS) is rationally designed and successfully fabricated by a facile dip-coating method via physical adsorption between 2D Se NSs and MS. The loading content of 2D Se NSs on the skeleton of the MS can be well controlled by dipping cycle. The results demonstrate that after the modification of 2D Se NSs on the MS, the wettability transition from hydrophilicity to hydrophobicity can be easily achieved, even at a very low loading of 2D Se NSs, and the highly stable photothermal conversion of the as-fabricated composites can be realized with a maximum temperature of 111 ± 3.2 °C due to the excellent photothermal effect of 2D Se NSs. It is anticipated that this composite will afford new design strategies for multifunctional porous structures for versatile applications, such as high-performance solar desalination and photothermal sterilization. Full article

A facile approach for developing an interfacial solar evaporator by heat localization of solar-thermal energy conversion at water-air liquid composed by in-situ polymerization of Fe₂O₃ nanoparticles (Fe₂O₃@PPy) deposited over a facial sponge is proposed. The demonstrated system consists of a floating solar receiver having a vertically cross-linked microchannel for wicking up saline water. The in situ polymerized Fe₂O₃@PPy interfacial layer promotes diffuse reflection and its rough black surface allows Omni-directional solar absorption (94%) and facilitates efficient thermal localization at the water/air interface and offers a defect-rich surface to promote heat localization (41.9 °C) and excellent thermal management due to cellulosic content. The self-floating composite foam reveals continuous vapors generation at a rate of 1.52 kg m⁻² h⁻¹ under one 1 kW m⁻² and profound evaporating efficiency (95%) without heat losses that dissipates in its surroundings. Indeed, long-term evaporation experiments reveal the negligible disparity in continuous evaporation rate (33.84 kg m⁻²/8.3 h) receiving two sun solar intensity, and ensures the stability of the device under intense seawater conditions synchronized with excellent salt rejection potential. More importantly, Raman spectroscopy investigation validates the orange dye rejection via Fe₂O₃@PPy solar evaporator. The combined advantages of high efficiency, self-floating capability, multimedia rejection, low cost, and this configuration are promising for producing large-scale solar steam generating systems appropriate for commercial clean water yield due to their scalable fabrication. Full article

Melamine sponge (MS) has the characteristics of multilayer network structure, high porosity, adjustable pore structure, and low price, which is considered to be an ideal material for oil leakage treatment. Here, a facile, economical, environmental friendly, and one step reaction was developed to fabricate Ag nanoparticles (NPs) decorated MS composite with tannic acid (TA) as a reducing agent. By reduction reaction, the super-hydrophobic and super-oleophylic surface of the MS–TA–Ag composite was formed, demonstrating a single selectivity for oil and water. Thus, the adsorption capacity of MS–TA–Ag composites for various oils/organic solvents can reach 48~129 times its own weight and and display superior efficiency to separate oil/organic solvent from the water. In addition, the MS–TA–Ag composite has stable super-hydrophobicity and reusability. It is exciting that modified MS exhibits excellent chemical stability properties after a long processing time with strong alkali, strong acids, and salt solutions. The simple strategy provides a method for the preparation of large-scale oil spill cleaning and recovery materials. Full article

Recently, flexible tactile sensors based on three-dimensional (3D) porous conductive composites, endowed with high sensitivity, a wide sensing range, fast response, and the capability to detect low pressures, have aroused considerable attention. These sensors have been employed in different practical domain areas such as artificial skin, healthcare systems, and human–machine interaction. In this study, a facile, cost-efficient method is proposed for fabricating a highly sensitive piezoresistive tactile sensor based on a 3D porous dielectric layer. The proposed sensor is designed with a simple dip-coating homogeneous synergetic conductive network of carbon black (CB) and multi-walled carbon nanotube (MWCNTs) composite on polydimethysiloxane (PDMS) sponge skeletons. The unique combination of a 3D porous structure, with hybrid conductive networks of CB/MWCNTs displayed a superior elasticity, with outstanding electrical characterization under external compression. The piezoresistive tactile sensor exhibited a high sensitivity of (15 kPa⁻¹), with a rapid response time (100 ms), the capability of detecting both large and small compressive strains, as well as excellent mechanical deformability and stability over 1000 cycles. Benefiting from a long-term stability, fast response, and low-detection limit, the piezoresistive sensor was successfully utilized in monitoring human physiological signals, including finger heart rate, pulses, knee bending, respiration, and finger grabbing motions during the process of picking up an object. Furthermore, a comprehensive performance of the sensor was carried out, and the sensor’s design fulfilled vital evaluation metrics, such as low-cost and simplicity in the fabrication process. Thus, 3D porous-based piezoresistive tactile sensors could rapidly promote the development of high-performance flexible sensors, and make them very attractive for an enormous range of potential applications in healthcare devices, wearable electronics, and intelligent robotic systems. Full article

Crude oil spills from offshore oil fields will cause serious pollution to the marine ecological environment. Many 3D porous materials have been used for oil–water separation, but they cannot be widely used due to complex preparation processes and expensive preparation costs. Here, a facile and cheap approach to disperse expanded graphite (EG), stearic acid, and Fe₃O₄ magnetic nanoparticles on the skeleton surface of polyurethane (PU) sponge to prepare the magnetic and hydrophobic composite polyurethane sponge for oil–water separation. The results show that the composite PU sponge had a strong oil absorption capacity for various oils, the oil adsorption capacities has reached 32–40 g/g, and it has become more hydrophobic. The addition of Fe₃O₄ magnetic nanoparticles endowed the sponge with magnetic responsivity, and the composite PU sponge still had a strong oil adsorption capacity after several adsorbing-squeezing cycles. The magnetic and hydrophobic composite polyurethane sponge is a very promising material for practical oil adsorption and oil–water separation. Full article

A versatile, facile, energy-saving, low-cost and plant-inspired self-assembly strategy was used to prepare super-hydrophobic coating in this study. Concretely, an appealing super-hydrophobicity surface was obtained by designing a molecular building block phytic acid (PA)-Fe (III) complex to anchor the substrate and hydrophobic thiol groups (HT). The facile and green modification method can be applied to variety of substrates. The as-prepared PA-Fe (III)–HT coated melamine composite sponge possesses both super-hydrophobic and superlipophilicity property. Moreover, it displays superior efficiency to separate the oil–water mixture and splendid oil spill cleanup. Full article