Separators play a pivotal role in the electrochemical performance and safety of lithium‐ion batteries (LIBs). The commercial microporous polyolefin‐based separators often suffer from inferior ...electrolyte wettability, low thermal stability, and severe safety concerns. Herein, a novel kind of highly flexible and porous separator based on hydroxyapatite nanowires (HAP NWs) with excellent thermal stability, fire resistance, and superior electrolyte wettability is reported. A hierarchical cross‐linked network structure forms between HAP NWs and cellulose fibers (CFs) via hybridization, which endows the separator with high flexibility and robust mechanical strength. The high thermal stability of HAP NW networks enables the separator to preserve its structural integrity at temperatures as high as 700 °C, and the fire‐resistant property of HAP NWs ensures high safety of the battery. In particular, benefiting from its unique composition and highly porous structure, the as‐prepared HAP/CF separator exhibits near zero contact angle with the liquid electrolyte and high electrolyte uptake of 253%, indicating superior electrolyte wettability compared with the commercial polyolefin separator. The as‐prepared HAP/CF separator has unique advantages of superior electrolyte wettability, mechanical robustness, high thermal stability, and fire resistance, thus, is promising as a new kind of separator for advanced LIBs with enhanced performance and high safety.
A new kind of highly flexible, porous, high‐wettability, fire‐resistant hydroxyapatite nanowire‐based separator with superior performance and high safety is prepared for advanced lithium‐ion batteries. The batteries with the hydroxyapatite nanowire‐based separators show better cyclability and enhanced rate capability compared with those with the commercial polypropylene separator. The as‐prepared batteries adopting the hydroxyapatite nanowire‐based separator can safely work at 150 °C.
Practical applications of nanostructured materials have been largely limited by the difficulties in controllable and scaled-up synthesis, large-sized highly ordered self-assembly, and macroscopic ...processing of nanostructures. Hydroxyapatite (HAP), the major inorganic component of human bone and tooth, is an important biomaterial with high biocompatibility, bioactivity, and high thermal stability. Large-sized highly ordered HAP nanostructures are of great significance for applications in various fields and for understanding the formation mechanisms of bone and tooth. However, the synthesis of large-sized highly ordered HAP nanostructures remains a great challenge, especially for the preparation of large-sized highly ordered ultralong HAP nanowires because ultralong HAP nanowires are easily tangled and aggregated. Herein, we report our three main research findings: (1) the large-scale synthesis of highly flexible ultralong HAP nanowires with lengths up to >100 μm and aspect ratios up to >10000; (2) the demonstration of a strategy for the rapid automated production of highly flexible, fire-resistant, large-sized, self-assembled highly ordered ultralong HAP nanowires (SHOUHNs) at room temperature; and (3) the successful construction of various flexible fire-resistant HAP ordered architectures using the SHOUHNs, such as high-strength highly flexible nanostructured ropes (nanoropes), highly flexible textiles, and 3-D printed well-defined highly ordered patterns. The SHOUHNs are successively formed from the nanoscale to the microscale then to the macroscale, and the ordering direction of the ordered HAP structure is controllable. These ordered HAP architectures made from the SHOUHNs, such as highly flexible textiles, may be engineered into advanced functional products for applications in various fields, for example, fireproof clothing.
Solar energy‐driven water evaporation is a promising sustainable strategy to purify seawater and contaminated water. However, developing solar evaporators with high water evaporation rates and ...excellent salt resistance still faces a great challenge. Herein, inspired by the long‐range ordered structure and water transportation capability of lotus stem, a biomimetic aerogel with vertically ordered channels and low water evaporation enthalpy for high‐efficiency solar energy‐driven salt‐resistant seawater desalination and wastewater purification is developed. The biomimetic aerogel consists of ultralong hydroxyapatite nanowires as heat‐insulating skeletons, polydopamine‐modified MXene as a photothermal material with broadband sunlight absorption and high photothermal conversion efficiency, polyacrylamide, and polyvinyl alcohol as reagents to lower the water evaporation enthalpy and as glues to enhance the mechanical performance. The honeycomb porous structure, unidirectionally aligned microchannels, and nanowire/nanosheet/polymer pore wall endow the biomimetic aerogel with excellent mechanical properties, rapid water transportation, and excellent solar water evaporation performance. The biomimetic aerogel exhibits a high water evaporation rate (2.62 kg m−2 h−1) and energy efficiency (93.6%) under one sun irradiation. The superior salt‐rejecting ability of the designed water evaporator enables stable and continuous seawater desalination, which is promising for application in water purification to mitigate the global water crisis.
A lotus stem‐inspired aerogel water evaporator with vertically aligned channels and low water evaporation enthalpy is fabricated using ultralong hydroxyapatite nanowires, polyacrylamide, polyvinyl alcohol, and polydopamine‐modified MXene, which exhibits a high water evaporation rate and high energy efficiency as well as stable and salt‐rejecting seawater desalination.
Water pollution and freshwater shortage have deteriorated the global water crisis. Developing sustainable methods to alleviate contaminated water has become an urgent affair. Herein, inspired by ...water transportation and transpiration of natural trees, the authors report an ultralong hydroxyapatite nanowires‐based biomimetic aerogel with vertically aligned channels and multiple functions for continuous flow catalysis, water disinfection, solar energy‐driven water purification, and seawater desalination. Ultralong hydroxyapatite nanowires act as carriers to immobilize catalyst nanoparticles and serve as building blocks to assemble with chitosan to form the biomimetic aerogel with structure‐function integration. Benefiting from the interconnected cellular structure, unidirectional aligned channels, nanowire‐interwoven networked pore wall, and evenly distributed catalyst nanoparticles, the biomimetic aerogel exhibits high catalytic activity (97.6% treatment efficiency) and permeability (1786 L m−2 h−1), excellent recyclability and stability in continuous flow catalytic degradation of methylene blue solely driven by gravity. The biomimetic aerogel exhibits excellent performance for bacteria removal and anti‐biofouling. The superior photothermal conversion and heat confinement properties enable the biomimetic aerogel with a high efficiency (86.7%) for solar energy‐driven seawater desalination and wastewater purification under one sun irradiation. The multifunctional biomimetic aerogel has promising applications in catalytic reactions, wastewater remediation, and environmental engineering.
A tree‐inspired multifunctional aerogel with vertically aligned channels is fabricated from ultralong hydroxyapatite nanowires, immobilized palladium nanoparticles, and chitosan through a unidirectional freeze‐drying approach. The biomimetic aerogel exhibits high performances in gravity‐driven continuous flow catalytic reactions, water disinfection, and solar energy‐driven water purification and seawater desalination.
A highly flexible and nonflammable inorganic hydroxyapatite (HAP) paper made from HAP ultralong nanowires is reported. The paper can be used for printing and writing and is promising for the ...permanent and safe storage of information, such as archives and important documents. The HAP paper is also an excellent and recyclable adsorbent for organic pollutants.
A highly flexible and nonflammable inorganic hydroxyapatite (HAP) paper made from HAP ultralong nanowires is reported. The paper can be used for printing and writing and is promising for the permanent and safe storage of information, such as archives and important documents. The HAP paper is also an excellent and recyclable adsorbent for organic pollutants.
Efficient utilization of abundant solar energy for clean water generation is considered a sustainable and environment friendly approach to mitigate the global water crisis. For this purpose, this ...study reports a flexible fire‐resistant photothermal paper by combining carbon nanotubes (CNTs) and fire‐resistant inorganic paper based on ultralong hydroxyapatite nanowires (HNs) for efficient solar energy‐driven water steam generation and water purification. Benefiting from the structural characteristics of the HN/CNT photothermal paper, the black CNT surface layer exhibits a high light absorbability and photothermal conversion capability, the HN‐based inorganic paper acts as a thermal insulator with a high temperature stability, low thermal conductivity, and interconnected porous structure. By combining these advantages, high water evaporation efficiencies of 83.2% at 1 kW m−2 and 92.8% at 10 kW m−2 are achieved. In addition, the HN/CNT photothermal paper has a stable water evaporation capability during recycling and long‐time usage. The promising potential of the HN/CNT photothermal paper for efficient production of drinkable water from both actual seawater and simulative wastewater samples containing heavy metal ions, dyes, and bacteria is also demonstrated. The highly flexible HN/CNT photothermal paper is promising for application in highly efficient solar energy‐driven seawater desalination and wastewater purification.
Highly flexible fire‐resistant photothermal paper is fabricated using ultralong hydroxyapatite nanowires and carbon nanotubes for highly efficient solar energy‐driven seawater desalination and wastewater purification, it has a high performance in recycling and long‐time usage, and it has promising application in the production of clean drinkable water from seawater and wastewater to mitigate the water scarcity crisis.
Owing to their high natural abundance, low cost, easy availability, and excellent magnetic properties, considerable interest has been devoted to the synthesis and applications of iron oxide ...nanostructured materials. Liquid‐phase synthesis methods are economical and environmentally friendly with low energy consumption and volatile emissions, and as such have received much attention for the preparation of iron oxide nanostructured materials. Herein, the liquid‐phase synthesis methods of iron oxide nanostructured materials including the co‐precipitation method, microemulsion method, conventional hydrothermal and solvothermal methods, microwave‐assisted heating method, sonolysis method, and other methods are summarized and reviewed. Many iron oxide nanostructured materials, self‐assembled nanostructures, and nanocomposites have been successfully prepared, which are of great significance to enhance their structure‐dependent properties and applications. The specific roles of liquid‐phase chemical reaction parameters in regulating the chemical composition, structure, crystallinity, morphology, particle size, and dispersive behavior of the as‐prepared iron oxide nanostructured materials are emphasized. The biomedical, environmental, and electrochemical energy storage applications of iron oxide nanostructured materials are discussed. Finally, challenges and perspectives are proposed for future investigations on the liquid‐phase synthesis and applications of iron oxide nanostructured materials.
Nanostructured iron oxides: This review article summarizes the liquid‐phase synthetic methods for iron oxide nanostructured materials, such as the co‐precipitation method, microemulsion method, conventional hydrothermal and solvothermal methods, microwave‐assisted heating method, sonochemical method, and other methods. In addition, the biomedical, environmental, and electrochemical energy storage applications of iron oxide nanostructured materials are discussed to emphasize their promising applications.
pH-responsive drug-delivery systems Zhu, Ying-Jie; Chen, Feng
Chemistry, an Asian journal,
February 2015, Letnik:
10, Številka:
2
Journal Article
Recenzirano
In many biomedical applications, drugs need to be delivered in response to the pH value in the body. In fact, it is desirable if the drugs can be administered in a controlled manner that precisely ...matches physiological needs at targeted sites and at predetermined release rates for predefined periods of time. Different organs, tissues, and cellular compartments have different pH values, which makes the pH value a suitable stimulus for controlled drug release. pH-Responsive drug-delivery systems have attracted more and more interest as "smart" drug-delivery systems for overcoming the shortcomings of conventional drug formulations because they are able to deliver drugs in a controlled manner at a specific site and time, which results in high therapeutic efficacy. This focus review is not intended to offer a comprehensive review on the research devoted to pH-responsive drug-delivery systems; instead, it presents some recent progress obtained for pH-responsive drug-delivery systems and future perspectives. There are a large number of publications available on this topic, but only a selection of examples will be discussed.
With the growing popularity of electrical communication equipment, high-performance electromagnetic interference (EMI) shielding materials are widely used to deal with radiation pollution. However, ...the large thickness and poor mechanical properties of many EMI shielding materials usually limit their applications. In this study, ultrathin and highly flexible Ti3C2T x (d-Ti3C2T x , MXene)/cellulose nanofiber (CNF) composite paper with a nacre-like lamellar structure is fabricated via a vacuum-filtration-induced self-assembly process. By the interaction between one-dimensional (1D) CNFs and two-dimensional (2D) d-Ti3C2T x MXene, the binary strengthening and toughening of the nacre-like d-Ti3C2T x /CNF composite paper has been successfully achieved, leading to high tensile strength (up to 135.4 MPa) and fracture strain (up to 16.7%), as well as excellent folding endurance (up to 14 260 times). Moreover, the d-Ti3C2T x /CNF composite paper exhibits high electrical conductivity (up to 739.4 S m–1) and excellent specific EMI shielding efficiency (up to 2647 dB cm2 g–1) at an ultrathin thickness (minimum thickness 47 μm). The nacre-inspired strategy in this study offers a promising approach for the design and preparation of the strong integrated and flexible MXene/CNF composite paper, which may be applied in various fields such as flexible wearable devices, weapon equipment, and robot joints.
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