Organic-inorganic Hybrid Structures Research Articles

A one pot synthesis and characterization of intrinsically fluorescent cross-linked polyphosphazene nanospheres

Novel inorganic-organic hybrid highly crosslinked and fluorescent polyphosphazene nanospheres were prepared via a one pot polycondensation polymerization method. Fluorescein and 4,4′-diaminodiphenylmethane were used as organic monomers in the synthesis of the nanospheres. The crosslinked structure of the nanospheres was formed with inorganic octachlorocyclotetraphosphazene rings. The characterization of the prepared nanospheres was performed by SEM, EDX, solid-state 31P-NMR, FTIR, XPS, XRD, DLS, and UV-vis techniques. The average particle size of the nanospheres was determined to be 343 nm. The fluorescence properties of the nanospheres were investigated. When they were excited at 470 nm, the nanospheres exhibited a fluorescence emission at 520 nm in ethanol. However, they did not show fluorescence emission at solid state. The nanospheres exhibited maximum emission at pH 9.0. The synthesized nanospheres have excellent photostability in 60 minutes at pH 9.0 owing to the crosslinked and inorganic-organic hybrid structure.

Study on properties of gelatin–silica mineralized wood composite

AbstractWood is a natural organic composite material that has abundant sources, is renewable, and exhibits an organized structure. However, the fast‐growing poplar tree is loose in texture and has poor physical, mechanical, and flame retardant properties. Inspired by the biomineralization mediated by the natural organic matrix, a biocompatible and mineral‐inducible gelatin solution is impregnated into the wood. Subsequently, the sol–gel method is used for the in‐situ mineralization of silica in wood pores and cell cavities using silica to prepare mineralized wood composite materials with excellent mechanical and flame retardancy properties. Fourier transform spectroscopy shows that wood and silica form an organic–inorganic hybrid structure, and scanning electron microscopy shows that gelatin coordinates with silica to form a dense microstructure. Compared with untreated wood, the compressive strength parallel to the grain, bending strength, and elasticity modulus of the mineralized wood were higher by 59.3%, 52.2%, and 46.2%, respectively. The peak heat release rate associated with cone calorimetry decreased by 45.8%. This effective and environment‐friendly method can improve the properties of wood. Furthermore, the preparation process is simple, green, and environment‐friendly, providing an alternative approach to wood modification research.

Reversible colossal barocaloric effect dominated by disordering of organic chains in (CH3–(CH2)n−1–NH3)2MnCl4 single crystals

Solid-state refrigeration based on the caloric effect is viewed as a promising efficient and clean refrigeration technology. Barocaloric materials were developed rapidly but have since encountered a general obstacle: the prominent caloric effect cannot be utilized reversibly under moderate pressure. Here, we report a mechanism of an emergent large, reversible barocaloric effect (BCE) under low pressure in the hybrid organic–inorganic layered perovskite (CH3–(CH2)n−1–NH3)2MnCl4 (n = 9,10), which show the reversible barocaloric entropy change as high as ΔSr ∼ 218, 230 J kg−1 K−1 at 0.08 GPa around the transition temperature (Ts ∼ 294, 311.5 K). To reveal the mechanism, single-crystal (CH3–(CH2)n−1–NH3)2MnCl4 (n = 10) was successfully synthesized, and high-resolution single-crystal X-ray diffraction (SC-XRD) was carried out. Then, the underlying mechanism was determined by combining infrared (IR) spectroscopy and density function theory (DFT) calculations. The colossal reversible BCE and the very small hysteresis of 2.6 K (0.1 K/min) and 4.0 K (1 K/min) are closely related to the specific hybrid organic–inorganic structure and single-crystal nature. The drastic transformation of organic chains confined to the metallic frame from ordered rigidity to disordered flexibility is responsible for the large phase-transition entropy comparable to the melting entropy of organic chains. This study provides new insights into the design of novel barocaloric materials by utilizing the advantages of specific organic–inorganic hybrid characteristics.

Correlating Symmetries of Low-Frequency Vibrations and Self-Trapped Excitons in Layered Perovskites for Light Emission with Different Colors.

The soft hybrid organic-inorganic structure of two-dimensional layered perovskites (2DLPs) enables broadband emission at room temperature from a single material, which makes 2DLPs promising sources for solid-state white lighting, yet with low efficiency. The underlying photophysics involves self-trapping of excitons favored by distortions of the inorganic lattice and coupling to phonons, where the mechanism is still under debate. 2DLPs with different organic moieties and emission ranging from self-trapped exciton (STE)-dominated white light to blue band-edge photoluminescence are investigated. Detailed insights into the directional symmetries of phonon modes are gained using angle-resolved polarized Raman spectroscopy and are correlated to the temperature-dependence of the STE emission. It is demonstrated that weak STE bands at low-temperature are linked to in-plane phonons, and efficient room-temperature STE emission to more complex coupling to several phonon modes with out-of-plane components. Thereby, a unique view is provided into the lattice deformations and recombination dynamics that are key to designing more efficient materials.

Cover Picture: Coordinated Anionic Inorganic Module—An Efficient Approach Towards Highly Efficient Blue‐Emitting Copper Halide Ionic Hybrid Structures (Angew. Chem. Int. Ed. 8/2022)

Copper halide based organic–inorganic hybrid structures exhibit great potential as light-emitting materials. In their Research Article (e202115225), Wei Liu, Gangfeng Ouyang et al. report a facile strategy for the synthesis of highly luminescent copper halide hybrid structures by fabricating a coordinated anionic inorganic module with a neutral organic ligand molecule. By using this approach, a family of blue-emitting copper halide hybrid ionic structures have been prepared with high internal quantum yields of up to 98 %.

Intrinsically fluorescent and quercetin loaded highly crosslinked polyphosphazene nanospheres: synthesis, characterization and fluorescence properties.

Highly crosslinked, inorganic-organic hybrid and intrinsically fluorescent polyphosphazene nanospheres bearing hydroxyl groups on the surface are facilely generated via a one-pot polycondensation of octachlorocyclotetraphosphazene, fluorescein and quercetin. The resulting nanospheres were characterised by scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), X-ray diffraction analysis (XRD) and ultraviolet-visible spectroscopy (UV-vis) techniques. The average diameter of the nanospheres was determined as 379 nm. Also, quercetin which is both a monomer and an anticancer drug was loaded to the nanospheres as 446 mg g-1. The obtained nanospheres possess outstanding disperse ability in both aqueous and organic solvents. Moreover, the nanospheres exhibited intrinsically fluorescence intensity and outstanding photobleaching stability under ultraviolet-visible irradiation, due to the highly crosslinked and inorganic-organic hybrid structure. Owing to these superior properties and novelty of synthesized nanospheres, they have a great potential in many applications such as fluorescent labels, sensors, cell imaging and as a nanocarrier of quercetin for cancer treatment.

Development of Photofunctional Devices Based on Organic–Inorganic Hybrid Structures

Development of Photofunctional Devices Based on Organic–Inorganic Hybrid Structures

Multifunctional polyethylene imine hybrids decorated by silica bioactive glass with enhanced mechanical properties, antibacterial, and osteogenesis for bone repair

Inorganic/organic hybrids and bioactive glasses demonstrate promising potential as bone substitute biomaterials. A sol-gel hybrid consisting of silica bioactive glass and biodegradable polymer can combine the high bioactivity of a glass with the toughness of a polymer. In this study, multifunctional hybrids with a combination of organic-inorganic hybrid structure class II consisting of polyethyleneimine (PEI) generation 4 (G4) and bioactive glass with enhanced mechanical properties, mineralization, antibacterial, and osteogenesis activities were synthesized by the sol-gel method. Glycidoxypropyl) trimethoxysilane (GPTMS) with different concentrations was used as a covalent bonding agent between PEI polymer and bioactive glass. The effect of GPTMS content was assessed in the presence and absence of calcium in the hybrid structures in terms of morphology, wettability, mechanical properties, antibacterial activity, cell viability, and in vitro osteogenic differentiation properties. By increasing the amount of GPTMS, the compressive strength increased from 1.95 MPa to 2.34 MPa, which was comparable to human trabecular bone. All the hybrids presented antibacterial activity against Staphylococcus aureus, forming an inhibition zone of 13–16 mm. An increase in cell viability of 82.22% in PSCaG90 was obtained after 1 day of MG-63 cell culture. Alkaline phosphatase expression and mineralization of MG-63 cells increased in the PSCaG90 hybrid in the absence of an osteogenic medium compared to PSG60 and PSG90. The PSCaG90 hybrid indicated considerable in vitro osteogenic capacity in the absence of a differentiation medium, expressing high levels of bone-specific proteins including collagen I (COL1A1), Runt-related transcription factor 2 (RUNX2), osteopontin (OPN), and osteocalcin (OCN), compared to calcium-free hybrids. Overall, our results suggest that the presence of calcium in the PSCaG90 leads to a significant increase in osteogenic differentiation of MG-63 cells even in the absence of differentiation medium, which suggests these hybrid structures with multifunctional properties as promising candidates for bone repair.

Preparation and Characterization of Narrow Size Distribution PMSQ Microspheres for High-Frequency Electronic Packaging

Polymethylsilsesquioxane (PMSQ) has become a kind of widely studied filler used in the electronic circuit board substrates due to its organic–inorganic hybrid structure, low dielectric constant, and good thermal stability, among other factors. Herein, the PMSQ microspheres were prepared by a two-step acid–base-catalyzed sol–gel method; the influences of reaction conditions including the ratio of water/methyltrimethoxysilane (MTMS), reaction temperature, concentration of the catalyst, and stirring time were systematically investigated; and the optimized reaction condition was then obtained towards a narrow particle size distribution and good sphericity. The microstructure of PMSQ microspheres was analyzed by the infrared spectrum and X-ray diffraction (XRD), which indicated that the as-prepared PMSQ had a ladder-dominant structure. The thermogravimetric analysis (TGA) demonstrated an excellent thermal stability of as-prepared PMSQ microspheres. More specifically, the dielectric constants at high frequency (1~20 GHz) of as-prepared PMSQ microspheres were measured to be about 3.7, which turned out a lower dielectric constant compared to SiO2 powder (≈4.0). This study paves the way to further improve the performance of the electronic circuit board substrates for the application of high-frequency electronic packaging.

Noble-Metal-Free Nanostructured and Graphene Supported Electrocatalysts for Water Splitting

Clean hydrogen production through water splitting is a direct and promising sustainable energy pathway to access and store non-fossil chemical fuels. Synthetic design strategies to access low cost, robust and high performance noble metal-free electrocatalysts are vital for forthcoming water splitting applications. To accomplish this goal, the nanoscale design of multifunctional catalysts based on cost-effective graphene supports, hollow nano-architectures and well-coordinated hybrid organic-inorganic structures has been attracting increasing research interest because of the flexible tuning options of their electronic states, chemical composition and local coordination environments.Over the last years, we have been implementing systematic investigations based on synthetic design, spectroscopy approaches and computational modeling toward the understanding of the mechanism of action in a series of novel, robust and efficient bi-functional electrocatalysts.Recently, we explored synergistic effects of NiFe alloys encapsulated into N-doped carbon nanotubes (N-CNTs) supported on reduced graphene (rGO) nanosheets for overall water splitting.[1] This so-called NiFe-N-CNT-rGO electrocatalyst was synthesized through a direct and flexible strategy using g-C3N4 as a precursor, where thermally reduced NiFe nanoparticles act as surface nucleation sites for C species to assist N-CNT growth through an unconventional reduction-nucleation-growth mechanism. The catalyst has a low overpotential of 270 mV for oxygen evolution reaction (OER), being superior in performance to a wide range of reported noble-metal-free catalysts. As revealed from density functional theory (DFT) calculations, N-doping and charge transfer at the CNT walls tune the free energy in the electronic structure toward adsorption of intermediates, which greatly enhanced catalytic performance. This synthetic strategy not only leads to excellent performance and opens up new avenues for other carbon-supported alloy catalysts, but its scalability and easy applicability also render it quite promising for large-scale water splitting applications.In parallel, we explored molecular strategies to conjugate single active sites of metal-phthalocyanine molecules MPc (M=Ni, Co, Fe) on GO.[2] We aim for a thorough understanding of the role of the local coordination environment around the single metal site in the synergistic mechanisms and the catalytic performance. With an advanced combination of ADF (annular dark field)-STEM, operando X-ray absorption spectroscopy and DFT calculations, we observed changes in the electronic and local structure environment of MPc-GO under operando electrochemical OER conditions. Single active metal Ni, Co, Fe sites attain high valence states due to chemisorbed OH− species upon catalytic activation, while the local orders suffer from structural distortion. These changes in the electronic and structural properties lead to the formation of HO-M-N4 moieties with high OER reactivity under operando conditions. These results provide new insight into the fundamental understanding of structure-performance relationships for single active site catalysts.Likewise, we studied hollow transition metal sulfide nanoboxes synthesized through anion exchange processes[3] between S2- and CN- species that lead to the formation of Prussian blue (PB), M-S@PB (M=Co, Fe, Ni) heterostructures. We found that the high performance of those nanostructures arises from in situ formation of active Co-Fe oxide/hydroxide species during OER, attaining a superior performance compared to noble-metal-catalysts such as RuO2, with a low overpotential of 286 mV and high durability over longer operational periods. The flexible tuning options of the electronic, chemical and local-atomic coordination of those nanostructures render them promising hybrid catalysts for dual OER and HER over an extended pH range.We have further explored new soft templating strategies for the first 1D cobalt coordination polymer electrocatalyst with bio-inspired features, and we applied state-of-the-art analytical techniques and computational modeling to monitor its formation in situ and to unravel its structure.[4] The highly durable 1D-cobalt coordination polymer catalyst implements strategies to transfer key motifs of inorganic materials into a hydrogen-bonded ligand environment, namely the embedment of the essential {H2O-Co2(OH)2-OH2} edge-site motif of cobalt oxide catalysts into a flexible and robust organic matrix. While this unconventional catalyst shows exceptional performance in commercial alkaline electrolyzers and organic transformations, its flexible structure offers new pathways toward the rational design of mixed molecular-solid disordered catalysts.[1] W. Wan, S. Wei, J. Li, C. A. Triana, Y. Zhou, G. R. Patzke, J. Mater. Chem. A 2019 (7) 15145.[2] W. Wan, C. A. Triana, J. Lan, J. Li, C. S. Allen, Y. Zhao, M. Iannuzzi, G. R. Patzke, ACS Nano 2020 (14) 13279.[3] Y. Zhao, C. K. Mavrokefalos, P. Zhang, R. Erni, J. Li, C. A. Triana, G. R. Patzke, Chem. Mater. 2020 (32) 1371.[4] C.A. Triana, R. More, A. J. Bloomfield, P. V. Petrovic, S. G. Ferroon, G. Stanley, S. D. Zaric, T. Fox, E. N. Brothers, S. W. Sheehan, P. T. Anastas, G. R. Patzke, Matter 2019 (1) 1354.

II-VI Organic-Inorganic Hybrid Nanostructures with Greatly Enhanced Optoelectronic Properties, Perfectly Ordered Structures, and Shelf Stability of Over 15 Years.

Organic-inorganic hybrids may offer material properties not available from their inorganic components. However, they are typically less stable and disordered. Long-term stability study of the hybrid materials, over the anticipated lifespan of a real-world electronic device, is practically nonexistent. Disordering, prevalent in most nanostructure assemblies, is a prominent adversary to quantum coherence. A family of perfectly ordered II-VI-based hybrid nanostructures has been shown to possess many unusual properties and potential applications. Here, using a prototype structure β-ZnTe(en)0.5-a hybrid superlattice-and applying an array of optical, structural, surface, thermal, and electrical characterization techniques, in conjunction with density-functional theory calculations, we have performed a comprehensive and correlative study of the crystalline quality, structural degradation, electronic, optical, and transport properties on samples from over 15 years old to the recently synthesized. The findings show that not only do they exhibit an exceptionally high level of crystallinity in both macroscopic and microscopic scale, comparable to high-quality binary semiconductors; and greatly enhanced material properties, compared to those of the inorganic constituents; but also, some of them over 15 years old remain as good in structure and property as freshly made ones. This study reveals (1) what level of structural perfectness is achievable in a complex organic-inorganic hybrid structure or a man-made superlattice, suggesting a nontraditional strategy to make periodically stacked heterostructures with abrupt interfaces; and (2) how the stability of a hybrid material is affected differently by its intrinsic attributes, primarily formation energy, and extrinsic factors, such as surface and defects. By correlating the rarely found long-term stability with the calculated relatively large formation energy of β-ZnTe(en)0.5 and contrasting with the case of hybrid perovskite, this work illustrates that formation energy can serve as an effective screening parameter for the long-term stability potential of hybrid materials. The results of the prototype II-VI hybrid structures will, on one hand, inspire directions for future exploration of the hybrid materials, and, on the other hand, provide metrics for assessing the structural perfectness and long-term stability of the hybrid materials.

A New Copper(I) Iodide Based Organic-Inorganic Hybrid Structure with Red Emission

A new organic-inorganic hybrid structure based on copper (I) iodide staircase chain 1D-Cu2I2(5-chloropyrimidine)2 (1) has been synthesized by a slow-diffusion method. It emits red emission peaking at 620 nm. The internal quantum yield (IQY) measured for this compound is 6.5% under 360 nm excitation. This compound exhibits potential as a non-rare-earth light-emitting phosphor alternative.

Organic–Inorganic Hybrid Structure as a Conductive and Transparent Layer for Energy and Optoelectronic Applications

In the era of hybrid organic devices, solution-processed metal-embedded polymer multilayer structures are potential candidates for transparent electrode applications. Here, an organic–inorganic–organic (OIO) layered structure has been fabricated as a metal oxide-free transparent conducting electrode, where a thin metal layer (Ag) was sandwiched between two organic polymer (polystyrene) layers. The metal layer was deposited by the DC sputtering technique, and the polymer layers were deposited by an easy and efficient dip coating technique with good thickness control. The thickness of the middle Ag film was varied from 4 to 30 nm to investigate its effect on the transparency and conductivity of the multilayered structure. The morphological behavior shows that a higher thickness of Ag gives a continuous layer formation and a smooth top surface of the layered structure, which is a vital feature of a good electrode. The results of various investigations of the OIO structure show promising optoelectrical performance for its applicability in transparent and flexible optoelectronics. Depth profiling in X-ray photoelectron spectroscopy (XPS) revealed that the Ag layer retains its metallic form mostly and only a small amount gets oxidized when exposed to the environment. In spite of the formation of silver oxide, an electrical resistivity of 1.1 × 10–4 Ω cm with an optical transparency of ∼75% was obtained in the OIO structure for an 8 nm thickness of the Ag layer. The key findings of the present investigations demonstrate a facile, low-cost, and effective method with a rational design for the fabrication and application of a transparent conducting electrode, which can be an alternative to indium tin oxide (ITO).

Robust and flexible transparent protective film fabricated with an ambient-curable hybrid resin

An ambient-curable hybrid resin (ACHR) terminated with trimethoxysilane functional groups, synthesized through a simple ring-opening reaction between 3-glycidyloxypropyltrimethoxysilane (KH560) and 4,4′-methylenebis (cyclohexylamine) (PACM), was applied to the surface of a transparent organic polymer to produce a robust, flexible, and transparent protective hybrid film, moisture cured at room temperature. The structure, morphology, and optical, mechanical, and thermal properties of the obtained hybrid film were evaluated. The hybrid film allowed the transmittance of more than 87% of visible light (at 600 nm), maintaining almost the same high transparency as bare PET film. The unique flexible segments and rigid segments in the inorganic–organic hybrid structure of the film realized superior resistance to bending and scratching. The hybrid film-coated PET demonstrated excellent flexibility, with an extremely low bending radius, illustrated by wrapping around a 1-mm mandrel bar without cracking. In addition, the hybrid film exhibited superior pencil hardness (of 2H) and excellent wear durability, i.e., no scratching after being subjected to 200 abrasion cycles using #0000 steel wool under a 19.6 kPa load. The robust, flexible, and transparent protective film developed here, and its simple and efficient preparation method, should have extensive application prospects.

Facile Strategy to Fabricate the Flame Retardant Polyamide 66 Fabric Modified with an Inorganic-Organic Hybrid Structure.

Recently, traditional flame retardant finishing with a single metal compound has been rarely applied owing to its low effectiveness and durability. This study reports metal ion finishing in combination with surface photografting modification (M/P technology) as a novel approach to incorporate an inorganic-organic hybrid structure containing an Fe3+ ion onto the surface of the polyamide (PA) 66 fabric. Specifically, the PA fabric was first surface-modified in the presence of acrylic acid (AA) and N,N'-methylene bisacrylamide (MBAAn) during photografting pretreatment under UV irradiation (step I), then further reacted with the Fe3+ ion in the metal ion finishing (step II). After treatment with M/P technology, the fabric exhibits the required excellent flame retardancy and dripping resistance. Here, flame retardant tests show that the treated PA fabric has the highest limiting oxygen index (LOI) value of 33.4 and no melt dripping during combustion. An interesting inorganic/organic composite thermal barrier consisting of an inorganic iron oxide nanoparticle (NP) outer layer and an organic micro-intumescent inner layer can be observed on the surface of the burnt fabric. This structure could be responsible for the significant enhancement in the fire performance of the treated fabric. Importantly, the treated fabric is also highly stable during the laundering procedure, which could retain a high Fe/C ratio and an acceptable LOI value of 27.8 after washing 45 times. This confirms the achievement of durable flame retardancy after treatment with M/P technology, and its possible interaction mechanism has been discussed here.

Biomimetic fabrication and application of fibrous-like nanotubes

AimsTo investigate the biomimetic fabrication of fibrous-like organic-inorganic hybrid structures via a simple bottom-up approach, viz. self-assembly of simple molecules, and apply fibrous-like composites as a novel primer to improve dentin bond strengths of self-etch adhesives. Materials and methodsThe resultants of commercial amorphous calcium phosphate (ACP) nanoparticles and 10-methacryloyloxydecyl dihydrogen phosphate (MDP) ethanol-aqueous solution were analyzed by TEM, SEM, XRD, DLS and AFM. The acid and alkali resistance of abovementioned self-assembled composites were analyzed with TEM. Micro-tensile bond strengths (MTBS) tests were performed after polished dentin surfaces were pretreated with self-assembled composites. The pretreated dentin surfaces and dentin-resin interfaces were characterized by SEM/TEM. Key findingsACP nanoparticles in MDP solution could self-assemble into fibrous-like nanotube structures in 8 nm diameter. Self-assembly and self-proliferation process went from ACP nanoparticles, dissolved ACP nanoparticles (less than 50 nm), twig-like structures and fibrous-like nanotubes to cellular networks. The fibrous-like nanotubes were only detected when the amount of ACP in reaction system were more than 0.01 g. The more ACP interacted with MDP, the more fibrous-like nanotubes were formed. After the dentin surfaces were treated with fibrous-like nanotube composites, MTBS could be significantly improved. Moreover, the fibrous-like nanotube structures could be resistant to acidic challenge, and were stable at least for 3 months. SignificanceThe fibrous-like nanotube structures could be self-assembled via a bottom-up approach at certain ratio of MDP and commercial ACP nanoparticles. The application of fibrous-like nanotube composites as a novel primer prior to self-etch adhesives greatly improved dentin bond strengths.

Strategies for optimizing the luminescence and stability of copper iodide organic–inorganic hybrid structures

In this article, the structural characteristics and synthetic methods of copper iodide hybrid materials are introduced, and the strategies for optimizing the stability and luminescence properties of these compounds are reviewed.

Bioprocess-inspired synthesis of multilayered chitosan/CaCO3 composites with nacre-like structures and high mechanical properties.

The formation of natural structures found in biological systems is wonderful and can be completed at ambient temperatures in contrast to artificial technologies wherein harsh conditions are common prerequisites. A new research direction, "bioprocess inspired manufacturing", is proposed for fabricating advanced materials with novel structures and functions. Nacre consists of an ordered multilayer structure of crystalline calcium carbonate lamellae separated by organic layers exhibiting mechanical toughness, which transcends that of its constituent components. Inspired by the nacre formation process, a microscale additive manufacturing mineralization method is proposed for achieving a multilayered organic-inorganic layered structure. In this work, layered calcite was synthesized on the surface of chitosan (CS) films at room temperature under the coordinated control of magnesium ions (Mg2+) and polyacrylic acid (PAA). The CS films and layered calcite are sequentially assembled in a layer-by-layer deposition approach to form an organic-inorganic hybrid structure. The nacre-like chitosan/CaCO3 (CS/CaCO3) composites exhibit high transparency and underwater superoleophobicity. Impressively, the hardness (2.35 ± 0.03 GPa) and Young's modulus (58.1 ± 0.5 GPa) of the as-prepared (CS/CaCO3) composites are comparable to those of their biological counterparts. This study provides a rational bioprocess-inspired room-temperature mineralization method to develop advanced composite materials with good performance.

Injectable antibacterial antiinflammatory molecular hybrid hydrogel dressing for rapid MDRB-infected wound repair and therapy

Multidrug resistant-bacteria (MDRB) impaired wound repair and regeneration remains a critical challenge. The development of multifunctional bioactive dressing with excellent wound healing and MDRB treating ability could probably address this problem. Herein, we developed an injectable multifunctional poly (citrate-glycol-siloxane)-based (PCGS) molecular hybrid hydrogel dressing for treating MDRB infection and enhancing wound healing. The PCGS-based hydrogel dressing possesses good injectability, controlled mechanical properties, temperature-responsive sol–gel behavior, broad-spectrum antibacterial activity including against MDRB (>99.99%). This dressing demonstrated the excellent cytocompatibility and could significantly enhance the activity of fibroblasts proliferation and migration of endothelial cells. The in vivo studies showed that PCGS-based dressing could significantly inhibit the MDRB infection on wound and promote the wound healing and skin appendage construction through reinforcing the early angiogenesis and decreasing the infection-derived inflammation. Our study suggests that PCGS-based hydrogel dressing with inorganic–organic hybrid structure at molecular level would have the promising potential in treating MDRB-infected wound and skin repair.

Dynamic Evolution of a Cathode Interphase Layer at the Surface of LiNi0.5Co0.2Mn0.3O2 in Quasi-Solid-State Lithium Batteries.

Intensive understanding of the surface mechanism of cathode materials, such as structural evolution and chemical and mechanical stability upon charging/discharging, is crucial to design advanced solid-state lithium batteries (SSLBs) of tomorrow. Here, via in situ atomic force microscopy monitoring, we explore the dynamic evolution process at the surface of LiNi0.5Co0.2Mn0.3O2 cathode particles inside a working SSLB. The dynamic formation process of the cathode interphase layer, with an inorganic-organic hybrid structure, was real-time imaged, as well as the evolution of its mechanical property by in situ scanning of the Derjaguin-Muller-Toporov modulus. Moreover, different components of the cathode interphase layer, such as LiF, Li2CO3, and specific organic species, were identified in detailat different stages of cycling, which can be directly correlated with the impedance buildup of the battery. In addition, the transition metal migration and the formation of new phases can further exacerbate the degradation of the SSLB. A relatively stable cathode interphase is key to improving the performance of SSLBs. Our findings provide deep insights into the dynamic evolution of surface morphology, chemical components and mechanical properties of the cathode interphase layer, which are pivotal for the performance optimization of SSLBs.