Organic-inorganic Hybrid Structures Research Articles

Remarkably boosted high-temperature energy storage of a polymer dielectric induced by polymethylsesquioxane microspheres.

Polymer dielectrics are the key materials in next-generation electrical power systems. However, they usually suffer from dramatic deterioration of capacitive performance at high temperatures. In this work, we demonstrate that polymethylsesquioxane (PMSQ) microspheres with a unique organic-inorganic hybrid structure can remarkably enhance the energy storage performance of a typical high-temperature dielectric polymer polyetherimide (PEI). Compared with traditional ceramic fillers, there exists -CH3 on the surface of PMSQ microspheres, which results in good compatibility between PMSQ and PEI. In addition, the PMSQ microspheres with excellent insulating properties can effectively block the charge transport, yielding significantly enhanced breakdown and energy storage performance. Consequently, the PEI based composite film with 5 wt% PMSQ microspheres exhibits ultrahigh energy storage densities of 12.83 J cm-3 and 9.40 J cm-3 with an efficiency (η) above 90% at 150 °C and 200 °C, respectively, which are 10.5 and 50.5 times those of the pure PEI film. This work demonstrates that microspheres with an organic-inorganic hybrid structure are excellent candidates for enhancing the high-temperature performance of polymer dielectrics, and these PMSQ/PEI composite films have huge potential for application in high-temperature film capacitors.

(RPh3P)[Mn(dca)3]: A Family of Glass-Forming Hybrid Organic-Inorganic Materials.

ABX3-type hybrid organic-inorganic structures have recently emerged as a new class of meltable materials. Here, by the use of phenylphosphonium derivatives as A cation, we study liquid- and glass-forming behavior of a new family of hybrid structures, (RPh3P)[Mn(dca)3] (R = Me, Et, Ph; dca = dicyanamide). These new compounds melt at 196-237 °C (Tm) and then vitrify upon cooling to room temperature, forming glasses. In situ glass formation of this new family of materials was probed on a large scale using a variable-temperature PXRD experiment. Structure analyses of the crystalline and the glasses were carried out by solid-state nuclear magnetic resonance spectroscopy and synchrotron X-ray total scattering techniques for using the pair distribution function. The mechanical properties of the glasses produced were evaluated showing promising durability. Thermal and electrical conductivities showed low thermal conductivities (κ ∼ 0.07-0.09 W m-1 K-1) and moderate electrical conductivities (σ ∼ 10-4-10-6 S m-1) at room temperature, suggesting that by the precise control of the A cation, we can tune meltable hybrid structures from moderate conductors to efficient thermal insulators. Our results raise attention on the practical use of this new hybrid material in applications including, e.g., photovoltaic devices to prevent light-deposited heat (owing to low κRT), energy harvesting thermoelectric, etc., and advance the structure-property understanding.

The Sol-Gel Process, a Green Method Used to Obtain Hybrid Materials Containing Phosphorus and Zirconium.

The sol-gel process is a green method used in the last few decades to synthesize new organic-inorganic phosphorus-containing hybrid materials. The sol-gel synthesis is a green method because it takes place in mild conditions, mostly by using water or alcohol as solvents, at room temperature. Therefore, the sol-gel method is, among others, a promising route for obtaining metal-phosphonate networks. In addition to phosphorus, the obtained hybrid materials could also contain titanium, zirconium, boron, and other elements, which influence their properties. The sol-gel process has two steps: first, the sol formation, and second, the transition to the gel phase. In other words, the sol-gel process converts the precursors into a colloidal solution (sol), followed by obtaining a network (gel). By using the sol-gel method, different organic moieties could be introduced into an inorganic matrix, resulting in organic-inorganic hybrid structures (sometimes they are also referred as organic-inorganic copolymers).

Achieving Significantly Boosted Dielectric Energy Density of Polymer Film via Introducing a Bumpy Gold/Polymethylsilsesquioxane Granular Blocking Layer.

Polymer dielectrics are the key materials for pulsed energy storage systems, but their low energy densities greatly restrict the applications in integrated electronic devices. Herein, a unique bumpy granular interlayer consisting of gold nanoparticles (Au NPs) and polymethyksesquioxane (PMSQ) microspheres is introduced into a poly(vinylidene fluoride) (PVDF) film, forming trilayered PVDF-Au/PMSQ-PVDF films. Interestingly, the Au/PMSQ interlayer arouses a dielectric enhancement of 47% and an ultrahigh breakdown strength of 704MVm-1, which reaches 153% of pure PVDF. It is revealed that the greatly enhanced breakdown strength originated from the Coulomb-blockade effect of Au NPs and the excellent insulating properties of PMSQ microspheres with a special molecular-scale organic-inorganic hybrid structure. Benefiting from the concurrently enhanced dielectric and breakdown performances, an outstanding energy density of 22.42Jcm-3 with an efficiency of 67.1%, which reaches 249% of that of the pure PVDF, is achieved. It is further confirmed that this design strategy is also applicable to linear dielectric polymer polyethyleneimine. The composites exhibit an energy density of 8.91Jcm-3 with a high efficiency of ≈95%. This work offers a novel and efficient strategy for concurrently enhancing the dielectric and breakdown performances of polymers toward pulsed power applications.

Develop a novel and multifunctional soy protein adhesive constructed by rosin acid emulsion and TiO2 organic-inorganic hybrid structure

Soy protein adhesives (SPI) exhibit broad prospects in substituting aldehyde-based resin due to the economic and environmental-friendly characteristics, but still face a challenge because of the dissatisfied bonding strength and terrible water resistance. Herein, prompted by organic-inorganic hierarchy, a multifunctional and novel soy protein adhesive (SPI-RAE-TiO2) consisting of rosin acid emulsion (RAE) and TiO2 nanoparticles (TiO2) were proposed. In comparison with original SPI, the dry and wet shear strengths of modified adhesive reached 2.01 and 1.21 MPa, respectively, which were increased by 130 % and 200 %. Furthermore, SPI-6RAE-0.5TiO2 was selected as the best proportion via the method of response surface methodology (RSM). What's more, SPI-6RAE-0.5TiO2 adhesive demonstrated prominent coating performance in both dry and wet surface conditions. Meanwhile, SPI-6RAE-0.5TiO2 adhesive possessed excellent mildew resistance and antibacterial ability with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), reflecting the antibacterial rates 97.71 % and 98.16 %, respectively. In addition, SPI-6RAE-0.5TiO2 adhesive also exhibited the outstanding green features such as the reduction of formaldehyde pollution and greenhouse effect through Life Cycle Assessment (LCA). Thus, this work provided a novel and functional approach to design multifunctional, superior-property and low-carbon footprint soy protein adhesive.

Strong and antistatic biomass adhesive for wood-based composites with electrostatic discharge protection function

Soybean protein adhesive, as an aldehyde-free biomass adhesive, has gained significant attention as an environmentally friendly material in recent years. It not only aligns with the objectives of the double carbon strategy but also contributes to the environmental protection strategy of reducing carbon emissions. And the functional modification of soybean protein adhesive and its wood composite hold great importance in expanding its application domains and meeting specialized requirements. This research focused on developing a robust, antistatic adhesive derived from soy protein as an alternative to formaldehyde-based resins, which represents a critical path in the advancement of wood-based composites that are free from formaldehyde and possess functional properties. However, ensuring the bonding strength of soy protein adhesive while developing antistatic adhesives and their wood-based composite materials is of great research value and challenge. Inspired by the organic-inorganic hybrid structure, this study aimed to prepare a strong and durable soy protein adhesive with excellent mechanical strength and multifunctionality by using a self-synthesized crosslinking agent called AP and the loaded two-dimensional MXene, which was stabilized in a dispersion of nanocellulose (CNC). The dry and wet shear strength of the resulting adhesive increased by 103.8 % and 113.8 % to 2.21 MPa and 1.24 MPa, indicating the stable crosslinking structure formed in adhesive system by the covalent bond between self-synthesized crosslinking agent AP and the carboxyl groups on proteins, as well as the hydrogen bond interactions between C-M and the proteins. Furthermore, the adhesive exhibited significant antistatic and self-extinguishing properties, with the particleboard modified by adhesive SPI/C-M/AP having a resistivity of 9.212 × 1011 Ω cm. The resistivity decreased with increasing MXene content, providing potential applications for places such as school computer rooms and factory electronic equipment rooms. This breakthrough in multifunctional biomass-based adhesives and composite materials enriches the preparation of new types of biomaterials with antistatic and flame retardant properties.

A new type of wood bio-adhesives production: Effect of hydrochar from sewage sludge on adhesives's physicochemical properties

This contribution discloses a new method to prepare formaldehyde-free plywood adhesive using hydrochar after hydrothermal carbonization (HTC) of sewage sludge (SS). Proteins and polysaccharides on the surface of hydrochar can react via cross-linking to form bio-adhesives. The bio-adhesives have an excellent wet shear strength value, meeting the Chinese national standard GB/T 9846-2015 (≥0.7 MPa). During HTC, SS will disrupt the extracellular polymer structure and release organic matter as well as hydrolysis, dehydration, and Maillard reaction occur to develop hydrophobicity in hydrochar. Ash in SS also can play a key role in improving the wet shear strength value of bio-adhesives due to its organic-inorganic hybrid structure. HTC temperature can also significantly influence bonding strength as modifier of the active functional groups in hydrochar.

The fabrication of organic-inorganic hybrid structure towards high mechanical property and improved flame retardancy

In order to design UPR composites with high mechanical property and improved flame retardancy, an organic-inorganic hybrid flame retardant (DA-Si-HNT) was fabricated by grafting silane coupling agent (KH560) and the phosphorus-nitrogen containing structure (DOPA-A, the production of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and adenine) on the surface of halloysite nanotube (HNTs). The UPR/DA-Si-HNT15 composites exhibited significant improvements in tensile strength, tensile modulus, and flexural strength, with respective increases of 65.6 %, 140.6 %, and 80.2 % compared to neat UPR. These enhancements can be attributed to the enhanced compatibility and interfacial force between the flame retardants and the polymer matrix. Meanwhile, it passed the UL-94 V-0 rating at a limiting oxygen index (LOI) value of 34.5 %. The peak of heat release rate (PHRR) and total heat release (THR) decreased by 49.5 % and 43.5 % comparing to that of UPR, indicating a sharp decline in the heat hazard. Moreover, an obvious catalytic carbonization effect in the condensed phase accompanied with moderate gas-phase effect jointly improved flame retardancy of the UPR/DA-Si-HNT15 composites.

An environmentally friendly multifunctional soy protein adhesive composed of rosin acid derivative inspired from organic-inorganic hybrid structure

Soy protein adhesives have the advantages of low price and renewability but are limited by terrible bonding strength and poor water resistance, which restricts the practical application. Herein, inspired by the structure of mussels and organic-inorganic hybrid strengthening mechanism, a novel and bio-based soy protein adhesive (SPI-RA-CSA) based on rosin acid derivative and calcium sulfoaluminate was generated. According to the optimization of response surface methodology (RSM), the best proportion of adhesive SPI-RA6-CSA1 was chosen. The dry and wet shear strengths of SPI-RA6-CSA1 adhesive reached 1.92 and 1.35 MPa, respectively, which were 120% and 210% higher than original soy protein adhesive. Meanwhile, SPI-RA6-CSA1 adhesive showed excellent coating performance even if it was coated on wet wood veneer. In addition, SPI-RA6-CSA1 adhesive effectively inhibited the formation of mold and exhibited outstanding antimicrobial ability for Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) with antimicrobial rates of 87.36% and 85.73%, respectively. What's more, SPI-RA6-CSA1 adhesive demonstrated prominent flame retardant properties reducing the harm of fire accidents. SPI-RA6-CSA1 adhesive also possessed the characteristics of low energy consumption and environmentally friendliness by Life Cycle Assessment (LCA). Therefore, this simple strategy provides workable guidance for the production of multifunctional and green soy protein adhesive.

Chelating Coordination Regulated Photochromic Electrospun Nanofibers for Waterproof and Long-Color-Retention Rewritable Wearables.

Photochromic materials with rapid color-switching, long color retention times, and rewritability are crucial for meeting the requirements of future rewritable ink-free media. However, these requirements are challenging to satisfy simultaneously due to the inherent constraints among these features. Herein, a novel photochromic nanofiber nonwoven fabric was designed and constructed based on a conjugated organic-inorganic hybrid structure through electrospinning and hot-pressing techniques. The as-prepared fabric can change color in merely 5 s under UV irradiation and can reach saturation within 2 min. In addition, upon the introduction of a potent metal chelator, its color retention time exceeds 14 days under ambient conditions, significantly longer than that of most rewritable materials recently reported (several hours to 5 days). Moreover, the fabric exhibits high writing resolution and can be photoprinted and heat-erased for over 100 cycles while still retaining 96% of its initial reflectivity. Hydrophobic thermoplastic polyurethane provides the fabric with excellent waterproof and antifouling properties, thus preventing the composite from swelling or collecting graffiti due to moisture or dust. This work exploits a competitive approach for designing flexible, rewritable, and superior functional wearables with practical applications.

Preparation of strong soy protein composite materials with thermal conductivity and biodegradability by constructing nanophase enhanced organic-inorganic hybrid structure

The development of multifunctional films with high strength, biodegradability, and excellent thermal conductivity has drawn increasing interest. In this study, inspired by the unique hybrid structure of oysters, a nanophase-reinforced organic–inorganic hybrid structure was built using polydopamine modified boron nitride (BN@PDA), soy protein isolate (SPI), dialdehyde cellulose (DAC), and polyethylene glycol (PEG) to develop a strong soy protein film with multifunctionalities. The resultant films displayed excellent thermal diffusion ability and exhibited high tensile strength (24.03 MPa) and thermal conductivity (TC, 2.96 W·m−1·K−1) under low BN load (<0.5%). Meanwhile, the formation of non-covalent cross-linking and organic–inorganic hybrid structure endowed the films with superior flexibility. Importantly, owing to the selection of bio-based materials for preparation, the SPI-based films exhibited good biodegradability. It is believed that this study provides a creative perspective for the development of value-added multifunctional film materials and has good application prospects in advanced bio-based thermal conductive materials.

ZnO vapor phase infiltration into photo-patternable polyacrylate networks for the microfabrication of hybrid organic–inorganic structures

The incorporation of inorganics into a patterned polymer can generate many new interesting properties in microfabricated structures.

Lipid cubic phase with an organic-inorganic hybrid structure formed by organoalkoxysilane lipid.

A lipid cubic phase encompassing a cross-linked siloxane structure was formed by the self-assembly of a synthetic organoalkoxysilane lipid in water. The spontaneous sol-gel reaction of the alkoxysilane moiety on the lipid head group produced an organic-inorganic hybrid material with a double gyroid Ia3d cubic structure.

Electroluminescent Clusters

AbstractOptoelectronic cluster materials emerge rapidly in recent years especially for light‐emitting devices, owing to their 100 % exciton harvesting and unique organic–inorganic hybrid structures with tunable excited‐state characteristics for thermally activated delayed fluorescence and/or phosphorescence and inheritable photo‐ and thermo‐stability. However, for efficient electroluminescence, excited‐state compositions of cluster emitters should be tuned through ligand engineering to enhance ligand‐centered radiative components and reduce cluster‐centered quenching states. Nonetheless, the balance of optoelectronic properties requires delicate and controllable ligand functionalization. On the other hand, in addition to balancing carrier fluxes, it showed that device engineering, especially host matrixes and interfacial optimization, can not only alleviate triplet quenching, but also modify processing and passivate defects. As consequence, the record external quantum efficiencies of cluster light‐emitting diodes already reached ≈30 %. Herein, we overview recent progress of electroluminescent cluster materials and discuss their structure–property relationships, which would inspire the continuous efforts making cluster light‐emitting diodes competent as the new generation of displays and lighting sources.

Electroluminescent Clusters.

Optoelectronic cluster materials emerge rapidly in recent years especially for light-emitting devices, owing to their 100 % exciton harvesting and unique organic-inorganic hybrid structures with tunable excited-state characteristics for thermally activated delayed fluorescence and/or phosphorescence and inheritable photo- and thermo-stability. However, for efficient electroluminescence, excited-state compositions of cluster emitters should be tuned through ligand engineering to enhance ligand-centered radiative components and reduce cluster-centered quenching states. Nonetheless, the balance of optoelectronic properties requires delicate and controllable ligand functionalization. On the other hand, in addition to balancing carrier fluxes, it showed that device engineering, especially host matrixes and interfacial optimization, can not only alleviate triplet quenching, but also modify processing and passivate defects. As consequence, the record external quantum efficiencies of cluster light-emitting diodes already reached ≈30 %. Herein, we overview recent progress of electroluminescent cluster materials and discuss their structure-property relationships, which would inspire the continuous efforts making cluster light-emitting diodes competent as the new generation of displays and lighting sources.

A versatile cold-curing wood adhesive derived from butylphenyl polyester

Although there have been notable advances in wood-based adhesive materials, the ability to rapidly bond wood under cold curing conditions at room temperature remains a challenge in these adhesives. Here, we report a new butylphenyl-derived polymer that can achieve super strong adhesion at room temperature by fast response at the wood interface. This behavior is achieved by the external reactive groups to create strong interfacial forces and the internal construction of organic-inorganic hybrid structures to reduce energy dissipation. Our research has established an effective method to modulate the viscoelasticity of the copolymer and optimize the adhesion properties of the adhesive at room temperature. The adhesive has a lap shear strength of 4.2 ± 0.17 MPa and also has a repair function that allows the repaired wood to withstand tensile forces of up to 470 N. It is anticipated that this dry, self-supporting, low-cost functional latex will be used as a commercial product for furniture restoration, wood industry and other applications.

Development of a universal sol–gel sorbent for fabric phase sorptive extraction and its application in tandem with high performance liquid chromatography-ultraviolet detection for the analysis of phthalates in environmental and drinking water samples

Most sorbent-based sample preparation methods are designed to interact with a class of analytes i.e., a polar sorbent for polar analytes, a non-polar sorbent for non-polar analytes, an ion-exchange sorbent for ionized compounds. A big challenge surfaces when making a choice of an appropriate sorbent when there is a mixture of compounds of varying polarities and ionization states in the complex sample matrices. Hence, the aim of this study was to develop a universal sol–gel sorbent coating for fabric phase sorptive extraction that would effectively and simultaneously extract polar, nonpolar, organic acids and bases via different intermolecular/interionic interactions. The universal sol–gel sorbent coated fabric phase sorptive extraction membrane was created by exploiting sol–gel surface coating technology to implant different functional moieties, ion exchanging ligands and an organic polymer that results in a 3-D organic–inorganic hybrid structure on the fabric substrate with a high level of selectivity/affinity for the target compounds. The preconcentrated extracts containing the isolated phthalates after the fabric phase sorptive extraction procedure were injected into the high-performance liquid chromatography-ultraviolet detection (HPLC-UV) system for the quantification. The FPSE-HPLC-UV method demonstrated a linear range between 50 and 1000 ng/mL for dimethyl phthalate, diethyl phthalate, dipropyl phthalate, diallyl phthalate, benzyl butyl phthalate, 1–10000 ng/mL for di-n-heptyl phthalate, 1–5000 ng/mL for di-n-heptyl phthalate, 10–5000 ng/mL for di-n-ethyl hexyl phthalate and 100–7500 ng/mL di-n-octyl phthalate. The intra-day and inter-day reproducibility (in terms of percentage relative standard deviation, %RSD) did not exceed 13.6. This method proves to be a selective, accurate, reproducible, cheap, and fast analytical approach for the quantitative and qualitative determination of the phthalates which is useful in crafting regulations for phthalates content in beverages and juices as well as in environmental monitoring.

Efficient healing of existed cracks in cement via synergistic effects of cement matrix activation and monomer polymerization

The effective repair of existing cracks can prolong the service life of infrastructures, which is of great significance for energy saving and emission reduction. A great deal of research on self-healing cement has been undertaken to efficiently prevent possible future cracking problems in buildings, but these methods do not deal with existing cracks. Herein, the efficient healing of existing cracks is achieved by the synergistic reaction of cement matrix activation and organic polymerization of sodium acrylate (ANa). ANa polymerization was systematically investigated for its effect on stimulated calcium silicate hydrate (C-S-H) and true healing systems in this study. The interconnected porous structure of sodium polyacrylate (PANa) observed during study suggested that ANa had been polymerized successfully under room temperature and the denser short rod-like C-S-H was also formed during the polymerization process. The formation of this organic-inorganic hybrid structure facilitates the rapid healing of existing cracks. When applied to cement, results showed that the compressive strength of specimens with the healing agent SS/PANa recovered 119.99% of its original strength and the micro-cracks of approximately 50 μm were completely sealed after 7-day curing. The ANa in the cracks helps enhance the reactivity of matrix and the polymerization improves the binding ability, forming an organic-inorganic composite network of the PANa and C-S-H. The composition and microstructure of the healed area revealed that the healing products were mainly composed of calcite (CaCO3), calcium hydroxide (CH), C-S-H and PANa.

Preparation of strong, water retention, and multifunctional soybean flour-based adhesive inspired by lobster shells and milk skin

The development of a water-retaining soybean flour-based adhesive with high water resistance, interfacial adhesion and mildew resistance is significant in replacing petroleum-based aldehyde-based resin. Drawing inspiration from lobster shells, soybean flour (SF), self-synthesized epoxy hyperbranched hydroxyethyl cellulose (EH) and calcium phosphate (CaP) oligomers were employed to prepare organic-inorganic hybrid composite adhesives based on hyperbranched structure. The EH component, abundant in active groups, enhanced the interfacial adhesion of the adhesives and served as an organic carrier for the mineralization of CaP oligomers. Prior to adhesive solidification, CaP oligomers mineralized to form an inorganic film akin to milk skin, which prevented water evaporation, resulting in a water retention time of 100 min for the adhesive. During adhesive curing, CaP oligomers with fluid-like behavior polymerized and mineralized, ultimately forming a continuous inorganic network of CaP crystals. This network, combined with the organic substrates (SF and EH), constituted an organic-inorganic hybrid structure, which bolstered the water and mildew resistance (20 days) of the adhesives. The prepressing intensity and wet shear strength of the resultant plywood increased by 168% and 396% to 0.67 MPa and 1.39 MPa, respectively, compared to those of the unmodified adhesive. The strength reached the leading level of the reported soybean flour adhesives. The biomimetic strategy employed here can be extended to high-performance gels and membrane materials, offering a novel modification approach for bio-composites.

Spatial Heterogeneity of Biexcitons in Two-Dimensional Ruddlesden-Popper Lead Iodide Perovskites.

Quantum confinement in two-dimensional (2D) Ruddlesden-Popper (RP) perovskites leads to the formation of stable quasi-particles, including excitons and biexcitons, the latter of which may enable lasing in these materials. Due to their hybrid organic-inorganic structures and the solution phase synthesis, microcrystals of 2D RP perovskites can be quite heterogeneous, with variations in excitonic and biexcitonic properties between crystals from the same synthesis and even within individual crystals. Here, we employ one- and two-quantum two-dimensional white-light microscopy to systematically study the spatial variations of excitons and biexcitons in microcrystals of a series of 2D RP perovskites BA2MAn-1PbnI3n+1 (n = 2-4, BA= butylammonium, MA = methylammonium). We find that the average biexciton binding energy of around 60 meV is essentially independent of the perovskite layer thickness (n). We also resolve spatial variations of the exciton and biexciton energies on micron length scales within individual crystals. By comparing the one-quantum and two-quantum spectra at each pixel, we conclude that biexcitons are more sensitive to their environments than excitons. These results shed new light on the ways disorder can modify the energetic landscape of excitons and biexcitons in RP perovskites and how biexcitons can be used as a sensitive probe of the microscopic environment of a semiconductor.