Inorganic Network Research Articles

Phosphoserine enhanced Cu-doped bioactive glass dynamic dual-network hydrogel for craniofacial bone defect repair.

Flexible hydrogels containing various osteogenic inorganic constituents, which can accommodate complicated shape variations, are considered as ideal grafts for craniofacial bone defect reconstruction. However, in most hybrid hydrogels, poor interaction between the polymer network and particles has detrimental effects on hydrogel rheological and structural properties, clinical manipulation and repair efficacy. In this article, we designed and prepared a series of hyaluronic acid composite hydrogel containing Cu-doped bioactive glass (CuBG) and phosphoserine (PS), in which hyaluronic acid was modified by methacrylate groups and phenylboronic acid groups to form a double crosslinked network. PS acted as an interaction bridge of CuBG particles and HAMA-PBA network to improve the mechanical properties of the composite hydrogels. The CuBG/PS hydrogels exhibited suitable rheological properties (injectable, self-healing, shape-adaptable), bone tissue integrating ability and anti-bacterial property. Meanwhile, we found that CuBG and PS have synergistic effect on improving osteogenic efficiency both in vitro and in vivo, particularly when the ratio of CuBG to PS is lower than 3 (9CB/3PS). This work provided a versatile and scalable approach to enhanced the interaction within inorganic particles and polymer network in hydrogels without extra modification on components.

Polyzwitterion-SiO2 Double-Network Polymer Electrolyte with High Strength and High Ionic Conductivity.

The key to developing high-performance polymer electrolytes (PEs) is to achieve their high strength and high ionic conductivity, but this is still challenging. Herein, we designed a new double-network PE based on the nonhydrolytic sol-gel reaction of tetraethyl orthosilicate and in situ polymerization of zwitterions. The as-prepared PE possesses high strength (0.75 Mpa) and high stretchability (560%) due to the efficient dissipation energy of the inorganic network and elastic characteristics of the polymer network. In addition, the highest ionic conductivity of the PE reaches 0.44 mS cm-1 at 30 °C owning to the construction of dynamic ion channels between the polyzwitterion segments and between the polyzwitterion segments and ionic liquids. Furthermore, the inorganic network can act as Lewis acid to adsorb trace impurities, resulting in a prepared electrolyte with a high electrochemical window over 5 V. The excellent interface compatibility of the as-prepared PE with a Li metal electrode is also confirmed. Our work provides new insights into the design and preparation of high-performance polymer-based electrolytes for solid-state energy storage devices.

Formation of inorganic liquid gallium particle-manganese oxide composites.

Gallium (Ga) is a low melting point post-transition metal that, under mild mechanical agitation, can form micron and submicron-sized particles with combined fluid-like and metallic properties. In this work, an inorganic network of Ga liquid metal particles was synthesised via spontaneous formation of manganese (Mn) oxide species on their liquid metallic surfaces forming an all-inorganic composite. The micron-sized Ga particles formed by sonication were connected together by Mn oxide nanostructures spontaneously established from the reduction of a Mn salt in aqueous solution slightly above the melting point of Ga. The formed Mn oxide nanostructures were found to coalesce from the surface of the Ga particles into a continuous inorganic network. The morphology of the composites could be altered by varying the Mn salt concentration and by performing post-treatment annealing. The composites presented a shell of various Mn oxide nanostructures including wrinkled sheets, rods and nanoneedles, around spherical liquid Ga particles, and a liquid metal core. The photoelectric and optical properties of the composites were thoroughly characterised, which revealed decreasing bandgaps and valence band edge characteristics as a function of increased Mn oxide coverage. The photoluminescence properties of the composites could be also engineered by increasing the Mn oxide coverage. The all-inorganic liquid Ga composite could be formed via a straightforward reduction reaction of a Mn-rich salt at the surface of liquid Ga particles with tunable surface properties for future optoelectronic applications.

An in situ formed inorganic conductive network enables high stability and rate capability of single-crystalline nickel-rich cathodes

In situ formed Li3PO4 coating layer enables high stability and rate capability of single-crystalline NCM cathode.

A p-type semi-conducting copper(i)-1,3-benzenedithiolate 2D coordination polymer with high Seebeck coefficient

A p-type semi-conducting and 2D coordination polymer, made of 1D copper(i)–sulfur inorganic networks, exhibits very high Seebeck coefficient for thermoelectricity.

Enhanced Structural Control of Soft-Templated Mesoporous Inorganic Thin Films by Inert Processing Conditions.

Mesoporous thin films are widely used for applications in need of high surface area and efficient mass and charge transport properties. A well-established fabrication process involves the supramolecular assembly of organic molecules (e.g., block copolymers and surfactants) with inorganic materials obtained by sol-gel chemistry. Typically, subsequent calcination in air removes the organic template and reveals the porous inorganic network. A significant challenge for such coatings is the anisotropic shrinkage due to the volume contraction related to solvent evaporation, inorganic condensation, and template removal, affecting the final porosity as well as pore shape, size, arrangement, and accessibility. Here, we show that a two-step calcination process, composed of high-temperature treatment in argon followed by air calcination, is an effective fabrication strategy to reduce film contraction and enhance structural control of mesoporous thin films. Crucially, the formation of a transient carbonaceous scaffold enables the inorganic matrix to fully condense before template removal. The resulting mesoporous films retain a higher porosity as well as bigger pores with extended porous order. Such films present favorable characteristics for mass transport of large molecules. This is demonstrated for lysozyme adsorption into the mesoporous thin films as an example of enzyme storage.

Highly flexible all-inorganic nanofiber networks with stress-accommodating microstructure for light-activated wearable chemiresistive sensor

Inorganic semiconductor chemiresistors have been the mainstream of well-explored gas sensing technology. However, the intrinsic fragile and rigid nature seriously impedes their future application in the thriving wearable sensing devices. Herein, we demonstrate a flexible all-inorganic semiconductor-based chemiresistive sensor through in-situ anchoring nanosheets-assembled SnO2/SnS2 sensing layer on flexible yttria-stabilized zirconia (YSZ) ceramic nanofiber networks. It is revealed that the flexible YSZ ceramic substrate possesses low section modulus in bending and good toughness that is mainly derived from its unique nanofiber structure (300 nm in diameter) and ultrafine grain size (16 nm). It is first demonstrated that nanosheets-assembled sensing layer characterized by abundant void spaces plays a pivotal role in affecting the flexibility of inorganic nanofiber networks. The void spaces between SnO2/SnS2 nanosheets, acting as stress-accommodating microstructures, could effectively releasing stress concentration, enabling abnormal mechanical flexibility of inorganic YSZ/SnO2/SnS2 network. In addition, to achieve more compatibility with wearable application and realize room-temperature gas sensing function, visible light rather than traditional high heat is employed as excitation source to activate the flexible YSZ/SnO2/SnS2 chemiresistor. This work shows the possibility of inorganic semiconductor chemiresistor for application in wearable sensing device and offers a valuable guidance for constructing flexible room-temperature inorganic chemiresistor.

Optimization and characterization of the ternary blended iron rich natural binder concrete system

Around the world, the infrastructure developmental activities searching for new generation cementing binders. Geopolymer is a hard stratum of non-crystalline inorganic alumino-silicate networks developed by alkali activated industrial by-product materials like fly ash, metakaolin and ground granulated blast furnace slag. Laterite is a natural iron-rich aluminosilicate binder material that could be used as a binder with an essential chemical composition. In this research, optimization of iron rich binder content is used to enhance the compressive strength of concrete. For this, various factors were considered and employed in the Taguchi’s experimental technique. An orthogonal array of L16 (4)5 of four parameter levels and four factors are considered to optimize the iron-rich natural material with metakaolin and GGBFS as ternary blend, the molarity of NaOH solution, Na2SiO3to NaOH ratio, and liquid by binder ratio. The results trials showed strength fluctuating between 16 and 60 N/mm2 and the optimized mix obtained as 65 N/mm2. The optimized samples were undergone material characterization to ensure the transformation of iron source activated compound combinations, and the phase changes using FTIR, XRD, SEM-EDS, DTA, Electron paramagnetic resonance spectroscopy, and Mossbauer Spectroscopy.

Synthesis, structural and optical properties of colloidal 2D organometal halide (C12H25-NH3)2PbI4 nanoparticles

The self-assembled IO hybrid semiconductors have been widely explored due to their unique characteristics of the formation of different dimensionalities crystal structural packing. The room temperature Mott-type excitons are formed as a result of quantum confinement and dielectric contrast effects. The excited free electron and hole bound together through strong coulomb interaction which is known as excitons and the excitons energy levels are present slightly below the conduction band. The large dielectric constant of extended inorganic network structure reduces the strong coulomb interaction between the excited free electron and holes known as Mott-type excitons. The Mott-type excitons has larger Bohr radius (30-100 A°) as compared to lattice spacing and having binding energies~10-30 meV. The different crystal structural packing are formed due to the structural reorganization of organic moiety (based on shape, size and position of amine group) within the extended inorganic layered structure. A systematic study of synthesis, structural and optical properties of 2D [(C12H25-NH3)2PbI4] nanoparticles are discussed and presented.

Durable self-cleaning nano-titanium dioxide superhydrophilic coating with anti-fog property

PurposeThis paper aims to design the nano-titanium dioxide (TiO2) coating system which has superhydrophilic property, self-cleaning mechanism and antifog property as well as strong adhesion on glass substrate.Design/methodology/approachTwo hydrophilic materials have been used such as TiO2 nanoparticles as fillers and hydrophilic copolymer, Pluronic F-127 by using simple sol–gel approach. The prepared solution was applied onto glass through dip- and spray-coating techniques and then left for drying at ambient temperature.FindingsThe nano-TiO2 superhydrophilic coating has achieved the water contact angle of 4.9° ± 0.5°. The superhydrophilic coating showed great self-cleaning effect against concentrated syrup and methylene blue where thin layer of water washes the dirt contaminants away. The nano-TiO2 coating exhibits great antifog performance that maintains high transparency of around 89% when the coated glass is placed above hot-fog vapor for 10 min. The fog droplets were condensed into water film which allowed the transmission of light through the glass. The strong adhesion of coated glass shows no total failure at scratch profile when impacted with scratch load of 500, 800 and 1,200 mN.Research limitations/implicationsFindings will be useful in the development of self-cleaning superhydrophilic coating that is applicable on building glass and photovoltaic panel.Practical implicationsThe developed nano-TiO2 coating is developed by the combination of hydrophilic organic copolymer–inorganic TiO2 network to achieve great superhydrophilic property, optimum self-cleaning ability and supreme antifog performance.Social implicationsThe findings will be useful for residents in building glass window where the application will reduce dust accumulation and keep the glass clean for longer period.Originality/valueThe synthesis of nano-TiO2 superhydrophilic coating which can be sprayed on large glass panel and cured at ambient temperature.

Highly tailorable, ultra-foldable, and resorbable thermoelectric paper for origami-enabled energy generation

Recently, owing to the increased focus on environmental initiatives such as the green campaign and green economy, thermoelectric (TE) energy harvesting technology using polymer-based TE materials has attracted significant attention. Among the various polymers used in TE materials, cellulose plays a crucial role in substituting petroleum-based polymers as it is an abundant natural organic biomass resource. Herein, we first developed the origami and kirigami-enabled resorbable TE paper, with a self-assembled inorganic particle network layer below the cellulose polymer bio-matrix layer, through a simple drop-casting process. The prepared p- and n-type TE papers exhibited relatively high-power factor values of 3.11 and 1.16 μW·m−1·K−2, respectively, at 298 K. Furthermore, the fabricated flexible TE energy harvester (f-TEH) achieved an output performance of 38.55 mV, 12.14 μA, and 95.17 nW for a temperature difference of 24 K without the degradation of electrical and mechanical stability. Finally, we demonstrated the high applicability of TE papers in TEHs of complicated shapes by cutting or folding the materials and analyzing their TE performance. We believe that the results of this study not only present a breakthrough in designing tailorable and foldable TEHs for energy harvesting applications but also have significant implications in the field of green technology.

Performance of resin–cement composite clad modified vitrified beads

In this study, organic–inorganic composite modified vitrified beads were prepared with a water-based acrylic resin and cement as modifiers. The effects of the modified cladding on the performance of the vitrified beads were investigated by varying the amount of emulsion and the volume of the spray. The volume of the vitrified beads to be modified was maintained at 100 cm3 and the total amount of cement was maintained at 5.0 g. The results showed that, when the amount of emulsion is 3.0 mL and the volume of the spray is 15.0 mL, the bulk density of the vitrified beads increases by 28.5 kg/m3, the volume water absorption decreases from 39.7% to 3.5%, and the cylinder compressive strength increases by 218.0 kPa. Moreover, the thermal conductivity increases by only 0.0033 W/(m‧K), the degree of bonding is relatively low, and the comprehensive performance is optimal. On the surface of the modified vitrified beads, some of the cement seals the open hole, and the rest of it adheres to the undamaged surface, which is conducive to the improvement of the strength of the material. On the one hand, the resin can fill the pores of cement, and form a staggered organic–inorganic network with cement. Meanwhile, it forms an organic film on the surface of the cement and the glazed layer to play a hydrophobic and strengthening role. On the other hand, it acts as a binder between the cement and the glazed layer to reduce the shedding of cement in the process of material use.

Highly conductive thin composite solid electrolyte with vertical Li7La3Zr2O12 sheet arrays for high-energy-density all-solid-state lithium battery

To achieve high energy density of all-solid-state lithium batteries, solid-state electrolytes (SSEs) are required to be thin and highly conductive. Although constructing efficient inorganic Li-ion transfer network can provide excellent conductivity for SSEs, it is still challenging for these SSEs to simultaneously realize thin thickness and mechanical stability. Herein, well-ordered vertical Li7La3Zr2O12 sheet arrays (VLSA) were prepared, followed by introducing triple-layer ion-conducting polymers to fabricate 8 μm-thick VLSA composite solid electrolyte (CSE). We demonstrate that vertical and short VLSA (major path, accounting for 71.4% of Li-ion transfer) and VLSA/polymer interface (minor path, 27.8%) contribute to the high ionic conductivity of 2.60 × 10−4 S cm−1 and ionic conductance of 0.5 S at 30 °C, ranking one of the highest values among reported SSEs. The stiff VLSA enhances the mechanical strength of CSE, while the polymer existing in VLSA channels serves as a deformable buffer, endowing CSE with bendable property. Besides, the trilayer polymer structure permits this electrolyte to be compatible with lithium anode and high-voltage cathode. Therefore, the high-loading LiNi0.5Co0.2Mn0.3O2 (NCM523) cell can be cycled with limited lithium anode (N/P ratio = 1.18) over 158 cycles with capacity retention upon 80%, realizing a high energy density of 458.4 Wh kg−1.

Performance improvement of magnesium oxychloride cement via nanoparticles-enhanced organic–inorganic hybrid network

It is a big challenge to improve both water resistance and mechanical properties for magnesium oxychloride cement (MOC). In this paper, hydroxyapatite (HA)/polyester (PEs) was introduced to improve both properties of MOC. The HA was evenly dispersed and had a good interfacial compatibility with the polyester, forming a stable nanoparticle reinforced organic–inorganic hybrid network (HAPEs). By introducing the organic–inorganic hybrid structure into MOC, the adverse effects caused by the uneven dispersion of nanoparticles can be avoided. The softening coefficient of the obtained MOC-HAPEs1.2% was 0.98, increasing by 206% compared to unmodified MOC. The enhanced water resistance was associated with the molecular network structure and abundant cross-linking points of the HAPEs. In the meantime, the mechanical properties of MOC were slightly improved. Moreover, the setting time of MOC was prolonged, which was conducive to the operability of its construction.

Solvent free sol-gel based synthesis of soft magnesium silicate

In this study, soft magnesium silicates were prepared via sol-gel method starting from diethylphosphatoethyltriethoxysilane (SiP), magnesium ethoxide and magnesium acetate. The thermal reaction of the different systems without any solvent was studied by a thermogravimetric analysis coupled to gas chromatography and mass spectroscopy in order to identify the volatile by-products and then suggest a reaction mechanism. The identification of several by-products formed during the reactions evidenced a non-hydrolytic sol-gel based route between the ethoxy and acetoxy groups of magnesium ethoxide and magnesium acetate respectively with the ethoxy groups of SiP. In addition, X-ray photoelectron spectroscopy analyses highlighted the creation of Mg–O–Si bonds. The viscoelastic behavior of the reactive systems allowed to confirm the formation of the network but also the determination of the gelation time. It corresponded respectively to 2150 and 1020 s for the reaction between magnesium ethoxide and SiP and magnesium acetate and SiP carried out at 170 °C. All these data confirm the formation of a “soft” inorganic network in that range of temperature. The graphical abstract represents first a schematic view of the studied reactions. The graph on the bottom-left corner shows the deconvolution of high resolution XPS spectra in the Mg (1s) region of MgOEt + SiP system treated at 450 °C. On the bottom-right corner, the evolution of tan (δ) at 170 °C under air during time sweeps at 1, 2, 3, and 5 rad/s for MgOEt + SiP system is presented.

Reprocessable polyhydroxyurethane networks reinforced with reactive polyhedral oligomeric silsesquioxanes (POSS) and exhibiting excellent elevated temperature creep resistance

The rapid development of covalent adaptable networks or vitrimers shows promise for addressing the long-standing recycling issues associated with conventional, permanently cross-linked thermosets. At the same time, it is important to demonstrate that properties of reprocessable polymer networks can be optimized to meet the ongoing demand for high-performance materials. We have fabricated reprocessable polyhydroxyurethane (PHU) network composites reinforced with reactive polyhedral oligomeric silsesquioxanes (POSS). With functionalized POSS serving as a fraction of the cross-linkers, the PHU–POSS network nanocomposites exhibit significantly enhanced storage modulus at the rubbery plateau region relative to the neat PHU network. With up to 10 wt% POSS loading, these network composites can undergo melt-state reprocessing at 140 °C with 100% property recovery associated with cross-link density. We also show that hydroxyurethane dynamic chemistry leads to excellent creep resistance at elevated temperature up to 90 °C and is unaffected by reactive incorporation of POSS. This study demonstrates the effectiveness of POSS as nanofillers for designing high-performance, organic−inorganic dynamic PHU networks with excellent reprocessability. • Dynamic PHU–POSS network composites are made with up to 10 wt% reactive POSS. • PHU–POSS network composites can be melt-reprocessed with 100% recovery of cross-link density. • Improved thermal stability and rubbery plateau modulus relative to the neat PHU network. • Excellent elevated-temperature creep resistance comparable to static networks.

Tough and Strong Waterborne Polyurethane Network Combined with Sub‐Nanoscaled Calcium Phosphate Oligomers for Protective Coating

AbstractThe optimal design of high wear‐resistance and durability of coatings using organic–inorganic interpenetrating networks has been a long‐term goal of researchers. Although some progress has been made in the modification of waterborne polyurethanes (WPU), there are still significant challenges in fabricating more durable polyurethane‐based protective coatings from the perspective of structural design at a molecular level. Here, a sub‐nanoscaled (<1 nm) inorganic calcium phosphate oligomer (CPO) is used to carry out organic–inorganic hybrid cross‐linking in a WPU network and precisely regulate the structure of the macromolecular network at the molecular level. The herein‐produced CPO‐WPU hybrid coating shows excellent wear resistance and water resistance. Taber abrasion tests demonstrate that the CPO‐WPU coating can be capable of 15 500 turns at a load of 750 g, 2.2 times that of pure WPU coating, and the water‐resistance of CPO‐WPU coating is significantly improved compared with WPU coating due to its well‐integrated organic–inorganic network. Overall, the CPO‐WPU coating material significantly improves the mechanical strength, wear‐resistance, and water‐resistance, compared with the original WPU coating and other modified polyurethane. This hybrid coating can provide a potential application in paper‐making, textiles, and furniture due to its unique organic–inorganic network, low cost, and green process.

Shape memory, thermal conductivity, and mechanical property of polylactic acid and natural rubber composites reinforced by an inorganic thermal conductive network

AbstractWith the development and application of thermotropic shape memory polymer materials in the biomedical field, it is very crucial for these materials to improve their thermal conductivity efficiency and shape memory recovery rate by endowing them a high thermal conductivity. In our work, a PLA/NR/T‐ZnOw/GR shape memory composite was prepared by melt blending with tetrapod zinc oxide whisker (T‐ZnOw) and graphene (GR) as the double inorganic fillers and polylactic acid (PLA) and natural rubber (NR) as the polymer matrix. The synergism of T‐ZnOw and GR constructs a three‐dimensional (3D) thermal conductive network, making the thermal conductivity of PLA/NR/5wt%T‐ZnOw/2.5wt%GR increase to 1.215 W∙(m∙K)−1. The addition of T‐ZnOw reduces the agglomeration of GR in the PLA/NR matrix and the interfacial thermal resistance between the fillers and the matrix. It also improves the heat transfer rate, resulting in an excellent shape memory of PLA/NR/T‐ZnOw/GR with a morphology recovery rate of ca. 96%, a fixed rate of 95% and high thermal stability. The presented biodegradable shape memory composite with the 3D thermal conductive network is promising in the fields of medical treatment and intelligent sensors.

Transition metal nitride/oxide-based multilayer PVD coating with sol–gel derived ormosil passivation layer as an efficient solar absorber: Studies on high temperature stability and performance evaluation

We describe a hybrid multilayer solar absorber coating consisting of physical vapor deposited (PVD) Ti interlayer, aluminum titanium nitride (AlTiN) main absorber layer, aluminum titanium oxynitride (AlTiON) semi-absorber layer, aluminum titanium oxide (AlTiO) anti-reflection layer and sol–gel deposited ormosil passivation layer. The ormosil layer, which is essentially organically modified silica, also acts like an anti-reflection coating, thus, increasing the absorptance (α) of the multilayer stack to ∼ 0.950 (c.f., α = 0.930 for the PVD coating on stainless steel substrate) along with an emittance (ε) of 0.17@82 °C. Generally, pure inorganic sol–gel coatings like silica contain defects, which allow gases and corrosive substances to penetrate the coating/substrate interface, thereby, deteriorating the performance of the coating under extreme environments. However, the presence of an organic moiety in the inorganic network results in a dense microstructure with improved mechanical flexibility and hardness. We discuss in detail the effect of ormosil layer on the performance of the PVD deposited solar absorber coating. We report that the unique and stable microstructure of the ormosil layer helps in increasing the thermal stability of the underneath PVD coated solar absorber coating, particularly suitable for applications in concentrating solar collectors useful for solar steam generation.

Lattice Dynamics and Structural Phase Transitions in Two-Dimensional Ferroelectric Methylhydrazinium Lead Bromide Investigated Using Raman and IR Spectroscopy

Two-dimensional (2D) lead halide perovskites are promising photovoltaic, light-emitting, nonlinear optical, and ferroelectric materials. Their key optoelectronic properties and polar order of organic cations are strongly affected by the dynamic response of the ionic lattice. Herein, we report polarized Raman and IR spectroscopy studies of methylhydrazinium lead bromide (MHy2PbBr4) exhibiting ferroelectric, photoluminescence, and multiple nonlinear optical phenomena. We determined the wavenumbers of longitudinal optical (LO) and transverse optical (TO) modes and their symmetries. These studies reveal that the dielectric response of MHy2PbBr4 is dominated by vibrations of the inorganic sublattice, which exhibits a large LO-–TO splitting (up to 44 cm–1). We also performed temperature-dependent Raman spectroscopy studies to monitor the effect of temperature on lattice dynamics and the effect of structural phase transitions on phonon modes. Raman spectroscopy data reveal that Raman bands are very narrow at 80 K, indicating a well-ordered structure. However, the increase of temperature leads to a very pronounced broadening of bands, indicative of a strong increase of lattice anharmonicity due to increased motional freedom of MHy+ cations and the inorganic network. Although former X-ray diffraction analysis showed that MHy2PbBr4 undergoes an order–disorder phase transition at 351 K, this transition leads to weak wavenumber shifts and broadening of Raman bands, more pronounced for modes related to the inorganic subnetwork. Furthermore, we do not observe any clear anomalies at 371 K, where the second phase transition into another disordered phase occurs. Our results indicate, therefore, that in contrast to many 2D lead halide perovskites, the dynamics of MHy+ cations and the inorganic network in MHy2PbBr4 do not exhibit pronounced slowing down at the order–disorder phase transition temperature but rather decrease gradually over a very large temperature range.