Inorganic-organic Hybrid Polymers Research Articles

Corrosion protection of mild steel via cerium nitrate loaded acrylic-vinyl polysilazane based hybrid coatings

This study presents an efficient anticorrosive coating based on an organic-inorganic hybrid polymer composed of methyl methacrylate, styrene, tert-butyl acrylate, and vinyl polysilazane. The synthesized resin exhibits excellent thermal resistance and stability, as confirmed by thermogravimetric analysis (TGA). Additionally, leveraging the resin's highly alkaline nature, cerium oxide (CeO2) nanoparticles were doped in situ within the polymer matrix. The hybrid resins were subsequently applied to mild steel panels using a dip-coating technique. The resulting coatings are transparent, flexible, thin, pore-free, and possess low surface roughness (<2.62 nm), along with good thermal stability (>350 °C). Their remarkable anticorrosive performance and durability are attributed to forming a highly crosslinked acrylic-polysilazane network, combined with a cerium oxide protective barrier layer that adheres to the substrate. Furthermore, the cerium ions suppress both cathodic and anodic corrosion reactions, enhancing the corrosion resistance. Notably, the coating system containing 2 wt% cerium achieved a high impedance value of 106 Ω cm2, corresponding to a corrosion rate of 0.112 × 10−5 mm/year. This study demonstrates that these acrylic-vinyl polysilazane coatings, incorporating ceria as a corrosion inhibitor, offer a promising alternative to conventional protection systems.

A novel organic-inorganic hybrid hollow polymer capsule with rich amino/imino groups for anionic contaminant removal in wastewater: Synthesis, performance and mechanism

Herein, we developed a new organic-inorganic hybrid polymer adsorbent, termed PECP, by one-step precipitation polycondensation between polyethyene polyamine and hexachlorocyclotriphosphazene. The morphology and microstructure of PECP were investigated by FTIR, SEM, TEM, XPS, XRD and N2 adsorption. Results show PECP owned a hollow capsule structure and lots of amino/imino groups. The adsorption capacity of PECP for anionic dye methyl orange (MO) was up to 1031.9 mg g-1. The adsorption process was very fast. After five cycles, the adsorption capacity of PECP for MO still remained at 89 % of the initial adsorption capacity. Meanwhile, PECP delivered a high adsorption capacity for other anionic contaminants like acid chrome blue K (1003.5 mg g-1), congo red (1152.2 mg g-1) and diclofenac sodium (914.2 mg g-1). In the binary systems contaminated with double dyes, the separation factors of MO for methylene blue, Rhodamine B and crystal violet were up to 450.8, 55.4 and 355.9, respectively. The experimental data unveiled that the MO removal by PECP was very consistent with the pseudo-second-order kinetic model and the Langmuir isotherm model. The removal process was spontaneous and endothermic. FTIR spectroscopy and XPS analysis confirmed the role of electrostatic force and hydrogen bond on the adsorption of MO on PECP.

Synthesis and Properties of Organic–Inorganic Materials Based on Polyurethane and MQ Resins

Cross-linked polyurethanes (PUs) were obtained by curing with MQ resins bearing oxymethyldimethylsiloxane or oxyethoxymethyldimethylsiloxane groups, their mixtures with 1,4-butanediol, and neat 1,4-butanediol and studied for their physico-mechanical properties. The MQ resins with functional hydroxy groups were found to act as polyols during curing of a urethane prepolymer. The network PU, obtained by curing with the MQ resins, represents a hybrid organic–inorganic polymer with bulk cross-links of inorganic nature, the surface groups of which are chemically bound to the polymer matrix. At a concentration of the MQ resins of 0.5 ppm, the properties of hybrid polyurethanes are comparable to those of the polyurethane obtained using 0.63 ppm of 1,4-butanediol.

Sulfur-Based Building Blocks in BN- and BO-Doped Inorganic–Organic Hybrid Polymers

Sulfur-Based Building Blocks in BN- and BO-Doped Inorganic–Organic Hybrid Polymers

Molecular design of highly Li-ion conductive cathode-electrolyte interface enabling excellent rate performance for lithium-ion batteries

The structural stability and ionic conductivity of the cathode electrolyte interface (CEI) film at high voltages are crucial to the nickel-rich layered cathode in Li-ion batteries (LIBs). These characteristics are largely determined by electrolyte components. Herein, an air-stable organic cyclophosphate salt named lithium 1, 3, 2-dioxaphosphinan-2-olate-2-oxide (LiDOP) is designed and synthesized as a CEI forming additive. It preferentially oxidizes and undergoes opening-ring polymerization under charging to form an organic–inorganic hybrid polymers with –LiPO4 segments and –(CH2)3– alternately connected on the cathode surface. Such a structure endows CEI film with high ionic conductivity, flexibility and mechanical strength, which can ameliorate the structure phase transformation, suppress the transition metal ion dissolution and enhance the interfacial stability at high cut-off voltage. The electrolyte with 0.2 wt% LiDOP endows 4.3 V-charged Li||LiNi0.8Co0.1Mn0.1O2 battery with 83.2 % capacity retention after 200 cycles at 5C rate. The graphite||NCM811 pouch cell shows a capacity retention of 85.6 % after 150 cycles under a 4.5 V voltage, while the cell without LiDOP shows only 23.5 %. Our work demonstrates the effectiveness of covalently coupled P-O-Li compounds as CEI film in stabilizing the interface, which provides a guidance for the electrolyte design in high-voltage LIBs.

CNT@SrTiO3 Nanocomposites Synthesized by In Situ Reaction for a High-Performance Flexible Supercapacitor.

This study presents the in situ synthesis of CNT@SrTiO3 nanocomposite films for the development of high-performance flexible supercapacitors. The synthesis process involved the use of organic-inorganic hybrid polymers containing metal elements as precursors for thermal decomposition reaction under a reducing atmosphere. Due to the formation of chemical bonding between Ti elements and the CNTs, the interface between STO and CNT surface could provide additional active sites for ion transport and storage. Thereby, the incorporation of SrTiO3 nanoparticles into CNTs enhanced the electrochemical performance of the resulting nanocomposite membranes. To further investigate the influence of STO content and synthesis temperature, we conducted a detailed analysis. The findings indicated that the CNT@STO film with 25% STO content, synthesized at 700 °C, and possessed optimal performance with an areal capacitance of 6682 mF·cm-2 at 5 mV·s-1. Furthermore, a symmetrical flexible supercapacitor assembled by two CNT@STO-25 electrodes demonstrated strong application potential in wearable devices, owing to its long cycle life, excellent flexibility, and high energy density of 430.2 μWh·cm-2 (corresponding power density of 4.5 mW·cm-2). Based on these results, we believe that this study provides a fresh idea for the development of novel flexible energy storage materials.

Direct Evidence of π–π Interactions in Transparent Organic–Inorganic Polymer Hybrids of Polystyrene and Silica Gel

Polystyrene and silica gel polymer hybrids derived from polystyrene and phenyltrimethoxysilane via π–π interactions were synthesized by a slight modification of the previous method. Spectroscopic evidence of the π–π interaction is provided. The obtained polymer hybrids were optically transparent, and no phase separation was observed by scanning electron microscopy measurements. In the FT-IR spectrum of the resulting polymer hybrids, the absorption peaks corresponding to C–H wagging vibration shifted to a lower wavenumber range as the content of silica in the hybrids increased. A UV–vis spectrum of the polystyrene and silica gel polymer hybrids showed a shoulder peak at around 260 nm that shifted toward longer wavenumbers side as the content of silica increased. These results clearly indicate that π–π interactions contribute to the formation of these transparent hybrids.

High‐performance ZSR/P(MMA/BA) composites with enhanced thermal and excellent water resistance properties

AbstractAcrylate had developed rapidly because of its excellent chemical resistance, high‐gloss surface, and weather resistance. However, the poor heat resistance of acrylate limited its application in coatings. To overcome this problem, an organic–inorganic hybrid polymer of zirconium silicone resin (ZSR)‐modified acrylate has been successfully synthesized by solution polymerization. The results indicated that the heat resistance of acrylate was significantly improved due to the SiOSi and SiOZr structures of ZSR and the increased cross‐linking density induced by ZSR. After the incorporation of ZSR, the decomposition temperatures of 5% of acrylate increased from 300.4 and 349.2°C. The performance of the ZSR/(P(MMA/BA)) showed no significant change in uniformly heating at 200°C for 24 h. The composite films showed hydrophobicity, with the contact angles increasing to more than 90°. The S4 sample displayed the outstanding comprehensive performance, that is, 5% weight loss at 341.3°C, water contact angle of 97.9°, elongation at break of 852%, and tensile strength of 9.9 MPa. The high‐performance heat resistant coating is a promising material for application in architecture, decoration, and mechanical equipment.

Near-infrared Y-branch polymer splitters realized with compact MMI structures for efficient power splitting

Optical splitters are promising photonic devices for next-generation photonic integrated circuits, which enable signal distribution and routing between the different components, facilitating complex optical functionalities on a single chip. This research introduces what we believe is a novel numerical technique for enhancing optical network efficiency by incorporating a taper-based step-index (SI) Y-branch multimode interference (MMI) splitter with organic-inorganic hybrid polymer materials. The proposed device comprises a core width of 5 µm for the input and output waveguides to satisfy the single-mode conditions. We designed and optimized the MMI splitter using the beam propagation method (BPM). The splitter demonstrates the power splitting property with an efficiency of 86%. The excess losses for the MMI splitter are 0.52 dB and 0.50 dB for TE and TM modes, respectively, at 1.55 µm. The polarization dependence loss (PDL) and propagation loss (PL) are 0.015 dB and 0.00019 dB/µm, respectively.

Micropatterning on PDMS by UV photolithography of an organic-inorganic hybrid polymer and its effect on human primary myoblasts growth

Micropatterning on PDMS by UV photolithography of an organic-inorganic hybrid polymer and its effect on human primary myoblasts growth

Polarization manipulation on step-index composite polymer beam splitters for photonics circuitry

This paper presents composite beam splitters realized with polymer materials for developing photonic integrated circuits. We used organic-inorganic hybrid polymer materials to form this composite beam splitter realized with step-index (SI) core profiles. We used the alternating direction implicit technique of the Rsoft CAD BeamPROP solver to design and analyze these beam splitters. We successfully examined and manipulated the beam splitter’s polarization dependency to obtain a 99% output efficiency with a 50:50 splitting ratio. The SI beam splitter exhibits an excess loss of 0.014 dB. When we apply polarized light in this beam splitter, the excess loss increases to 2 dB, and this loss gradually decreases as the angle of incident light increases. The excess loss reduces to 0.05 dB at the 31-degree angles of the incident polarized light. We also investigated the crosstalk of this beam splitter by varying the wavelength, and it is evident that the lowest crosstalk is −19.77 dB at the polarized angle of 31°.

Ambient solid-state triplet-triplet annihilation upconversion in ureasil organic-inorganic hybrid hosts.

Triplet-triplet-annihilation upconversion (TTA-UC) has attracted significant attention as an approach to harvest low energy solar photons that cannot be captured by conventional photovoltaic devices. However, device integration requires the design of solid-state TTA-UC materials that combine high upconversion efficiency with long term stability. Herein, we report an efficient solid-state TTA-UC system based on organic-inorganic hybrid polymers known as ureasils as hosts for the archetypal sensitiser/emitter pair of palladium(ii) octaethylporphyrin and diphenylanthracene. The role of the ureasil structure on the TTA-UC performance was probed by varying the branching and molecular weight of the organic precursor to tune the structural, mechanical, and thermal properties. Solid-state green-to-blue UC quantum yields of up to 1.86% were observed under ambient conditions. Notably, depending on the ureasil structure, UC emission could be retained for >70 days without any special treatment, including deoxygenation. Detailed analysis of the structure-function trends revealed that while a low glass transition temperature is required to promote TTA-UC molecular collisions, a higher inorganic content is the primary factor that determines the UC efficiency and stability, due to the inherent oxygen barrier provided by the silica nanodomains.

Development of a Polymer-Based Silicon-NMC Solid-State Cell

Solid-state batteries are seen as the next generation of battery technology with the promise of high energy density and improved safety as compared to conventional lithium-ion batteries. To achieve these goals, high-capacity negative electrodes, e.g., silicon or lithium, need to be combined with high capacity and high voltage positive electrodes, e.g., Ni-rich NMC. This combination of active materials provides a number of significant challenges for the solid-state electrolyte. If silicon is used as the anode active material, significant volume changes during lithiation/delithiation occur. These volume changes lead to a variety of problems including irreversible loss of lithium and eventual disintegration of the electrodes, resulting in capacity fade. Therefore, the electrolyte must be sufficiently elastic to buffer these changes. If Ni-rich NMC is used as a cathode active material, then the electrolyte must be stable at voltages up to at least 4.2 V. There are currently few, if any, electrolyte solutions that can address these challenges simultaneously.In the ASTRABAT project, a silicon-NMC solid-state cell has been developed based on two tailored polymer electrolytes, which allows the specific challenges of each cell compartment to be addressed separately. A vinylidene fluoride copolymer-based electrolyte has been developed for use as a catholyte and a hybrid inorganic-organic polymer electrolyte as the anolyte. This work will report a characterization of both electrolytes, along with their electrochemical performance in solid-state half-cells and full-cells.

Front Cover: 1,2,5‐Azadiborolane as a Building Block for Inorganic–Organic Hybrid Polymers (Eur. J. Inorg. Chem. 3/2024)

Front Cover: 1,2,5‐Azadiborolane as a Building Block for Inorganic–Organic Hybrid Polymers (Eur. J. Inorg. Chem. 3/2024)

1,2,5‐Azadiborolane as a Building Block for Inorganic–Organic Hybrid Polymers

AbstractThe incorporation of BN units in organic scaffolds by isoelectronic/isosteric substitution of selected CC couples has emerged as an efficient tool to produce new materials with useful properties and functions. The knowledge about BN‐doped inorganic–organic hybrid polymers, however, is still rather scarce. This is especially true for linear or cyclolinear macromolecules that feature longer inorganic chains. Herein, we introduce 1,2,5‐azadiborolane as a polymer building block for the first time. An attempt to apply it for the synthesis of a cyclolinear poly(iminoborane) resulted after only two B−N coupling events in the formation of a molecular compound comprising a chain of three nitrogen and two boron atoms – as confirmed by single‐crystal X‐ray diffractometry. In combination with a p‐phenylene diamine‐based co‐monomer, we accomplished to incorporate the 1,2,5‐azadiborolane into a hybrid polymer of considerable molecular weight that features a B2N3 chain. We additionally synthesized a small molecular model compound for the polymer and characterized it crystallographically as well. Comparison of the UV‐vis spectra of the monomer, the oligomer, and the polymer revealed systematic red‐shifts of the longest‐wavelength absorption band with increasing number of BN units in the chain.

(Invited) Solid State Hybrid Inorganic Organic Polymer Electrolytes for Advanced Sodium Secondary Batteries

The large-scale rollout of electric vehicles, smart grids and portable electronics is expected to require an amount of energy storage devices that the Li-ion technology alone will not be able to satisfy. In this concern, a quest for novel electrochemical energy storage technologies has started [1]. Sodium secondary batteries appear to be a good choice due to: (i) the high availability of raw materials; (ii) the low cost of sodium; (iii) the low sodium standard reduction potential; and (iv) the similarity between the chemistries of sodium and lithium, which facilitates the transition between the two technologies. Up to date, the best-performing electrolytes for the reversible deposition of sodium are based on organic solvents, which suffer from safety concerns and a poor stability towards sodium metal. Thus, research activities in this field are devoted to the development of safe and stable solid state electrolytes able to efficiently transport Na+ ions.Inspired by the pioneering work done by Di Noto and co-workers [2-4], herein we present a family of hybrid inorganic-organic polymer electrolytes (HIOPEs) for advanced solid state sodium secondary batteries. The initial HIOPE is obtained by means of a reaction between zirconium ethoxide and polyethylene glycol (PEG400). The resulting material is doped with sodium perchlorate as source of Na+ ions. In this system a 3D network is obtained, where inorganic zirconium metal nodes are interconnected by means of organic PEO chains. The latter ensure flexibility to the overall structure. Na+ ions are coordinated by and exchanged between the oxygen atoms of the ethereal functionalities of PEO chains. In addition, to guarantee a good structural stability, positively charged Zr nodes partially coordinate perchlorate anions, thus raising the sodium transference number. After doping with the poly(ethylene glycol) dimethyl ether (PEGDME250) plasticizer, a room temperature conductivity higher than 10-4 S cm-1 is demonstrated. An advanced study of the thermal and structural properties of the proposed materials is presented, with a particular focus on the interactions established between the different chemical species and complexes composing the HIOPEs. The conduction mechanism is elucidated starting from the results obtained in a wide range of temperatures from broadband electrical spectroscopy studies. Taking all together, this study offers insights on the application of non-traditional solid state electrochemical functional components as replacements for conventional solvents in the emerging field of sodium secondary batteries. Acknowledgments The project “Interplay between structure, properties, relaxations and conductivity mechanism in new electrolytes for secondary Magnesium batteries” (Grant Agreement W911NF-21-1-0347-(78622-CH-INT)) of the U.S. Army Research Office. The project “ACHILLES” (prot. BIRD219831) of the University of Padua. The project “VIDICAT” (Grant Agreement 829145) of the FET-Open call of Horizion 2020. The project TRUST (protocol 2017MCEEY4) of the Italian MIUR funded in the framework of “PRIN 2017” call.

Molecular Layer Deposition of Organic–Inorganic Hafnium Oxynitride Hybrid Films for Electrochemical Applications

The molecular layer deposition (MLD) method can be used to deposit hybrid organic–inorganic films with precisely defined composition, flexible properties, and conformality on different substrates. In this study, hafnium-based organic–inorganic hybrid polymer films were studied as potential coatings for silicon nanoparticles (SiNPs) used in composite lithium-ion battery (LIB) anodes, an application which requires the film to be both flexible and stable under electrochemical conditions. Hf-hybrid films were successfully deposited by MLD using sequential exposure of the homoleptic tetrakis(dimethylamido) hafnium complex and ethanolamine as the reactants. The self-limiting surface reactions lead to a constant growth per cycle (GPC) of ∼2.0 Å/cycle at 120 °C. Temperature-dependent growth was observed, with the GPC decreasing from ∼2.5 to ∼1.1 Å/per cycle as the temperature was increased from 65 to 145 °C. Scanning transmission electron microscopy and electron energy loss spectroscopy mapping confirm that a thin, dense, and conformal Hf-based MLD layer is deposited on the SiNPs. The presence of expected C–N, C–O, and −CH2 moieties in the MLD films was confirmed by Fourier transform infrared spectroscopy. Hafnium nitride and hafnium oxide bonds within the hybrid thin films were identified by X-ray photoelectron spectroscopy. Characterization results indicated that the deposited hafnium-based organic–inorganic hybrid films contain both metal oxynitride bonds and organic bonds, including C–C, C–O, and C–N. This Hf-based MLD thin film was tested on LIB SiNP composite anodes as an artificial solid–electrolyte interphase, with results showing that the capacity retention increased by about 35% after 110 cycles in a LIB application.

Gold metallization of hybrid organic-inorganic polymer microstructures 3D printed by two-photon polymerization

Two-photon polymerization is a femtosecond laser-based technique enabling printing of three-dimensional structures down to submicron resolution within photocurable polymers. Rendering the dielectric 3D printed structures conductive can be of great benefit for various applications in domains such as energy, photonics, or multifunctional devices. In this work, the microstructures of interest are made of a silicon-zirconium hybrid organic-inorganic polymer exhibiting low shrinkage during development. A simple and efficient metallization method by electroless plating is investigated to deposit a gold layer on the surface of the printed microstructures. The influence of the method parameters on the quality and properties of the deposited layer is studied. Among these parameters, the surface modification agent concentration and step duration, as well as the seeding solution concentration, must be adapted to the specific case of the considered hybrid microstructures. The concentration of metal ions in the plating bath is the most influential parameter on the morphology of the deposited gold layers. In particular, higher concentrations lead to smooth and continuous layers with electrical conductivities higher than half that of bulk gold. Finally, the deposited layers are shown to coat 3D printed microstructures of arbitrary shapes, thus confirming the conformality of the method at the micrometric scale.

A Non-Hydrolytic Sol–Gel Route to Organic-Inorganic Hybrid Polymers: Linearly Expanded Silica and Silsesquioxanes

Condensation reactions of chlorosilanes (SiCl4 and CH3SiCl3) and bis(trimethylsilyl)ethers of rigid, quasi-linear diols (CH3)3SiO-AR-OSi(CH3)3 (AR = 4,4'-biphenylene (1) and 2,6-naphthylene (2)), with release of (CH3)3SiCl as a volatile byproduct, afforded novel hybrid materials that feature Si-O-C bridges. The precursors 1 and 2 were characterized using FTIR and multinuclear (1H, 13C, 29Si) NMR spectroscopy as well as single-crystal X-ray diffraction analysis in case of 2. Pyridine-catalyzed and non-catalyzed transformations were performed in THF at room temperature and at 60 °C. In most cases, soluble oligomers were obtained. The progress of these transsilylations was monitored in solution with 29Si NMR spectroscopy. Pyridine-catalyzed reactions with CH3SiCl3 proceeded until complete substitution of all chlorine atoms; however, no gelation or precipitation was found. In case of pyridine-catalyzed reactions of 1 and 2 with SiCl4, a Sol-Gel transition was observed. Ageing and syneresis yielded xerogels 1A and 2A, which exhibited large linear shrinkage of 57-59% and consequently low BET surface area of 10 m2⋅g-1. The xerogels were analyzed using powder-XRD, solid state 29Si NMR and FTIR spectroscopy, SEM/EDX, elemental analysis, and thermal gravimetric analysis. The SiCl4-derived amorphous xerogels consist of hydrolytically sensitive three-dimensional networks of SiO4-units linked by the arylene groups. The non-hydrolytic approach to hybrid materials may be applied to other silylated precursors, if the reactivity of the corresponding chlorine compound is sufficient.

A Brief Overview of the Microstructural Engineering of Inorganic-Organic Composite Membranes Derived from Organic Chelating Ligands.

This review presents a concise conceptual overview of membranes derived from organic chelating ligands as studied in several works. The authors' approach is from the viewpoint of the classification of membranes by matrix composition. The first part presents composite matrix membranes as a key class of membranes and makes a case for the importance of organic chelating ligands in the formation of inorganic-organic composites. Organic chelating ligands, categorized into network-modifying and network-forming types, are explored in detail in the second part. Four key structural elements, of which organic chelating ligands (as organic modifiers) are one and which also include siloxane networks, transition-metal oxide networks and the polymerization/crosslinking of organic modifiers, form the building blocks of organic chelating ligand-derived inorganic-organic composites. Three and four parts explore microstructural engineering in membranes derived from network-modifying and network-forming ligands, respectively. The final part reviews robust carbon-ceramic composite membranes as important derivatives of inorganic-organic hybrid polymers for selective gas separation under hydrothermal conditions when the proper organic chelating ligand and crosslinking conditions are chosen. This review can serve as inspiration for taking advantage of the wide range of possibilities presented by organic chelating ligands.