Preparation and characterization of organic–inorganic hybrids and coating films from 3‐methacryloxypropylpolysilsesquioxane

3‐Methacryloxypropylpolysilsesquioxane (MA‐PS) was prepared by acid‐ or base‐catalyzed hydrolytic polycondensation of 3‐methacryloxypropyltrimethoxysilane (MAS). MA‐PS coating film was prepared by dip‐coating on organic, metal and inorganic substrates, including poly(ethylene terephthalate), aluminum, stainless steel, and glass. The coating films on poly(ethylene terephthalate) and glass showed high adhesive strength. The hardness of coating films increased with increasing heat treatment temperature, whereas they decreased with increasing H₂O/MAS molar ratio. The refractive index of coating films increased with increasing heat treatment temperature. In addition, flat and transparent free‐standing films (0.24–0.27 mm thickness) were prepared from MA‐PS that were crack‐free after heat treatment at 1000 °C. Copyright © 2001 John Wiley & Sons, Ltd.     

Microstructure and protonic conductivity of H3PO4‐doped polyethylenimine–siloxane chemically covalently organic–inorganic hybrids

The chemically covalent polyethylenimine–siloxane hybrids doped with various amounts of ortho‐phosphoric acid (H₃PO₄) were prepared and characterized by FTIR, DSC, TGA, and solid‐state NMR spectra. The protonic conduction behavior of these materials was also investigated by means of impedance measurements. These observations indicate that the hydrogen bonding and protonic interactions exist between the dopant H₃PO₄ and the hybrid host, resulting in an increase in T _g of polyethylenimine segments. These hybrids are thermally stable up to 200 °C from TGA analysis. Conductivity studies show an Arrhenius behavior characteristic and the Grotthus‐like proton conduction, and a high conductivity of 10^?2–10^?3 S cm^?1 at 110 °C in dry atmosphere for the hybrid membrane with H₃PO₄/EI of 0.5. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2135–2144, 2006     

Characterization of proton‐conducting organic–inorganic polymeric materials by ASAXS

The distribution of ZrO₂ and phosphotungstic acid (PTA) in a matrix of sulfonated polyether ketone was investigated by anomalous small‐angle X‐ray scattering (ASAXS). Scattering curves were obtained using X‐ray energies near the Zr and W absorption edges, allowing the independent analysis of the distribution of ZrO₂ and PTA in the sample. The interaction between both inorganic components improved their dispersion considerably when compared with films containing just one of the additives. The synergism was correlated to previous investigations concerning proton conductivity and permeability of the membranes developed for direct methanol fuel cell. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2981–2992, 2005     

Advances in organic–inorganic hybrid sorbents for the extraction of organic and inorganic pollutants in different types of food and environmental samples

The efficiency of the extraction and removal of pollutants from food and the environment has been an important issue in analytical science. By incorporating inorganic species into an organic matrix, a new material known as an organic–inorganic hybrid material is formed. As it possesses high selectivity, permeability, and mechanical and chemical stabilities, organic–inorganic hybrid materials constitute an emerging research field and have become popular to serve as sorbents in various separaton science methods. Here, we review recent significant advances in analytical solid‐phase extraction employing organic–inorganic composite/nanocomposite sorbents for the extraction of organic and inorganic pollutants from various types of food and environmental matrices. The physicochemical characteristics, extraction properties, and analytical performances of sorbents are discussed; including morphology and surface characteristics, types of functional groups, interaction mechanism, selectivity and sensitivity, accuracy, and regeneration abilities. Organic–inorganic hybrid sorbents combined with extraction techniques are highly promising for sample preparation of various food and environmental matrixes with analytes at trace levels.     

Solid polymer electrolytes. VI. Microstructure of organic–inorganic hybrid networks composed of 3‐glycidoxypropyltrimethoxysilane and LiClO4 and affected by different synthetic routes

Hybrid organic–inorganic materials derived from 3‐glycidoxypropyltrimethoxylsilane were prepared via two different synthetic routes: (1) the HCl‐catalyzed sol–gel approach of silane followed by the lithium perchlorate (LiClO₄)/HCl‐catalyzed opening of epoxide and (2) the simultaneous gelation of tin/LiClO₄‐catalyzed silane/epoxide groups. LiClO₄ catalyzed the epoxide polymerization, and its effects on the structures of these hybrid materials were studied by NMR. The structure of the inorganic side was probed by solid‐state ²⁹Si NMR spectroscopy, and the characterizations of the organic side and the chemical processes involved in the different synthetic routes were performed with solid‐state cross‐polarity/magic‐angle‐spinning ¹³C NMR. The different synthetic routes significantly affected the polymerization behaviors of the organic and inorganic sides in the presence of LiClO₄. A larger amount of LiClO₄ promoted the opening of epoxide and led to the formation of longer poly(ethylene oxide) chains via the HCl‐catalyzed sol–gel approach, whereas in the case of the tin‐catalyzed approach, the faster polymerization of the inorganic side hindered the growth of the organic network. The addition of LiClO₄ was proven to be without crystalline salt present in the hybrid networks by wide‐angle X‐ray powder diffraction. Also, the interactions between the ions and hybrid host, examined with Fourier transform infrared and ⁷Li proton‐decoupled magic‐angle‐spinning NMR, further demonstrated that extensive ion aggregation existed in these hybrid materials. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 151–161, 2004     

Unusual inorganic phase formation in ultraviolet‐curable organic–inorganic hybrid films

Inorganic–organic hybrid materials were prepared with a cycloaliphatic epoxide adduct of linseed oil with tetraethylorthosilicate (TEOS) oligomers via a cationic UV‐curing process. The TEOS oligomers were prepared in the presence of water and ethanol with hydrochloric acid as a catalyst. The TEOS oligomers were characterized with ¹H and ²⁹Si NMR and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. Hybrid films were cured, and the dynamic mechanical and thermal properties of the hybrid films were evaluated as a function of the TEOS oligomer content. The morphology of the hybrid films was examined with atomic force microscopy, transmission electron microscopy, and small‐angle light scattering. The microscopy and dynamic mechanical data indicated that the hybrid films were heterogeneous materials with various inorganic particle sizes dispersed within the organic matrix. In addition, ²⁹Si solid‐state NMR spectroscopy was used to investigate the coupling between the silicate region and organic regions. A schematic model is proposed to address structural features of hybrid materials. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1607–1623, 2005     

Effect of anion of polyoxometalate based organic–inorganic hybrid material on intumescent flame retardant polypropylene

In this work, 12‐tungestocobaltic acid based organic–inorganic hybrid material, [Bmim]₆CoW₁₂O₄₀ (CoW) was synthesized and applied as a synergist in polypropylene (PP)/intumescent flame retardant (IFR) composites. The flame retardant properties were investigated by the limiting oxygen index (LOI), UL‐94 vertical burning test, thermal gravimetric analyzer (TGA), cone calorimeter and scanning electron microscopy (SEM) etc. The results showed that the PP composites with 16 wt% IFR and 1 wt% CoW achieves the UL‐94 V‐0 rating and gets a LOI value 28.0. However, only add no less than 25 wt% single IFR, can the PP composites obtain the UL‐94 V‐0 rating, which suggests that CoW has good synergistic effects on flame retardancy of PP/IFR composites. In addition, the SEM and cone calorimeter tests indicated the CoW improves the quality of char layer. The rate of char formation has been enhanced also because of the existence of CoW. It is the combination of a better char quality and a high rate of char formation promoted by CoW that results in the excellent flame retardancy of PP/IFR composites. Copyright © 2016 John Wiley & Sons, Ltd.     

Facile synthesis of core‐shell organic–inorganic hybrid nanoparticles with amphiphilic polymer shell by one‐step sol–gel reactions

Organic–inorganic hybrid core‐shell nanoparticles with diameters ranging from 100 to 1000 nm were prepared by a one‐pot synthesis based on base catalyzed sol–gel reactions using tetraethoxysilane and a triethoxysilane‐terminated polyethylene‐b‐poly(ethylene glycol) as reactants. Data from TEM, TGA, and solid‐state NMR analysis are in agreement with the formation of core‐shell nanoparticles with an inorganic‐rich core and an external shell consisting of an amphiphilic block copolymer monolayer. The influence of the organic–inorganic ratio, solution concentration, and postcuring temperature on core and shell dimensions of the nanospheres were investigated by TEM microscopy. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1699–1709, 2008     

Effect of monomer structures and preparation methods on the morphology and properties of UV cured organic–inorganic hybrid films

The effects of preparation methods and monomer chemical structures on the microstructure, morphology, and properties of the hybrid films were studied. 7DBPA‐3S was synthesized by the sol–gel reaction of precondensed silica particles with alkoxysilane‐modified polymers DBPA. DBP‐POBG3T3 was prepared by the radiation curing of comb‐like UV curable alkoxysilanes POBG3T3 with UV curable polymer DBP, followed by the sol–gel reaction of alkoxysilanes. The DBP‐POBG3T3 film consisted of polymer matrix and large tethered aggregates with tiny silica connected by organic chains. On the contrary, silica nanoparticles were well‐dispersed in the 7DBPA‐3S hybrid film. The TEM, energy dispersive X‐ray Si‐mapping and P‐mapping images are good experimental approaches to characterize the texture of the tethered aggregates. The 7DBPA‐3S hybrid composite with well‐dispersed silica nanoparticles exhibited smoother surface, higher transparency, and better thermal stability than the DBP‐POBG3T3 composite did. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1152–1165, 2007     

Acrylic polymer/silica organic–inorganic hybrid emulsions for coating materials: Role of the silane coupling agent

Acrylic polymer/silica organic–inorganic hybrid emulsions were synthesized by a simple method, that is, a conventional emulsion polymerization and subsequent sol–gel process, to provide water‐based coating materials. The acrylic polymer emulsions contained a silane coupling agent monomer, such as methacryloxypropyltriethoxysilane, to form highly solvent‐resistant hybrid films. On the other hand, the hybrid films from the surface‐modified polymer emulsions, in which the silane coupling agent was located only on the surface of the polymer particles and the particle core was not crosslinked, did not exhibit high solvent resistance. A honeycomblike array structure, which was derived from the polymer particles (diameter ≈ 50 nm) and the silica domain, on the hybrid film surfaces was observed by atomic force microscopy. The crosslinked core part and silane coupling agent containing the shell part of the polymer particles played important roles in attaining high solvent resistance. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4736–4742, 2006     

Isostructural organic–inorganic hybrid compounds: triethylcholine tribromidocadmate and triethylcholine tribromidomercurate

In order to search for new anionic architectures and develop useful organic–inorganic hybrid materials in halometallate systems, two new crystalline organic–inorganic hybrid compounds have been prepared, i.e. catena‐poly[triethyl(2‐hydroxyethyl)azanium [[bromidocadmate(II)]‐di‐μ‐bromido]], {(C₈H₂₀NO)[CdBr₃]}_n, (1), and catena‐poly[triethyl(2‐hydroxyethyl)azanium [[bromidomercurate(II)]‐di‐μ‐bromido]], {(C₈H₂₀NO)[HgBr₃]}_n, (2), and the structures determined by X‐ray diffraction analysis. The compounds are isostructural, crystallizing in the space group P2₁/n. The metal centres are five‐coordinated by bromide anions, giving a slightly distorted trigonal–bipyramidal geometry. The crystal structures consist of one‐dimensional edge‐sharing chains of MBr₅ trigonal bipyramids, between which triethylcholine counter‐cations are intercalated. O—H...Br hydrogen‐bonding interactions are present between the cations and anions.     

Preparation of an organic–inorganic hybrid based on synergy of Brønsted and Lewis acid centres as heterogeneous magnetic nanocatalyst for ultrafast synthesis of acetaminophen

A heterogeneous nanocatalyst based on a Cu(II) complex containing phosphotungstic acid and N/O‐donor ligands supported on cobalt ferrite nanoparticles was successfully prepared. The synthesized nanocatalyst was characterized using various techniques. The magnetic nanocatalyst was examined as an efficient and synergistic catalyst for ultrafast synthesis of acetaminophen at room temperature and under solventless conditions. The examined synergistic nanocatalyst, which has both Lewis and Brønsted acidic sites, could be easily separated from the reaction system and reused several times without significant loss of its activity. The synthesized acetaminophen was also fully characterized.     

Liquid‐crystalline organic–inorganic hybrid polymers with functionalized silsesquioxanes

Liquid‐crystalline (LC) hybrid polymers with functionalized silsesquioxanes with various proportions of LC monomer were synthesized by the reaction of polyhedral oligomeric silsesquioxane (POSS) macromonomer with methacrylate monomer having an LC moiety under common free‐radical conditions. The obtained LC hybrid polymers were soluble in common solvents such as tetrahydrofuran, toluene, and chloroform, and their structures were characterized with Fourier transform infrared, ¹H NMR, and ²⁹Si NMR. The thermal stability of the hybrid polymers was increased with an increasing ratio of POSS moieties as the inorganic part. Because of the steric hindrance caused by the bulkiness of the POSS macromonomer, the number‐average molecular weight of the hybrid polymers gradually decreased as the molar percentage of POSS in the feed increased. Their liquid crystallinities were very dependent on the POSS segments of the hybrid polymers behaving as hard, compact components. The hybrid polymer with 90 mol % LC moiety (Cube‐LC90) showed liquid crystallinity, larger glass‐transition temperatures, and better stability with respect to the LC homopolymer. The results of differential scanning calorimetry and optical polarizing microscopy showed that Cube‐LC90 had a smectic‐mesophase‐like fine‐grained texture. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4035–4043, 2001     

Sunlight curable hybrid organic–inorganic methacrylic‐based coatings: analysis of the cure mechanism and functional properties

An experimental ultraviolet (UV) polymerizable hybrid organic–inorganic protective coating, mainly intended for the surface protection of porous calcareous stone substrates, has been recently proposed and patented. The hybrid product evidenced an extraordinary hydrophobicity character, able to guarantee a high protection of the stone against water actions, as well as a high traspirability. Furthermore, it is able to equal the performance of commercial available coatings, with the important adjunctive advantage to be free solvent. The application of this product involves the use of a “dual curing” treatment, necessary to harden the coating applied on the substrate, representing this latter a technological limit. The dual curing treatment consists of 6 hr of exposure to a UV‐lamp plus 1 hr at 140°C in oven. In order to avoid this procedure, not easy to realize in situ, two different modifications of the composition of the hybrid product are proposed in this paper. The first one allows the photopolymerization of the hybrid coating only by sunlight exposure. The second one, even though requiring a UV exposure to photo‐polymerize the coating, does not need the subsequent thermal treatment at 140°C. Several experimental characterizations were performed on the newly developed hybrid products, in order to select an optimal composition for the formulations. The selected innovative products were, finally, applied on a calcareous stone substrate, typical of Apulia Region (Pietra Leccese, PL). Both coatings exhibit excellent water‐repellent action and a slight variation of the natural stone color. Copyright © 2014 John Wiley & Sons, Ltd.     

An organic–inorganic hybrid compound containing imidazolium cations and a one‐dimensional lithium hexacyanidocobaltate‐based anionic framework

An organic–inorganic hybrid compound, catena‐poly[bis(3H‐imidazol‐1‐ium) [[tetracyanido‐κ⁴C‐cobalt(III)]‐μ‐cyanido‐κ²C:N‐[diaqualithium(I)]‐μ‐cyanido‐κ²N:C]], {(C₃H₅N₂)₂[CoLi(CN)₆(H₂O)₂]}_n, was synthesized by the reaction of Li₃[Co(CN)₆] with imidazolium chloride in aqueous solution. The compound crystallizes in the monoclinic space group C2/c (data collected at 273 K). In the crystal structure, neighbouring [Co(CN)₆]³⁻ anionic units are linked by Li⁺ cations through the cyanide groups in a trans mode, forming a one‐dimensional zigzag chain structure extending along the c axis. A three‐dimensional supramolecular network is formed through hydrogen‐bonding interactions and is further stabilized by weak CN...π interactions between the cyanide groups and the imidazolium cations.     

Synthesis and characterization of organic–inorganic hybrid block copolymers containing a fully condensed ladder‐like polyphenylsilsesquioxane

A series of inorganic–organic hybrid block copolymers were synthesized via atom transfer radical polymerization using a fully condensed, ladder‐like structured polyphenylsilsesquioxane end‐functionalized macroinitiator. The inorganic portion, ladder‐like polyphenylsilsesquioxane, was synthesized in a one‐batch, base‐catalyzed system, whereas organic hard and soft monomers, styrene, and n‐butyl acrylate, were polymerized and copolymerized on the ends of the linear, inorganic backbone. Synthesized hybrid diblock, triblock, and random copolymers were characterized by ¹H NMR, ²⁹Si NMR, gel permeation chromatography, static light scattering, Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. Hybrid block copolymers were well‐defined with low polydispersity (<1.4) and exhibited enhanced thermal properties in the form of increased glass transition and degradation onset temperatures over their organic analogues.© 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Synthesis,characterization, and proton‐conducting properties of organic–inorganic hybrid membranes based on polysiloxane zwitterionomer

The synthesis and characterization of a series of zwitterionic hybrid membranes based on a zwitterionic siloxane precursor (ZS) are described. Flexible, transparent, optically homogeneous films were prepared. With the further incorporation of poly(ethylene glycol) (PEG), the hybrid films became more flexible but translucent. The structure of the inorganic sides was probed with solid‐state ²⁹Si NMR spectroscopy, and the organic sides and the chemical process involved were characterized with solid‐state ¹³C cross‐polarization/magic‐angle spinning NMR. A higher content of ZS led to higher proton conductivity of the hybrid electrolytes. Moreover, the proton conductivity was enhanced by the addition of the plasticizing component of PEG to the hybrid matrix; this was ascribed to the increased water uptake and free volume of the hybrid matrix and the dissociation of sulfonic acid groups. The proton conductivity of these hybrid membranes could be increased up to 3.5 × 10^?2 S/cm by the temperature and relative humidity being increased to 85 °C and 95%, respectively. The proton‐conduction behavior of these hybrid membranes is also briefly discussed. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3444–3453, 2006     

Synthesis and optical properties of organic–inorganic hybrid semi‐interpenetrating polymer network gels containing polyfluorenes

Organic–inorganic hybrid semi‐interpenetrating polymer network (semi‐IPN) gels containing polyfluorenes (PFs) are synthesized by hydrosilylation reaction of joint and rod molecules in toluene, where PFs are poly(9,9‐dihexylfluorene‐2,7‐diyl) (PF6) or, poly(9,9‐dioctylfluorene‐2,7‐diyl) (PF8), joint molecules are 1,3,5,7‐tetramethylcyclotetrasiloxane (TMCTS), or 1,3,5,7,9,11,13,15‐octakis(dimethylsilyloxy)pentacyclo‐[9,5,1,1,1,1]octasilsesquioxane (POSS), and rod molecules are 1,5‐hexadiene (HD) or 1,9‐decadiene (DD). The semi‐IPN gels containing low molecular weight PF6 show higher photoluminescence efficiency (?_g) than the toluene solution of PF6L (?_s). The semi‐IPN gels composed of long rod molecule of DD and cubic joint molecule of POSS show the most effective increase in the emission intensity. The emission intensity of PF6L increases as formation of the network in the POSS‐DD semi‐IPN gel. The POSS‐DD semi‐IPN gels containing high molecular weight PF6 and PF8 also show the increase of emission intensity than those of the toluene solutions. The semi‐IPN synthesized in cyclohexane show syneresis and phase separation between network structure and PF chains. The semi‐IPN gels containing PF8 show emission peaks at 450 and 470 nm derived from β‐sheet structure of PF8. A systematic study clears correlation between emission property and network structure and/or composition of semi‐IPN gels. The semi‐IPN gels provide emissive self‐standing soft materials with high efficiency and in a narrow wavelength range emission. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 973–984     

Synthesis and optical properties of σ–π conjugated organic–inorganic hybrid gels

Organic–inorganic hybrid gels containing Si‐vinylene units have been synthesized by a hydrosilylation reaction of tri‐ or tetra‐ethynyl aryl compounds, 1,3,5‐triethynylbenzene (TEB), 3,3′,5,5′‐tetraethynylbiphenyl (TEBP), or tetrakis(4‐ethynylphenyl)methane (TEPM), and bisdimethylsilyl compounds, 1,1,3,3‐tetramethyldisiloxane (TMDS) or 1,4‐bisdimetylsilylbenzene (BDMSB), in toluene. Network structure of the resulting gels was quantitatively characterized by a scanning microscopic light scattering. The reactions yielded the gels having homogeneous network structure of 1.5–2.9 nm mesh size under the monomer concentrations that were relatively higher than the critical gelation concentration. The gels obtained from TEB showed broad absorption in the range from 340 to 370 nm, and emission in the range from 440 to 490 nm. The TEB–BDMSB gels showed remarkable red shift of the emission in comparison with that of the corresponding reaction solutions derived from the network formed by σ–π conjugation. The TEPM–TMDS, BDMSB gels exited by 280 nm showed not only the emission peak at around 360 nm derived from TEPM, but the broad peak at around 420 nm, which should be derived from interaction between phenyl groups of TEPM in the gels. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1360–1368     

Synthesis of organic‐inorganic hybrid gels by means of thiol‐ene and azide‐alkene reactions

Organic–inorganic hybrid gels have been synthesized from a multi‐vinyl functional cyclic siloxane, 1,3,5,7‐tetravinyltetramethylcyclotetrasiloxane (TVMCTS), or a cubic silsesquioxane, octavinyloctasilasesquioxane (PVOSS), and α,ω‐dithiol compounds, 1,6‐hexanedithiol (HDT), 1,10‐decanedithiol (DDT), using thiol‐ene reaction in toluene. The network structure of the resulting gels, mesh size and mesh size distribution, was quantitatively characterized by means of a scanning microscopic light scattering (SMILS). The gels obtained from TVMCTS‐HDT formed homogeneous network structure with 1.5–1.6 nm mesh. Relaxation peaks derived from large clusters and/or micro gels were detected in the SMILS analysis of the TVMCTS‐DDT, PVOSS‐HDT, and PVOSS‐DDT gels besides those from the small meshes. The organic–inorganic hybrid gels were also synthesized from TVMCTS, PVOSS with α,ω‐diazide compounds, 1,6‐hexanediazide (HDA), 1,10‐decanediazide (DDA), using azide‐alkene reaction in toluene. All the gels obtained with the azide‐alkene reaction formed the homogeneous network structure. Enthalpy relaxation at the glass transition of the dried samples was detected by differential scanning calorimetry to study the network uniformity of the original gels. The gels synthesized by the azide‐alkene reaction showed larger enthalpy than the gels synthesized by the thiol‐ene reaction, indicating homogeneous network structure in the former gels. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2229–2238