Organic-inorganic Polymer Research Articles

Surface modified Al 2 O 3 in fluorinated polyimide/Al 2 O 3 nanocomposites: Synthesis and characterization

Organic–inorganic hybrid materials consisting of inorganic materials and organic polymers are a new class of materials, which have received much attention in recent years. In the present investigation, at first, the surface of nano-alumina (Al 2 O 3 ) was treated with a silane coupling agent of $\boldsymbol{\gamma} $ -aminopropyltriethoxysilane (KH550), which introduces organic functional groups on the surface of Al 2 O 3 nanoparticles. Then fluorinated polyimide (PI) was synthesized from 4,4 ′ -(hexafluoroisopropylidene) diphthalic anhydride and 4,4 ′ -diaminodiphenylsulfone. Finally, PI/modified Al 2 O 3 nanocomposite films having 3, 5, 7 and 10% of Al 2 O 3 were successfully prepared by an in situ polymerization reaction through thermal imidization. The obtained nanocomposites were characterized by fourier transform infrared spectroscopy, thermogravimetry analysis, X-ray powder diffraction, UV-Vis spectroscopy, field emission scanning electron microscopy and transmission electron microscopy. The results show that the Al 2 O 3 nanoparticles were dispersed homogeneously in PI matrix. According to thermogravimetry analysis results, the addition of these nanoparticles improved thermal stability of the obtained hybrid materials.

High Seebeck effects from conducting polymer: Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) based thin-film device with hybrid metal/polymer/metal architecture

Conductive polymers are of particular interest for thermoelectric applications due to their low thermal conductivity and relatively high electrical conductivity. In this study, commercially available conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) was used in a hybrid metal/polymer/metal thin film design in order to achieve a high Seebeck coefficient with the value of 252 μV/k on a relatively low temperature scale. Polymer film thickness was varied in order to investigate its influence on the Seebeck effect. The high Seebeck coefficient indicates that the metal/polymer/metal design can develop a large entropy difference in internal energy of charge carriers between high and low-temperature metal electrodes to develop electrical potential due to charge transport in conducting polymer film through metal/polymer interface. Therefore, the metal/polymer/metal structure presents a new design to combine inorganic metals and organic polymers in thin-film form to develop Seebeck devices.

Physicochemical and Rheological Properties of Novel Magnesium Salt-Polyacrylamide Composite Polymers

Two series of novel inorganic-organic composite polymers have been prepared through physical blending of magnesium chloride and magnesium hydroxide respectively with polyacrylamide aqueous solution. The physicochemical properties of the magnesium salt-polyacrylamide composite polymers were tuned by varying the ratio between the magnesium salt (e.g., magnesium chloride and magnesium hydroxide) and polyacrylamide. Characterizations of magnesium salt-polyacrylamide composite polymers were carried out via FTIR and TEM. Parameters such as solution conductivity and viscosity were also taken into account to characterize the physicochemical properties of the composite polymer aqueous solutions. Magnesium chloride-polyacrylamide (MCPAM) composite polymer aqueous solutions have a higher conductivity compared to magnesium hydroxide-polyacrylamide (MHPAM) composite polymer aqueous solutions. The viscosities of the MHPAM composite polymer aqueous solutions were found higher than MCPAM composite polymer aqueous solutions. The rheological properties of the composite polymer aqueous solutions were investigated using steady-state flow and oscillatory frequency sweep within the linear viscoelastic region. Shear-thinning effect was observed for both composite polymer systems when the shear rate increases. In oscillatory frequency sweep tests, both composite polymer systems show that the viscoelastic behaviors depend strongly on the magnesium salt concentrations. Viscous behavior was found to be dominant for both composite polymer systems.

Assembly of a New Three-Dimensional Metal-Organic Framework With V-Shaped Carboxylate Ligand and Rigid N-Donor Ligand

A new inorganic-organic coordination polymer based on a “V” shape linking unit 3,3′,4,4′-oxydiphthalic acid (H4ODPA),1,2–bis (4-pyridyl)ethene(bpe) and Co(II) ions, [Co2(ODPA)(bpe)(μ2-H2O)]n (1), has been prepared and structurally characterized by single-crystal X-ray diffraction analysis. Compound 1 adopts a novel 3D CdSO4-type topological framework containing nanotube channels. Moreover, the coordination chemistry of ODPA ligand is also discussed.

Virus-based piezoelectric energy generation

Piezoelectric materials can convert mechanical energy into electrical energy, and piezoelectric devices made of a variety of inorganic materials and organic polymers have been demonstrated. However, synthesizing such materials often requires toxic starting compounds, harsh conditions and/or complex procedures. Previously, it was shown that hierarchically organized natural materials such as bones, collagen fibrils and peptide nanotubes can display piezoelectric properties. Here, we demonstrate that the piezoelectric and liquid-crystalline properties of M13 bacteriophage (phage) can be used to generate electrical energy. Using piezoresponse force microscopy, we characterize the structure-dependent piezoelectric properties of the phage at the molecular level. We then show that self-assembled thin films of phage can exhibit piezoelectric strengths of up to 7.8pmV(-1). We also demonstrate that it is possible to modulate the dipole strength of the phage, hence tuning the piezoelectric response, by genetically engineering the major coat proteins of the phage. Finally, we develop a phage-based piezoelectric generator that produces up to 6nA of current and 400mV of potential and use it to operate a liquid-crystal display. Because biotechnology techniques enable large-scale production of genetically modified phages, phage-based piezoelectric materials potentially offer a simple and environmentally friendly approach to piezoelectric energy generation.

Paramagnetic self‐assembled nanoparticles as supramolecular MRI contrast agents

Nanometer-sized materials offer a wide range of applications in biomedical technologies, particularly imaging and diagnostics. Current scaffolds in the nanometer range predominantly make use of inorganic particles, organic polymers or natural peptide-based macromolecules. In contrast we hereby report a supramolecular approach for the preparation of self-assembled dendritic-like nanoparticles for applications as MRI contrast agents. This strategy combines the benefits from low molecular weight imaging agents with the ones of high molecular weight. Their in vitro properties are confirmed by in vivo measurements: post injection of well-defined and meta-stable nanoparticles allows for high-resolution blood-pool imaging, even at very low Gd(III) doses. These dynamic and modular imaging agents are an important addition to the young field of supramolecular medicine using well-defined nanometer-sized assemblies.

A novel polymer technology for underfill

AbstractCapillary type underfill is still the mainstream underfill for mass production flip chip applications. Flip chip packages are migrating to ultra low-k, Pb-free, 3D and fine pitch packages. Underfill selection is becoming more critical. This paper discusses the performance and potential of underfills using a novel organic-inorganic hybrid polymer technology.Compared to eutectic and high lead solder, tin-silver-copper solder has lower C.T.E., higher elasticity and greater brittleness. In light of these properties, it is generally better to select high Tg and lower CTE underfill in order to prevent bump fatigue during reliability testing. Given the brittleness of low-k dielectric layers of flip chips, the destruction of low-k layers by stress inside the flip chip packages has become a major issue. Underfills for low-k packages should have low stress, and the warpage should be small. It is expected that as the low-k trend expands, the underfill is required to provide less stress. Low Tg underfill shows lower warpage. New chemical technologies have been developed to address the needs of underfills for low-k/Pb-free flip chip packages, specifically organic-inorganic hybrid polymer compounds. The organic-inorganic hybrid polymer provides excellent cure properties which enable a balanced combination of low stress and good bump protection. The material properties of the underfill were characterized using Differential Scanning Calorimetry (DSC), Thermo-Mechanical Analysis (TMA), and Dynamic Mechanical Analysis (DMA). A daisy-chained test vehicle was used for reliability testing. A detailed study is presented on the underfill properties, reliability data, as well as finite element modeling results.

Fabrication and properties of PVA-TiO2 hydrogel composites

The preparation and properties of PVA-TiO2 hydrogel composites have been studied in this research. The results show that tensile strength and compression modulus of PVA-TiO2 hydrogel composites increased significantly, but the elongation did not changed obviously compared with the PVA hydrogel, indicating the good interaction between inorganic nanoparticles and organic polymer. Friction performance of the hydrogels was discussed, the friction of PVA-TiO2 hydrogel composites decrease than the PVA hydrogel and friction coefficient up to 0.001. The possible mechanism of friction was discussed.

Advances in monolithic porous materials tailored in liquid media: around inorganic oxides and organic polymers

This review briefly surveys, with an emphasis on the author’s works, porous monoliths tailored by liquid-phase synthesis. Porous structures ranging from mesopore to macropore regions are induced in sol–gel polymerizing systems, which yield various porous materials such as inorganic oxides, organic–inorganic hybrids, crosslinked polymers, and carbons. It should particularly be noted that the networks must be homogeneous enough to obtain monolithic materials with fine pore structures, and for this purpose, the chemical reactions must be carefully designed and controlled. With exemplifying alkoxy-derived sol–gel systems and controlled/living radical polymerization systems, pore formations and applications of resultant materials are demonstrated.

Controlled network structure and its correlations with physical properties of polycarboxyl octaphenylsilsesquioxanes-based inorganic–organic polymer nanocomposites

Polycarboxyl octaphenylsilsesquioxanes (polycarboxyl-OPS) containing different numbers of reactive carboxyl groups per OPS molecule were synthesized, which were then utilized as nanofillers and macromolecular cross-linkers to cure diglycidyl ether of bisphenol-A (DGEBA) to yield a series of novel inorganic/organic polymer nanocomposites. The network structures and cross-linking densities were modulated by varying the contents of polycarboxyl-OPS in the system. The interface between OPS and DGEBA matrix was remarkably enhanced by the strong covalent bonds as evidenced by the complete disappearance of the carboxyl absorption at 1699 cm−1, the epoxy group at 915 cm−1 and the newly emerged strong peak of ester bond at 1725 cm−1 in the FTIR spectra. All the OPS/DGEBA cured samples are transparent, and the wide angle X-ray diffractions (WAXD) exhibited similar amorphous patterns to the pure DGEBA resin, whereas the peak at ∼8° corresponding to OPS aggregations were absent, indicating a homogeneous dispersion of OPS within the DGEBA matrix. The correlations between network structures, viscoelastic behaviors, cross-linking densities, inter-segmental distances, glass transition temperatures, flexural properties and thermal stability of OPS/DGEBA products were systematically investigated by means of dynamic mechanical analysis (DMA), DSC, TGA, scanning electron microscopy (SEM) and WAXD methods.

Polyphosphazene Elastomers, Gels, and Other Soft Materials.

Nearly all soft materials are based on organic polymer molecules. In other words they are derived from macromolecules constructed around the chemistry of carbon. Yet there are roughly 100 other elements in the periodic table that could in principle provide the building blocks for polymers and for soft materials. A few "inorganic" elements are incorporated into gels and related materials. Examples include silicate, aluminate, and titanate sol-gel substances, but the opportunities for diversification within these systems are relatively limited. The poly(organosiloxanes) (silicones) were the first hybrid inorganic-organic polymers to be discovered and they continue to play a major role in research and technology. Nevertheless, a need exists for additional systems that have the structural diversity found in the field of organic polymers, combined with the attributes of inorganic skeletal elements rather than carbon. It is with this objective in mind that we have devoted several decades to exploring the synthesis and diversification of the polyphosphazenes.

Reversible electroswitchable luminescence in thin films of organic–inorganic hybrid assemblies

In this study, reversible electroswitched luminescence is realized in a novel hybrid composite of organic-inorganic polymers and Pyronin Y-doped silica nanoparticles (PYDS) in aqueous solutions for the first time. The electrochromic material, poly (3,4-ethylenedioxythiophene) (PEDOT), is electrodeposited on the electrode in the presence of phosphododecamolybdic acid (PMo(12)). The luminescence of PYDS can be effectively switched between "on" and "off" states by applying oxidation and reduction potentials of PEDOT via the corresponding luminescence quenching effect. The electrochromic devices (ECDs) we report here exhibit lots of advantages, such as easy fabrication, high contrast of fluorescence response, good reversibility, and long-time stability. The creative application of PEDOT in ECDs in aqueous solutions is anticipated to offer important hints and a basis for other organic materials in the field of photoelectric devices.

The anomalous behavior of physical-chemical parameters during polymerization of organic-inorganic polymer systems based on reactive oligomers

AbstractDependencies of physical-chemical characteristics on structure development during polymerization of organic-inorganic systems (OISs) have been investigated. The non-monotonic behavior of the physical parameters has been found. This effect was explained by complicated structure of OISs, which consists of two interpenetrating hybrid organic-inorganic networks, which are characterized by different rate of the structure formation.

Metalcone and Metalcone/Metal Oxide Alloys Grown Using Atomic and Molecular Layer Deposition

Atomic and molecular layer deposition (ALD & MLD) techniques can be used to fabricate various hybrid organic-inorganic polymer films. One class of hybrid organic-inorganic films are metal alkoxide polymers that are formed from organometallic precursors and organic alcohols. These metal alkoxide polymers are called "metalcones". The metalcones can also be mixed with metal oxides to grow metalcone/metal oxide alloys. This paper will overview some of the new metalcones and metalcone/metal oxide alloys that can be grown and some of their properties. Zircone MLD films were grown using zirconium tert-butoxide (ZTB) and ethylene glycol (EG) at 145°C. Alucone alloy films were grown by combining Al2O3 ALD and alucone MLD at 135°C. Zircone alloy films also were fabricated by combining ZrO2 ALD and zircone MLD at 145°C. These new materials offer a tool set for engineering the functional properties of thin films.

The Thermal and Mechanical Properties of Ultra-High Molecular Polyethylene/Montmorillonite Clay (UHMWPE/MMT) Nanocomposites Using Gel and Pressure-Induced Flow Process (PIF)

This paper examines hybrid organic-inorganic polymer nanocomposites incorporating organically modified montmorillonite (MMT) and ultra-high molecular weight polyethylene (UHMWPE). UHMWPE/MMT hybrid nanocomposites were prepared using gel and pressure-induced flow (PIF) processing methods at a gel concentration of 8 wt.% UHMWPE with various organoclay contents (0, 5, 10, 15, and 20 pphr). The interlayer properties of the nanocomposites were studied by X-ray diffraction (XRD) transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The thermal and mechanical interfacial properties of the nanocomposites were investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and the use of a universal test machine (UTM). XRD and TWM indicated that the nanocomposites were formed upon dispersion of MMT in the polymer matrix. From the DSC, TGA and DMA results, we found that the thermal stability of the UHMWPE nanocomposites increased as the MMT content increased. The nanocomposites showed higher tensile strengths than those of pure UHMWPE gel sheet. These findings indicate that the interfacial and mechanical properties were improved by the addition of MMT and PIF processing.

Experimental research on inhibition performances of the sand-suspended colloid for coal spontaneous combustion

Serious mine fire disasters have occurred in Northwest China where there are abundant coal resources. For the shortage of water and loess, a large cost of conventional grouting slurry is needed. However, plenty of sand and fly ash resources have been found there. In order to improve the quality of sand injection and reduce the wastage of water during grouting, a kind of new compound material of sand-suspended colloid, which is composed of mineral inorganic gel and organic polymer, was developed in this paper. And the inhibition performance experiments of the sand-suspended colloid were carried out. The results show that the sand-suspended colloid efficaciously affected the oxidation characteristics above the critical temperature during the acceleration oxidation of the lignite and fat-gas coal samples and restrained the oxidation course by increasing the activation energy, so that it reduced the contents of CO and C2H4 and depressed the oxidation rate during the coal spontaneous combustion, and finally inhibited the coal spontaneous combustion.

Functionalization of lignin: Synthesis of lignophenol‐graft‐poly(2‐ethyl‐2‐oxazoline) and its application to polymer blends with commodity polymers

AbstractLignophenol (LP)‐graft‐poly(2‐ethyl‐2‐oxazoline) (POZO) was prepared to reuse lignin, an industrial waste material, and to produce novel LP‐based polymer blends with poly(vinyl chloride) (PVC), poly(bisphenol A carbonate) (PC), polyvinylpyrrolidone (PVP), and polystyrene (PSt) as commodity polymers. The resulting graft polymer was soluble in various types of organic solvents such as chloroform, THF, acetone, and methanol, unlike LP. The miscibility of LP‐graft‐POZO with commodity polymers was measured by differential scanning calorimetry (DSC) to determine the glass transition temperatures (Tg). In the cases of the blends of LP‐graft‐POZO with PVC, PC, and PVP, the Tg values decreased during the second scan. Moreover, in the cases of the blends with PVC and PVP, the Tg values were not detected during the third scan. Therefore, it was inferred that LP‐graft‐POZO was miscible with PVC, PC, and PVP while forming single phases; in particular, the blends of LP‐graft‐POZO with PVC and PVP exhibited a secondary miscibility because the Tg values were not detected. Furthermore, the blend of LP‐graft‐POZO with PC exhibited better thermostability than LP and LP‐graft‐POZO. These results indicated that LP blended with POZO could be used as a polymer additive and as an adhesive to combine different polymers, organic–inorganic polymers, etc. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Distributed feedback grating fabricated from hybrid polymer precursor gel by employing short‐pulse laser interference for photopumped polymer laser applications

The application of hybrid polymer precursor gel for distributed feedback (DFB) grating laser fabricated by short‐pulse laser interference has been investigated. The precursor gel was prepared by sol–gel process from siloxane‐modified methacrylate monomer. The molecular structure characterization results show the formation of inorganic networks within the precursor gel, which further undergoes the formation of organic–inorganic polymer network by photopolymerization. The laser interference was performed by using the frequency‐tripled output of nanosecond Nd–YAG laser. The fabricated DFB gratings exhibit photopumped lasing actions with high consistency between the grating periodicity (between 380 and 1030 nm) and the lasing wavelength, which appears at the wavelength of the second‐order Bragg reflection. The atomic force microcopy measurements clearly show the formation of surface relief (corrugated) structure in those gratings. The mechanism of surface relief formation is attributed to a fast photo‐induced swelling process, which is unique property belonging to this kind of hybrid polymer precursor gel. Copyright © 2011 John Wiley & Sons, Ltd.

Interplay between structural and electrochemical properties of Pt-Rh carbon nitride electrocatalysts for the oxygen reduction reaction

This report describes a new family of bimetal carbon nitride (CN) electrocatalysts for the oxygen reduction reaction (ORR) for application in polymer electrolyte membrane fuel cells (PEMFCs). The materials, which bear active sites based on Pt and Rh, are prepared with a three-step protocol consisting of: (1) the synthesis of a homogeneous zeolitic inorganic–organic polymer electrolyte (Z-IOPE) precursor; (2) the pyrolysis of the precursor at a temperature T f = 400, 500, 600, 700 or 900 °C; (3) the activation, yielding the final product. It is found that T f has a major effect on the structure and the electrochemical properties of these electrocatalysts, as determined from a wide array of independent characterization techniques including: high-resolution thermogravimetry (HR-TGA); Fourier-transform medium infrared (FT-MIR), Fourier-transform far infrared (FT-FIR) and confocal micro-Raman spectroscopies; powder X-ray diffraction (powder XRD); X-ray photoelectron spectroscopy (XPS); and electrochemical investigations carried out with the cyclic voltammetry thin-film rotating disk electrode (CV-TF-RDE) method. All the information is integrated to propose a comprehensive model correlating the effect of T f on the structure of the materials with the corresponding electrochemical performance. The best results in the ORR are obtained with materials prepared at 600 ≤ T f ≤ 700 °C. These systems present the optimal compromise between the size of the metal-rich nanoparticles, the degree of graphitization of the carbon nitride support and the concentration of ligands blocking the active sites. The best Pt-Rh electrocatalysts exhibit an ORR activity very similar to the Pt/C reference. In addition, the peculiar structure of the proposed materials, which are characterized by active sites supported on the carbon nitride bulky materials, results in a better tolerance toward typical contaminants in the ORR process such as chloride anions with respect to the Pt/C reference.

Formation of macroporous organic‐inorganic polymer hybrids using tea extract

AbstractMacroporous organic–inorganic polymer hybrids were prepared from poly(vinyl pyrrolidone), and inorganic alkoxides. To a reaction mixture of poly(vinyl pyrrolidone) and tetramethoxysilane, extract from tea leafs and HCl aqueous solution in methanol were added. The resulting mixture was constantly stirred at room temperature for 1 h and heated at 60°C for two weeks. Consequently, the corresponding polymer hybrid became a macroporous material having a pore size from 3.26 to 20.86 μm. We succeeded in finding that the pruned tea leafs were able to utilize the synthesis of novel macroporous materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011