Organic Polymer Composites Research Articles

Electrospun metal–organic framework polymer composites for the catalytic degradation of methyl paraoxon

Electrospun polymer fibers containing poly(methyl methacrylate) (PMMA), Ti(OH)4, and UiO-66 convert a chemical warfare agent simulant to non-toxic product via catalytic hydrolysis.

Contact printing of a quantum dot and polymer cross-reactive array sensor

Contact printing of Quantum Dot (QD) and organic polymer (OP) composites is explored as an alternate method of fabricating a cross-reactive chemical sensor array. Sensing layers fabricated by inkjet printing and contact printing methods are compared, showing that contact printing methods demonstrate a more uniform distribution of the QDs and higher signal to noise ratios (SNRs) when exposed to chemical vapors. A cross-reactive array was then fabricated with CdSe QDs and five OPs and exposed to the vapor of 15 common laboratory solvents. Principal component analysis (PCA) of the data showed high dimensionality of the sensor array response and linear discriminant analysis (LDA) produced correct classification of the target analytes in 100% of test cases.

Molecular design of photorefractive polymers

This review article describes the current state-of-the-art research on organic photorefractive polymer composites. A historical background on photorefractive materials is first introduced and is followed by a discussion on the opto-physical aspects and the mechanism of photorefractivity. The molecular design of photorefractive polymers and organic compounds is discussed, followed by a discussion on optical applications of the photorefractive polymers.

Employing 532 nm Wavelength in a Laser Ultrasound Interferometer Based on Photorefractive Polymer Composites

Laser ultrasonic (LUS) receivers based on photorefractive (PR) materials are contactless and adaptive interferometers, which are used widely for materials characterization. Here, we present a simple LUS interferometer at 532 nm operating wavelength based on organic PR polymer composites (PVK/ECZ/C60) doped with the nonlinear chromophore 4-[4-(diethylamino)-2-hydroxyben-zylideneamino] benzonitrile (Dc). A picoseconds laser at 1064 nm wavelength is used to generate ultrasound pulses in aluminum plates and by using this LUS polymer interferometer, detection of these ultrasound waves is remotely performed at the surface of the specimens. The LUS sensor is used to determine the thickness of aluminum plates about 0.25 mm, 3 mm and 10 mm. We also show the potential of this polymer receiver for detection of an artificial defect in a metal sample.

Organic-inorganic hybrid material and multifunctional fibers

Organic-inorganic hybrid materials can achieve the multi-scale composites of organic polymers and inorganic materials in the nano or molecular level. On one hand, such hybrid materials can exert each components characteristics. On the other hand, they reflect the unique collaboration features, such as new performance and multifunction. This principle can also be implemented in organic-organic hybrid system. With the continuous development of industrial fiber materials, their applications continue to be expanded. The development of new polymer materials to achieve multifunctional fibers has become a hot topic. According to the requirement of multifunctional fibers development, researchers try to build hybrid functional materials at the molecular level, build hybrid functional materials system and fiber-forming polymer hybrid system using the methods of structural design and construct interface combining with the organic-inorganic hybrid mechanism. This paper takes the structural design and condensed control of fiber-forming polymers, the structure-controllable preparation of nano-fibers and low-dimensional nano-fibers for example, introducing the research progress of organic-inorganic hybrid principles in the aspect of multi-functional fibers. Finally, it prospects the development of multifunctional organic-inorganic hybrid fibers.

Ag+-ion conducting Nano-Composite Polymer Electrolytes (NCPEs): Synthesis, characterization and all-solid-battery studies

Ag+-ion conducting Nano Composite Polymer Electrolyte (NCPE) films: [90PEO: 10AgCF3SO3]+xAl2O3, where x=0.5, 1, 1.5, 2, 3, 4, 5wt.(%), have been prepared by a completely dry hot-press technique in place of the traditional solution-cast method. NCPE film, basically a two-phase organic composite polymer electrolyte, has been synthesized using Solid Polymer Electrolyte (SPE) composition: [90PEO: 10AgCF3SO3], identified as one of the high conducting films with room temperature (300K) ionic conductivity (σrt)~7.12×10−7S/cm and having superior mechanical flexibility, as 1st-phase host and nano-particles (size<50nm) of an insulating/inert filler material Al2O3 as 2nd-phase dispersoid. Filler particle concentration dependent conductivity measurements revealed NCPE film: [(90PEO: 10AgCF3SO3)+3Al2O3] as Optimum Conducting Composition (OCC) with σrt~2.57×10−6S/cm. A conductivity enhancement of more than 3-fold could be achieved in SPE as a consequence of dispersal of Al2O3 nano-particles. Also, NCPE OCC film physically appeared relatively more stable/flexible as compared to SPE host film. The characterization of ion transport properties in SPE host and NCPE OCC films has been done in terms of ionic conductivity (σ) and total ionic (tion)/cation (t+) transference numbers. These ionic parameters have been evaluated experimentally using different ac/dc techniques. The temperature dependent conductivity has also been studied and the activation energy (Ea) was computed by liner least square fitting of Arrhenius plot. The material characterization was done by analyzing X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) responses on the film samples. All-Solid-State batteries in the cell configuration Ag (anode)//NCPE OCC film//(I2+C+NCPE) (cathode) have been fabricated and the cell-potential discharge performances have been studied under varying load conditions. An Open Circuit Voltage (OCV)~0.56V was obtained. Some important cell parameters have been evaluated from the cell potential discharge profiles. The battery performed quite satisfactorily especially under low current drain states.

Formation of PVP hollow fibers by electrospinning in one-step process at sub and supercritical CO2

It was well known that electrospinning is one of the simple technical methods for the production of polymer nanoparticles and nanofibers. Various polymers have been successfully electrospun into ultrafine particles and fibers in recent years mostly in solvent solution and some in melt form. In this work, hollow fibers with walls made of organic polymer composites have been formed by electrospinning in a single processing step under pressurized carbon dioxide (CO2). The experiments were conducted at 313K and ∼8MPa. The capability and feasibility of this technique was demonstrated by the production of polyvinylpyrrolidone (PVP) fibers whose size and wall thickness could be independently varied by controlling a set of experimental parameters. The PVP fibers had an average pore diameter 2–4μm. At low pressures (<5MPa; subcritical conditions), the solid fibers were formed, the baloon-like structures of PVP was formed with increasing pressure of CO2 at 8MPa (supercritical condition)

Preparation of Marcoporous and Hollow Silica Microspheres with Raspberry-Like Organic Composite Particles as Templates

Marcoporous silica hollow microspheres were prepared by poly (acrylic acid)@poly (ethyleneglycol dimethacrylate-co-4-vinylpyridine) (PAA@P(EGDMA-co-VPy)) composite particles with raspberry-like structure as the template. P(EGDMA-co-VPy) and PAA microspheres were prepared by distillation precipitation polymerization respectively. The raspberry-like organic composite polymer particles were obtained through the self-assembly of PAA microspheres on P(EGDMA-co-VPy) microspheres. Then, Silica layer was coated on the composite particles with Stöber method in an alkaline environment. The marcoporous silica hollow microspheres were received after the calcination to remove the organic template. The diameter of the marcoporous silica hollow microspheres, hollow inner core and the pore size of silica layer was about 2.0 μm, 1.5 μm and 20-130 nm, respectively.

Laser ultrasonic receivers based on organic photorefractive polymer composites

We present two laser ultrasonic receivers based on organic photorefractive polymer composites with 2- (4-bis(2-methoxyethyl)aminobenzylidene)malononitrile (AODCST) or 2-dicyanomethylen-3-cyano-5,5-dimethyl- 4-(4 0 -dihexylaminophenyl)-2,5-dihydrofuran nonlinear optical chromophores. Experimental results show sensi- tivities of the ultrasonic receivers of *9.5 9 10 -8 nm (W/Hz) 0.5 for both composites, and a faster response time (*60 ms) for the AODCST-based laser ultrasonic recei- ver. We show that such LUS detectors are highly suitable for contactless thickness measurements of aluminum, steel sheets and defect detection with an accuracy of 100 lm.

Organic polymer composite random laser operating underwater

In this work, an organic composite polymer random laser (RL) operating underwater has been studied. The RL structure used in the test is a rod-shaped composite, formed by a mixture of an organic green light-emitting polymer and a UV transparent polymer matrix. RL action was sustained by both the multiple scattering and whispering-gallery-mode effect. The demonstration of RL action and the test of its operation lifetime in such an organic composite RL operating in water suggest the feasibility of its promising future applications in areas of underwater optical communications and/or remote optical sensing.

Interdigitated coplanar electrodes for enhanced sensitivity in a photorefractive polymer

Organic photorefractive polymer composites can be made to exhibit near 100% diffraction efficiency and fast writing times, though large external slants are needed to project the applied field onto the grating vector. We show here that the use of interdigitated electrodes on a single plane provides similar performance to these standard devices and geometries but without a external slant angle. This new device's structure also greatly improves the diffraction efficiency and sensitivity compared to less slanted standard devices necessary for some real applications, such as holographic displays, optical coherence imaging, and in-plane switching.

Highly biocompatible multi-walled carbon nanotube–chitosan nanoparticle hybrids as protein carriers

Carbon nanotube (CNT)–organic polymer hybrids have important potential applications in the immobilization of therapeutic biomolecules. Recently developed CNT–organic polymer composites require the use of organic solvents for their preparation and have limited polymer functionalization. To address these limitations, multi-walled CNT (MWCNT)–chitosan nanoparticle (CS NP) hybrids have been synthesized in situ by an ionotropic gelation process, which is extremely mild and involves the mixture of two aqueous solutions at room temperature. The MWCNT–CS NP hybrids were characterized by atomic force microscopy and thermogravimetric analysis. Under optimal conditions the CS NP can be tethered to the MWCNT surface in high density and with relatively uniform coverage. The MWCNT–CS NP hybrids show good dispersibility and stability in aqueous solutions. In order to evaluate the potential utilization of the hybrids as protein carries the cytotoxicity to HeLa cells and protein immobilization (of bovine serum albumin (BSA), used here as a model) capacity of the hybrids were investigated in detail. The results demonstrate that the MWCNT–CS NP hybrids are biocompatible at concentrations up to 100μgmL−1 for 24h incubation. The MWCNT–CS NP hybrids improve the BSA immobilization efficiency 0.8 times and simultaneously decrease the cellular toxicity by about 50% compared with carboxylated MWCNT.

Flocculation of kaolin in water using novel calcium chloride-polyacrylamide (CaCl 2-PAM) hybrid polymer

The flocculation of kaolin suspension in water using a novel calcium chloride-polyacrylamide hybrid polymer has been studied. A redox initiation system – (NH 4) 2S 2O 8 and NaHSO 3 was used to initiate free radical solution polymerization of one molar acrylamide solution at 50 °C. One mole of calcium chloride was blended with polymerized acrylamide solution to synthesis a novel inorganic–organic composite polymer (CaCl 2-PAM hybrid polymer). The CaCl 2-PAM hybrid polymer was characterized using Fourier transform infrared spectrometer (FT-IR) and transmission electron microscopy (TEM). TEM image showed that the CaCl 2-PAM hybrid has a bulky and web-like nature. The CaCl 2-PAM hybrid polymer was used in flocculating kaolin suspension. A factorial design was used in screening the factors for the flocculation of kaolin suspension to study the effect of two operating parameters (pH and dosage). The kaolin suspension flocculation was found to be pH and dosage dependent. Response surface methodology was done using central composite design and showed that the CaCl 2-PAM hybrid polymer was able to reduce >98.0% of turbidity. The optimal operating condition was reported between pH 2 and 2.5 and dosage between 2 and 3 mg/L.

ChemInform Abstract: Organic Polymer Composites as Robust, Non‐Covalent Supports of Metal Salts.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Giant magnetoresistance in composites of organic polymers with manganese acetylacetonate and lanthanum-praseodymium chlorides exhibiting ionic conductivity

We present a new giant magnetoresistance (GMR) material composed of polyaniline, polystyrene, sulfur, manganese acetylacetonate, lanthanum, and praseodymium chlorides. These compounds were mixed and processed mechanochemically to obtain thin films. External magnetic field of 6000 Oe increases conductivity of films by more than 300%. Analysis of transient current kinetics after application of constant voltage (10 V) to samples showed the existence of three types of charge carriers, which we identified as e−, H+, and Cl−. Contribution of functional groups of polyaniline and elemental sulfur S in the formation of the above charge carriers in this new GMR composite material is discussed.

Organic polymer composites as robust, non-covalent supports of metal salts

A novel organic polymer composite for the encapsulation of metal catalysts and applications to synthesis are described here.

DYNAMIC HOLOGRAPHIC IMAGING USING PHOTOREFRACTIVE POLYMERS BASED ON A BORONATE-DERIVATIVE NONLINEAR CHROMOPHORE

We report dynamic holographic imaging with organic photorefractive polymer composites, doped with the electro-optic chromophore (2-(p-chlorophenyl)-(3′-nitrobenzo[d])-(4′′-methoxybenzo[h])-1,3-dioxa-6-aza-2-boracyclonon-6-ene, a push-pull molecule derived from a new class of boronates. The composites are based on the photoconductor poly(9-vinylcarbazole) (PVK) as the polymer matrix, and 9-ethylcarbazole (ECZ) as the plasticizer, with the fullerene C 60 as sensitizer. A tilted four-wave mixing geometry was used to record and reconstruct two-dimensional test objects, using a 10 mW He – Ne laser (632.8 nm). The recording response time was less than one second for a light intensity of ≈350 mW/cm 2 in each writing beam. The erasing time had a similar value. These composites have been used for over one year with no appreciable signs of degradation or crystallization.

Preparation of hierarchically organized calcium phosphate–organic polymer composites by calcification of hydrogel

A novel type of calcium phosphate–organic polymer composite having a hierarchical structure was prepared by calcification of a poly(acrylic acid) hydrogel. Macroscopically, an organic gel containing phosphate ions was transformed into an opaque solid material by diffusion of calcium ions. We observed the formation of micrometer-scale layered structures consisting of nanoscale crystals of hydroxylapatite (HAp) in the opaque products. The laminated architecture resulting from the periodic precipitation of calcium phosphate varied with the reaction conditions, such as the concentrations of the precursor ions and the density of the gel. The nanoscopic structure of HAp crystals was modified by the addition of gelatin to the polymer matrix.

Interpenetrating organic conducting polymer composites based on polyaniline and poly(3,4-ethylenedioxythiophene) from sequential electropolymerization

Interpenetrating organic polymer composites consisting of two conducting polymers have been successfully prepared by sequential electropolymerization of the parent monomers: aniline and 3,4-ethylenedioxythiophene. The electropolymerization of poly(3,4-ethylenedioxythiophene) (PEDOT) and polyaniline (PANI) was carried out in acetonitrile solution. In the first step, a potentiostatic electrodeposition of PEDOT was performed. Then in the second step, a potentiostatic electrodeposition of PANI was carried out, in acetonitrile solution without addition of protic acid, in the potential range where PEDOT was in its oxidized and conducting states. We observed that the oxidized PEDOT film exhibited a Lewis acid behavior that allowed the polymerization of polyaniline on PEDOT modified electrode in the absence of protic acid. A mechanism of the polymerization of PANI onto PEDOT was proposed. The electrochemical properties of the composite films have been analyzed by means of cyclic voltammetry and in situ resistometry. In the case of the interpenetrating composite based on PEDOT/PANI, the variation of the electronic resistance as a function of potential displayed a drastic change comparing to that of PEDOT or PANI alone. These results indicated that the obtained electroactive material was not a bilayer or sandwhich structure but an interpenetrating composite in which the two conducting polymers interacted each other to give new electrical properties. Also, we observed an increase of the stability of PANI in the PEDOT/PANI composite when the measurements were carried out in acidic aqueous solution. An important advantage of these organic conductive polymer composites is the simplicity of their preparation.

Preparation and cyclic voltammetry studies on nickel-nanoclusters containing polyaniline composites having layer-by-layer structures

We suggest a novel route for the preparation of organic conductive polymer composites that are doped by the programmable controlled dispersion of nickel-nanoclusters into a polymer matrix having structure of layer-by-layer. The layered structures of polyaniline composites containing nickel-nanoclusters (PANI-Ni) were prepared electrochemically by a two-pot process in 0.1 M H 2SO 4 and 0.5 M NiSO 4. We discuss on what is intrinsic nature of the mutual influences of the PANI chains and nickel-nanoclusters within a PANI-Ni film, on the change in structural morphology, and on the broadening and shifts of anodic waves to higher potentials during cyclic voltammetry. Also the role of nickel-nanoclusters as a source supplying protons to promote the protonation to form polaron and bipolaron charge carriers of PANI was suggested.