Organic Inorganic Hybrid Nanocomposites Research Articles

Al-doped cellulose ZnO hybrid nanocomposite

Cellulose based inorganic–organic hybrid nanocomposite was fabricated by growing ZnO nanorods on a transparent and flexible cellulose film. To improve its electrical and electromechanical properties, Al doping to ZnO was achieved during the ZnO nanorod growing by a hydrothermal synthesis with different ratio of Al and Zn derivative chemicals. As increasing the Al dopant ratio, the morphology changes from nanorod to the nanoplate. The Al dopant ratio also influences the electrical properties of the hybrid nanocomposite. 1.2% of Al/Zn molality ratio is found to be a critical value that changes the morphology and improves the electrical and electromechanical properties. Detail phenomenon and possible mechanism around the critical value of Al/Zn molarity ratio is discussed.

PEG‐based organic–inorganic hybrid coatings prepared by the sol–gel dip‐coating process for biomedical applications

In the present work, the application of functional coatings on metallic implants was proposed to delay implant failure by improving tissue tolerance and implant osseointegration. Three bioactive and biocompatible organic–inorganic hybrid nanocomposites, consisting of polyethylene glycol (PEG) embedded in a SiO2, ZrO2, and TiO2 matrix, respectively, were synthesized via the sol–gel method. Materials in the sol phase were used to dip‐coat titanium grade 4 substrates for use as dental and orthopedic implant models. To investigate the influence of the glass matrix and the polymer amount on the coating structure, and thus on their biological properties, several hybrids were obtained by adding different weight percentages of PEG to each glass matrix. Attenuated total reflectance Fourier transform infrared spectroscopy confirmed the presence of the polymer in the nanocomposites and scanning electron microscopy showed that an increase in the PEG content allows crack‐free coatings to be obtained. Moreover, the bioactivity and biocompatibility of both the uncoated and coated titanium implants were investigated and compared by an in vitro test. The results revealed that coated substrates have more enhanced biological performance than the uncoated ones. The bioactivity is not significantly affected by either the inorganic matrix or the PEG amount, whereas the presence of polymer makes the films more biocompatible. POLYM. ENG. SCI., 57:478–484, 2017. © 2017 Society of Plastics Engineers

Preparation of hydrophobic organic-silicanano composites

ABSTRACTIn this paper, we use silica nanoparticles modified by methacryloxy propyl trimethoxylsilane (KH570) as the core material, and employ polymers including hexafluorobutyl methacrylate (HFMA), dodecafluoroheptyl methacrylate (DFMA) and acrylic ester as the shell materials to prepare the hydrophobic inorganic–organic hybrid nanocomposites with a seed emulsion polymerization strategy. The size, morphologyandproperties of the core-shell structured nanoparticles are investigated by TEM and SEM. The results showthat the polymer nanocomposite has three concentric layers with silica nanoparticles in the center, acrylic polymer as the internal shell and fluorosilicone polymer as the outmost shell. By controlling the ratio of the silica nanoparticles and monomers, we can achieve each composite particle has the core-shell structure with silica nanoparticles as the core and the thin layer of fluorosilicone polymer as the shell. Compared with the traditional polymer film, the nanocomposite film shows a hydrophobic property with a contact angle of up to 100 degree. Therefore, it is feasible to prepare hydrophobic organic–inorganic nanocomposites using the method proposed here.

A two-dimensional hexagonal boron nitride/polymer nanocomposite for flexible resistive switching devices

Organic–inorganic hybrid nanocomposites are an attractive choice for various electronic device applications.

Synthesis of layered zinc hydroxide intercalated with dodecyl sulfate organic-inorganic hybrid nanocomposite as a fiber coating for the headspace solid-phase microextraction of aromatic hydrocarbons from water.

We describe the synthesis of a layered zinc hydroxide-dodecyl sulfate organic-inorganic hybrid nanocomposite as a new solid-phase microextraction fiber. The fiber coating can be prepared easily in a short time and the reaction is at room temperature; it is mechanically stable and exhibits relatively high thermal stability. The synthesized layered zinc hydroxide-dodecyl sulfate nanocomposite was successfully prepared and immobilized on a stainless steel wire and evaluated for the extraction of aromatic compounds from aqueous sample solutions in combination with gas chromatography and mass spectrometry. The method yields good results for some validation parameters. Under optimum conditions (extraction time: 15 min, extraction temperature: 50°C, desorption time: 1 min, desorption temperature: 250°C, salt concentration: 0.5 g/mL), the limit of detection and dynamic linear range were 0.69-3.2 ng/L and 10-500 ng/L, respectively. The method was applied to the analyses of benzene, toluene, ethylbenzene, and o-, p-, and m-xylenes in two real water samples collected from the Aji river and Mehran river, Tabriz, Iran. Under optimum conditions, the repeatability and reproducibility for one fiber (n = 3), expressed as the relative standard deviation, was 3.2-7.3% and 4.2-11.2% respectively. The fibers are thermally stable and yield better recoveries than conventional methods of analysis.

Inorganic-organic hybrid coating material for the online in-tube solid-phase microextraction of monohydroxy polycyclic aromatic hydrocarbons in urine.

An inorganic-organic hybrid nanocomposite (zinc oxide/polypyrrole) that represents a novel kind of coating for in-tube solid-phase microextraction is reported. The composite coating was prepared by a facile electrochemical polymerization strategy on the inner surface of a stainless-steel tube. Based on the coated tube, a novel online in-tube solid-phase microextraction with liquid chromatography and mass spectrometry method was developed and applied for the extraction of three monohydroxy polycyclic aromatic hydrocarbons in human urine. The coating displayed good extraction ability toward monohydroxy polycyclic aromatic hydrocarbons. In addition, long lifespan, excellent stability, and good compression resistance were also obtained for the coating. The experimental conditions affecting the extraction were optimized systematically. Under the optimal conditions, the limits of detection and quantification were in the range of 0.039-0.050 and 0.130-0.167 ng/mL, respectively. Good linearity (0.2-100 ng/mL) was obtained with correlation coefficients larger than 0.9967. The repeatability, expressed as relative standard deviation, ranged between 2.5% and 9.4%. The method offered the advantage of process simplicity, rapidity, automation, and sensitivity in the analysis of human urinary monohydroxy polycyclic aromatic hydrocarbons in two different cities of Hubei province. An acceptable recovery of monohydroxy polycyclic aromatic hydrocarbons (64-122%) represented the additional attractive features of the method in real urine analysis.

Fabrication of Polyethylene/MoS2 nanocomposites using a novel exfoliated-MoS2–MgCl Bi-supported Ziegler-Natta catalyst via in-situ polymerization

A novel exfoliated-MoS2 (EMoS2)–MgCl bi-supported Ziegler-Natta catalyst was synthesized by the reaction of Grignard reagent and EMoS2, followed by anchoring with TiCl4. The tendency of the individual EMoS2 layers to aggregate was prevented by covering them with solid-state Ziegler-Natta catalyst. The resultant catalyst was applied to ethylene polymerization, forming polyethylene (PE)/EMoS2 organic-inorganic hybrid nanocomposites. The resultant products had a flake-shape morphology, with EMoS2 well dispersed in the PE matrix. In addition, the thermal stability and mechanical properties of PE were significantly enhanced by the introduction of EMoS2.

Polymerization of β‐cyclodextrin in the presence of bentonite clay to produce polymer nanocomposites for removal of heavy metals from drinking water

New hybrid organic–inorganic nanocomposites consist of β‐cyclodextrin (β‐CD)/epichlorohydrin (ECH), and bentonite clay were prepared by direct intercalation through one step emulsion polymerization. The structure and thermal stability of prepared nanocomposites were investigated by Fourier‐transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), field emission‐scanning electron microscopy (FE‐SEM), energy dispersive X‐ray analysis (EDAX), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), differential of differential scanning calorimetry (DDSC), thermogravimetric analysis (TGA) and differential thermogravimetric (DTG) analyses. The observed results show that the β‐CD polymer/clay nanocomposites (β‐CD–ECH polymer/clay) with higher thermal stability than β‐CD–ECH polymer were successfully prepared. The removal of heavy metals such as Cu(II), Zn(II) and Co(II) ions from drinking water was studied using a batch method at ambient temperature. The removal percentage and distribution coefficients (Kd) were determined for the adsorption system. It was found that the β‐CD–ECH polymer/clay nanocomposites showed higher removal capacity for Co2+, Cu2+ and Zn2+ ions in comparison with β‐CD–ECH polymer. The selectivity order could be given as Zn2+ > Cu2+ > Co2+. Copyright © 2016 John Wiley & Sons, Ltd.

Novelty Designed Hybrid Organic-Inorganic Nanocomposites from Functional Palm Oil

Polyurethanes (PUs) are very versatile polymeric materials with a wide range of physical and chemical properties. PUs also have desirable properties such as high abrasion resistance, tear strength, shock absorption, flexibility and elasticity. Although they have poor thermal stability that however can be improved by using treated clay. The objective of the present work is to study the thermal stability of polyurethane, polyurethane/montmorillonite (PU CTAB-mont 3% wt) and polyurethane/montmorillonite that contain moca nanocomposites are based on palm oil polyol. The interest of investigating the synthesis of polyurethane/clay nanocomposites based on palm oil polyol is to explore the use of palm oil polyol to replace petrochemical based polyol partially. Polyurethane/clay nanocomposites were prepared by a pre-polymer method and were evaluated by fourier transform infrared spectra (FTIR) to determine micro-domain structures of segmented PU, PU CTAB-mont 3% wt, and PU Moca CTAB-mont 3% wt. The morphology of the nanocomposites were characterized by X-ray diffraction (X-RD) and flame retardant was investigated with thermogravimetric analysis (TGA). The result showed that adding clay and moca demonstrated better thermal stability in comparison with the virgin polyurethane.Keywords : Nanocomposite, polyurethane, synthesis, palm oil polyol

Synthesis and characteristics of polyaniline/zirconium oxide conductive nanocomposite for dye adsorption application

The organic–inorganic hybrid nanocomposite of polyaniline/zirconium oxide was synthesized through the chemical method, using the ammonium persulfate as an oxidant. The developed adsorbent was characterized using various analytical techniques such as scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The developed nanocomposites i.e. polyaniline modified with ZrO2 and polyaniline were used as effective adsorbents for the rapid removal of methylene blue from the solvent phase. The effects of different system variables such as initial dye concentration, temperature and contact time were well studied and investigated. From the optimized parameter results obtained it was found that as contact time increases, the dye removal efficiency also increases. Additionally as the temperature increased the amount of adsorption also increased. The results indicated that the polyaniline modified with ZrO2 and polyaniline nanocomposite have considerable potential for the removal of methylene blue from aqueous solution. The adsorption capacities (qmax) of polyaniline modified with ZrO2 (PANI/ZrO2) and polyaniline (PANI) for methylene blue in terms of monolayer adsorption were 77.51 and 192.30mg/g, respectively.

Multifunctional properties of organic-inorganic hybrid nanocomposites based on chitosan derivatives and layered double hydroxides for ocular drug delivery

To improve the ocular bioavailability of the model drug of pirenoxine sodium (PRN), organic-inorganic hybrid nanocomposites including layered double hydroxides (LDH) and chitosan derivatives (chitosan-glutathione (CG), chitosan-glutathione-valine (CG-V) and chitosan-glutathione-valine-valine (CG-VV)) were designed and characterized. In vivo precorneal retention study on rabbits showed that mean residence time (MRT) and area under the curve (AUC0–6h) of CG-PRN-LDH nanocomposite eye drop was up to 2.1-fold and 6.3-fold higher than those of commercial product, respectively. In vitro corneal penetration on rabbits demonstrated that the cumulative permeation of CG-VV-PRN-LDH nanocomposite dispersion was increased by 5.2 folds compared to that of commercial product, which may be due to the active transport effect of the nanocomposites by peptide transporter-1 (PepT-1). In addition, the ex vivo fluorescence imaging showed that fluorescent intensity of crystalline lens in rabbits was increased after the administration of PRN-LDH, CG-PRN-LDH, CG-V-PRN-LDH and CG-VV-PRN-LDH (in increasing order) nanocomposite eye drop. Finally, in vivo distribution evaluation in ocular tissues of rabbits revealed that AUC0–8h and MRT in crystalline lens exhibited 14.7-fold and 2.2-fold increase in CG-VV-PRN-LDH nanocomposite eye drop group than those of commercial group, respectively. In summary, the organic-inorganic hybrid nanocomposites with multifunctional properties may be a promising ocular drug delivery system to achieve prolonged precorneal retention, better corneal permeability and enhanced ocular bioavailability. Statement of SignificanceDue to several structural and physiological intraocular barriers, drug delivery to the ocular mid-posterior segments still faces great challenges. In this manuscript, organic-inorganic hybrid nanocomposites based on chitosan derivatives and layered double hydroxides (LDH) were designed and constructed. Multifunctional properties of these hybrid nanocomposites were due to the possible active targeting to the peptide transporter-1 on the corneal epithelial cells, the bioadhesive ability and permeation enhancement of chitosan derivatives, and the electrostatic adsorption of LDH. Prolonged precorneal retention, better corneal permeability and enhanced ocular bioavailability of the model drug pirenoxine sodium were observed. Chitosan derivatives-LDH hybrid nanocomposites may be a promising ophthalmic drug system for the treatment of ocular diseases of mid-posterior segments.

Intercalation polymerization of allene hydrocarbons in polar and nonpolar media

Organomodified layered aluminosilicates and hybrid organic–inorganic nanocomposites based on Na+-montmorillonite, Cloisite 20A, and allene hydrocarbons have been obtained under the action of rhodium chloride. The intercalation polymerization includes the cation-exchange reaction, the intercalation of hydrated rhodium chloride (RhCl3 ∙ 4H2O) into layered silicates, and the in situ oligomerization of allene or 1,1-dimethylallene. The reaction is performed in polar (Na+-montmorillonite) and nonpolar (Cloisite 20A) solvents. Detailed X-ray diffraction studies of the resulting products show that, depending on the reagent concentrations and ratios, oligoallene- and oligo(1,1-dimethylallene)-modified nanofillers with both intercalated and exfoliated morphologies can be obtained. Three independent phases are detected, which suggests the formations of structures with different types of organophilic layers. The structures and properties of polymers and composites obtained by the rhodium chloride-catalyzed polymerization of allene in toluene or a water-ethanol mixture in the presence of aluminosilicates are studied by X-ray diffraction, IR spectroscopy, and differential scanning calorimetry. The polyallenes synthesized in different media are shown to have identical structures (1,2,1,2-addition) and crystallinities (m.p. 124–126°C), but different degrees of aluminosilicate exfoliation in nanocomposites.

Immobilization of chymotrypsin on silver nanoparticles

The method of immobilization of chymotrypsin based on the reduction reaction of silver nitrate with sodium borohydride in an aqueous medium in the presence of the enzyme was developed. Chymotrypsin was simultaneously a stabilizer of silver nanoparticles in solution. The dimensional characteristics, as well as proteolytic and bactericidal activity of the synthesized nanocomposites were studied. It is shown that the hybrid organic-inorganic nanocomposites based on chymotrypsin and silver nanoparticles are able to perform an increased proteolytic activity in comparison with the native enzyme in the pH range corresponding to wound surface, and suppress pathogenic flora of various microorganisms.

The combination of adsorption by functionalized halloysite nanotubes and encapsulation by polyelectrolyte coatings for sustained drug delivery

A novel organic–inorganic hybrid nanocomposite was established for the sustained release of an analgesic.

Dispersion Control and Characterization of the SiO2/PMMA Particles Using Surface Charge

Poly-methylmetacrylate (PMMA) is mainly applied in the plastic manufacturing industry, but PMMA is weak and gradually got discolor. The strength of PMMA can be improved through organic-inorganic hybrid nano composites with inorganic nano particles such as, or ZrO. However, inorganic nano particles are mostly agglomerated spontaneously. In this study, the zeta potential is controlled using different types of organic solvent with different concentrations, dispersibillity of nano particles on the PMMA particle are analyzed. When 3 M acetic acid is used, absolute value of the zeta potential is higher, nano particle is well attached, and dispersed on the PMMA particle surface. Results indicate that the absolute value of the zeta potential affects the stability of dispersion.

Organic–inorganic hybrid nanocomposites based on chitosan derivatives and layered double hydroxides with intercalated phacolysin as ocular delivery system

This study was mainly aimed to evaluate the potential use of a novel ocular drug delivery system, organic–inorganic hybrid nanocomposites based on chitosan derivatives and layered double hydroxides (LDH). Organic polymers of chitosan–glutathione (CG) and pre-activated chitosan–glutathione (CG-2MNA) were successfully synthesized and characterized. LDH with intercalated phacolysin (PCL), including larger hexagonal LDH–PCL (Lh-LDH–PCL), larger spherical LDH–PCL (Ls-LDH–PCL), smaller hexagonal LDH–PCL (Sh-LDH–PCL), CG hybrid LDH–PCL (LDH–PCL-CG), and CG-2MNA hybrid LDH–PCL (LDH–PCL-CG-2MNA), were prepared. The nanocomposites with particle size of 107.2–274.9 nm were characterized by powder X-ray diffraction, Fourier transform infrared, transmission electron micrographs, etc. In vivo precorneal retention studies showed that the detectable time of all nanocomposites was prolonged from 2 to 6 h in comparison to PCL saline. Accordingly, the AUC0–6h values of Lh-LDH–PCL, Ls-LDH–PCL, Sh-LDH–PCL, LDH–PCL-CG, and LDH–PCL-CG-2MNA nanocomposites were increased by 2.27-, 2.08-, 3.08-, 4.67-, and 3.36-fold, respectively. The Draize test and hematoxylin and eosin staining demonstrated that modified LDH had no eye irritation after single and repeated administration. These results indicated that chitosan derivatives-LDH hybrid nanocomposite dispersion could be a promising ocular drug delivery system to improve precorneal retention time of drugs. Thiolated chitosan-LDH hybrid nanocomposite dispersion could be a promising ocular drug delivery system to improve precorneal retention time of drugs and may facilitate penetration of drugs into tissues of the eyes.

Hybrid Nanocomposites Based on Epoxy/silsesquioxanes Matrices Reinforced with Multi-walled Carbon Nanotubes

The aim of this work was the synthesis of hybrid organic-inorganic epoxy-copolysilsesquioxane nanocomposites reinforced with multi-walled carbon nanotubes (MWCNT). Copolysilsesquioxanes oligomers from 3-aminopropyltriethoxysilane (APTES) and phenyltriethoxysilane (PTES) precursors have been synthesized by a sol-gel process and chemically incorporated to an epoxy resin based on diglycidyl ether of bisphenol A (DGEBA). MWCNT (0.25 wt%) was added to the hybrid matrixes with different degrees of condensation. Fourier transform infrared analysis showed that a high degree of cure was achieved, suggesting that the MWCNT did not affect the curing reaction of the hybrid matrixes. Hybrid nanocomposites obtained by sonication technique presented improvement on thermal stability, exhibiting onset degradation temperatures higher than 340 °C under N2. Tensile tests presented Young’s modulus and maximum stress values up to 2.9 GPa and 47 MPa, respectively, indicating that the new hybrid epoxy/MWCNT nanocomposites show a moderate enhancement of the mechanical properties in comparison with the neat epoxy resin.

The tumor-targeting core–shell structured DTX-loaded PLGA@Au nanoparticles for chemo-photothermal therapy and X-ray imaging

In this study, an organic–inorganic hybrid nanocomposite was synthesized by deposition of Au onto the surface of docetaxel (DTX)-loaded poly (lactide-co-glycolide) (PLGA) nanoparticle cores to form the core–shell structured DTX-loaded PLGA@Au nanoparticles. The tumor targeting peptide, angiopep-2, was then introduced onto the gold nanoshell through Au–S bond, achieving drug delivery with active targeting capability. This novel system allowed combined chemotherapy and thermal therapy for cancer, resulting from DTX and gold nanoshell. The formation of tumor-targeting gold nanoshell surrounding PLGA nanocore, designated as ANG/GS/PLGA/DTX NPs, was confirmed by its surface plasmon resonance (SPR) band in the UV–Vis spectrum and by a transmission electron microscope (TEM). The release profiles of DTX from this system showed strong dependence on near-infrared (NIR) laser. Compared with DTX alone, the ANG/GS/PLGA/DTX NPs afforded much higher anti-tumor efficiency without obvious toxic effects. Besides, it also showed potential X-ray imaging ability. These results demonstrated that the tumor-targeting core–shell structured DTX-loaded PLGA@Au nanoparticles could be used as a multifunctional nanomaterial system with NIR-triggered drug-releasing properties for tumor-targeted chemo-photothermal therapy and theranostics.

NOVEL NANOSIZED FRICTION MODIFIERS FOR ENGINE, GEARBOX AND ROLLING BEARINGS LUBRICANTS

In this paper the tribological performances of graphene oxide nanosheets in mineral oil under wide spectrum of conditions, from boundary and mixed lubrication to elastohydrodynamic regimes, are reported. Nanosheets of graphene oxide prepared by a modified Hummer method have been dispersed in Group I mineral oil. The formulated lubricant has been tested through a ball on disc setup tribometer to quantify the friction reduction with respect to the base mineral oil. The good friction and anti-wear properties of the graphene-oil mixture may possibly be attributed to the small structure of the nanosheets and their extremely thin laminated structure, which offer lower shear stress and prevent direct interaction between metal asperities in engine applications as well as gearbox environment. The results clearly prove that graphene platelets in oil easily form protective film to prevent the direct contact between steel surfaces and, thereby, improve the frictional behaviour of the base oil. This evidence is also related to the frictional coefficient trend in the boundary regime. Furthermore, hybrid organic–inorganic nanocomposites with different composition were successfully tested as antifriction and antiwear additives for grease lubricants as potential breakthrough media in rolling bearings applications.

Synthesis and characterization of sustainable polyurethane based on epoxy soybean oil and modified by double-decker silsesquioxane

A series of environmentally friendly and sustainable polyurethanes using epoxy soybean oil as feedstock were synthesized with the introduction of double-decker silsesquioxane. Feature is that through the two-step polymerization, double-decker octaphenylsilsesquioxanetetraol was added to partially replace 1,4-butanediol acting as chain extender, and petroleum-based polyol was effectively replaced for polyurethane synthesis. On top of that, POSS tetraol was prepared and characterized by 1H NMR and MALDI-TOF MS. As for the organic–inorganic hybrid nanocomposites, their structures and properties were investigated by FTIR, DSC, TGA, SEM, tensile test techniques, and static contact angle. DSC analysis showed that covalent incorporation of POSS into the PU network would increase the glass transition temperature (T g) of the systems. TG analysis demonstrated that the hybrid nanocomposites were indeed more oxidative thermal stable, compared to virgin polyurethane especially at high temperature. SEM revealed that both nano- and micro-sized POSS aggregates were shown to be dispersed heterogeneously in the polyurethane matrix, despite the expectation to be dispersed or corporate into molecular chains by chemical bonding between OH and NCO. According to the tensile test results, POSS-containing nanocomposites exhibited an increased modulus with an increasing POSS concentration at low POSS content, and with high loading, these values would decline. The results of the static contact angles revealed that the hydrophobicity of the hybrid material was significantly improved with the inclusion of POSS.