Organic-inorganic Hybrid Composites Research Articles

Synthesis of mesoporous nickel–titanium-trimesic acid inorganic–organic hybrid composite in ionic liquid microemulsions for adsorption of rhodamine B from aqueous solution

For the first time, mesoporous nickel–titanium-trimesic acid (NTT) inorganic–organic hybrid composite was synthesized in water-in-[Bmim]PF6 ionic liquid microemulsions using the trimesic acid (BTC) as the linker. The synthesized NTT was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) analysis, powder X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) methods, etc. Then, the isotherm and kinetic of adsorption were studied. The experimental data were well fitted with isotherm models of Langmuir and Freundlich (IMLF) at 298 K and 308 K and better fitted with the isotherm model of Langmuir (IML) at 318 K with the adsorption capacity of 662.212 μmol/g (maximum). The adsorption of rhodamine B (RhB) on NTT can be described by pseudo-second-order (PSO) kinetic model. This proposed method for synthesis of mesoporous NTT inorganic–organic hybrid composite is facile, environment-friendly and operated at room temperature, which could be applied to synthesis of other mesoporous inorganic–organic hybrid composites.

Mechanism of carboxymethyl chitosan hybrid montmorillonite and adsorption of Pb(II) and Congo red by CMC-MMT organic-inorganic hybrid composite

The carboxymethyl-chitosan-montmorillonite (CMC-MMT) organic-inorganic hybrid material was applied to adsorb Pb(II) and Congo red (CR) anionic dye from aqueous solution. Molecular dynamics(MD) simulation was carried out to reveal the mechanism of CMC hybrid MMT. The results suggested that CMC has been adsorbed on the interlayer space and surface of MMT, hydrogen bonds had been formed between hydroxyl & carboxyl groups of CMC with the surface of MMT, Van der Waals interaction was also existed, while amino groups of CMC hadn't obvious interaction with the surface of MMT. Batch experiments were executed to investigate the adsorption effect of CMC-MMT was compared with Na-MMT and CMC. The results showed that CMC-MMT exhibited the higher adsorption capacity than Na-MMT and CMC, The OH and COOH or NH2 groups of CMC chains may serve as electrostatic interaction active sites and coordination sites, which improved the adsorption performance of CMC-MMT on Pb(II)，and the insertion of CMC enlarged the inter-layer space of MMT, resulting in more surface active sites in the CMC-MMT hybrid composite, which increased the adsorption of organic pollutant CR. The kinetic and isotherm studies indicated that the pseudo-second-order and the Langmuir model well described the adsorption equilibrium of Pb(II) and CR on CMC-MMT.

Enhanced mechanical and biological characteristics of PLLA composites through surface grafting of oligolactide on magnesium hydroxide nanoparticles.

Poly(l-lactic acid) (PLLA) is a biocompatible and biodegradable polymer that has received much attention as a biomedical material. However, PLLA also produces by-products that acidify the surrounding tissues during in vivo degradation, which induces inflammatory responses. To overcome these problems, magnesium hydroxide nanoparticles (nano-magnesium hydroxide; nMH) were added to the PLLA matrix as a bioactive filler that can suppress inflammatory responses by neutralizing the acidified environment caused by the degradation of PLLA. Despite the advantages of nMH, the strong cohesion of these nanoparticles toward each other makes it difficult to manufacture a polymer matrix containing homogeneous nanoparticles through thermal processing. Here, we prepared two types of surface-modified nMH with oligolactide (ODLLA) utilizing grafting to (GT) and grafting from (GF) strategies to improve the mechanical and biological characteristics of the organic-inorganic hybrid composite. The incorporation of surface-modified nMH not only enhanced mechanical properties, such as Young's modulus, but also improved homogeneity of magnesium hydroxide particles in the PLLA matrix due to the increase in interfacial interaction. Additionally, the PLLA composites with surface-modified nMH exhibited reduced bulk erosion during hydrolytic degradation with lower cytotoxicity and immunogenicity. Hemocompatibility tests on the PLLA composites with nMH showed a higher albumin to fibrinogen ratio (AFR) and a lower influence of platelet activation, when compared with unmodified control samples. Taken all together, the surface-modified nMH could be seen to successfully improve the physical and biological characteristics of polymer composites. We believe this technology has great potential for the development of hybrid nanocomposites for biomedical devices, including cardiovascular implants.

Performance Enhancement of Solution-Processed Organic Memories by Exploiting Synergistic Organic–Inorganic Hybrid Composites

Organic–inorganic hybrid composites (HCs) comprising functionalized 2D materials have been given exceptional importance and have been actively employed as memory materials toward development of nex...

One-pot synthesis of organo-silica hybrids with high thermal properties via a simple sol–gel process

Organic–inorganic hybrid composites have received much attention of scientists in the recent years due to the notable improvement of thermal properties without using of organic or inorganic nanoparticles. Hence, we have developed a facile strategy to prepare a 3D hybrid network based on silane materials and novolac resin via sol–gel process. At first step, novolac resin was prepared by general procedure with appropriate thermal properties and then modified with (3-chloropropyl)triethoxysilane (CPTES) to form MNR. In second step, to cure MNR and prepare hybrid composite structures, general amine-cured system and sol–gel process were applied to prepare MNH and MNSG samples, respectively. XRD analysis was used to support the formation of silane networks in hybrid samples. Investigation of thermal properties by DSC and TGA showed that cured samples had much higher thermal stability and char yield with respect to novolac and modified resin (MNR) originated from formation of 3D Si–O–Si network. Presented method limited some disadvantages of using nanoparticles such as aggregation and poor distribution. Such hybrid composites with high thermal stability have potential applications in advanced fields such industrial molds, coatings, adhesives and composites.

Flexible and Ultrasensitive Piezoelectric Composites Based on Highly (00l)‐Assembled BaTiO3 Microplatelets for Wearable Electronics Application

AbstractPiezoelectric wearable electronics with flexibility and high sensitivity have received increasing attention in the fields of health monitoring, flexible robots, and artificial intelligence. Here, a flexible organic–inorganic hybrid composite for wearable electronics application based on (00l)‐aligned BaTiO3 (BT) single‐crystal microplatelets is prepared by layer‐by‐layer self‐assembly technology. For the polyvinylidene fluoride‐trifluoroethylene (P(VDF‐TrFE))/BT single‐crystal microplatelets composite film, the sensitivity is nearly 20 times higher than that of its counterparts of P(VDF‐TrFE)/BT microparticles composite film and pure P(VDF‐TrFE) film. The orderly alignment of BT microplatelets also has been found advantageous to the strength of the composite film. The tensile strength is up to 204.3 MPa even at a high inorganic phase content of 53.8 wt% in P(VDF‐TrFE)/BT single‐crystal microplatelets composite film, which is four times that of pure P(VDF‐TrFE) film. Moreover, the flexible piezoelectric wearable device based on P(VDF‐TrFE)/BT single‐crystal microplatelets film effectively provides detailed information for monitoring human activities such as pronunciation, frequency, and waveform of pulse beating, and motion states. This high sensitivity, high strength, and flexible piezoelectric composite provides much potential on the applications of wearable equipments and health monitoring devices.

Removal of the synthetic hormone methyltestosterone from aqueous solution using a β-cyclodextrin/silica composite

Contamination of water with steroid residues can cause a number of environmental damages, affecting exposed organisms including man. The development of technologies for treatment or removal of this type of micropollutant from water is of paramount importance. In this study, citric acid was used to functionalize β-Cyclodextrin (bCD) on the silica surface generating an organic-inorganic hybrid composite for application in molecular sequestration. The functionalization percentage was high, with about 62.6% of the composite mass corresponding to the organic part of the material. 13C NMR and infrared spectroscopic analysis indicate that the functionalization mechanism occurs by an esterification reaction between the citric acid with the silanol groups from silica and the primary hydroxyls of the bCDs. Fast adsorption of the methyltestosterone steroid was observed at acid pH, with a high adsorption capacity of 11 mg g−1. The best kinetic and isotherm models fit indicated that the adsorption occurred by a physical mechanism at independent sites with the steroid molecule possibly captured by two bCDs. The removal process was spontaneous and exothermic, with the existence of weak interactions between the hormone and the composite, and its regeneration is quite fast efficient with the displacement of the complexation equilibrium. The results obtained in this study demonstrate the considerable potential of the composite for use in the treatment of wastewater containing the steroid studied, and its efficacy should be evaluated for other steroid molecules.

Organic-inorganic hybrid composites as an electron injection layer in highly efficient inverted green-emitting polymer LEDs

Abstract Organic-inorganic hybrid light-emitting diodes (HyLEDs) consist of an organic emission layer in combination with at least one metal oxide charge injection layer, typically in an inverted structure. Low temperature, solution processing of metal oxide charge injection layers is one of the key factors in reducing the manufacture cost of HyLEDs. Herein, we report the use of composite materials, comprising conjugated polyelectrolytes (CPE) and zinc oxide nanoparticles (ZnO NPs), as the electron injection layer (EIL) in highly-efficient, green-light-emitting poly (9,9-dioctylfluorene-co-benzothiadiazole) (F8BT) polymer LEDs that are carefully optimised for use in an inverted HyLED architecture for the first time. The composite CPE:ZnO EILs are processed via a room temperature, one-step, solution deposition and enable superior device performance relative to ZnO NPs on their own. We find that specifically, they (i) improve EIL morphology, reducing surface roughness as well as pin-hole size and density, (ii) induce a favourable vacuum level shift for electron injection by coordinate bonding between the CPE and ZnO constituents, and (iii) reduce interfacial quenching by passivation of ZnO chemical defects caused by oxygen vacancies. This work is also the first demonstration that blending ZnO NPs and CPE supports much faster electroluminescence turn-on times (~7.12 μs) than for traditional ZnO/CPE bilayer devices (~0.4 s) via ‘locking’ of the CPE mobile ions, as well as higher device performance. This demonstrates good suitability for display applications. After optimisation of the EIL composition and the thickness of the F8BT emissive layer, we achieve promising device efficiencies of 16.5 cd/A and 5.4 lm/W for devices with a 1.1 μm thick F8BT layer, which is particularly relevant for potential roll-to-roll fabrication. These results clearly demonstrate the potential that this organic-inorganic composite EIL material has for the realisation of cheap, scalable and highly efficient, printable HyLED devices.

Insight into the formation mechanism of azo dye-based hybrid colorant: Physico-chemical properties and potential applications

This paper presents a novel method for preparing organic-inorganic hybrid composites by precipitation of monocarboxylic azo dye (MCD) using aluminum-magnesium hydroxycarbonate (LH) as a host. Secondary ion mass spectrometry (TOF-SIMS), solid state nuclear magnetic resonance (13C MAS NMR), powder X-ray diffraction (XRD), thermogravimetric analysis (TG-DTA) and scanning electron microscopy (SEM) were performed to characterize the structure of the synthesized hybrid colorant. TOF-SIMS displayed the presence of C17H13N4O3−Mg2+ ions in the LH matrix. The X-ray diffraction pattern showed that the formation of azo dye-LH complexes strongly affected the crystal structure of the LH mineral suggesting existence a new organic-inorganic hybrid. Incorporation of the monocarboxylic dye into the LH mineral contributed to the appearance of new peaks in the diffraction pattern, which did not belong to either the azo dye or the LH carrier. The thermostability of the pure dye and LH/pigment was investigated using TOF-SIMS, TG-DTA and UV–Vis spectroscopy. The TOF-SIMS technique was found to be a very promising tool for evaluating the chemical composition of organic-inorganic materials and monitoring their thermal stability. The thermal stability, photostability as well as solvent resistance of the chromophore were enhanced significantly. This is mainly attributed to strong interactions between the carboxylic group in the dye and the Mg2+ in the inorganic matrix. This simple strategy for the preparation of hybrid composites can be easily applied for the design of novel multifunctional organic-inorganic pigments.

Characterization and Structure⁻Property Relationships of Organic⁻Inorganic Hybrid Composites Based on Aluminum⁻Magnesium Hydroxycarbonate and Azo Chromophore.

In this study, novel organic–inorganic composites were prepared by the complexation of dicarboxylic azo dye (AD) with aluminum–magnesium hydroxycarbonate (AlMg–LH). This procedure provides an effective method for the stabilization of dicarboxylic organic chromophores on an AlMg−LH host. The structures of the hybrid composites were examined by X-ray diffraction (XRD), secondary ion mass spectrometry (TOF-SIMS), 27-Al solid-state nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric analysis (TGA) and scanning transmission electron microscopy (STEM). The TOF-SIMS method was applied to investigate the metal–dye interactions and to monitor the thermal stability of the organic–inorganic complexes. Secondary ion mass spectrometry confirmed the presence of a characteristic peak for C18H10O5N2Mg22+, indicating that both carboxylic groups interacted with AlMg−LH by forming complexes with two Mg2+ ions. Modification with hybrid pigments affected the crystal structure of the AlMg−LH mineral, as shown by the appearance of new peaks on the X-ray diffraction patterns. Adsorption of the dicarboxylic chromophore not only led to significantly enhanced solvent resistance but also improved the thermal and photostability of the hybrid pigments. We propose a possible arrangement of the azo dye in the inorganic matrix, as well as the presumed mechanism of stabilization.

Sol gel synthesis of hybrid chitosan/calcium aluminosilicate nanocomposite membranes and its application as support for CO2 sensor

Modification of chitosan with cross-linkers, blends with various kinds of polymers, nanoparticles and new organic–inorganic hybrid composites in order to obtain some improved properties attached more attention nowadays due to their good sensitivity in changing electrical and optical properties. In the current work modified hybrid chitosan/calcium aluminosilicate (CH/CAS) nanocomposite membranes and doped with (3, 5 & 7 mol%) Al2O3 nanoparticles were synthesized via sol–gel process in acidic conditions, which can be efficiently employed to capture CO2 gas at lower and moderate temperatures. Furthermore, the fabricated CH/CAS nanocomposite membrane loading with (3, 5 & 7 mol%) Al2O3 were investigated using XRD, SEM, FTIR and dielectric measurements. The results indicated that the incorporation of Al2O3 in CH/CAS matrix significantly affected on the structural, dielectric and appeared good reliability for sensing CO2 at atmospheric pressure. The dielectric behaviour for the prepared CH/CAS indicates that the dielectric constant (ε′) decreases. According to XRD the introducing of Al2O3 leads to increase the crystallinity of the system and thus the dipoles of the system orient hardly with the applied field and results in lesser dielectric constant (ε′). Correspondingly, the CH/CAS nanocomposite membranes were characterized and its performance as CO2 gas sensor was evaluated.

Construction of bioinspired organic-inorganic hybrid composite by cellulose-induced interfacial gelation assisted with Pickering emulsion template

The construction of organic-inorganic hybrid materials has shown great potential for the development of multifunctional superior protein-based composites. However, it is still a challenge to effectively disperse and dominate the mineralization of inorganic minerals in a hybrid system. In this study, we presented a simple and green strategy to construct a biomineralized soy protein (SP)-based hybrid resin with a controllable mineralized skeleton. It was found that the Pickering emulsion served as a mineralized template efficiently inducing the uniform dispersion of inorganic particles while the incorporated cellulose nanocrystals (CNC) were able to regulate the mineralization process, thus forming an optimized mineralized skeleton structure. Acting as a reactive reinforcer, the regulated mineralized skeleton formed in situ interactions with SP matrix, giving rise to the multiple covalent and ionic crosslinking networks. As a result, the introduction of mineralized skeleton increased the wet shear strength of composites from 0.46 MPa to 1.21 MPa, exhibiting a 163% increment compared to the pristine SP composite. Moreover, the formation of rigid inorganic mineralized skeleton in hybrid SP-based resin facilitated an obvious improvement of thermal stability compared with the control samples. Overall, we envisage that this strategy could provide a creative strategy for the design and fabrication of superior sustainable biocomposites for engineered wood products.

Fabrication and performance of a polyurethane hybrid composite with waste red mud

Polyurethane‐based organic–inorganic hybrid composite is attracting increasing attention due to its excellent performance and low cost. Herein, a facile and effective strategy has been proposed for the fabrication of polyurethane/red mud hybrid composite by anchoring red mud particles into a polyurethane frame. The resulting hybrid composite was mainly composed of amorphous polyurethane and crystalline red mud, and its probable formation mechanism was proposed. The polyurethane/red mud composite with micron particles uniformly embedded into the organic phase exhibited satisfactory mechanical performance, and its compressive and flexural strength could come up to 38.6 and 12.4 MPa after complete curing, respectively. Moreover, the hybrid composite displayed impressive thermal stability, flame retardancy, storage stability, and reinforcement performance. The obtained polyurethane/red mud composite shows potential applications in multiple fields (roadway, dam, underground engineering, etc.). POLYM. COMPOS., 40:2424–2431, 2019. © 2018 Society of Plastics Engineers

New organic-inorganic hybrid composites based on cellulose nanofibers and modified Laponite

Abstract The combination of cellulosic materials and clays, such as Laponite, can provide composites with superior optical and mechanical properties compared to pristine cellulose. Synthetic clays can also be used as a host matrix for the immobilization of luminescent complexes, as the incorporated complexes may present enhanced emission quantum efficiency, photo and thermostability compared to the non-immobilized ones. In this way, we, herein, report the preparation of luminescent composites through the incorporation of a Eu(III) complex [Eu3+(tta)n] containing Laponite (Lap) into cellulose nanofibers (CNF). The thermogravimetry results show that the obtained CNF/Lap@[Eu3+(tta)n] films present higher thermal resistance than the CNF film. The Eu3+(tta)n species were found in the composite structure with preserved luminescence characteristics, and no leaching or degradation of the organic ligand was observed with the preparation of the composites.

Improved organic-inorganic/graphene hybrid composite as encapsulant for white LEDs: Role of graphene, titanium (IV) isopropoxide and diphenylsilanediol

We report a graphene embedded organic-inorganic hybrid (O-I hybrid) composites that can be utilized as robust encapsulants for white light emitting diodes (WLEDs). The effect of graphene and monomers on the thermal resistance, refractive index (RI), transparency, thermal conductivity, and thermal aging stability of the encapsulant were studied. This study has explicitly unveiled that the embedded graphene played a multifunctional role in producing a high-performance encapsulant. Compared with graphene free O-I hybrid encapsulant, RI, thermal conductivity and heat dissipation ability of the graphene embedded encapsulants were significantly improved. After continuous operation for 10 days, the color rendering index (Ra) of WLED with graphene embedded encapsulants changed from 89.5 to 89.2 (driving current 100 mA), while the correlated color temperature (CCT) altered from 4535 to 4546. Its luminous efficiency changed from 82.9 to 81.2 lm/W. The WLEDs with graphene embedded O-I hybrid encapsulant exhibited long-term stability. This work has paved the way for rational design and assembly of graphene embedded composites as robust materials for various requirements of WLED applications.

Synthesis of titania nanoparticle-dispersed hybrid membranes from allyloxytitanium and phosphonic acid derivatives for fuel cell

Inorganic-organic hybrid membranes consisting of an aliphatic backbone and amorphous TiO2 nanoparticles (NPs) were synthesized from tetraallyloxytitanium and phosphonic acid methacrylate via a simple copolymerization-hydrolysis method. Tetraallyoxytitanium (TAT) was copolymerized with 2-hydroxyethyl methacrylate acid phosphate (HEMAP), and then hydrolyzed, yielding inorganic-organic hybrid composites. IR and 13C NMR spectroscopy confirmed the formation of the inorganic-organic hybrid structure. TEM and SAXS showed that amorphous TiO2 NPs were dispersed in the polymer matrix. The membranes exhibited good thermal stability up to 180 °C. The aliphatic chains of the methacrylate derivative dispersed with TiO2 NPs improved the mechanical properties of the membranes. The tensile modulus of the HEMAP/TAT membrane with a composition of 95:5 was 505 MPa. The conductivity of the 95:5 membranes was 4.1 × 10-2 S cm-1 at 130 °C and 100% relative humidity (RH), while it was 4.7 × 10-4 S cm-1 at 130 °C and 19.3% RH. The peak power of the 95:5 membrane was 4.8 mW/cm2 at 140 °C and 30% RH. The cell utilizing the hybrid membrane was operated at 140 °C and 30% RH for 72 h without any drop in cell voltage.

Performance evaluation of free-silicon organic-inorganic hybrid (SiO2-TiO2-PVP) thin films as a gate dielectric

An approach to achieve the transparent thin film transistors (TTFTs) using transparent electrodes such as ITO or FTO for gate, source and drain electrodes (Free-silicon gate electrode). On the other hand, the high-k transparent metal oxides can be used for this purpose in gate dielectric by a low temperature sol-gel technique. Furthermore, not only use of high-k organic materials in gate dielectric reduces the leakage current but also it improves the device flexibility. The organic-inorganic hybrid composites of SiO2/TiO2-PVP (STP) with different TiO2 ratios are deposited on PET-ITO substrates (Free-silicon gate electrode) as gate dielectric. The thermal behavior and structural characterization of STP films are done by TGA, XRD and XPS analyses. The AFM analyze of STP films shows that they have very smooth surface. A transparent thin layer of ZnO is used as a transistor channel by sputtering technique. Evaluation on electrical performance of OFETs exhibits that they have high mobility, low threshold voltage and acceptable Ion/Ioff ratio.

In-situ synthesis and structural characterization of cellulose-silica aerogels by one-step impregnation

Cellulose-silica aerogels (CSAs) are organic-inorganic hybrid composites possessing both the porous characteristics and high mechanical properties. In this paper, two kinds of CSAs were in-situ synthesized by facile one-step impregnating cellulose layers directly into silica hydrosols and alcosols, respectively. The porous microstructures and the bonding linkage were investigated by means of Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption-desorption porosimetry. The results show that the silica particles successfully in-situ crosslink on/into the cellulose matrix and maintain the porous characteristics. The regeneration of the CAs directly in the alcosols is more beneficial to realize the crosslinking between silica particles and cellulose fibrils. The silica modification tends to increase the mechanical properties over those of the CAs due to the additional effects of silica particles impregnating into cellulose matrix.

Polyethyleneimine (PEI) loaded MgO-SiO2 nanofibers from sepiolite minerals for reusable CO2 capture/release applications

CO2 capture and storage (CCS) by advanced materials and technologies will play a significant role in reducing industrial or human caused CO2 emissions. In this article, a clay mineral based CO2 absorbent was prepared by impregnating polyethyleneimine (PEI) onto acid modified fibrous sepiolite. X-ray diffraction (XRD), Fourier transform microscopy (FTIR), thermogravimetric analysis (TGA), and N2 adsorption - desorption isotherms accompanied BET (Brunauer-Emmett-Teller) analysis were used to characterize the raw mineral and the prepared absorbents as well as their CO2 adsorption performances. After the acid treatment, the raw sepiolite changed into amorphous silica (SiO2) containing a small amount of MgO, but maintained their nanowire morphology, the SBET value of acid treated Sep was 4 times larger and pore volume was about 2 times higher than the raw mineral. The MgO-SiO2 nanowires and polyethyleneimine (PEI) successfully formed an organic-inorganic hybrid composite. A maximized adsorption capacity of 2.48mmol/g at 75°C was reached in CO2 adsorption/desorption measurement when the composite contained 50wt% PEI. The product also showed an excellent adsorption repeatability, above 98% of the optimized CO2 adsorption capacity could be maintained after 10 circles tests, which confirmed that the fibrous MgO-SiO2 assembly optimal amount of PEI is a promising solid absorbent in CO2 gases controlling fields.

Antibiocorrosive epoxy-based coatings with low friction and high scratch resistance

We have created inorganic-organic hybrid composites and antibiocorrosive coatings based on an epoxy modified with silicon-containing polyepoxies and bioactive coordination compounds. The scratch resistance was determined using a conical diamond indenter with linearly increased load. Repetitive scratching along the same groove (sliding wear determination) was also performed. Whether in single or in repetitive scratching, for most hybrids the residual depth is shallower than for the pure epoxy. Dynamic friction was determined on a pin-on-disk tribometer using steel pins. Lower friction is accompanied by higher scratch resistance. Surface morphology seen in scanning electron microscopy (SEM) shows that increasing modifier content causes more ductile behavior with less crack nucleation; no debris formation is observed. The composites were also characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Isothermal aging and water absorption ability (WH2O) of the hybrids were determined. The hybrids are optically transparent, visually homogeneous, with smooth surfaces.