Organic-inorganic Hybrid Composites Research Articles

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.

Cellulose–Polyvinyl Alcohol–Nano-TiO2 Hybrid Nanocomposite: Thermal, Optical, and Antimicrobial Properties against Pathogenic Bacteria

ABSTRACTCellulose fiber-reinforced composite has received great attention due to the high strength, stiffness, biodegradability, and renewability of the excellent natural biomaterials. Cellulose nanofibers for the development of organic–inorganic hybrid composite is relatively new filed of research. Cellulose macro and nanofibers can be used as reinforcement in the hybrid composite because of improved mechanical, thermal, optical, electrical, morphological, and biological properties. The hybrid nanocomposites were synthesized by an in situ sol–gel process in the presence of coupling agent. The sol–gel process has definitely proven its potential by providing the synthesis of various functional organic–inorganic hybrid nanocomposites through an in situ sol–gel process. The hybrid nanocomposites have been prompted by the ability to control the morphology of final materials. The photoluminescence spectral studies indicate that the emission shifts toward higher wavelength (326–532 nm) accompanied by a reduction in impurity centers with increasing concentration of poly(vinyl alcohol)–TiO2 and hybrid nanocomposite. The final nanostructured TiO2 hybrid nanocomposites with particle size ranging from 0.32 to 20 nm were characterized by Field -emission transmission electron microscopy (FE-TEM) analysis. Furthermore, cellulose–poly(vinyl alcohol)–nano-TiO2 hybrid composite was characterized by Fourier transform infrared, X-ray diffraction, UV, Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), FE-SEM–EDX, Field-emission scanning electron microscopy (FE-SEM), and FE-TEM analysis. The different analysis results of the hybrid composite indicate the optical transparency, optical properties, Tg, crystallinity, thermal stability, and controlled morphology of hybrid nanocrystalline composites. Finally, the cellulose–poly(vinyl alcohol)—nano-TiO2 hybrid nanocomposites were tested against pathogens such as Gram-positive Bacteria Bacillus cereus and Gram-negative Escherichia coli for antimicrobial activity. These results show that the hybrid composite exhibited excellent antimicrobial properties against pathogens.

Synthesis and characterization of CeO2 nanoparticles on porous carbon for Li-ion battery

Carbon based materials have long been investigated as anodes for lithium ion batteries. Among these materials, porous carbon holds several advantages such as high stability, high specific surface area, and excellent cycling capability. To further enhance the energy storage performance, ceramic nanomaterials have been combined with carbon based materials as hybrid anodes for enhanced specific capacity. The use of metal oxide ceramic nanomaterials could enhance the surface electrochemical reactivity thus leads to the increasing of capacity retention at higher number of cycles. In this research, we synthesized ceria (CeO2) nano-particles on porous carbon to form inorganic-organic hybrid composites as an anode material for Li-ion battery. The high redox potential of ceria is expected to increase the specific capacity and energy density of the system. The electrochemical performance was determined by a battery analyzer. It is observed that the specific capacity could be improved by 77% using hybrid composites anode. The material morphology, crystal structure, and thermal stability were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), and Thermogravimetric Analysis (TGA).

Synthesis of inorganic-organic hybrid membranes consisting of organotrisiloxane linkages and their fuel cell properties at intermediate temperatures

Inorganic-organic hybrid membranes consisting of an aliphatic main-chain polymer and trisiloxane bond were synthesized using a simple, one-pot process from a trisiloxane derivative, phosphonic acid acrylate, and vinylbenzotriazole. 1,5-Divinyl-3-phenylpentamethyltrisiloxane (DPPMTS) was copolymerized with 2-hydroxyethyl methacrylate acid phosphate (HEMAP), and N-vinylbenzotriazole (VBT), yielding inorganic-organic hybrid composites. The formation of the inorganic-organic hybrid structure was confirmed by IR, 13C, and 29Si NMR spectroscopy. The membranes exhibited good thermal stabilities up to 200 °C. The aliphatic chains of the methacrylate derivative copolymerized with trisiloxane in the hybrid membranes improved the mechanical properties of the membranes. The tensile modulus of the VBT/HEMAP/DPPMTS membrane with a composition of 1:9:5 was 1.19 GPa. The conductivities of the 1:9:5 membranes were 5.3 × 10−2 S cm−1 and 4.1 × 10−4 S cm−1 at 100 and 19.3% relative humidity (RH), respectively, and 130 °C. The membrane electrode assembly (MEA) using the hybrid membrane exhibited a peak power of 7.8 mW cm−2 at 140 °C and 30% RH.

Photocatalytic degradation of Rhodamine B over a novel mesoporous titanosilicate/g-C3N4 nanocomposite under direct sunlight irradiation

A novel heterojunction of mesoporous titanosilicate/graphitic carbon nitride (TSCN) inorganic-organic hybrid composite has been developed. The synthesized mesoporous TSCN nanocomposites were characterized by various analytical techniques for structural and chemical properties. Finely distributed porous titanosilicate was observed on the surface of the g-C3N4 from the FE-SEM and TEM analysis. More significantly, the TSCN nanocomposite exhibited enhanced photocatalytic activity in the degradation of Rhodamine B (RhB) under sunlight irradiation. The optimum photocatalytic activity of TSCN10 at 10 wt% of g-C3N4 under visible light is almost 5 and 3 fold higher than pure titanosilicate (TS) and pure g-C3N4 (CN) respectively. The synthesized photo-catalysts are highly stable even after five successive experimental runs. The improved photocatalytic performance of the TSCN10 hybrid nanocomposite photo-catalysts under visible light irradiation was due to the high surface area and synergistic effect. Therefore, TSCN10 hybrid photo-catalyst is a promising material for energy conversion and environmental remediation.

Phase segregation and self-nano-crystallization induced high performance Li-storage in metal-organic framework bulks for advanced lithium ion batteries

Recently, metal organic framework (MOF) materials in nano-scale have gained enormous interest in Li-ion batteries (LIBs), while those in bulks usually exhibit poor Li-ion storage performance. Herein, we report how to obtain impressive Li-ion storage performance by using MOF bulks firstly. Through suitable design, incorporating small inorganic nano-domains with various dimensions into the MOF bulks, the forming metal inorganic-organic hybrid composites (M-IOHCs) could store Li-ions twice more than that of the metal based MOF (M-MOF) bulks. Except for the good Li-ion storage performance, exemplified M-IOHCs also exhibit enhancing cyclibility of more than 400 cycles with tripled capacity and 100% capacity retention. The enhanced Li-ion storage capability and cyclibility is attributed not only to local phase segregation in MOF bulks induced by ultra small inorganic nano-domains and the self-nano-crystallization of MOF bulks and the later forming inorganic nanocrystals themselves, but also to the stabilized frameworks comprised of metal oxide inorganic nanocrystals and enwrapped C-N organic species which brought up no aggregation or grow-up of the inorganic active materials common in new generation electrode materials. Application of the M-IOHCs in full cells was exemplified by Ni-IOHCs anode and commercial LiFePO4 cathode, which delivers excellent energy and power performance.

Combined membrane emulsification with biomimetic mineralization: Designing and constructing novel organic-inorganic hybrid microspheres for enzyme immobilization

The organic-inorganic hybrid composites displayed great potential for biotechnological and biomedical application. In this research, a novel and facile method for preparing organic-inorganic hybrid microspheres was developed by a synergy of membrane emulsification and biomimetic mineralization. The gelatin solution (water phase) was mixed with the liquid paraffin (oil phase) at 60 °C and a coarse W/O emulsion was produced by magnetic stirring. The coarse emulsion was extruded through a Shirasu Porous Glass (SPG) membrane, and then was slowly dropleted into the pre-hydrolyzed tetraethoxysilane (TEOS), which acted as silicon precursor. The biomimetic mineralization was occurred in situ under the catalysis of gelatin, while silica was formed around the gelatin emulsion droplets, resulting in the final gelatin/silica hybid microspheres. These microspheres were characterized by a variety of techniques, including SEM, TEM, EDS, TGA/DTA, and DSC. The gelatin/silica hybrid microspheres present a mass fraction of the inorganic component as high as 46%, while their glass (Tg) and melting (Tm) transition temperature raised by 9 °C and 40 °C, respectively. Catalase (CAT) was immobilized in the obtained novel gelatin-silica hybrid microspheres as the model enzyme. Due to the protective effect of carriers, the pH tolerance stability, storage and recycling stability of the immobilized CAT were all improved in comparison with free CAT.

Functionalization of silica gel with 5-hydroxymethylfurfural: preparation, characterization and preliminary verification

Herein, we report the organic–inorganic hybrid composites comprising surficial-modified silica gel with 5-HMF as a solid phase for liquid chromatography.

Development of bone-like zirconium oxide nanoceramic modified chitosan based porous nanocomposites for biomedical application

Here, zirconium oxide nanoparticles (ZrO2 NPs) were incorporated for the first time in organic-inorganic hybrid composites containing chitosan, poly(ethylene glycol) and nano-hydroxypatite (CS-PEG-HA) to develop bone-like nanocomposites for bone tissue engineering application. These nanocomposites were characterized by FT-IR, XRD, TEM combined with SAED. SEM images and porosity measurements revealed highly porous structure having pore size of less than 1μm to 10μm. Enhanced water absorption capacity and mechanical strengths were obtained compared to previously reported CS-PEG-HA composite after addition of 0.1–0.3wt% of ZrO2 NPs into these nanocomposites. The mechanical strengths and porosities were similar to that of human spongy bone. Strong antimicrobial effects against gram-negative and gram-positive bacterial strains were also observed. Along with getting low alkalinity pH (7.4) values, similar to the pH of human plasma, hemocompatibility and cytocompatibility with osteoblastic MG-63 cells were also established for these nanocomposites. Addition of 15wt% HA-ZrO2 (having 0.3wt% ZrO2 NPs) into CS-PEG (55:30wt%) composite resulted in greatest mechanical strength, porosity, antimicrobial property and cytocompatibility along with suitable water absorption capacity and compatibility with human pH and blood. Thus, this nanocomposite could serve as a potential candidate to be used for bone tissue engineering.

Effects of asperities and organic-inorganic interactions on the strength of nacre-mimetic composites

Nacre is a natural organic-inorganic hybrid composite, whose hierarchical structure has a complex influence on its high strength. Many structural features have been discovered, which influence the mechanical properties of nacre, and the authors have a particular interest in the role of the asperities and organic-inorganic interactions. In this study, a composite was prepared which mimics the asperity structure using clay minerals. Organic-inorganic bonding was induced with silane treatment. Both factors increased the yield strength of the composites; however, different deformation behavior was exhibited. It was found that asperities improved the strength of the composite, and that composition influences the stiffness of the composite. The organic-inorganic interaction between the resin and the other components of the composite reduced the deformation of the composite and consequently improved strength.

Is the snail shell repair process really influenced by eggshell membrane as a template of foreign scaffold?

Biominerals are inorganic-organic hybrid composites formed via self-assembled bottom up processes under mild conditions. Biominerals show interesting physical properties, controlled hierarchical structures and robust remodeling or repair mechanisms. Biological processes associated with biominerals remain to be developed into practical engineering processes. Therefore, the formation of biominerals is inspiring for the design of materials, especially those fabricated at ambient temperatures. The study described herein involves the influence of chicken outer eggshell membrane on the type of calcium carbonate (CaCO3) polymorph deposited on the shell of the land snail Helix aspersa during the repair process after an injury. A piece of snail shell was removed by perforating a hole from the largest body whorl. The operated area was left either uncovered or covered with either a thermoplastic flexible polyolefin-based film Parafilm® or a piece of chicken eggshell membrane. The repaired shells of control and experimental animals were analyzed using SEM, EDS, Raman and FTIR spectroscopies. We found that in the presence of eggshell membrane, the polymorph deposited on the substratum during the first hours resembles calcite, the polymorph present in eggshell normal formation, but at 24 and 48h, when snail mantle cells produced their normal organic matrix (mainly β-chitin plus proteins and proteoglycans), the polymorph deposited is aragonite, the characteristic polymorph of Helix shell. Therefore, the eggshell membrane influences the type of polymorph, but only in the initial stages of biomineral deposition, before an organic matrix layer is deposited by the snail.

Molybdenum carbide microcrystals: Efficient and stable catalyst for photocatalytic H2 evolution from water in the presence of dye sensitizer

Rod-like molybdenum carbide (Mo2C) microcrystals were obtained from the pyrolysis of Mo-containing organic-inorganic hybrid composite. We investigated the photocatalytic H2 evolution activity of Mo2C by constructing a Mo2C-dye sensitizer photocatalyst system. A high quantum efficiency of 29.7% was obtained at 480 nm. Moreover, Mo2C catalyst can be easily recycled by simple filtration.

Silica decorated on porous activated carbon nanofiber composites for high-performance supercapacitors

Abstract A hybrid of silica decorated on porous activated carbon nanofibers (ACNFs) is fabricated in the form of a web via electrospinning and an activation process as an electrode material for electrochemical capacitors in an organic electrolyte. The introduction of PhSiH 3 (PS) into the polyacrylonitrile (PAN) solution induces a porous ACNF structure containing silica nanoparticles (NPs) via the spontaneous sol-gel process of PS by steam in the subsequent physical activation process. These inorganic-organic hybrid composites of porous ACNF containing silica NPs show superior specific capacitance and energy density in electrochemical tests, along with good rate capability and excellent cycle life in an organic electrolyte, which is attributed to the combination of ACNF's high surface area and silica's hydrophilicity. The electrochemical performance decreases with increasing PS concentration, and this trend is consistent with the specific surface area results, which reveal the rapid formation of a double layer.

Quantum dot–polymer composites based on nanoporous polypropylene films with different draw ratios

Hybrid composites of polymers with fluorescent nanoparticles are unique materials combining good mechanical properties of the host polymer matrices and luminescent properties of the embedded nanoparticles. Here, we report on the optical characterization of novel inorganic–organic hybrid composites based on nanoporous polypropylene (PP) as a polymer matrix and quantum dots (QDs) as a fluorescent inorganic component. The first type of the composite films is prepared by absorption of CdSe/ZnS QDs onto the porous structure of the PP films, followed by annealing at 170°C, i.e., above the melting point of the PP. The second type of the composite films is obtained by filling of porous QD–PP composites with a nematic liquid crystalline (LC) mixture. Both types of composites are characterized by low light scattering, which makes it possible to study their optical properties by absorbance and fluorescence spectroscopies. TEM and confocal fluorescence microscopy have been used to analyze the aggregation of QDs in composites of different types. It has been shown that introduction of QDs into PP with a low draw ratio decreases the degree of alignment of LC molecules embedded into the pores of QD–PP composite films.

Synthesis of inorganic-organic hybrid membranes consisting of triazole linkages formed by the azide-alkyne click reaction

Inorganic-organic hybrid membranes consisting of aliphatic main chains and triazole rings were synthesized via copolymerization of a methacryloxysiloxane derivative with phosphonic acrylate, followed by hydrolysis. Hydroxyethyl methacrylate acid phosphate (HEMAP) was copolymerized with 3-methacryloxypropylmethyl-dimethoxysilane (MPMDMS), and then reacted with diethyl (4-(1-(3-(trimethoxysilyl)propyl)-1,2,3-triazol-4-yl)phenyl)phosphonate (TMSTAzPP), yielding inorganic-organic hybrid composites. The triazole ring of TMSTAzPP was constructed via the azide-alkyne click reaction using nanoporous Cu. IR, 13C, and 29Si NMR spectroscopy supported the formation of the inorganic-organic hybrid structure including a triazole ring. The membranes showed good thermal stability up to 180°C. The conductivity of the HEMAP/MPMDMS/TMSTAzPP membrane with a composition of 7:1:3 was higher than that of the HEMAP/MPMDMS membrane with a composition of 10:1. The conductivities of the 12:1:3 membranes at 130°C were 1.05×10−1Scm−1 and 1.68×10−4Scm−1 at 100% and 19.3% relative humidities (RHs), respectively. The power density of the 12:1:3 membrane was 3.9mWcm−2 at 140°C and 30% RH.

Frequency Dependence of Electrical Parameters of an Organic-Inorganic Hybrid Composite Based Humidity Sensor

The present study highlights the interdependence of ambient humidity levels on the electrical parameters of organic-inorganic hybrid composite based humidity sensor at varied AC frequencies of input signal. Starting from the bottom, the layer stack of the fabricated humidity sensor was 200-nm silver (Ag) thin film and 4 μm spun-coated PEPC+NiPC+Cu2O active layer. Silver thin films were deposited by thermal evaporator on well cleaned microscopic glass slides, which served as a substrate. Conventional optical lithography procedure was adapted to define pairs of silver-silver surface electrodes with two sorts of configurations, i.e., interdigitated and rectangular. Humidity-sensitive layers of organic-inorganic composite were then spun-cast upon the channel between the silver electrodes. The changes in relative humidity levels induced variation in capacitance and impedance of the sensors. These variations in electrical parameters of sensors were also found to be highly dependent upon frequency of input AC signal. Our findings reveal that the organic-inorganic composite shows higher humidity sensitivity at smaller orders of frequency. This finding is in accordance with the established fact that organic semiconductors-based devices are not applicable for high frequency applications due to their lower charge carrier mobility values. Two distinct geometries of semiconducting medium between the silver electrodes were investigated to optimize the sensing parameters of the humidity sensor. Furthermore, the effect of temperature change on the resistance of organic composite has also been studied.

Colorimetric Fluorescent Nanosensor Based on Hexamethylene Diisocyanate for Fluorescent Responses and Adsorption of Heavy Metal Ions.

An inorganic-organic hybrid material based on magnetic Fe3O4@SiO2 nanoparticles was synthesized for fluorescent responses and removal of heavy metal ions, in which superparamagnetic Fe3O4@SiO2 nanoparticles were firstly prepared and modified with hexamethylene diisocyanate (HDI) instead of 3-isocyanatopropyltriethoxysilane (IPTES) as the organic coupling agent, and then a rhodamine derivative with spirolactam structure (Rho-en) was conjugated on the HDI functionalized Fe3O4@SiO2 nanoparticles through isocyanate groups. Both of functionalized Fe3O4@SiO2 nanoparticles based on IPTES and HDI were characterized by FT-IR and XPS, and the results indicated that HDI was a good alternative as chemical bridge for surface modification on the surface of Fe3O4@SiO2 nanoparticles. The inorganic-organic hybrid composites synthesized based HDI showed naked-eye color changes and fluorescent responses towards Zn2+, Cd2+, Mn2+, Pb2+, Hg2+ and Fe3+, which could serve as the available proofs for the qualitative analysis. Moreover, the as-obtained composites not only had excellent adsorption capability for Pb2+ and Hg2+, but also showed strong magnetic sensitivity, which could help to the removal and separation of functionalized magnetic nanocomposites after capturing the heavy metal ions. In addition, the plausible interaction mode of functionalized Fe3O4@SiO2 nanoparticles with heavy metal ions was discussed.

Dispersion and Stabilization of Quantum Rod Through Semi-interpenetrating Network Formation

PEO-b-PPO-b-PEO를 기본 구조로 한 F127, L64 등의 pluronic은 수용액에서 미세상분리에 의하여 자기조립하고 그 중심부에 소수성의 분자들을 담지할 수 있는 응용가능성이 높은 고분자이다. 수십 나노 미터의 길이를 가진 막대모양 나노결정인 막대형 양자물질(quantum rod; QR) 콜로이드를 소수성 상호작용으로 담지한 뒤, 곧바로 반상호침투 구조체를 제조하여 장기간 형광 세기의 현저한 저하가 없는 안정한 유-무기 복합 나노소재를 수월하게 만들 수 있다. 우리가 제조한 F127-QR-sIPN 나노구조체는 표면이 poly(ethylene oxide)(PEO)로 둘러싸여 생체적합성이 우수하며 형광특성을 가진 QR이 세포섭취됨에 따라 형광 이미징도 가능함을 보였다.

Multifunctional optical sensing probes based on organic-inorganic hybrid composites.

Several hybrid sensing materials, which are prepared by the covalent grafting of organic fluorescent molecules onto inorganic supports, have emerged as a novel and promising class of hybrid sensing probes and have attracted tremendous interest. In comparison to the organic fluorescent sensors, the hybrid sensing probes incorporate the beneficial chemical/physical properties of the organic molecules and inorganic materials, which accelerate the development of hybrid materials for ion recognition and removal. Hence, the novel hybrid sensing materials can selectively monitor and efficiently remove specific analytes, which can provide a novel opportunity to synthesize multifunctional hybrid materials. Considerable efforts have been devoted to developing effective and innovative approaches for the design and synthesis of hybrid sensing materials that can display highly desirable performance for ion detection and removal. This tutorial review firstly presents a brief description of the hybrid materials and mesoporous silica materials and then classifies the hybrid sensing materials into several categories, including mesoporous silica based hybrid sensors, magnetic core-shell particle based hybrid sensors, magnetic nanoparticle based hybrid sensors, polymer based hybrid sensors, surface-grafted composite based hybrid sensors, and host-guest interaction based hybrid sensors, followed by a detailed summary of the design and synthesis of hybrid sensing materials and their applications in environmental and biological fields. Hopefully, this review will provide perspectives and guidelines for the development and further research of hybrid sensing materials.