Preparation Of Hybrid Materials Research Articles

Fast mechanochemical synthesis of carbon nanotube-polyaniline hybrid materials

Abstract

Controlled Synthesis of Cu and Cu₂O NPs and Incorporation of Octahedral Cu₂O NPs in Cellulose II Films.

In this study, Cu and Cu2O nanoparticles (NPs) were synthesized through chemical reduction of soluble copper-chelating ligand complexes using formaldehyde as a reducing agent. The influence of various chelating ligands, such as ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and a surface-active derivative of DTPA (C12-DTPA), as well as surfactants (i.e., hexadecyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium chloride (DoTAC), sodium dodecyl sulfate (SDS), and dimethyldodecylamine-N-oxide (DDAO)), on morphology and the composition of produced NPs was investigated. In the absence of surfactants, spherical copper particles with polycrystalline structure could be obtained. X-ray diffraction (XRD) analysis revealed that, in the presence of EDTA, the synthesized NPs are mainly composed of Cu with a crystallite size on the order of 35 nm, while with DTPA and C12-DTPA, Cu2O is also present in the NPs as a minority phase. The addition of ionic surfactants to the copper–EDTA complex solution before reduction resulted in smaller spherical particles, mainly composed of Cu. However, when DDAO was added, pure Cu2O nano-octahedrons were formed, as verified by high-resolution scanning electron microscopy (HR-SEM) and XRD. Furthermore, a hybrid material could be successfully prepared by mixing the octahedral Cu2O NPs with cellulose dissolved in a LiOH/urea solvent system, followed by spin-coating on silica wafers. It is expected that this simple and scalable route to prepare hybrid materials could be applied to a variety of possible applications.

Silica–Conjugated Polymer Hybrid Fluorescent Nanoparticles: Preparation by Surface-Initiated Polymerization and Spectroscopic Studies

Organic/inorganic hybrid nanoscale materials possess fascinating optical, electronic, magnetic, and catalytic properties that are promising for a variety of practical applications. Such properties can be dramatically affected by the hierarchical structure and molecular organization in the nanomaterials. Herein, we employed surface-initiated Kumada catalyst-transfer polymerization to prepare hybrid materials consisting of shells of conjugated polymers (CPs)—polythiophene or poly(p-phenylene)—and their block copolymers covalently attached to the surface of silica nanoparticles. Because of the controlled chain-growth mechanism of surface-initiated polymerization, we obtained structurally well-defined CP blocks in the diblock copolymer shells, which produced distinct spectroscopic properties related to the intraparticle excitation energy transfer between the nanoscale polymer shell components, as well as the formation of interfacial exciplex states. The spectroscopic phenomena were further understood via time...

Precise Synthesis of Well-Defined Inorganic-Organic Hybrid Particles.

Synthesis of hybrid particles toward precisely designed hierarchical nanoarchitectures is summarized. In order to satisfy the demands for a variety of materials' performances, the selection of materials, composition and synthesis is carefully done. Flow reactors are one of the useful synthetic means to prepare hybrid materials, especially those with hierarchically and precisely designed multi-components hybrid particles, owing to the efficient mixing and heat exchange in the reactor as well as its connectable (both parallel and sequential) feature. In this review article, after the summary of the preparation of hybrids based on oxides and organics through conventional batch reactors, the application of flow reactors to the preparation of various hybrid particles is introduced to highlight the present status and future possibility of the flow reactor synthesis.

Fabrication of Ag and Au nanoparticles in cross-linked polymer microgels for their comparative catalytic study

Abstract Three dimensional cross-linked polymer microgels with temperature responsive N-isopropyl acrylamide (NIPAM) and pH sensitive methacrylic acid (MAA) were successfully synthesized by free radical emulsion polymerization with different amounts of MAA. Silver and gold nanoparticles with the size of 6.5 nm and 3.5 nm (±0.5 nm), respectively were homogeneously reduced inside these materials by chemical reduction method at pH 2.78 and 8.36 for the preparation of hybrid materials. The samples were characterized by FT-IR, DLS and TEM techniques. The catalytic activity of the hybrid materials was investigated for the reduction of 4-nitrophenol (4-NP) using NaBH4 as reducing agent by UV-Vis spectroscopy. The hybrid polymer network synthesized at pH 8.36 showed enhanced catalytic efficiency compared to the catalysts synthesized at pH 2.78. In this study, it has been stated that the catalyst activity strongly depends on the amount of MAA, pH value during synthesis and the type of entrapped metal nanoparticles.

A New Dimension for Low-Dimensional Carbon Nanostructures

In this issue of Chem , Martin, Guldi, and colleagues describe the preparation and study of one of the first examples of near-infrared-absorbing donor-acceptor materials based on carbon nanotubes and graphene. These materials show charge-transfer interactions in both the ground and excited states.

In-Situ Metallization of Thermally-Treated Tobacco Mosaic Virus Using Silver Nanoparticles

Tobacco mosaic virus (TMV) is used as an organic biotemplate to prepare hybrid materials with silver nanoparticles (AgNPs). In this study, the native rod-like TMV structure was transformed into spherical particles using a thermal treatment; subsequently, the external surface of the thermally-treated TMV (TT-TMV) were In-Situ covered with AgNPs through cycles of sequential reduction using sodium borohydride. The as-grown nanoparticles show a bimodal distribution on the surface of the TT-TMVs after the fifth nucleation cycle. Results of characterization of the metallized TT-TMV by dynamic light scattering, transmission electron microscopy, atomic force microscopy, and energy-dispersive X-ray spectroscopy accordingly show the effect of cycling on the morphology of the AgNPs/TT-TMV hybrids.

Silica Mineralization of DNA-Inspired 1D and 2D Supramolecular Polymers.

The preparation of hybrid materials from supramolecular polymers through the sol‐gel process is presented. Supramolecular polymers are assembled from phosphodiester‐linked pyrene oligomers and act as water‐soluble one‐ or two‐dimensional templates for silicification. The fibrillary and planar morphologies of the assemblies, as well as the excitonic interactions between the chromophores, remain unaffected by the silicification process.

Zinc(II) Hexafluoroacetylacetonate Complexes of Alkoxyamines: NMR and Kinetic Investigations. First Step for a New Way to Prepare Hybrid Materials.

AbstractA series of Zn(hfac)2 alkoxyamines (diethyl(2,2‐dimethyl‐1‐(tert‐butyl‐(1‐pyridylethoxy)amino)propyl)phosphonate) coordinated at ortho, meta and para positions of their pyridyl moiety were prepared and their homolysis rate constants kd measured. Up to a 30‐fold increase in kd was observed for the meta‐(Zn‐RR/SS) and para‐(Zn‐RR/SS) regioisomers. Moreover, the activation is also controlled by the amount of pyridine, used as a ligand competitor. XRD, 1H and 31P NMR spectra show very different structures for each complexes in solid state and in solution depending on the diastereosiomers and on the regioisomers.

Photoactive materials based on semiconducting nanocarbons – A challenge opening new possibilities for photocatalysis

This perspective paper introduces the concept that nanocarbons and related materials such as carbon dots are an interesting intrinsic photocatalytic semiconducting material, and not only a modifier of the existing (semiconducting) materials to prepare hybrid materials. The semiconducting properties of the nanocarbons, and the possibility to have the band gap within the visible-light region through defect band engineering, introduction of light heteroatoms and control/manipulation of the curvature or surface functionalization are discussed. These materials are conceptually different from the “classical” semiconducting photocatalysts, because semiconductor domains with tuneable characteristics are embedded in a conductive carbon matrix, with the presence of various functional groups (as CO groups) enhancing charge separation by trapping electrons. These nanocarbons open a range of new possibilities for photocatalysis both for energetic and environmental applications. The use of nanocarbons as quantum dots and photoluminescent materials was also analysed.

Analyte-triggered luminescence of Eu3+ ions encapsulated in Nafion membranes -preparation of hybrid materials from in membrane chemical reactions-

The possibility to perform chemical reactions inside polymer materials opens a unique opportunity to control and prepare materials for diverse solid-state applications. Based on the affinity of Eu3+ ions for oxygen functionalities, in this work we report the luminescence enhancement of Eu3+ ions inserted in Nafion membranes (Naf/Eu3+) by in-situ complexing to oxalate. The formation of a europium-oxalate type complex enhances Eu3+ luminescence emission, which could be exploited for the construction of devices for oxalate sensing and the fabrication of highly luminescent materials. Possible analytical applications of Naf/Eu3+ membranes were evaluated by fluorescence spectroscopy through the linear response with concentration. The complex formation was followed by infrared spectroscopy and SEM-EDS analysis.

Combined Approach for the Development of Efficient and Safe Nanoantimicrobials: The Case of Nanosilver-Modified Polyurethane Foams

Silver nanophases are routinely used as bioactive additives in commercial products. Besides their antimicrobial activity, nanosafety issues regarding the application of (silver-based) nanoantimicrobials should be considered, as well. In this study, we modified polyurethane foams, typically employed in air filtration and stuffing, by photodeposited silver nanoparticles for preparing hybrid materials (Ag-PU) with antibacterial properties. The composite materials were characterized in terms of morphology, surface chemical composition, ionic release in contact media, bioactivity, as well as whole nanoparticle release. Cytocompatibility was also assessed on 3T3 mouse fibroblasts. The proposed systematic approach allows for defining suitable composite final properties, in terms of bioactivity and safety, by properly tuning the deposition parameters.

One-step preparation of sulfonated carbon and subsequent preparation of hybrid material with polyaniline salt: a promising supercapacitor electrode material

The present trend to increase the energy density of electrochemical supercapacitor is to hybrid the electrochemical double layer capacitance electrode materials of carbon with loading or encapsulation of transition metal oxide or conductive polymeric pseudocapacitor materials as the binary or ternary hybrid electrochemical active materials. In this work, we selected polyaniline salt-sulfonated carbon hybrid (PANI-SA•C SA ) as a cheaper electrode material for supercapacitor electrode. Sulfonated carbon (C SA ) was prepared from hydrothermal carbonization of furaldehyde and p-toluenesulfonic acid. Polyaniline-sulfate salt containing sulfonated carbon was prepared by chemical oxidative polymerization of aniline using ammonium persulfate in presence of sulfuric acid and sulfonated carbon via aqueous, emulsion and interfacial polymerization pathways. Formation of hybrid material was confirmed from scanning electron microscopy. Among the hybrid prepared with three different polymerization pathways, hybrid prepared by aqueous polymerization pathway showed better electrochemical performance. The specific capacitance of the hybrid prepared via aqueous polymerization was 600 F g−1, which is higher than that of the pristine PANI-SA (350 F g−1) and C SA (30 F g−1). Hybrid material was subjected for 8000 charge-discharge cycles and at 8000 cycles; it showed 88% retention of its original specific capacitance value of 485 F g−1 with coulombic efficiency (97–100%). These results showed that C SA micro spheres prevent the degradation of PANI-SA chains during charge/discharge cycles. Specific capacitance, cycle life, low solution resistance, low charge transfer resistance and high phase angle value of PANI-SA•C SA supercapacitor cell indicates a higher performance supercapacitor system.

High performance ceramic-based phthalonitrile micro and nanocomposites

The current review discusses the effects of adding various types of ceramic fillers on the curing behavior, thermal, mechanical, anticorrosion, and UV shielding properties of the bisphenol-A based phthalonitrile resins. The effects of different ceramic filler contents and sizes as well as their surface treatments are also discussed in terms of their impact on the morphology and mechanisms of enhancement. The synergistic effect obtained by these combinations extends the use of the phthalonitrile resins to more exigent applications such as aerospace and military. The presented results reveal the significant advantages that can be obtained from the preparation of hybrid materials based on phthalonitrile resins and open the way for further research in the field.

ChemInform Abstract: Design of a Confined Environment Using Protein Cages and Crystals for the Development of Biohybrid Materials

AbstractReview: 130 refs.

Electrochemical Determination of Aluminium By Oxidation of Dopamine Using Platinum Nanoparticles on MWCNT As Sensor

Aluminum (Al) is the most abundant metallic element and constitutes about 8% of the earth's crust. The aluminium is related to different neurological disorders like Alzheimer's, bipolar, depression, etc. As well as anemia, also reduces the absorption of calcium causing pain, deformities and broken bones.1-2 The development of nanotechnology has led to a growing interest in the study and design of nanosensors, in order to improve selectivity, limit of detection, reproducibility and durability of the current sensors.4-5 In this paper is repoted the preparation of hybrid material based on platinum nanoparticles (NP Pt) on multiwall carbon nanotubes (MWCNT) prepared by inverse microemulsion method using sodium dodecyl sulfate (SDS) as surfactant in a mixture of hexane/isopropanol/water. The hybrid material was characterized by transmission electron microscopy (TEM). The hybrid material showed small spherical nanoparticles with average sizes of 2.15±0.54 nm, well as thermogravimetric analysis a load of 20% platinum. The NP Pt/MWCNT hybrid material use for determining Al+3 using dopamine as a chelating molecule for the indirect determination of the aluminum by differential pulse voltammetry in neutral medium. Under optimal experimental conditions it was determined the sensitivity of the NP Pt/ MWCNT sensor was 27.75 μA/ppb Al+3 with a linear response range from 0 up to 15 ppb Al3+.

Epoxy Sol-Gel Hybrid Thermosets

Sol-gel methodologies are advantageous in the preparation of hybrid materials in front of the conventional addition of nanoparticles, because of the fine dispersion of the inorganic phase that can be reached in epoxy matrices. In addition, the use of organoalkoxysilanes as coupling agents allows covalent linkage between organic and inorganic phases, which is the key point in the improvement of mechanical properties. The sol-gel process involves hydrolysis and condensation reactions under mild conditions, starting from hydrolysable metal alkoxides, generally alkoxy silanes. Using the sol-gel procedure, the viscosity of the formulation is maintained, which is an important issue in coating applications, whereas the transparency of the polymer matrix is also maintained. However, only the proper combination of the chemistries and functionalities of both organic and inorganic structures leads to thermosets with the desired characteristics. The adequate preparation of hybrid epoxy thermosets enables their improvement in characteristics such as mechanical properties (modulus, hardness, scratch resistance), thermal and flame resistance, corrosion and antimicrobial protection, and even optical performance among others.

Antimicrobial nanomaterials for food packaging applications

Food packaging industry presents one of the fastest growing industries nowadays. New trends in this industry, which include reducing food as well as packaging waste, improved preservation of food and prolonged shelf-life together with substitution of petrochemical sources with renewable ones are leading to development of this industrial area in diverse directions. This multidisciplinary challenge is set up both in front of food and material scientists. Nanotechnology is recently answering to these challenges, with different solutions-from improvements in materials properties to active packaging solutions, or both at the same time. Incorporation of nanoparticles into polymer matrix and preparation of hybrid materials is one of the methods of modification of polymer properties. Nano scaled materials with antimicrobial properties can act as active components when added into polymer, thereby leading to prolonged protective function of pristine food packaging material. This paper presents a review in the field of antimicrobial nanomaterials for food packaging in turn of technology, application and regulatory issues.

Combination of photoinduced copper(i) catalyzed click chemistry and photosol–gel reaction for the synthesis of hybrid materials

We investigate in this work a novel one-step methodology for preparing hybrid materials by combining photoinduced sol–gel polymerization and light-induced CuAAC reaction.

Preparation of hybrid materials for controlled drug release

Authors obtained hybrid organic–inorganic materials applied in sustained drug delivery. The materials are ibuprofen as a model drug, hydroxyapatite and three different polymers as supports. Influence of the type of employed polymer, an inorganic carrier, on the properties and drug release profiles was estimated. Flory–Huggins interaction parameters, the dispersive component of surface free energy and acid-base characteristic of the surface were used to assess the behavior of the composites in terms of drug release. The experiments were carried out with the use of inverse gas chromatography (IGC), Fourier transform infrared (FTIR) and ultraviolet (UV) techniques. FTIR and ATR-FTIR spectra were collected. The values of parameter obtained for all investigated materials (excluding poly(L-lactide) (PLA2)) indicate low or medium activity. The strongest interactions (the lowest values of the Flory–Huggins parameter) are observed for PLA2 composition, while the weakest interactions for systems with polyethylene glycol (PEG). Finally, drug release profiles are shown. For materials prepared with Eudragit® (EUD) and PLA, the release of drug was much smaller, which corresponds to lower values of Flory–Huggins parameter. The executed experiments allowed the estimation of the properties of prepared composites. Prepared materials present properties required in sustained drug release and may be successfully applied as drug delivery systems.