Nanoscale Composite Materials Research Articles

Thermal Behaviors and Interaction Mechanism of Ammonium Dinitramide with Nitrocellulose.

The initial interaction mechanism is very important for the design and safety of nano-scale composite energetic materials composed of ammonium dinitramide (ADN) and nitrocellulose (NC). The thermal behaviors of ADN, NC and an NC/ADN mixture under different conditions were studied by using differential scanning calorimetry (DSC) with sealed crucibles, an accelerating rate calorimeter (ARC), a self-developed gas pressure measurement instrument and a DSC-thermogravimetry (TG)-quadrupole mass spectroscopy (MS)-Fourier transform infrared spectroscopy (FTIR) combined technique. The results show that the exothermic peak temperature of the NC/ADN mixture shifted forward greatly in both open and closed circumstances compared to those of NC or ADN. After 585.5 min under quasi-adiabatic conditions, the NC/ADN mixture stepped into the self-heating stage at 106.4 °C, which was much less than the initial temperatures of NC or ADN. The significant reduction in net pressure increment of NC, ADN and the NC/ADN mixture under vacuum indicates that ADN initiated the interaction of NC with ADN. Compared to gas products of NC or ADN, two new kinds of oxidative gases O2 and HNO2 appeared for the NC/ADN mixture, while NH3 and aldehyde disappeared. The mixing of NC with ADN did not change the initial decomposition pathway of either, but NC made ADN more inclined to decompose into N2O, which resulted in the formation of oxidative gases O2 and HNO2. The thermal decomposition of ADN dominated the initial thermal decomposition stage of the NC/ADN mixture, followed by the oxidation of NC and the cation of ADN.

Characterization of Electrospinning Prepared Nitrocellulose (NC)-Ammonium Dinitramide (ADN)-Based Composite Fibers.

Nanoscale composite energetic materials (CEMs) based on oxidizer and fuel have potential advantages in energy adjustment and regulation through oxygen balance (OB) change. The micro- and nanosized fibers based on nano nitrocellulose (NC)-ammonium dinitramide (ADN) were prepared by the electrospinning technique, and the morphology, thermal stability, combustion behaviors, and mechanical sensitivity of the fibers were characterized by means of scanning electron microscope (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), gas pressure measurement of thermostatic decomposition, laser ignition, and sensitivity tests. The results showed that the prepared fibers with fluffy 3D macrostructure were constructed by the overlap of micro/nanofibers with the energetic particles embedded in the NC matrix. The first exothermic peak temperature (Tp) of the samples containing ADN decreased by 10.1 °C at most compared to that of ADN, and the pressure rise time of all the samples containing ADN moved forward compared to that of the sample containing NC only. Furthermore, ADN can decrease the ignition delay time of NC-based fibers under atmosphere at room temperature from 33 ms to 9 ms and can enhance the burning intensity of NC-based fibers under normal pressure. In addition, compared to the single high explosive CL-20 or RDX, the mechanical sensitivities of the composite materials containing high explosive CL-20 or RDX were much decreased. The positive oxygen balance of ADN and the intensive interactions between ADN and NC can reduce the ignition delay time and promote the burning reaction intensity of NC-based composite fibers, while the mechanical sensitivities of composite fibers could be improved.

A covalent organic framework-based nanoreactor for enhanced photothermal therapy via inhibiting intracellular heat defense systems.

Herein, we report an indocyanine green (ICG)-decorated and glucose oxidase (GOx)-loaded nanoscale composite COF material via a stepwise post-synthetic modification. The obtained GOx@COF-ICG can achieve synergistic inhibition of intracellular heat defense systems through starvation therapy to enhance photothermal therapy of tumors.

Application of polyaniline-manganese nano-composite for water pollution control

Water resources are currently being contaminated as a result of the rapid rise of industrialization, urbanization, population growth, and climate change. The biggest risk for many nations is a lack of clean, fresh water. The focus and attention of numerous scientists and governmental organizations have recently turned to water purification techniques. For efficient and effective sanitization of water bodies, academics from all over the world are focusing on water purification technologies centered on nanotechnology. Due to their great surface area, high chemical reactivity, excellent mechanical strength, and low cost, nanoscale composite materials offer a significant potential to cleanse water in a variety of ways. Polymer nano-composites (Polyaniline-Mn) have been selected as an effective and economical solution for wastewater pollution treatment. An effectiveness of polymer nano-composites for water purification is provided in this research.

Morphology-size synergy strategy of SiC@C nanoparticles towards lightweight and efficient microwave absorption

Micro nanocomposites with multi-media components and rich heterogeneous interfaces have been proved to be the preferred electromagnetic functional bodies, especially in the field of electromagnetic wave absorption. The special composite structure of hollow, mesoporous and core–shell has excellent adjustable potential, it is also a high-quality route to expand electromagnetic characteristics. Herein, a synergistic strategy for sphere-line morphology evolution and particle size control of SiC/C composites by varying the calcination temperature and pH environment is proposed. The results show that the sample calcined at 1350 ℃ is hollow mesoporous [email protected] microsphere ([email protected]), it has the most excellent microwave absorption (MA) performance when the amount of ammonia is 3 ml, its effective absorption bandwidth (EAB) is 5.61 GHz at 2.1 mm, and the maximum reflection loss (RLmin) is −45.61 dB at 13.2 GHz. The excellent performance is due to the combination of good impedance matching and strong dielectric loss brought by semiconductor SiC/C composites. Multi-angle control strategy of hollow mesoporous [email protected] heterostructure and particle size can effectively adjust the electromagnetic parameters, which provides useful thinking for the design of other nano-scale dielectric composite materials.

Enhanced photodegradation of 2,4-dinitrophenol by n–p type TiO2/BiOI nanocomposite

Photocatalysis has recently been regarded as one of the most viable technologies for water treatment. Scholars all over the world are focusing on nanocomposites for water treatment for efficient and effective sanitization of bodies of water. Because of their high surface area, high chemical reactivity, excellent mechanical strength, low cost, and nanoscale composite materials have enormous potential to purify water in a various way. In this study, n-type TiO2 was synthesized and tailored to produce a TiO2/BiOI n–p nanocatalyst for enhanced photodegradation of 2,4-dinitrophenol (2,4-DNP) under UV-A and solar light respectively. Because of the formation of a heterojunction between BiOI and TiO2, the photocatalytic activity in TiO2/BiOI absorbs strongly in both the UV and visible regions and it has a lower recombination rate of the e-/h+ pairs. Furthermore, the generation of OH•, O2•– radicals during the oxidation process is attributed to the photodegradation of 2,4-DNP. The results revealed that the TiO2/BiOI manifest outperformed BiOI and TiO2 in terms of photocatalytic function. XRD, BET, HR-SEM-EDX with ECM, HR-TEM, FT-IR, PL, and UV-DRS techniques determined the photocatalyst composition. The HR-SEM images clearly showed that the particles are less than 27 ​nm in size. Thus, nanocomposite materials have played an important role in water purification.

Sono-catalysis preparation and alternating magnetic field/glutathione-triggered drug release kinetics of core-shell magnetic micro-organogel

Microscale or nanoscale composite materials may be a promising carrier candidate to complete the loading and delivery for hydrophobic drugs. In our current study, novel magnetic micro-organogel with core-shell structure was successfully prepared by a sono-catalysis method. The as-synthesized magnetic micro-organogel had a well-defined spherical morphology, an appropriate stability in the aqueous media and a strong loading capability for hydrophobic drugs, and showed an excellent field-oriented ability for drug delivery which responded to the dosage of magnetic nanoparticles. By evaluating the ability to release the drugs, the magnetic micro-organogel displayed a good glutathione (GSH)-stimuli sensitivity since its protein shell was mainly formed by the sulfydryl crosslinking among BSA molecules, and also had a fine alternating magnetic field (AMF)-triggered releasing behavior owing to the thermo-reversible phase transition of its gel core. Furthermore, the kinetic studies discussed a few releasing mechanisms dependent on the redox effect and the magnetothermal performance. Thus, the magnetic micro-organogel would be a potential targeted carrier for dual-stimuli-responsive release of hydrophobic drugs.

Synthesis and Catalytic Properties of CoFe<sub>2</sub>O<sub>4</sub>/Fe<sub>2</sub>O<sub>3</sub> Nanosized Composite Material

The present research is devoted to the formation process of a nanoscale composite material with the composition of CoFe2O4/α-Fe2O3. The synthesized material has been studied by the following methods: x-ray phase analysis and scanning electron microscopy. The produced sample is analyzed to be a CoFe2O4 cabic spinel with a unit cell parameters of a = 0.8394 nm and α-Fe2O3. The average crystallite size of the resulting samples, determined by the Debye-Scherrer equation, is 4.8 nm for the cobalt (II) ferrite and 7.9 nm for α-Fe2O3. Reaction rate increase is determined by the incease in hydrogen peroxide amount in the solution. The synthesized composite material is found to exhibit increased catalytic activity in the oxidative degradation reaction of organic dye by hydrogen peroxide. The catalytic activity is established to be particularly high, when the process is occurring in acidic medium. The obtained samples have a highly developed surface and may be of interest as catalysts, adsorbents.

Interfacial indentations in biological composites

Biocomposites comprise highly stiff reinforcement elements connected by a compliant matrix material. While the interfacial elastic properties of these biocomposites play a key role in determining the mechanical properties of the entire biocomposite, these properties cannot be measured directly from standard nanomechanical experiments. Developing a method for extracting the interfacial elastic properties in biocomposites is, therefore, a major objective of cutting-edge biomaterials science. Here, using mechanical modeling and Finite-Element simulations, we analyze the interfacial force–depth relationships, stress distribution, and indentation modulus of standard nanoindentation testing in biocomposites, and we establish an analytical framework that connects these results to the elastic properties of the underlying matrix and reinforcement components. The resulting analytical framework is general and holds for a broad range of biocomposites, thus enabling a deeper understanding of the mechanical characteristics of functional interfaces in various biomaterials. Moreover, this framework can be adapted to account for synthetic, microscale, and nanoscale composite materials, and thereby promotes the development of advanced interfacial configurations with specialized mechanical capabilities.

Carbonic Anhydrase Carrying Electrospun Nanofibers for Biocatalysis Applications.

Enzymes are efficient biocatalysis that catalysis a large number of reactions due to their chemical, regional, or stereo specifities and selectivity. Their usage in bioreactor or biosensor systems has great importance. Carbonic anhydrase enzyme catalyzes the interconversion between carbon dioxide and water and the dissociated ions of carbonic acid. In organisms, the carbonic anhydrase enzyme has crucial roles connected with pH and CO2 homeostasis, respiration, and transport of CO2/bicarbonate, etc. So, immobilization of the enzyme is important in stabilizing the catalyst against thermal and chemical denaturation in bioreactor systems when compared to the free enzyme that is unstable at high temperatures and extreme pH values, as well as in the presence of organic solvents or toxic reagents. Nano-scale composite materials have attracted considerable attention in recent years, and electrospinning based all-nanocomposite materials have a wide range of applications. In this study, electrospun nanofibers were fabricated and used for the supporting media for carbonic anhydrase enzyme immobilization to enhance the enzyme storage and usage facilities. In this article, our motivation is to obtain attractive electrospun support for carbonic anhydrase enzyme immobilization to enhance the enzyme reusability and storage ability in biocatalysis applications. In this article, we propose electrospun nanofibers for carbonic anhydrase carrying support for achieving our aforementioned object. In the first part of the study, agar with polyacrylonitrile (PAN) nanofibers was directly fabricated from an agar-PAN mixture solution using the electrospinning method, and fabricated nanofibers were cross-linked via glutaraldehyde (GA). The morphology, chemical structure, and stability of the electrospun nanofibers were characterized. In the second part of the study, the carbonic anhydrase enzyme was immobilized onto fabricated electrospun nanofibers. Then, enzyme activity, the parameters that affect enzyme immobilization such as pH, enzyme amount, immobilization time, etc. and reusability were investigated. When the scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) analysis results are combined in the characterization process of the synthesized electrospun nanofibers, the optimum cross-linking time is found to be 8 hours using 5% glutaraldehyde cross-linking agent. Then, thermal stability measurements showed that the thermal stability of electrospun nanofibers has an excellent characteristic for biomedical applications. The optimum temperature value was found 37°C, pH 8 was determined as an optimum pH, and 100 ppm carbonic anhydrase enzyme concentration was found to be optimum enzyme concentration for the carbonic anhydrase enzyme immobilization. According to the kinetic data, carbonic anhydrase immobilized electrospun nanofibers acted as a biocatalyst in the conversion of the substrate to the product in 83.98%, and immobilized carbonic anhydrase enzyme is reusable up to 9 cycles in biocatalysis applications. After applying the framework, we get a new biocatalysis application platform for carbonic anhydrase enzyme. Electrospun nanofibers were chosen as the support material for enzyme immobilization. By using this approach, the carbonic anhydrase enzyme could easily be used in the industrial area by cost-effective advantageous aspects.

Effective Remediation of an Antibacterial Drug from Aqua Matrix Using CaFe2O4/ZrO2 Nanocomposite Derived via Inorganic Chemical Pathway: Statistical Modelling by Response Surface Methodology

With the rapid development in nanotechnology, the preparation of novel self-assembled nanoscale composite materials and their numerous environmental applications have become a promising area of research among the environmental scientists. In view of above, the present study aims at fabrication of a mesoporous nanoscale material of calcium ferrite-zirconium oxide-magnetic nanocomposite (CF-ZrO-MNC) to explore its application in adsorption-driven remediation process of tetracycline (TC). The characterisation study of the so-prepared CF-ZrO-MNC has revealed the presence of 0.1213 cc/g of mesoporous volume with a specific surface area of 95.32 m2/g. A comparative study performed between CF-ZrO-MNC, CaFe2O4 and ZrO2 nanoparticles has proven the superior adsorption capability of CF-ZrO-MNC for TC over the pure phases of parent CaFe2O4 and ZrO2 nanoparticles. The optimisation of TC adsorption process was performed by response surface methodology, which has revealed that 98.14% of TC removal can be obtained within 60 min of contact time using 4.0 g/L of CF-ZrO-MNC dose with 40.0 mg/L of TC concentration at solution pH 6.0. The kinetic and isotherm studies have presented pseudo-second-order kinetic and Freundlich isotherm model as the best-fitted models, respectively. The results of Langmuir isotherm model fitting indicated that CF-ZrO-MNC poses 92.59 mg/g of maximum TC adsorption capacity which has been proven to be highly effective as compared to previously reported adsorbents for the remediation of TC from aqueous media.

Efficient removal of methyl orange by a flower-like TiO2/MIL-101(Cr) composite nanomaterial.

Nano-scale MOF composite materials prepared by combining inorganic semiconductors with controllable pore structures and functional active sites for the effective removal of organic dyes will exhibit more excellent adsorption activity. In this paper, MIL-101(Cr) was used as a carrier and two-step hydrothermal methods were successfully used to prepare flower-like TiO2/MIL-101(Cr) composite nano-adsorbents with different sizes. The results of XRD, SEM, XPS and other characterization methods showed that when the molar ratio of Ti : Cr was 0.2 : 1, the composite nano-adsorbent exhibited better adsorption performance and removal efficiency for methyl orange (MO) in aqueous solution. By assembling TiO2 on MIL-101(Cr), Ti replaced part of Cr, and the positively-charged TiO2/MIL-101(Cr) nanocomposite and negatively-charged MO in aqueous solution formed a strong interaction force. In addition, the π-π packing interactions of the benzene ring of MIL-101(Cr) and the electrostatic force between TiO2 and MIL-101(Cr) also enhanced the performance and adsorption efficiency of the adsorbent to a certain extent. The BET results showed that the large specific surface area and average pore diameter of the TiO2/MIL-101(Cr) nanocomposites effectively improved the adsorption performance of the composites. The results showed that the MO removal efficiency of 20% TiO2/MIL-101(Cr) can reach 93.03% at 80 min. But when 20% TiO2/MIL-101(Cr) was used to adsorb 70 mg·L-1 MO, the experimental maximum adsorption capacity was 242.02 mg·g-1.

Cerium-doped mesoporous BaTiO3/TiO2 nanocomposites: structural, optical and photocatalytic properties

Nanoscale composite materials based on cerium, barium titanate and titanium dioxide were synthesized by thermal hydrolysis. The obtained individual TiO2, BaTiO3 and as-synthesized Ce/xBaTiO3/TiO2 semiconductive nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive spectrometry, transmission electron microscopy, nitrogen adsorption–desorption, UV–vis diffuse reflectance spectroscopy, and Fourier transform infrared spectroscopy. The structural investigations revealed that all prepared powders were nanocrystalline with an average crystallite size within the range of 5–17 nm. Analysis of nitrogen adsorption–desorption isotherms for the synthesized nanocomposites showed the presence of a hysteresis loop, which is evidence for the mesoporous structure of the powders. The photocatalytic degradation of the model pollutants (Safranine T and Rhodamine B) was carried out under UV irradiation. Ce/xBaTiO3/TiO2 nanocomposites showed higher photocatalytic activity compared to pure TiO2 and BaTiO3 as well as BaTiO3/TiO2. An increase of the amount of BaTiO3 in Ce/xBaTiO3/TiO2 samples by more than 12% reduces the photocatalytic activity of nanocomposites while doping of BaTiO3/TiO2 samples with cerium increases their photoactivity.

Immediate release of helicid from nanoparticles produced by modified coaxial electrospraying

In this paper, a modified coaxial electrospraying process was explored for the generation of novel nanoscale composite materials. A solution comprising 5% (w/v) of the model drug helicid and 10% (w/v) polyvinylpyrrolidone (PVP) K10 in a mixture of N,N-dimethylacetamide and ethanol (4:6, v:v) was employed as the shell working liquid. This could not be processed into a solid product when processed by single-fluid electrospraying. However, when undertaking co-axial electrospraying with a core shellac solution (40% w/v in ethanol) solid particles were obtained. An extremely thin nanocoating layer of drug-polymer composite with an estimated thickness of 7 nm was deposited on a shellac core. X-ray diffraction and infrared spectroscopy demonstrated that the drug was converted into an amorphous nanocomposite with the PVP in the shell layer, losing its original crystalline state. In vitro dissolution tests revealed that all the helicid loading could be released within one minute, suggesting the particles have potential applications to deliver very rapid therapeutic effects. Mechanisms are proposed underlying the formation and functional performance of the materials.

Electrospinning based all-nano composite materials: Recent achievements and perspectives

Abstract Nanoscale composite materials have received more and more attention in recent years. All-nano composite material produced by electrospinning is a rising field, which is in the basic research and primary development stage. Due to the multifunctional properties of these composite materials, they are expected to be applied in many fields. This review focuses on recent progress in reported electrospinning based all-nano composite materials for various applications, such as membrane filtration, adsorption of harmful substances, photo/chemical/electro catalysis, biological medicine, electronic nanodevices, energy storage and conversion, and electromagnetic interference shielding and stealth materials. Finally, we propose our personal insights into future research opportunities and challenges in the hope of stimulating more researchers to engage in this novel field of electrospinning based all-nano composite materials for innovative applications.

Effect of the C and S additives on structural, optical, and photocatalytic properties of TiO2

Nanoscale composite materials based on titanium dioxide, sulphur, and carbons were obtained. The samples were characterized using X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, Brunauer–Emmett–Teller and Barret–Joiner–Halenda methods, electron paramagnetic resonance spectroscopy, and ultraviolet–visible and infrared spectroscopy. X-ray powder diffraction revealed the phase of anatase in all composites and appearance of rutile phase for samples with high sulphur content. It was established that composites consist of nanoparticles ca. 6–10 nm. Analysis of nitrogen adsorption–desorption isotherms for the synthesized samples showed the presence of a hysteresis loop which is the evidence for mesoporous structure of the powders. Absorption spectra of nanocomposites showed a bathochromic shift compared with the absorption band of pure TiO2. It was found that modification of titanium dioxide with sulphur and carbons leads to bandgap narrowing of composites. Nanocomposite samples showed higher photocatalytic activity in the destruction of safranin T under ultraviolet and visible irradiation compared to pure titanium dioxide. It can be connected with the participation of additives in the inhibition of electron–hole recombination, prolongation of charges lifetime, increasing of efficiency of interfacial charge separation, and formation of doping electronic states.

Investigation of biogenic iron-containing nanoscale composite materials

Biogenic composites are interesting as green and sustainable precursors for preparation of advanced materials of various applications. Biomaterials from Leptothrix group bacteria cultivated in two feeding media of silicon-iron-glucose-peptone (SIGP) and Lieske were studied. Iron-containing biogenic powders and biofilms on silica gel covered aluminum plates were prepared. They were studied to elucidate the effect of the plates in the process of growing biogenic iron nanotubes. The cultivation period was varied from 4 to 30 days. Biomass phase composition and physicochemical properties were studied by Mossbauer spectroscopy at room and low temperature, as well as by means of powder XRD, FTIRS, and SEM methods. Mossbauer analysis offered us a unique possibility to register iron oxide species at the different steps of biogenic material formation. Tetrahedrally coordinated iron species were registered at an early stage of biofilm formation. So, important results on the mechanism of biomineralization process are obtained. The reaction of CO oxidation on prepared biomaterials was studied using in situ DRIFTS. Comparative analysis of the obtained materials and examination of spent samples showed differences in their phase composition, stability and dispersity. Changes of the phase composition were observed during catalytic tests with biomasses obtained in Lieske feeding media. No differences in biogenic powder and biofilm composition and dispersity were registered when SIGP media was used neither for studied bacteria cultivation period nor in spent catalysts. These results indicated the stabilizing effect of extra silicon content in the feeding media. Formation of iron oxihydroxide nanotubes was also established in this case.

Damage effects of proton beam irradiation on single layer graphene

Graphene was first discovered in 2004 (Novoselov K S, et al. 2004 Science 306 666), it is a single atomic layer of sp2-bonded carbon atoms arranged in a honeycomb-like lattice. According to its extraordinary electronic, mechanical, thermal and optical properties, one can expect it to have a variety of applications in nanoscale electronics, composite materials, energy storage, and biomedicine fields. Although many experimental and theoretical studies on graphene have been carried, there still exist many obstacles to its applications. A representative example is nanoscale electronics (e.g., field-effect transistors and optoelectronic devices) that requires non-zero band-gap. Therefore, introducing defects into graphene and leading to band-gap opening are key steps for its technique applications.Recently, ion beam irradiation as a defects introducing technique was performed by Lee et al. (2015 Appl. Surf. Sci. 344 52) and Zeng et al. (2016 Carbon 100 16) through 5, 10, and 15 MeV protons and highly charged ions (HCIs) irradiating the graphene separately. Considering the advantages of simplity for preparing samples and feasibility in atmospheric condition of Raman spectroscopy compared with common characterization techniques (high resolution transmission electron microscopy, scanning electron microscopy, atomic force microscopy) for nano-materials, in both studies, Raman spectroscopy is used to obtain the evolution of ID/IG (ID is the peak intensity excited by defects, IG is the peak intensity origining from lateral vibration of carbon atoms) with different energies and fluences, respectively. In this work, considered are the following points:1) the absence of quantitive characterization for defects in the above two studies; 2) the low displacement energy of 25 eV required for a carbon atom to be knocked out (Zhao S J, et al. 2012 Nanotechnology 23 285703); 3) the complex interaction between HCIs and material. The irradiation effects of single layer graphene on silicon substrate are investigated by 750 keV and 1 MeV proton bombarding. This introduces the defects into graphene and thus leads to band-gap opening. By comparing Raman spectra of the samples before and after irradiation, a quantitive characterization about defects in graphene is achieved. Detailed analysis shows that 1) the value of ID/IG increases with the energy loss of incident proton, which is consistent with the result of SRIM simulation; 2) the average distance of defects LD increases with the incident proton energy; 3) the defect density nD decreases with the incident proton energy. These indicate that the damage effect for MeV protons in single layer graphene with substrate is similar to those in three-dimensional materials. The method presented here may facilitate the understanding of the physical mechanism of MeV proton interaction with two-dimensional materials, and provide a potential way of controlling the electronic structure and band-gap.

Fundamental aspects of electrochemically controlled wetting of nanoscale composite materials.

Electroactive films based on conducting polymers have numerous potential applications, but practical devices frequently require a combination of properties not met by a single component. This has prompted an extension to composite materials, notably those in which particulates are immobilised within a polymer film. Irrespective of the polymer and the intended application, film wetting is important: by various means, it facilitates transport processes - of electronic charge, charge-balancing counter ions ("dopant") and analyte/reactant molecules - and motion of polymer segments. While film solvent content and transfer have been widely studied for pristine polymer films exposed to molecular solvents, extension to non-conventional solvents (such as ionic liquids) or to composite films has been given much less attention. Here we consider such cases based on polyaniline films. We explore two factors, the nature of the electrolyte (solvent and film-permeating ions) and the effect of introducing particulate species into the film. In the first instance, we compare film behaviours when exposed to a conventional protic solvent (water) with an aprotic ionic liquid (Ethaline) and the intermediate case of a protic ionic liquid (Oxaline). Secondly, we explore the effect of inclusion of physically diverse particulates: multi-walled carbon nanotubes, graphite or molybdenum dioxide. We use electrochemistry to control and monitor the film redox state and change therein, and acoustic wave measurements to diagnose rheologically vs. gravimetrically determined response. The outcomes provide insights of relevance to future practical applications, including charge/discharge rates and cycle life for energy storage devices, "salt" transfer in water purification technologies, and the extent of film "memory" of previous environments when sequentially exposed to different media.

A micromechanics approach for effective elastic properties of nano-composites with energetic surfaces/interfaces

The mechanics of structure genome is generalized to model nanocomposites taking into account the surfaces/interfaces stress effect at nano-scale. This full field micromechanics approach is applied to predict the effective properties of composites containing nano-inhomogeneities. Examples of binary composite materials, fiber reinforced composite materials and particle reinforced composite materials are used to demonstrate the robustness and accuracy of this micromechanics theory with surfaces/interfaces effects. The size-dependency of the overall elastic moduli shows the importance of energetic surfaces/interfaces in modeling the mechanical behavior of nano-scale composite materials. The proposed micromechanics approach is versatile enough to be applied for estimating the effective elastic properties of many nano-composite materials.