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[en] The research on establishing the mechanism for the radiation-induced change in the structure and properties of materials in this project was performed to develop the radiation-based fundamental technology and establish the basement for the creation of a new radiation technology and industry. - The mechanism for the radiation crosslinking and grafting of polymer was discovered through investigating the thermal, mechanical, and morphological change in the irradiated polymer under the various conditions. Radiation effect on the commercial fluoropolymers under different atmospheres was investigated, and thereby, documenting the basic data for the radiation processing of the commercial fluoropolymers. - In addition, the outstanding radiation-resistant LDPE/MWCNT nanocomposite was newly developed to improve the radiation-resistance of a polymer as a cable-insulating material. The mechanism for the radiation-induced aging of an aromatic PEEK as a cable-insulating material was found out, and the lifetime of the aged PEEK was estimated through a thermally accelerated aging test.
[en] The intent of this research effort is to prove the hypothesis that: Through the employment of controlled processing parameters which are based upon integrated advanced material characterization and multi-physics material modeling, bulk nanolayered composites can be designed to contain high densities of preferred interfaces that can serve as supersinks for the defects responsible for premature damage and failure.
[en] Highlights: • The effect of RGO nanosheets on the electroactive polar β phase of P(VDF-TrFE) was explored. • RGO nanofillers act as a polling medium in the P(VDF-TrFE) matrix. • Enhancement in energy harvesting was observed with increasing of RGO concentration.
[en] Published data on nanostructured materials prepared by electrospinning are analyzed and generalized. Particular attention is devoted to the design and properties of nanocomposite fibrous materials and methods for modification and functionalization of fibre surface. The prospects for the application of non-woven materials for biotissue engineering and for the development of smart materials are considered. The bibliography includes 330 references
[en] In recent years, the development of biodegradable materials from renewable sources based on polymeric biomaterials have grown rapidly due to increase environmental concerns and the shortage of petroleum sources. In this regard, naturally renewable polymers such as starch has shown great potential as environmental friendly materials. Besides, the unique properties of starch such as biodegradable and non-toxic, biocompatible and solubility make them useful for a various biomedical applications. Regardless of their unique properties, starch materials are known to have limitations in term of poor processability, low mechanical properties, poor long term stability and high water sensitivity. In order to overcome these limitations, the incorporation of nano size fillers into starch materials (nanocomposites) has been introduced. This review aims to give an overview about structure and characteristics of starch, modification of starch by nanocomposites and their potential for biomedical applications. (paper)
[en] Electro-conductive nanocomposites have several applications in biomedical field. Development of a biocompatible electro-conductive polymeric materials is therefore of prime importance. In this study, electro-conductive nanofibrous mats of PLGA/CNT were fabricated through different methods including blend electrospinning, simultaneous PLGA electrospinning and CNT electrospraying and ultrasound-induced adsorption of CNTs on the electrospun PLGA nanofibers. The morphology and diameter of fibers were characterized by SEM and TEM, showing the lowest average diameters of 477 ± 136 nm for PLGA/MWCNT blend nanocomposites. MWCNT-sprayed PLGA specimens showed significant lower water contact angle (83°), electrical resistance (3.0 × 104 Ω) and higher mechanical properties (UTS: 5.50 ± 0.46 MPa) compared to the untreated PLGA scaffolds. Also, results of PC12 cell study demonstrated highest viability percentage on the MWCNT-sprayed PLGA nanofibers. We propose that the conductive nanocomposites have capability to use as tool for the neural regeneration and biosensors. .
[en] Are define nanomaterials those materials which have at least one dimension in the range between 1 and 100 nm. By the term nanotechnology refers, instead, to the study of phenomena and manipulation of materials at the atomic and molecular level. The materials brought to the nanometric dimensions take particular chemical-physical properties different from the corresponding conventional macro materials. Speaking about the structure of nanoscale, you can check some basic properties materials (eg. Melting temperature, magnetic and electrical properties) without changing its chemical composition. In this perspective are crucial knowledge and control of production processes in order to design and get the nanomaterial more suitable for a specific application. For this purpose, it describes a series of processes of production of nanomaterials with application examples.
[it]Si definiscono nanomateriali quei materiali che hanno almeno una dimensione nell’intervallo compreso tra 1 e 100 nm. Con il termine nanotecnologia si fa riferimento, invece, allo studio dei fenomeni e della manipolazione dei materiali a livello atomico e molecolare. I materiali portati alle dimensioni nanometriche assumono particolari proprietà chimico-fisiche differenti dai corrispondenti macromateriali convenzionali. Intervenendo sulla struttura dei materiali a scala nanometrica è possibile controllarne alcune fondamentali proprietà (ad es. temperatura di fusione, proprietà magnetiche ed elettriche) senza variarne la composizione chimica. In tale ottica sono di fondamentale importanza la conoscenza e il controllo dei processi produttivi al fine di progettare e ottenere il nanomateriale più adatto a una specifica applicazione. A tale scopo vengono descritti una serie di processi di produzione dei nanomateriali con esempi applicativi
[en] The pinning of grain interfaces plays an important role in determining the coercivity of nanocomposite magnets. Here, based on pinning effect, a simple model was proposed to correlate the pinning strength with microstructural parameters. A structural factor K has been used to describe the contribution of the phase composition and grain size of hard and soft phases to pinning strength. The model can be used to estimate the pinning strength of nanocomposite magnets, which is important for the design and fabrication of nanocomposite magnets with high coercivity.
[en] Soft robotics is an emerging field targeting at the development of robotic bodies and architectures characterized by flexibility, adaptability, and motility typical of that of biological systems. The use of electroactive ionic polymer–metal nanocomposites able to reversibly deform in response to low-intensity electric fields constitutes a promising solution for the implementation of actuators into soft robots. Currently, the use of this class of nanocomposites is hampered by several drawbacks, mainly related to the mismatch between the mechanical properties of the polymer and the metallic electrodes compromising their stability and resilience upon cyclic deformation.Here, we report and discuss on the use of supersonic cluster beam implantation (SCBI) as an effective strategy for the fabrication of soft electroactive ionic polymeric nanocomposite actuators. SCBI relies on the use of supersonically accelerated beams of neutral metal nanoparticles that can be aerodynamically collimated and directed onto a polymeric target to generate thin nanostructured metal layers physically interpenetrating with the polymer.Soft electroactive actuators based on engineered ionogel and ionogel-based hybrid nanocomposites provided with monolithically integrated cluster-assembled gold electrodes will be discussed. These systems can undergo long-term bending deformation in a low-voltage regime, due to the nanostructured electrode resilience. The use of cluster-assembled nanostructured electrodes opens new opportunities for the high-throughput manufacturing of soft ionic actuators with excellent mechanical resiliency, high-performance actuation, and high durability.
[en] Highlights: • A simple model for tunneling conductivity of polymer-CNT nanocomposites is suggested. • Interphase thickness, fraction of networked CNTs, and tunneling distance are assumed. • The model expresses the percolation threshold and the fraction of networked CNTs. • The model is tested using experimental results from the literature and parametric analyses. • The predictions show good agreement with the experimental results in all samples.