Molecular self-assembly is the spontaneous association of molecules under equilibrium conditions into stable, structurally well-defined aggregates joined by noncovalent bonds. Molecular self-assembly is ubiquitous in biological systems and underlies the formation of a wide variety of complex biological structures. Understanding self-assembly and the associated noncovalent interactions that connect complementary interacting molecular surfaces in biological aggregates is a central concern in structural biochemistry. Self-assembly is also emerging as a new strategy in chemical synthesis, with the potential of generating nonbiological structures with dimensions of 1 to 10(2) nanometers (with molecular weights of 10(4) to 10(10) daltons). Structures in the upper part of this range of sizes are presently inaccessible through chemical synthesis, and the ability to prepare them would open a route to structures comparable in size (and perhaps complementary in function) to those that can be prepared by microlithography and other techniques of microfabrication.

Molecular self-assembly and nanochemistry: A chemical strategy for the synthesis of nanostructures

Thermal Conductivity of Polymer-Based Composites: Fundamentals and Applications

Dielectric polymer nanocomposites are rapidly emerging as novel materials for a number of advanced engineering applications. In this Review, we present a comprehensive review of the use of ferroelectric polymers, especially PVDF and PVDF-based copolymers/blends as potential components in dielectric nanocomposite materials for high energy density capacitor applications. Various parameters like dielectric constant, dielectric loss, breakdown strength, energy density, and flexibility of the polymer nanocomposites have been thoroughly investigated. Fillers with different shapes have been found to cause significant variation in the physical and electrical properties. Generally, one-dimensional and two-dimensional nanofillers with large aspect ratios provide enhanced flexibility versus zero-dimensional fillers. Surface modification of nanomaterials as well as polymers adds flavor to the dielectric properties of the resulting nanocomposites. Nowadays, three-phase nanocomposites with either combination of fillers...

Recent Progress on Ferroelectric Polymer-Based Nanocomposites for High Energy Density Capacitors: Synthesis, Dielectric Properties, and Future Aspects.

Study of flexible nanodielectric materials (FNDMs) with high permittivity is one of the most active academic research areas in advanced functional materials. FNDMs with excellent dielectric properties are demonstrated to show great promise as energy-storage dielectric layers in high-performance capacitors. These materials, in common, consist of nanoscale particles dispersed into a flexible polymer matrix so that both the physical/chemical characteristics of the nanoparticles and the interaction between the nanoparticles and the polymers have crucial effects on the microstructures and final properties. This review first outlines the crucial issues in the nanodielectric field and then focuses on recent remarkable research developments in the fabrication of FNDMs with special constitutents, molecular structures, and microstructures. Possible reasons for several persistent issues are analyzed and the general strategies to realize FNDMs with excellent integral properties are summarized. The review further highlights some exciting examples of these FNDMs for power-energy-storage applications.

Flexible Nanodielectric Materials with High Permittivity for Power Energy Storage

Electronic skin devices capable of monitoring physiological signals and displaying feedback information through closed-loop communication between the user and electronics are being considered for next-generation wearables and the 'Internet of Things'. Such devices need to be ultrathin to achieve seamless and conformal contact with the human body, to accommodate strains from repeated movement and to be comfortable to wear. Recently, self-healing chemistry has driven important advances in deformable and reconfigurable electronics, particularly with self-healable electrodes as the key enabler. Unlike polymer substrates with self-healable dynamic nature, the disrupted conducting network is unable to recover its stretchability after damage. Here, we report the observation of self-reconstruction of conducting nanostructures when in contact with a dynamically crosslinked polymer network. This, combined with the self-bonding property of self-healing polymer, allowed subsequent heterogeneous multi-component device integration of interconnects, sensors and light-emitting devices into a single multi-functional system. This first autonomous self-healable and stretchable multi-component electronic skin paves the way for future robust electronics.

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An integrated self-healable electronic skin system fabricated via dynamic reconstruction of a nanostructured conducting network.

Effect of the surface roughness on interfacial properties of carbon fibers reinforced epoxy resin composites

Preparing a biobased (biomass-based) high performance epoxy resin with extremely large biomass content is of great importance for sustainable development. Herein, a new epoxy resin with a precise structure, bis(2-methoxy-4-(oxiran-2-ylmethyl)phenyl)furan-2,5-dicarboxylate (EUFU-EP), was synthesized from two biobased green and low toxic compounds (2,5-furandicarboxylic acid and eugenol) and the biomass content of EUFU-EP is as large as 93.3%. In addition, a new biobased epoxy resin, EUFU-EP/MHHPA, was prepared by using methyl hexahydrophthalic anhydride (MHHPA) as the curing agent and 2-ethyl-4-methylimidazole as the curing accelerator. The curing reactivity and integrated performances including thermal and mechanical properties as well as flame retardancy of the cured resin were systematically researched and compared with those of petrochemical resource-based epoxy resin (DGEBA/MHHPA) consisting of commercial diglycidyl ether of bisphenol A (DGEBA), MHHPA and 2-ethyl-4-methylimidazole. Results show that E...

Biobased Heat Resistant Epoxy Resin with Extremely High Biomass Content from 2,5-Furandicarboxylic Acid and Eugenol

The production of carbon nanotube/epoxy composites with a very high dielectric constant and low dielectric loss by microwave curing

A novel hybridized multifunctional filler (CPBN), cyclotriphosphazene/hexagonal boron nitride (hBN) hybrid, was synthesized by chemically coating hBN with hexachlorocyclotriphosphazene and p-phenylenediamine, its structure was systemically characterized. Besides, CPBN was used to develop new flame retarding bismaleimide/o,o′-diallylbisphenol A (BD) resins with simultaneously high thermal conductivity and thermal stability. The nature of CPBN has a strong influence on the flame behavior of the composites. With the addition of only 5 wt % CPBN to BD resin, the thermal conductivity increases 2 times; meanwhile the flame retardancy of BD resin is remarkably increased, reflected by the increased limited oxygen index, much longer time to ignition, significantly reduced heat release rate. The thermogravimetric kinetics, structures of chars and pyrolysis gases, and cone calorimeter tests were investigated to reveal the unique flame retarding mechanism of CPBN/BD composites. CPBN provides multieffects on improving...

Multifunctional cyclotriphosphazene/hexagonal boron nitride hybrids and their flame retarding bismaleimide resins with high thermal conductivity and thermal stability.

A novel fully end-capped hyperbranched polysiloxane (Am-HPSi) with large branching degree and amine-groups was successfully synthesized by a controlled hydrolysis of phenyltrimethoxysilane and γ-aminopropyl triethoxysilane, and its structure was characterized by nuclear magnetic resonance (1H-NMR and 29Si-NMR) and Fourier transform infrared (FTIR) spectra as well as gel permeation chromatography (GPC). In addition, Am-HPSi was used to develop a new modified bismaleimide resin with simultaneously improved flame retardancy and other typical properties. The incorporation of Am-HPSi to 4,4′-bismaleimidodiphenyl methane/2,2′-diallyl bisphenol A (BDM/DBA) resin not only obviously increases the thermal resistance, moisture resistance, impact strength, and dielectric properties, but also remarkably improves the flame retardancy. Specifically, the average heat release rate and total heat release of modified BDM/DBA resin with 10 wt% Am-HPSi are only 37 % and 23 % of that of neat BDM/DBA resin, respectively. A synergistic flame retarding mechanism is believed to be attributed to these results, which includes improving thermal stability, producing non-combustible gas, acting in the condensed phase, and providing a barrier for heat and mass transfer owing to the introduction of Am-HPSi to BDM/DBA resin. These attractive features of Am-HPSi/BDM/DBA resins suggest that the method proposed herein is a new approach to develop high performance resins for cutting-edge industries.

Flame retardancy materials based on a novel fully end-capped hyperbranched polysiloxane and bismaleimide/diallylbisphenol A resin with simultaneously improved integrated performance

Li Yuan

Papers

Effect of the surface roughness on interfacial properties of carbon fibers reinforced epoxy resin composites

Biobased Heat Resistant Epoxy Resin with Extremely High Biomass Content from 2,5-Furandicarboxylic Acid and Eugenol

The production of carbon nanotube/epoxy composites with a very high dielectric constant and low dielectric loss by microwave curing

Multifunctional cyclotriphosphazene/hexagonal boron nitride hybrids and their flame retarding bismaleimide resins with high thermal conductivity and thermal stability.

Flame retardancy materials based on a novel fully end-capped hyperbranched polysiloxane and bismaleimide/diallylbisphenol A resin with simultaneously improved integrated performance