Biocompatible Mesoporous Hollow Carbon Nanocapsules for High Performance Supercapacitors.

A facile and general method for the controllable synthesis of N-doped hollow mesoporous carbon nanocapsules (NHCNCs) with four different geometries has been developed. The spheres (NHCNC-1), low-concaves (NHCNC-2), semi-concaves (NHCNC-3) and wrinkles (NHCNC-4) shaped samples were prepared and systematically investigated to understand the structural effects of hollow particles on their supercapacitor performances. Compared with the other three different shaped samples (NHCNC-1, NHCNC-2, and NHCNC-4), the as-synthesized semi-concave structured NHCNC-3 demonstrated excellent performance with high gravimetric capacitance of 326 F g-1 (419 F cm-3) and ultra-stable cycling stability (96.6% after 5000 cycles). The outstanding performances achieved are attributed to the unique semi-concave structure, high specific surface area (1400 m2 g-1), hierarchical porosity, high packing density (1.41 g cm-3) and high nitrogen (N) content (up to 3.73%) of the new materials. These carbon nanocapsules with tailorable structures and properties enable them as outstanding carriers and platforms for various emerging applications, such as nanoscale chemical reactors, catalysis, batteries, solar energy harvest, gas storage and so on. In addition, these novel carbons have negligible cytotoxicity and high biocompatibility for human cells, promising a wide range of bio applications, such as biomaterials, drug delivery, biomedicine, biotherapy and bioelectronic devices

Mechanical protection for composite structures submitted to low energy impact

Composite materials are widely used in aeronautical structures. These materials can be submitted to low energy impacts like tool drop, routine operations… Such impacts can generate damages in the material that significantly reduce the structure strength. A solution to reduce the severity of damages due to impact is to add a mechanical protection on composite structures (patent n° 2 930 478). In this paper, an experimental study on different concepts of protective layers is presented. This protection is made of a certain thickness of low density energy absorbent material (foam, honeycomb or stacking of hollow spheres) and a thin layer of composite laminate (Kevlar). Experimental impact tests with a spherical impactor of 20 mm diameter at low velocity and low energy are made on aluminum plates, with different protections, and for different levels of energy. Analyses of Load/Displacement curves enable to study the capability of each mechanical protection to absorb energy. Resistance of these protections is then compared and discussed, taking into account the thickness and the surface density of the protections

Dielectric molding apparatus Patent

Dielectric apparatus for heating, fusing, and hardening of organic matrix to form plastic material into shaped produc

Study and production of polybenzimidazole billets, laminates, and cylinders

Mechanical properties and physical, chemical, and thermal tests of polybenzimidazole and carbon fabric laminates for spacecraft thermal insulatio

Sprayable low density ablator and application process

A sprayable, low density ablative composition is described consisting esentially of: (1) 100 parts by weight of a mixture of 25-65% by weight of phenolic microballoons, 0-20% by weight of glass microballoons, 4-10% by weight of glass fibers, 25-45% by weight of an epoxy-modified polyurethane resin, 2-4% by weight of a bentonite dispersing aid, and 1-2% by weight of an alcohol activator for the bentonite; (2) 1-10 parts by weight of an aromatic amine curing agent; and (3) 200-400 parts by weight of a solvent

A Review on Utilization of Light Weight Fly Ash Cenosphere as Filler in both Polymer and Alloy-Based Composites

 Fly Ash Cenospheres (FACs) are obtained from the coal power plants in the form of hollow spherical particles by burning the coal. FAC was started to use in early 1980-1985 as lightweight filler material in producing composites of cementitious and at present many researchers are focusing on use of FAC as filler in polymer and metals. In this paper, the systematic review on research activities and application of FAC in manufacturing light weight products are done. The FAC influence on the mechanical and physical properties of incorporated polymer and alloy based composites were summarized. Prospects of future for its use were also suggested and summarized in this paper

Ablative performance of various low-density elastomeric composites

Performance of low density silicone-phenolic and commercial ablative composite

Innovative Approach For Production Of Epoxy Syntactic Foams Consisting Of Epoxy Hollow

Epoxy spheres were fabricated via coating technique which utilized series of epoxy/curing agent mixture onto expanded polystyrene beads (EPS) formulated at ratio of 1:0.5 (epoxy rich), 1: 1(equivalent ratio) and 1:2 (amine rich) and their characteristic were investigated in term of differential scanning calorimeter (DSC), appearance and compressive behaviour. The results showed that EHS produced using epoxy/curing agent ratio of 1:1, exhibited smooth coating surface and yielded strong shell structure reflected from analysis of curing characteristic using DSC technique. An innovative approach involving vacuum assisted technique for preparation of syntactic foam made of epoxy hollow spheres and epoxy resin was introduced to be compared with syntactic foam produced through conventional technique; mold-casting technique. In this study, the resultant specimen was characterized for density and compression properties. Effect of different processing techniques on specimen was analysed through stress-strain curve and failure pattern of the syntactic foam filled EHS with the same EHS size. The vacuum assisted technique has successfully reduced voids within the matrix that was produced due to the processing technique and subsequently resulted in higher compressive strength and modulus. Specimen produced by the vacuum assisted technique was further investigated by varying several aspects in terms of cell sizes (BASF 403, BASF 303 and B-Normal) and internal structure of EHS (supported and unsupported). The effect of compression test orientation on the specimen failure pattern was also examined to assist in explaining in stress-strain curve difference. Under compressive loading, the failure initiated when stress concentrated on the weakest epoxy spheres slowly propagated through adjacent spheres and displayed wider horizontal plateau. When almost all sphere have been successfully collapsed, there was a drastic increase in stress on the stress-strain curve and this indicated that failure mechanism occurred via uniform densification throughout the specimen

Preliminary investigation of ablative material response to high-intensity CO2 laser radiation

Performance tests for ablative materials subjected to high intensity carbon dioxide laser radiatio

Stabilization of peptide-based vesicles via in situ oxygen-mediated cross-linking

Reversible vesicles from poly(L-glutamic acid) 65-block-poly[(L-lysine)-ran-(L-3,4-dihydroxyphenylalanine)] 75 [PLGA 65-b-P(LL-r-DOPA) 75] block copolypeptide adopt different configurations depending on the surrounding pH. At pH=3, AFM and TEM images show ellipsoidal morphologies, whereas at pH=12 both TEM and AFM reveal the formation of hollow vesicles. At pH=12, the P(LL-r-DOPA) block forms the internal layer of the vesicle shell and the subsequent oxygen-mediated oxidation of the phenolic groups of the DOPA lead to the formation of quinonic intermediates, which undergo intermolecular dimerization to stabilize the vesicles via in situ cross-linking. Consequently, the vesicles maintain their shape even when the pH is reversed back to 3, as confirmed by AFM and TE