Progress in research areas eligible for carbon airgel
Aerogels has been hailed as the new materials to change the world in high-tech fields of aerospace, defense and construction, industrial pipe insulation and other civilian areas have a very wide range of applications . Structurally, theis zero-dimensional quantum dots, one-dimensional or two-dimensional nanowire films such as low-dimensional nano-structure three-dimensionally assembled nanoporous ultra-light material. Low-dimensional structures of various variables, such as geometry, size, density, surface topography, chemical properties and other parameters, will have a significant impact on the final properties of the obtained airgel. To date, a variety of low-dimensional structures can be assembled into different airgel, but the size of these units are in the nanostructure 100 nm, or even just a few nanometers. Preparation of a structural unit size greater than 100 nm (i.e., submicron) to the great challenges of the airgel, which is mainly caused by two reasons: First, the larger the size of the airgel structural units, a specific surface area which is smaller (both inverse relationship). The structural unit of submicron order, whether it is an inorganic material (high density) or organic (low density), specific surface area of the airgel obtained are very small, thus losing the excellent large specific surface area airgel wherein; the second is whether the connection between the structural unit nanoscale physical or chemical bonding effect, as the structural unit size becomes larger, the proportion of the total number of atoms at a drastically reduced atom thus assembled airgel as the material of the structural unit will grow in size rapidly becomes brittle. In response to these challenges, researchers Suzhou Nanotechnology and Nano-bionics Institute of Zhang with the leadership team and the airgel professor, University of London and University of Science and Technology of China Song Wenhui, Professor Yan Lifeng and other cooperation to achieve an average diameter of 220 nm conductive polymer ( polyaniline, polypyrrole copolymers) hollow spheres as a precursor to graphene oxide as crosslinking agent, has a sol – gel process critical step, supercritical fluid extraction, high temperature heat treatment process or the like (FIG. 1), was successfully obtained a novel all-carbon airgel, i.e. graphene crosslinked carbon airgel hollow spheres (FIG. 2). Graphene crosslinking agent is present, the point between the ball and the ball contact point in contact across cleverly converted, thus improving the mechanical properties of the final airgel; using hollow spheres, and hollow spheres submicron in shell create a large number of pores, to ensure that the final airgel obtained with a large specific surface area; Conductive polymer precursor is selected such that the final all-carbon airgel achieved element doped with nitrogen. Graphene crosslinked carbon hollow spheres having a low density aerogels obtained study (51-67mg / cm3), high conductivity ((263-695S / m), high specific surface area (569-609m2 / g), high Young \’s modulus (1.8MPa) and many other advantages, expected energy (capture, storage, conversion), sensors, catalysis, adsorption, separation, field of functional composite materials have been widely used. For example, the hollow carbon graphene crosslinked ball airgel material is applied as an electrode in the thermoelectric output U- pool chemical, the battery up to 1.05 W · m-2 (6.4 W · Kg-1), the energy conversion efficiency is relatively high as 1.4% of the Carnot cycle, these Numerical values far higher than the same type of device. this work provides a good idea for the design of large particles assembled into airgel, solves the problem of preparing a submicron functional structural units airgel techniques. correlation results published in nano Energy.. – on (2017, 39, 470 477) co-first authors of the Chinese Academy of sciences Suzhou Institute of nano master\’s thesis for students Dongtai Peng and breaks in the work of the national Natural Science Foundation of China (51572285,21373024), Science and Technology (2016YFA0203301 .) and the financial support of nano CAS carbon airgel hollow spheres routing FIG. 1 is a schematic view of the graphene crosslinked hollow spheres carbon aerogels FIG 2 graphene crosslinking: (a) the airgel petals; a scanning electron micrograph (b) airgel; (c) a transmission electron micrograph of the airgel; (d) the nitrogen adsorption-desorption curve airgel.