Preparation Of Biomorphic Porous Carbon And Functionalized Modification Of Its Cell Wall

Wood is a natural composite material overbearing millions of year's genetic evolution and natural selection. It shows an anisotropic, open-cellulose morphology with excellent strength at low density, high stiffness, elasticity, and tolerance to damage on the micro- to macro scale. Wood can be in-situ or after-carbonized used as matrix to turn into mechanical or functional inorganic materials. In this paper, a variety of wood are controlled carbonized under argon atmosphere to turn to a biomorphic porous carbon (BPC), then modificate its cell wall with SiC layer and ZnO Particles. A series of methods are adapted to characterize the obtained materials and investigate the property. Also, a pilot study of the mechanism of the procedure is proposed.Systematically investigation of four kind of typical native wood, pine, aspen, basswood, and bamboo on microstructure, density and porosity in different carbonization temperature is carried out. Pine wood is selected as a focus to study the pyrolysis and carbonize procedure using FTIR, Raman, XPS, XRD technologies. TG-DTG is exploited here to study the anti-oxidation property of pine char. The result shows that the microstructure and pore distribution vary with different wood; porosity of the char raises and the corresponding density drop with the increase of carbonize temperature. The material exhibit various surface and internal atomic arrangement and chemical state with different carbonize temperature. The oxidation process of pine char starts at 396.8oC, which reaches a peak with 37.7% residual mass and ends at 587.7oC; the process shows a"self-acceleration"characterization.Precursor Infiltration and Pyrolysis Technology (PIP) is utilized here to turn polycabosilane (PCS) into SiC on BPC, fabricating pore size controllable SiC/BPC composite material. SEM equipped with EDS is used to exam the interface of C/SiC and the changes of morphology of the sample with increasing of PIP cycle. XRD, BET method, mechanical test is carried out to characterize the phase compound, the apparent surface area change and mechanical property of the sample. TG-DTG is exploited to study the anti-oxidation property and mechanism of the composite. The result exhibits that amorphous state SiC coated on BPC bonded well on the carbon surface with a gradient change in C and Si element; The pores evaluate from rectangular to ellipse and finally circle with PIP cycles; the mechanical properties strengthen first with the PIP cycle and then surrender; a maximμm axial compress strength of 56.7Mpa occurred in 5 cycles, while 17.0Mpa of radical in 6 cycles; with the increasing of cycles, the specific area decreases; SiC coating on BPC can raise the oxidation temperature by 150oC.A pilot study on the surface modification of"plant"micro-nano ZnO structure is developed. To effectively plant ZnO, three kind of surface treatment is rendered, which are spraying of Au particle, coating of TEOS thin film and Seeding [Zn]2+ crystal. The effect of reaction time on the size of ZnO crystal in solution, concentration of solution on the morphology of ZnO on BPC and surface treatment method on the morphology of ZnO are studied. The result shows that growth time have little effect on the size of ZnO crystal; while concentration of the reaction solution is a key factor; Au particles can not act as catalyst and lead an epitaxial growth of ZnO, while TEOS film can improve the surface group which better for ZnO nucleation and growth; radial ZnO crystal cluster and be grown on seeded BPC surface, which provide a feasible way of preparation of ZnO functionalized bio-porous carbon and supply sample for property test.