Graphite carbon foam films prepared from porous polyimide with in situ formed catalytic nickel particles

Abstract

This article describes the preparation of porous polyimide composites and carbon foam films with uniform and controllable porous structures, using nickel oleate as a pore-forming agent and as a precursor for catalyst formation for the carbonization process. Pore formation occurs by a phase separation initially producing a dispersion of nickel oleate liquid in the polyamide acid film. Subsequent heat treatment induces decomposition of the nickel oleate accompanied by the evolution of foam forming gas. Small nickel particles, formed by the decomposition of nickel oleate, melt as the process temperature rises above 1200 C and these molten nickel particles then play an important catalytic role in promoting the graphitization of the polyimide composites as part of a dynamic process forming pores proceeding through the thickness of the film. These porous structures are maintained after the removal of the nickel by pyrolysis. The thermal behavior and structure of the porous polyimide films were examined and the porosity and stacking structures of the carbon foam films formed by polyimide pyrolysis were investigated. The results indicate that the pore size of the carbon foams could be controlled over a broad range by varying the nickel oleate content participating in the polymerization reaction.

Preparation and Characterization of Novel Fe2O3-Flaky Coated Carbon Fiber by Electrospinning and Hydrothermal Methods

“…The XRD pattern of the as-obtained carbonized PAN fiber is shown in Figure 2. The broad peaks centered at around 26.2 ∘ and 43.7 ∘ are attributed to the (002) and (010) planes of the graphite carbon structure (JCPDS 41-1487) [19]. The fact that 002 diffraction peaks are relatively low in intensity and broad in shape suggests that as-prepared carbon nanofibers possess low graphitization and crystallization.…”

Accelerating the graphitization process of polyimide by addition of graphene

“…Many researchers have already noted that the graphitization process of carbon could be accelerated in the presence of some additives . Noda et al studied the graphitization process of coke with calcium hydroxide as a catalyst, and they found the graphitization of coke started at a temperature as low as 800°C with the coexistence of calcium hydroxide .…”

“…This result was amazing because the coke graphitize only above 2500°C without additive under atmospheric pressure. Matsuo and Fuertes indicated that Ni was a very effective catalyst to convert carbon into graphite at low temperature . However, the residual additives are usually harmful for the further application of graphite …”

Core–shell construction of metal@carbon by mechanochemically recycling plastic wastes: towards an efficient oxygen evolution reaction

“…As indicated from the XRD results (Fig. 5e), the Ni@PMMA-450/600 catalyst existed mainly in the form of NiO, metallic Ni, and Ni 3 C. Most of the carbon atoms formed an epitaxial graphite monolayer on the (111) plane of the Ni crystallites and finally precipitated in the form of graphitic carbon (OLC) at an appropriate temperature (600–850 °C), 70,71 and some combined with Ni to generate Ni 3 C, while NiO was further oxidized to Ni 2 O 3 . As the temperature increased, the peaks attributed to Ni 3 C and Ni 2 O 3 gradually disappeared, and the diffraction peak of metallic Ni became more intense and narrow.…”