Process-dependent effects of water on the chemistry of aluminum oxide and aromatic polyimide interface in composite materials

High-Energy Electron-Irradiated Fluorinated Ethylene Polypropylene Copolymer Coatings on Al Substrates for Enhanced Metal Adhesion and Protection

“…For HAXPES, θ was varied to observe changes in the chemical state at various depths from the sample surface. More information regarding the shallower regions was derived by using a lower θ. ,− According to the TPP–2M formula, , the inelastic mean free path λ was 12.6 nm for the photoelectrons with a kinetic energy of 7662 eV, corresponding to C 1s, and the bulk Al matrix (density: 2.7 g/cm 3 ). The θ values of 30 and 80° enabled analysis at maximum depths of 18.9 and 37.2 nm, respectively, which were calculated from 3λ × sin θ (95% of the signal was derived from 3λ) …”

“…Time-of-Flight Secondary Ion Mass Spectrometry. A ToF-SIMS 5 spectrometer (IONTOF GmbH, Munster, Germany) was used with the analysis chamber under ultrahigh-vacuum (UHV) conditions with a pressure of 1.0 × 10 −6 Pa. 5,6 A pulsed and bunched Bi 3 ++ primary ion beam (30 keV and 0.2 pA) was used to irradiate the samples in the spectrometry mode for analyses of the outermost surface and depth profile. The pulse widths were 9.0 and 6.0 ns, and the cycle time was 100 μs.…”

“…For decades, metal–polymer composites have played an important role in a wide range of industrial fields, including microelectronics, medical equipment, automobiles, and aerospace. − Among commercial polymers, fluorocarbon polymers (FPs) have excellent nonadhesiveness and low friction, in addition to high heat and chemical resistances. − These properties make FPs an ideal coating material for metal sliding parts in various industrial products. However, their nonadhesiveness also makes it extremely difficult for them to adhere to or combine with metals, which has prevented their wider application.…”

“…In this study, we developed a novel analytical approach to link the morphology, diffusion, and chemical interactions to the adhesion at the interface between the FP coating and metal substrate. First, a cryogenic setup was employed to reduce the electron beam damage during TEM observation. , In addition, the samples were fabricated by an improved process to model the FP–metal interface for analysis by synchrotron hard XPS (HAXPES). ,,− The fabrication process is based on that previously proposed for a Cu/PI bilayer structure, which can control the Cu film thickness to a precision of 1 nm, and has been used to laminate flexible printed circuits with Cu . We used these techniques to clarify the changes in the elemental diffusion and chemical bonding state at the interface between a fluorinated ethylene–polypropylene (FEP) coating and Al substrate due to the 1000 keV electron irradiation.…”

Enhanced toughness and gas permeabilities of polyimide composites derived from polyimide matrix and flower‐like polyimide microparticles

“…[6][7][8][9][10] According to some reported literature, there have been many kinds of particles or fillers used for PI modification, including graphene, graphene oxide, carbon nanotubes, organic covalent framework (COF) materials, metal organic framework materials, polymer, metal and oxide particles, etc. [11][12][13][14][15][16][17][18][19][20] Under the combined action of functional particles and appropriate composite methods, the properties of PIs, including mechanical, thermal, electrical, gas separation, tribological properties, and atomic oxygen resistance, have been obviously improved. [21][22][23][24][25][26][27][28][29] It is well known that the interfacial interaction between the organic matrix and the fillers directly affects the properties of the composites.…”