Recently, Carbon fiber reinforced thermoplastic polymer (CFRTP) has been widely used in automotive, aviation, and aerospace. However, the traditional epoxy Carbon fiber (CF) sizing for thermosetting composites was unsuitable for high‐performance CFRTP due to the high‐molding temperatures and incompatibility between them. Herein, a novel semi‐aromatic polyamide‐imide (PAI) backbone structure with multi‐ethoxy pendant groups was designed and synthesized via click‐reaction and solvent‐free polymerization. Waterborne PAI sizing was prepared via self‐emulsifying without surfactants. CF/PEEK (polyether‐ether‐ketone) and CF/PEI (polyether‐imide) composites were manufactured. Results showed that novel PAI had excellent thermal stability and solubility, PAI sizing was stable after 6‐month‐storage. Mechanical performances and hydrothermal aging resistance of composites were improved. Compared with commercial‐sized CF (eCF)/PEI, the flexural strength of sCF/PEI increased by 35.2% to 753.47 MPa, and retention rates of them with aging also increased. Noted, mechanisms of interface enhancement were revealed by quantum chemical calculations, ππ stacking and hydrogen bonding between PAI and PEI, PEEK was found.

PrefaceSince the first theoretical prediction of a half-metallic material -one in which the electrons of one spin participate in conduction while those of the other do not -was published in 1983, much effort has been exerted to understand, predict, and grow new half-metallic materials. A main impetus for this effort has been the great potential for half-metals (HMs) in spintronics -a new generation of electronics in which the electron spin, as well as its charge, is exploited to achieve substantial reductions in size and/or improvements in performance. In an HM, the electrons of one spin channel are metallic while those of the other are insulating, the spin polarization at Fermi level is complete (100%), and the magnetic moment is an integer. Partially spin-polarized spintronic materials, such as Co/Fe layered structures, have already led to breakthroughs in information storage and processing technologies, such as magnetoresistance (MR)-based read heads, magnetic random access memory (MRAM), and spin-current switches. Because HMs exhibit very large (ideally, infinite) MRs, it is not surprising that the design and realization of HM devices have been among the hottest topics in condensed matter physics and materials science in recent years.Tremendous theoretical, experimental, and technological progress in the understanding of half-metallic materials has been achieved in the past few years, and the scientific literature has grown correspondingly. It is opportune, therefore, to summarize the main concepts, results, and advances in order to spark and facilitate new research and provide a solid and coherent foundation for new researchers in this exciting field. These are the goals we set out to achieve in the present monograph, at a level appropriate for advanced undergraduate or graduate students in physics, chemistry, and materials science.In the introductory chapter, we give an overview of the main features, similarities, and differences among the three main classes of HMs which have emerged to date. We discuss key features from both a theoretical Half-metallic Materials and Their Propertiesand technological point of view. We emphasize the three basic interactions underlying half-metallic properties in all such materials in the hope that new half-metallic materials may be realized by tuning each of the interactions independently. For device applications, it is necessary to understand both electronic and magnetic properties. Substantial progress has been achieved both experimentally and theoretically in the endeavor to understand and predict the properties of half-metallic materials. In Chapter 2, we provide a discussion of the key experimental and theoretical techniques, as appropriate for each class of material, which have been employed to date in order to achieve that understanding and predictive capability. The three main classes of half-metallic materials that have emerged to date are: (i) the Heusler alloys; (ii) transition-metal oxides; and (iii) pnictides, chalcogenides, and carbides with the zincblende (...

Crystal orientations in metals electrodeposited on a cathode rotating at 3000 rpm were stud!ed by electron diffraction ; results were compared with those on a stationary cathode. It was found that orientation could (a) be destroyed, (b) be changed to another type, or (c) remain unchanged. These observations were satisfactorily explained by considering the effect of the forced convection of rotation on the nature of the diffusion layer surrounding the cathode and, thus, on the amount of hydrogen codeposited, the latter being known as an important factor controlling the crystal orientation in electrodeposited metals. Under bath conditions used in this work, presence of a magnetic field of 5400 gauss strength, either perpendicular or parallel to the cathode, had no effect on the types of crystal orientation in iron, nickel, and cobalt deposits. However, when the field was perpendicular to the cathode, the surface of these deposits became very rough and covered with projections protruding in the direction of the field. A possible explanation of this observation was given.

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The extensive use of unsaturated polyester resins and their composites has resulted in an increasingly aggravating problem of waste materials which are difficult to remold or degrade endowed by their highly crosslinked network. A simple and facile recovery method to fully degrade resins remains challenging so far. Here, a hindered C–O bond with a carbonyl group in the β-position of steric ester was introduced into the design and preparation of a dimethacrylate monomer and its self-polymerized unsaturated polyester resin. The obtained resin with good thermal, mechanical, and solvent-resistance properties could be efficiently degraded within 3.5 h at 90 °C at an 80% concentration of aqueous hydrazine hydrate. Selective cleavage of the hindered bond due to steric and electronic effects was activated by the prior addition of the introduced carbonyl group. Degradation products rich in benzene and carboxyl/carboxylate groups respectively could be separated readily according to the water solubility, being expected to be reused as a flocculant and other functional additives. This work provides a promising strategy for the facile recycling of unsaturated polyester resins.