Fast and simultaneous growth of graphene,intermetallic compounds,and silicate on Cu–Ni alloy foils

A graphene bilayer was grown on copper–nickel alloy foils (30 at-% Ni: 70 at-% Cu designated as a 30Ni–70Cu) via an inductively coupled plasma–chemical vapor deposition chamber, and was characterized. The first layer fully covered the foil, while there was partial coverage of the second layer. At the same time, the alloy catalyst produced a compound of magnesium silicate in some regions and of copper sulfide in other regions on which a graphene monolayer simultaneously grew without any discontinuity or boundaries of the 1st graphene monolayer between simultaneous growth and graphene-only growth regions. Compared with Cu foils, the alloy foils led to faster growth of the graphene film in graphene-only growth regions, while maintaining the same quality, homogeneity, and thickness uniformity as a monolayer graphene grown on Cu. Raman spectroscopy and scattering demonstrated that the 2D and D bands of the Raman spectra were in the same position for the monolayer graphene on 30Ni–70Cu regardless of the grown regions and for the graphene on the Cu with a full width at half maximum of ∼38 cm⁻¹ ranging from 30 to 55 cm⁻¹ of 2D, and without a D band in the spectra of the graphene monolayer and bilayer. Thus the resulting graphene growth is affected primarily by the Cu catalyst, partly by the compounds grown simultaneously with the graphene monolayer on the foil surface via thermal reactions of the impurities dissolved in the alloy matrix, and partly by the Ni. The quality of the graphene is dependent on the major composition of Cu catalyst in the alloy foils. On the other hands, the alloying element of Ni governs the growth kinetics unless the alloy foils is covered with the intermetallic compounds and silicate.     

Effects of Polymeric Stabilizers on the Synthesis of Gold Nanoparticles

Gold nanoparticles （AuNPs） stabilized with sodium alginate （SA）, glycol chitosan （GC）, polyvinyl alcohol （PVA）, and polyethyleneimine （PEI） were synthesized in aqueous solutions at room temperature. Different sizes and size distributions of AuNPs were obtained according to the polymeric stabilizers. The mean particle diameters of AuNPs synthesized with GC and PVA as stabilizers were about 5.1 and 5.3 nm, respectively, while those of AuNPs stabilized with SA and PEI were 8.4 and 10.8 nm, respectively. When SA was used, relatively large particles aggregated to form large clusters. In the case of GC, a number of small particles built up large clusters. When PVA was used, the size and the number of nanoperticles were estimated small with a low weight content of Au. For this reason, the PVA-stabilized AuNPs formed clusters with a small hydrodynamic size. The AuNPs synthesized in the aqueous solution of PEI without a reducing agent, sodium borohydride, were uniform in size and formed the smallest nanoclusters （67.4 nm）. In this case, the highest Au content was obtained. Sufficiently grown nanoparticles with a high Au content and a limited hydrodynamic size are considered to be suitable for a variety of applications.     

Thermoplastische Hybridlaminate mit variabler Metallkomponente

Hybrid laminates combine the positive properties of the metal and fibre reinforced plastic (FRP) components. Advantages of the FRP, like formability, recyclability as well as suitability for mass production, provide an outstanding advantage over thermosetting matrices. For the production of the hybrid laminates, at first continuous fibers and thermoplastic films are pre‐consolidated to fibre‐reinforced unidirectional tapes. Subsequently, these are pressed together with the metal component in a loadcapable optimized arrangement. Thereby the interface between the FRP and the metal foils is of crucial importance. This paper focuses on hybrid laminates with carbon‐fiber reinforced polyamide (CF‐PA6) functioning as core layers and glass‐fiber reinforced polyamide (GF‐PA6) as intermediate layers between the centre and metal component. Laminates in 2/1 and 3/2 structure with two respectively three metal layers and one respectively two FRP layers are examined. For the metal foil, the aluminium alloy EN AW‐6082 and the titanium alloy Ti3Al2.5V (Grade 9) are used. The production of these laminates, development and adjustment of the interface and the evaluation of mechanical properties are investigated in this article.     

Three‐Dimensional Nanofabrication by Block Copolymer Self‐Assembly

Thin films of block copolymers are widely seen as enablers for nanoscale fabrication of semiconductor devices, membranes, and other structures, taking advantage of microphase separation to produce well‐organized nanostructures with periods of a few nm and above. However, the inherently three‐dimensional structure of block copolymer microdomains could enable them to make 3D devices and structures directly, which could lead to efficient fabrication of complex heterogeneous structures. This article reviews recent progress in developing 3D nanofabrication processes based on block copolymers.