To progress from the laboratory to commercial applications, it will be necessary to develop industrially scalable methods to produce large quantities of defect-free graphene. Here we show that high-shear mixing of graphite in suitable stabilizing liquids results in large-scale exfoliation to give dispersions of graphene nanosheets. X-ray photoelectron spectroscopy and Raman spectroscopy show the exfoliated flakes to be unoxidized and free of basal-plane defects. We have developed a simple model that shows exfoliation to occur once the local shear rate exceeds 10(4) s(-1). By fully characterizing the scaling behaviour of the graphene production rate, we show that exfoliation can be achieved in liquid volumes from hundreds of millilitres up to hundreds of litres and beyond. The graphene produced by this method performs well in applications from composites to conductive coatings. This method can be applied to exfoliate BN, MoS2 and a range of other layered crystals.

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Scalable production of large quantities of defect-free few-layer graphene by shear exfoliation in liquids

During the last decade, biodegradable metallic stents have been developed and investigated as alternatives for the currently-used permanent cardiovascular stents. Degradable metallic materials could potentially replace corrosion-resistant metals currently used for stent application as it has been shown that the role of stenting is temporary and limited to a period of 6–12 months after implantation during which arterial remodeling and healing occur. Although corrosion is generally considered as a failure in metallurgy, the corrodibility of certain metals can be an advantage for their application as degradable implants. The candidate materials for such application should have mechanical properties ideally close to those of 316L stainless steel which is the gold standard material for stent application in order to provide mechanical support to diseased arteries. Non-toxicity of the metal itself and its degradation products is another requirement as the material is absorbed by blood and cells. Based on the mentioned requirements, iron-based and magnesium-based alloys have been the investigated candidates for biodegradable stents. This article reviews the recent developments in the design and evaluation of metallic materials for biodegradable stents. It also introduces the new metallurgical processes which could be applied for the production of metallic biodegradable stents and their effect on the properties of the produced metals.

https://www.mdpi.com/1422-0067/12/7/4250/pdf

Biodegradable Metals for Cardiovascular Stent Application: Interests and New Opportunities

Materials with controllable stiffness are of great interest to many fields, including medicine and robotics. In this paper we develop a new type of variable stiffness material based on the combination of a rigid low-melting-point-alloy (LMPA) microstructure embedded in soft poly(dimethylsiloxane) (PDMS). This material can transition between rigid and soft states by controlling the phase of the LMPA through efficient, direct Joule-heating of the LMPA microstructure. The devices tested demonstrate a relative stiffness change of >25× (elastic modulus is 40 MPa when LMPA is solid and 1.5 MPa when LMPA is liquid) and a fast transition from rigid to soft states (<1 s) at low power (<500 mW). Additionally, the material possesses inherent state (soft and rigid) and strain sensing (GF = 0.8) based on resistance changes.

/pdf/variable-stiffness-material-based-on-rigid-low-melting-point-3627trtk1m.pdf

Variable stiffness material based on rigid low-melting-point-alloy microstructures embedded in soft poly(dimethylsiloxane) (PDMS)

source allows for production of nano-silicon at the industry level with excellent electrochemicalperformance as an anode material for Li-ion batteries. The addition of NaCl, as an effective heat scavengerfor the highly exothermic magnesium reduction process, promotes the formation of an interconnected 3Dnetwork of nano-silicon with a thickness of 8-10 nm. Carbon coated nano-silicon electrodes achieveremarkable electrochemical performance with a capacity of 1024 mAhg

Scalable Synthesis of Nano-Silicon from Beach Sand for Long Cycle Life Li-ion

Here we review the characteristics of “van der Waals epitaxy” (vdWE) as an alternative epitaxy mechanism that has been demonstrated as a viable method for circumventing the lattice matching requirements for epitaxial growth. Particular focus is given on the application of vdWE for nonplanar nanostructures. We highlight our works on the vdWE growth of nanowire arrays, tripods, and tetrapods from various semiconductors (ZnO, ZnTe, CdS, CdSe, CdSxSe1−x, CdTe, and PbS) on muscovite mica substrates, irrespective of the ensuing lattice mismatch. We then address the controllability of the synthesis and the growth mechanism of ZnO nanowires from catalyst-free vdWE in vapor transport growth. As exemplified herein with optical characterizations of ZnO and CdSe nanowires, we show that samples from vdWE may possess properties that are as excellent as those from conventional epitaxy. With our works, we aim to advocate vdWE as a prospective universal growth strategy for nonplanar epitaxial nanostructures.

Recent developments and future directions in the growth of nanostructures by van der Waals epitaxy

Handbook of Industrial Mixing: Science and Practice

Foundations Of Materials Science And Engineering is writen by William Smith in English language. Release on 2009-04-09, this book has 1056 page count that contain essential information with easy reading experience. The book was publish by McGraw-Hill Science/Engineering/Math, it is one of best engineering & transportation book genre that gave you everything love about reading. You can find Foundations Of Materials Science And Engineering book with ISBN 0073529249.

Joan Schweikart

Papers

Handbook of Industrial Mixing: Science and Practice

An Introduction to Materials Engineering and Science for Chemical and Materials Engineers

Variable Speed Drives: Principles and Applications for Energy Cost Savings