Human tissue is structured mainly of self-assembled polymers (proteins) and ceramics (bone minerals), with metals present as trace elements with molecular scale functions. However, metals and their alloys have played a predominant role as structural biomaterials in reconstructive surgery, especially orthopedics, with more recent uses in non-osseous tissues, such as blood vessels. With the successful routine use of a large variety of metal implants clinically, issues associated with long-term maintenance of implant integrity have also emerged. This review focuses on metallic implant biomaterials, identifying and discussing critical issues in their clinical applications, including the systemic toxicity of released metal ions due to corrosion, fatigue failure of structural components due to repeated loading, and wearing of joint replacements due to movement. This is followed by detailed reviews on specific metallic biomaterials made from stainless steels, alloys of cobalt, titanium and magnesium, as well as shape memory alloys of nickel–titanium, silver, tantalum and zirconium. For each, the properties that affect biocompatibility and mechanical integrity (especially corrosion fatigue) are discussed in detail. Finally, the most critical challenges for metallic implant biomaterials are summarized, with emphasis on the most promising approaches and strategies.

Metallic implant biomaterials

http://smartsys.eng.utoledo.edu/publications/Manufacturing%20and%20processing%20of%20NiTi%20implants%20A%20review.pdf

Manufacturing and processing of NiTi implants: A review

Ti-based alloys are finding ever-increasing applications in biomaterials due to their excellent mechanical, physical and biological performance. Nowdays, low modulus β-type Ti-based alloys are still being developed. Meanwhile, porous Ti-based alloys are being developed as an alternative orthopedic implant material, as they can provide good biological fixation through bone tissue ingrowth into the porous network. This paper focuses on recent developments of biomedical Ti-based alloys. It can be divided into four main sections. The first section focuses on the fundamental requirements titanium biomaterial should fulfill and its market and application prospects. This section is followed by discussing basic phases, alloying elements and mechanical properties of low modulus β-type Ti-based alloys. Thermal treatment, grain size, texture and properties in Ti-based alloys and their limitations are dicussed in the third section. Finally, the fourth section reviews the influence of microstructural configurations on mechanical properties of porous Ti-based alloys and all known methods for fabricating porous Ti-based alloys. This section also reviews prospects and challenges of porous Ti-based alloys, emphasizing their current status, future opportunities and obstacles for expanded applications. Overall, efforts have been made to reveal the latest scenario of bulk and porous Ti-based materials for biomedical applications.

/pdf/new-developments-of-ti-based-alloys-for-biomedical-1vs3nsqg8x.pdf

New Developments of Ti-Based Alloys for Biomedical Applications

Renewable energy technology has been considered as a "MUST" option to lower the use of fossil fuels for industry and daily life. Designing critical and sophisticated materials is of great importance in order to realize high-performance energy technology. Typically, efficient synthesis and soft surface modification of nanomaterials are important for energy technology. Therefore, there are increasing demands on the rational design of efficient electrocatalysts or electrode materials, which are the key for scalable and practical electrochemical energy devices. Nevertheless, the development of versatile and cheap strategies is one of the main challenges to achieve the aforementioned goals. Accordingly, plasma technology has recently appeared as an extremely promising alternative for the synthesis and surface modification of nanomaterials for electrochemical devices. Here, the recent progress on the development of nonthermal plasma technology is highlighted for the synthesis and surface modification of advanced electrode materials for renewable energy technology including electrocatalysts for fuel cells, water splitting, metal-air batteries, and electrode materials for batteries and supercapacitors, etc.

Plasma-Assisted Synthesis and Surface Modification of Electrode Materials for Renewable Energy

Shape-Memory Materials

To obtain highly reversible conversion reactions, high Coulombic efficiencies, and long lifetimes in SnO2-based anodes for lithium storage, a new ternary SnO2–Mn–graphite composite has been constructed by scalable ball-milling. It is demonstrated that nanosized Mn additives successfully inhibit Sn coarsening, and favor the formation of oxygen vacancies in SnO2, which together promote the high reversibility of conversion reactions in lithiated SnO2. The SnO2–Mn binary hybrid with 30 wt% Mn contributes a stable long-life with a capacity retention of 100% after 900 cycles at 1 A g−1. The ternary SnO2–Mn–graphite composite demonstrates high average initial Coulombic efficiencies of ∼77%, large stable capacities of 850 mA h g−1 at 0.2 A g−1, and long lifetimes of more than 1000 cycles at both high rates (2 A g−1) and narrow potential ranges (0.01–2.4 V), with Coulombic efficiencies of 99.7%, which are among the best reported so far for SnO2-based anode materials. The simple material design strategy and fabrication method, together with the excellent electrochemical performances, demonstrate that this new ternary SnO2–Mn–graphite composite could contribute a new class of Sn-based anode materials for high capacity battery applications.

Inhibiting grain coarsening and inducing oxygen vacancies: the roles of Mn in achieving a highly reversible conversion reaction and a long life SnO2–Mn–graphite ternary anode

Porous NiTi shape memory alloy (SMA) has been successfully prepared by hot isostatic pressing (HIP) of elemental Ni and Ti powder. The alloy has isotropic and uniform pore distribution of spherical pores ranged from 50 to 200 μm. The microstructure, martensitic transformation behavior and mechanical properties of this porous NiTi SMA aged at different conditions were studied. It has been found that the phase transformation behavior of porous NiTi SMA is similar to that of the dense Ni-rich NiTi alloys. The porous NiTi SMAs can exhibit almost complete superelasticity at human body temperature.

Microstructure and martensitic transformation behavior of porous NiTi shape memory alloy prepared by hot isostatic pressing processing

Unveiling critical size of coarsened Sn nanograins for achieving high round-trip efficiency of reversible conversion reaction in lithiated SnO2 nanocrystals

A stable and high-capacity anode for lithium-ion battery: Fe2O3 wrapped by few layered graphene

MXenes have attracted great interest in various fields, and pillared MXenes open a new path with larger interlayer spacing. However, the further study of pillared MXenes is blocked at multilayered state due to serious restacking phenomenon of few-layered MXene nanosheets. In this work, for the first time, we designed a facile NH4+ method to fundamentally solve the restacking issues of MXene nanosheets and succeeded in achieving pillared few-layered MXene. Sn nanocomplex pillared few-layered Ti3C2Tx (STCT) composites were synthesized by introducing atomic Sn nanocomplex into interlayer of pillared few-layered Ti3C2Tx MXenes via pillaring technique. The MXene matrix can inhibit Sn nanocomplex particles agglomeration and serve as conductive network. Meanwhile, the Sn nanocomplex particles can further open the interlayer spacing of Ti3C2Tx during lithiation/delithiation processes and therefore generate extra capacity. Benefiting from the “pillar effect,” the STCT composites can maintain 1016 mAh g−1 after 1200 cycles at 2000 mA g−1 and deliver a stable capacity of 680 mAh g−1 at 5 A g−1, showing one of the best performances among MXene-based composites. This work will provide a new way for the development of pillared MXenes and their energy storage due to significant breakthrough from multilayered state to few-layered one.

/pdf/partial-atomic-tin-nanocomplex-pillared-few-layered-ti3c2tx-5382p024rj.pdf

Bin Yuan

Papers

Inhibiting grain coarsening and inducing oxygen vacancies: the roles of Mn in achieving a highly reversible conversion reaction and a long life SnO2–Mn–graphite ternary anode

Microstructure and martensitic transformation behavior of porous NiTi shape memory alloy prepared by hot isostatic pressing processing

Unveiling critical size of coarsened Sn nanograins for achieving high round-trip efficiency of reversible conversion reaction in lithiated SnO2 nanocrystals

A stable and high-capacity anode for lithium-ion battery: Fe2O3 wrapped by few layered graphene

Partial Atomic Tin Nanocomplex Pillared Few-Layered Ti3C2Tx MXenes for Superior Lithium-Ion Storage.