Über die Darstellung arsenfreier Chemikalien

Arsenic contamination of coarse‐grained and nanostructured nitinol surfaces induced by chemical treatment in hydrofluoric acid

“…8 Severe plastic deformation (SPD) allows to develop nanostructured nitinol and to enhance mechanical and shape memory properties of the alloy. 9 Two important requirements should be realized for a good biocompatibility of NiTi alloy: (i) There should be a thick oxide surface layer to insure corrosion resistance and to reduce the risk of nickel release and subsequent interaction of toxic Ni with the human body, and (ii) there should be a rough nitinol surface at the bone/implant interface to enhance the rate of osseointegration and biomechanical fixation promoted by strong adhesion between bone tissue and the implant. The roughness of the nitinol surface can be increased by chemical treatment, for instance in HF solution.…”

“…10 However, the acid treatment might reduce the thickness of the oxide layer and increase the nickel release within the human body and should therefore be controlled by surface studies of nitinol. Additionally, it is a long-standing problem to synthesize arsenic-free chemicals, 9 which applies in particular to the preparation of hydrofluoric acid. 11 Therefore, we have performed detailed X-ray photoelectron spectroscopy (XPS) measurements, studying core levels of untreated and chemically treated coarse-grained and nanostructured nitinol, giving special care to surface concentrations of Ni and As.…”

Microdetermination of Arsenic

“…At this concentration, ordinary c. p. zinc dissolves rapidly, but there is a fairly long lag before the reaction becomes visually perceptible. To avoid this period, various methods of sensitizing the zinc have been used (2, 14, IS,22,44,46,47,53,55). Immersion in 0.5 per cent copper sulfate solution, in 1 to 3 hydrochloric acid containing 0.5 per cent of stannous chloride, and in 1 to 3 hydrochloric acid was tried in this laboratory.…”