ZIB

Hits per page

hits 1 - 2 | 2 hits

Sorting

Electronic Resource

Gold uptake by Chlorella vulgaris (1995)

Ting, Y. P. ; Teo, W. K. ; Soh, C. Y.

Springer

Journal of applied phycology 7 (1995), S. 97-100

add to mindlist on the mindlist

Details

ISSN: 1573-5176

Keywords: gold ; Chlorella vulgaris ; physical/chemical treatment ; carboxyl ; FTIR ; XPS ; X-ray photoelectron spectroscopy

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract This paper describes a study on the uptake of gold (III) ions by viable and treated cells of the unicellular alga, Chlorella vulgaris. Inactivating the algal cells by various physical/chemical treatments resulted in a considerable enhancement in the uptake capacity over the pristine cells. X-ray Photoelectron Spectroscopy (XPS) analyses confirmed the deposition of elemental gold, Au (O), on the cell surface, indicating that a reduction process has taken place. XPS results also suggested an increase in the oxidized carbon species, carboxyl species in particular, on the surfaces of the treated cells. FTIR spectroscopy results revealed that the carboxyl group was involved mainly in the binding of the gold on the surface of both the viable and treated cells.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00003557

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Recovery of gold by electroless precipitation from acid solutions using polyaniline (1994)

Ting, Y. P. ; Neoh, K. G. ; Kang, E. T. ; [et al.]

Chichester : Wiley-Blackwell

Journal of Chemical Technology AND Biotechnology 59 (1994), S. 31-36

add to mindlist on the mindlist

Details

ISSN: 0268-2575

Keywords: polyaniline ; Au reduction ; acid solution ; redox states ; XPS ; Chemistry ; Biochemistry and Biotechnology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Process Engineering, Biotechnology, Nutrition Technology

Notes: The oxidation of the leucoemeraldine (LM) and emeraldine (EM) states of polyaniline (PAN) and the subsequent reprotonation and reduction of the nigraniline (NA) and pernigraniline (PNA) in acid gold solution were utilized for the spontaneous and sustained reduction of gold. The rate of Au reduction is strongly dependent on the intrinsic oxidation state of the polymer and the polymer surface area. The rate also increases with decreasing pH of the chloroauric solution to about pH ∼ 1. X-ray photoelectron spectroscopic (XPS) results indicate that only elemental gold or Au(0) accumulates on the polymer surface. The N1s core-level spectra of the protonated and base form of EM films after Au reduction confirm that the intrinsic structure of the polymer remains intact. The process, however, is limited by the decreasing effective surface area of the polymer due to Au deposition. The results indicate that an LM film accumulated up to five times its own weight of Au (Au/monomer mole ratio 〉 2) before the recovery rate was significantly retarded.

Additional Material: 7 Ill.