4th EucheMs chemistry congress

Poster Session 2
s1251
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - Nanochemistry, Nanotechnology
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MetAL oxide nAno-SheetS with (111) SurfACeS
AS CAtALyStS And CAtALySt SuPPortS
r. riChArdS 1
1 Colorado School of Mines, Chemistry and Geochemistry,
Golden, USA
The interface of the fields of catalysis and nanoscale
materials is one of the most exciting areas of modern science and
is at the forefront of the quest for a “green” and sustainable future.
Recent progress on new methods to control the size, shape and
composition of nanoscale materials and their application in
renewable energy technologies are particularly intriguing.
Recently, the Richards’ research group has developed techniques
to produce a number of new nanoscale materials that have
demonstrated unique physical and chemical properties through
controlled facetting. Here, recent highlights regarding these
materials and their applications will be presented with a particular
focus towards nanostructured metal oxides. MgO and NiO have
a typical rocksalt structure and although the stoichiometry and
crystallinity change little, the morphology can vary in shape,
particle size and surface structure. The (100) facet of the rocksalt
structure is unambiguously the most stable due to its low surface
energy, therefore, it is unaminously the surface demonstrated by
current wet chemical preparations. Numerous studies have
demonstrated that the shape and size of crystalline MgO and NiO
are highly influential on the adsorption properties. Furthermore,
nanoscale MgO has been reported to be extremely effective for
the destructive adsorption of numerous environmental toxins and
several chemical warfare agents (VX, sarin, mustard gas).
However, the (111) surface consists of alternating polar
monolayers and thus, a strong electrostatic field perpendicular to
the (111) surface is created. Such a surface has provided a
prototype for the study of surface structure and surface reactions,
which drew great attention for both experimental and theoretical
studies. These studies imply the importance of size and shape
control in metal oxide synthesis for their applications.
Keywords: green chemistry; nanostructures; Heterogeneous
catalysis; Supported catalysts;
4 th EucheMs chemistry congress
P - 0 7 7 8
An effiCient And oPtiMized
AMinoSiLAnizAtion of ti6AL4v ALLoy for
BioMediCAL deviCeS
A. rodríGuez-CAno 1 , M. C. fernández-CALderón 2 ,
M. A. PAChA-oLivenzA 3 , r. BABiAno 4 , P. CintAS 4 ,
M. L. GonzáLez-MArtín 3
1 Universidad de Extremadura. Centro de Investigación
Biomédica en Red en Bioingeniería Biomateriales y
Biomedicina (CIBER-BBN), Química Orgánica e Inorgánica,
Badajoz, Spain
2 Universidad de Extremadura. Centro de Investigación
Biomédica en Red en Bioingeniería Biomateriales y
Biomedicina (CIBER-BBN), Ciencias Biomédicas, Badajoz,
Spain
3 Universidad de Extremadura. Centro de Investigación
Biomédica en Red en Bioingeniería Biomateriales y
Biomedicina (CIBER-BBN), Física Aplicada, Badajoz, Spain
4 Universidad de Extremadura, Química Orgánica e Inorgánica,
Badajoz, Spain
Titanium and titanium alloys are widely employed in biomedical
implants due to their chemical inertia and biocompatibility. [1] The latter
is generally improved by forming thin films of bioactive small molecules
on the metal surface, thus preventing bacterial adhesion which
represents a major concern. A common chemical functionalization of
such alloys involves silanization with organosilanes such as
(3-aminopropyl)triethoxysilane (APTES), thereby resulting in an
aminated surface. Unfortunately, the amount of amino groups
deposited and therefore available to further modification is not
routinely evaluated. Moreover, there is confusion as to which reaction
conditions will produce a stable and densely aminated film. [2]
In this communication we report an efficient and
reproducible methodology for coating Ti6Al4V alloy with
(3-aminopropyl)trimethoxysilane (APTMS). The influence of
reaction time, water concentration, reaction temperature, and
cross-linking conditions on surface coverage was studied.
Ninhydrin assays were systematically employed to assess the
density of amino groups. XPS, FTIR-ATR, and SEM analyses
helped us to determine changes in both surface composition and
roughness.
In addition, bacterial adhesion and biofilm formation of
Staphylococcus ATCC35983 and S. epidermidis ATCC35984
were also evaluated on both silanized disks according to the
above-mentioned protocol and those exposed subsequently to
degradation with PBS. Adhesion and biofilm formation decreased
with respect to oxidized control disks.
Acknowledgments. This work was supported by grants from the
Ministry of Science and Innovation (MAT2009-14695-C04-01,
MAT2009-14695-C04-03 and CTQ2010-18938), Gobierno de
Extremadura (Ayudas a Grupos Consolidados: GR10049 and
GR10149) and FEDER (Fondo Europeo de Desarrollo
Regional, Una Manera de Hacer Europa). One of us (ARC)
thanks the Ministry for a scholarship (BES-2010-033417).
references:
1. Geetha M, Singh AK, Asokamani R, Gogia AK.
Prog Mater Sci 2009, 54, 397-425.
2. Kingshott P, Andersson G, McArthur SL, Grieser HJ.
Curr Op Chem Biol 2011, 15, 667-676.
Keywords: titanium; alloys; material science; self-assembly;
biological activity;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc