| 43436 |
Creator |
c3baa1aae2495d9fcf383c433b46bfe0 |
| 43436 |
Creator |
ext-512ab1438504811af917e65b264a5159 |
| 43436 |
Creator |
ext-5cea6d238fb9c308efc3621d061f6b1d |
| 43436 |
Creator |
ext-d9a22cdeeeb71dd6cad021083ea54f3b |
| 43436 |
Date |
2004-11-01 |
| 43436 |
Is Part Of |
repository |
| 43436 |
abstract |
The objective of this research was to investigate nanoscale adhesion in a number of
scientifically interesting systems. To do this, self-assembled monolayers (SAMs) of
alkanethiols and dialkyl disulfides have been formed on thermally evaporated gold
films, presenting a variety of chemically modified surfaces. Adhesion studies involving
atomic force microscopy (AFM), nanoparticles and living cells have been performed
employing the SAMs.
<br></br><br></br>
The wetting behaviour, elemental composition, thickness and surface topography of
the SAMs were assessed. Only one of the SAM compounds was found to have not formed
a SAM successfully. The compound contained a terminal quaternary pyridinium moiety,
and it is believed the SAM formation was unsuccessful due to interaction between the
iodide counterion and the gold surface.
<br></br><br></br>
The contact angle titration behaviour of the SAMs was investigated over the pH range
3-9, employing aqueous buffer solutions at high and low electrolyte concentrations.
It was found that both pH and electrolyte concentration had little or no effect on
the contact angle titration behaviour of the SAMs.
<br></br><br></br>
The effect of pH on the adhesion of poly(styrene) nanoparticles presenting a range
COOH and NH<sub>2</sub> surface chemistries was studied, using SAMs presenting CH<sub>3</sub>,
COOH, OH, and pyridine moieties. Adhesion was generally found to decrease with increasing
pH due to increased repulsive forces between surfaces. A range of surface morphologies
for the adsorbed nanoparticles was observed.
<br></br><br></br>
AFM adhesion measurements were performed in aqueous electrolyte solutions over the
pH range 3-9, employing aqueous buffer solutions at high and low electrolyte concentrations.
Adhesion was found to vary with both pH and electrolyte concentration, with the wetting
behaviour of the surfaces, surface charge and contact area between surfaces affecting
the measured forces.
<br></br><br></br>
Finally, the settlement and adhesion of zoospores of the green alga <i>Ulva linza</i>
and the diatom <i>Navicula perminuta</i> to eight of the SAMs, with SAM surface chemistry
and SAM alkyl chain length the system variables. Adhesion was influenced by the surface
chemistry and wetting behaviour of the SAMs. The adhesion of both organisms to methyl-terminated
SAMs was found to decrease with increasing SAM alkyl chain length, which was attributed
to changes in the phase state and tribology of the SAMs. The adhesion of <i>Navicula
perminuta</i> to SAMs was also affected by the surface chemistry of the SAM. |
| 43436 |
authorList |
authors |
| 43436 |
presentedAt |
ext-4b2564fcc605926b957e19f2289c5a33 |
| 43436 |
status |
nonPeerReviewed |
| 43436 |
type |
AcademicArticle |
| 43436 |
type |
Article |
| 43436 |
label |
Bowen, James ; Manickam, Mayandithevar; Kendall, Kevin and Preece, Jon A. (2004).
BioNanoAdhesion. In: ACORN Annual Event, 1-2 Nov 2004, Manchester, UK. |
| 43436 |
label |
Bowen, James ; Manickam, Mayandithevar; Kendall, Kevin and Preece, Jon A. (2004).
BioNanoAdhesion. In: ACORN Annual Event, 1-2 Nov 2004, Manchester, UK. |
| 43436 |
Title |
BioNanoAdhesion |
| 43436 |
in dataset |
oro |