Colloids and Surfaces A: Physicochem. Eng. Aspects 500 (2016) 203–213
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Colloids and Surfaces A: Physicochemical and
Engineering Aspects
journa l h om epage: www.elsevier.com/locate/colsurfa
Development of in situ soft colloidal probe atomic force microscopy
for probing the adhesion between wood extractives and model
surfaces
Yuen Yue Tham
a
, Karen R. Stack
a
, Desmond E. Richardson
b
, Paul J. Molino
c
,
Michael J. Higgins
c
, Trevor W. Lewis
a,∗
a
University of Tasmania, School of Physical Sciences (Chem), Hobart, Tas 7001, Australia
b
Norske Skog Paper Mills Australia Ltd, Boyer, Tas 7140, Australia
c
University of Wollongong, ARC Centre of Excellence Electromaterials Science, Intelligent Polymer Research Institute, AIIM Facility, Wollongong, NSW,
Australia
h i g h l i g h t s
•
A new method developed to attach
soft colloid onto tipless AFM can-
tilever.
•
Adhesion forces of abietic acid and
wood extractives (WE) are lowest on
cellulose.
•
On chromium, adhesion forces are
highest for abietic acid (AA) and WE.
•
Adhesion forces of AA and WE on
cellulose and chromium are compa-
rable.
•
AA, instead of TrO and OA, prefer-
entially transfers from cellulose to
chromium.
g r a p h i c a l a b s t r a c t
a r t i c l e i n f o
Article history:
Received 29 January 2016
Received in revised form 4 April 2016
Accepted 8 April 2016
Available online 13 April 2016
Keywords:
Wood extractives
Model compound
Colloidal probe atomic force microscopy
Force measurement
Cellulose
Chromium
a b s t r a c t
A new method to attach colloidal particles in situ directly onto atomic force microscopy (AFM)
cantilevers was developed and used as colloidal probes. In this method, cantilever surfaces were
hydrophobically functionalised and the colloids adhered without glue in an aqueous environment.
Experiments measuring the interaction forces between colloidal probes, composed of either wood
extractives or a range of model compounds normally present in wood extractives, and glass, cel-
lulose, and chromium surfaces were carried out. Wood extractive colloids exhibited the strongest
adhesion to glass control surface (7.0 mN m
−1
), followed in decreasing order by triolein, abietic acid
and oleic acid colloids (3.9 mN m
−1
, 2.2 mN m
−1
and 1.2 mN m
−1
respectively). Adhesion onto a cellulose
surface was strongest for triolein colloids (8.1 mN m
−1
) followed by oleic acid colloids (6.1 mN m
−1
),
while adhesion forces for abietic acid and wood extractives colloids were similar (4.9 mN m
−1
and
4.3 mN m
−1
, respectively). When attached to a chromium surface adhesion forces of abietic acid and
wood extractives were strongest and similar (3.6 mN m
−1
and 3.9 mN m
−1
, respectively); the weakest
interaction at this surface was recorded for oleic acid colloids (0.8 mN m
−1
). Similar adhesion forces
Abbreviations: AA, abietic acid; AFM, atomic force microscopy; NaCl, sodium chloride; OA, oleic acid; PEI, poly(ethylene)imine; TrO, triolein; WE, wood extractives.
∗
Corresponding author.
E-mail address: Trevor.Lewis@utas.edu.au (T.W. Lewis).
http://dx.doi.org/10.1016/j.colsurfa.2016.04.023
0927-7757/© 2016 Elsevier B.V. All rights reserved.