Third Day Poster Session, 17 June 2010 - NanoTR-VI

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Poster Session, Thursday, June 17
Theme F686 - N1123
The Creation of Hydrophobic Clay Surfaces with Long Chain Hydrocarbon
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UH. Hasan YolcuUP P*, Ahmet GürsesP P, and Metin AçkyldzP P,
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PAtaturk University, K.K. Education Faculty, Dep. of Chemistry, 25240 Erzurum
Abstract- In this study, the presence of lotus effect for the clay modified by using long chain hydrocarbon was investigated. It was
found the powder sample comparison with pellet form exhibits super hydrophobic character. This may be attributed to the changing of
roughness on the surface of modified clay particles depending on pressing and to the creating of higher energy surface with the adsorption of
long chain hydrocarbon onto interlayer region of clay.
Non wettable surfaces with high water contact angle
(WCA) and facile sliding of drops are called super
hydrophobic surface. Superhydrophobic surfaces with
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water contact angles larger than 150P received a lot
of research attention, due to important applications ranging
from self cleaning materials to microfluidic devices [1, 2].
Many surfaces in nature are highly hydrophobic and self
cleaning (e.g. lotus leaves). The design synthesis and
application of new kinds of super hydrophobic and self
cleaning organic or inorganic material will be essential and
important task to fulfill [3].
The clay sample was purified by sedimentation, dried at
vacuum oven and sieved to give a 38-85 m (>%92) size
fraction using ASTM Standard sieves. Different amounts
of hydrocarbon (0.05-1.0 g) was mixed with 500 mL
aqueous solutions of CTAB (100, 200, 240, 260, 300, and
320 mg/L). The mixture was shaken at 293 K, for 30 mins
and 1g clay sample was added to this mixture and shaken
for 30 mins in a thermostatic shaker at 200 rpm. The
modified clay samples which produced by above
procedure were filtered through filter paper of Whatman
41 and dried at 383 K in a vacuum oven for 2 h.
and water droplets leads to gaining the hydrophobic
character of samples. But the powder organoclay has
superhydrophobic character, probably due to lotus effect.
The variation of initial CTAB concentration doesn’t
significantly affect the contact angles of the pellet and
powder samples (Figure 2).
Figure 2. Effect of initial CTAB concentration on the contact
angle
Intensity (counts)
2000
1600
1200
800
Raw clay
*Corresponding author: HThasanyolcu@atauni.edu.trT
[1] M. Ma and R. M. Hill. Curr. Opin. Colloid Interface Sci. 11,
193-202 (2006).
[2] A. Tuteja, et al. Science. 318, 1618 -1622 (2007).
[3] X , Feng and L, Jiang,. Adv. Mater. 18, 3063-3078 (2006).
[4] H.Y. Erbil et al, Science. 299, 1377 (2003).
400
0
2 12 22 32
2Theta (deg)
Figure 1. X-ray diffraction spectrums for raw clay and produced
organo-clay
The XRD patterns shows the intensities of peaks for the
organo-clay sample were significantly decreased with
compared the raw clay. This attributed to the presence of
exfoliated clay layers. It can be said that the basal spacing
increases, depending on ion-exchange occurred between
+
CTAP bounded hydrocarbon and the cations in the
interlayer region of clay (Figure 1).
In this work, the contact angles for the powder
organoclay sample and pellet form were compared. It was
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found that powder samples have 146P angle
indicating the presence of lotus effect. On the other hand,
the surface roughness of modified clay particles changes
depending on pressing and the contact angle values
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measured on the pellet reduce to about 90 P P. This shows
that the effect of surface roughness on the hydrophobic
character is predominant comparison with surface energy.
Water droplets cannot penetrate into the pores of the
hydrophobic surfaces due to the trapped air [4]. In the both
forms, the reducing of contact areas between the surface
6th Nanoscience and Nanotechnology Conference, zmir, 2010 735