Photonic crystals in biology - NanoTR-VI

P ionsPP haveP contactPoster Session, Thursday, June 17Theme F686 - N1123The Creation of Hydrophobic Clay Surfaces with Long Chain Hydrocarbon111UH. Hasan YolcuUP P*, Ahmet GürsesP P, and Metin AçkyldzP P,1PAtaturk University, K.K. Education Faculty, Dep. of Chemistry, 25240 ErzurumAbstract- In this study, the presence of lotus effect for the clay modified by using long chain hydrocarbon was investigated. It wasfound the powder sample comparison with pellet form exhibits super hydrophobic character. This may be attributed to the changing ofroughness on the surface of modified clay particles depending on pressing and to the creating of higher energy surface with the adsorption oflong chain hydrocarbon onto interlayer region of clay.Non wettable surfaces with high water contact angle(WCA) and facile sliding of drops are called superhydrophobic surface. Superhydrophobic surfaces with0water contact angles larger than 150P received a lotof research attention, due to important applications rangingfrom self cleaning materials to microfluidic devices [1, 2].Many surfaces in nature are highly hydrophobic and selfcleaning (e.g. lotus leaves). The design synthesis andapplication of new kinds of super hydrophobic and selfcleaning organic or inorganic material will be essential andimportant task to fulfill [3].The clay sample was purified by sedimentation, dried atvacuum oven and sieved to give a 38-85 m (>%92) sizefraction using ASTM Standard sieves. Different amountsof hydrocarbon (0.05-1.0 g) was mixed with 500 mLaqueous solutions of CTAB (100, 200, 240, 260, 300, and320 mg/L). The mixture was shaken at 293 K, for 30 minsand 1g clay sample was added to this mixture and shakenfor 30 mins in a thermostatic shaker at 200 rpm. Themodified clay samples which produced by aboveprocedure were filtered through filter paper of Whatman41 and dried at 383 K in a vacuum oven for 2 h.and water droplets leads to gaining the hydrophobiccharacter of samples. But the powder organoclay hassuperhydrophobic character, probably due to lotus effect.The variation of initial CTAB concentration doesn’tsignificantly affect the contact angles of the pellet andpowder samples (Figure 2).Figure 2. Effect of initial CTAB concentration on the contactangleIntensity (counts)200016001200800Raw 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).40002 12 22 322Theta (deg)Figure 1. X-ray diffraction spectrums for raw clay and producedorgano-clayThe XRD patterns shows the intensities of peaks for theorgano-clay sample were significantly decreased withcompared the raw clay. This attributed to the presence ofexfoliated clay layers. It can be said that the basal spacingincreases, depending on ion-exchange occurred between+CTAP bounded hydrocarbon and the cations in theinterlayer region of clay (Figure 1).In this work, the contact angles for the powderorganoclay sample and pellet form were compared. It was0found that powder samples have 146P angleindicating the presence of lotus effect. On the other hand,the surface roughness of modified clay particles changesdepending on pressing and the contact angle values0measured on the pellet reduce to about 90 P P. This showsthat the effect of surface roughness on the hydrophobiccharacter is predominant comparison with surface energy.Water droplets cannot penetrate into the pores of thehydrophobic surfaces due to the trapped air [4]. In the bothforms, the reducing of contact areas between the surface6th Nanoscience and Nanotechnology Conference, zmir, 2010 735