Experimental Research on Hydrophilic Property of Stainless Steel Bionic Non-smoothed Surface Yan Li 1, a * and Guangrui Shang 1, b

Transcription

1 6th International Conference on Management, Education, Information and Control (MEICI 06) Eperimental Reearch on Hydrophilic Property of Stainle Steel Bionic Non-moothed Surface Yan Li, a and Guangrui Shang, b School of Mechanical Engineering at Jilin Engineering Normal Univerity, Changchun Jilin 005, China a liyan096@6.com, b hgr888@6.com Keyword: Bionic; Crown height; Interval; Contact angle; Stainle teel Abtract. The laer preciion machining wa performed on the urface of the formed pherical non-mooth lattice, lead to an increae in material urface hydrophilic tendency. The influence of ball crown height and interval on wettability ha been tudied. The reult how that the ball crown lattice have been increaed the apparent contact area between the water droplet and the urface leading to the decreaing of apparent contact angle up to 8.5% and the urface hydrophilicity i ameliorated. Introduction The factor that affect the wettability of the material were the interface tenion of the material and the appearance of the material urface [-9]. the field of mechanical engineering and medical engineering commonly ued in the field of tainle teel a the reearch object, uing laer preciion proceing technology contructed pherical cap hape non-mooth bionic urface, mooth pherical urface hape on the urface wettability of the material effect of micron level wa invetigated, which improved the hydrophilicity of the tainle teel (Cr8Ni9Ti), provide a new idea for the improvement of the urface wettability of the material. Material and Equipment The tainle teel cylindrical ample wa 8mm in diameter and the height wa 0mm. After cutting and polihing, Surface roughne wa le than 0.8 micron, and the ample wa tored in the alcohol container. Uing CNC laer engraving machine adjuted the trength of the current, fill pacing, tep length and frequency to control the non-mooth pherical urface diameter, pacing, column pacing and the height. The urface topography analyi intrument wa ued for the analyi. Drop Method Seile wa ued to complete the contact angle meaurement, the intrument meaurement angle range wa 0-80 degree, the meaurement error wa 0. degree. The data wa meaured at point, and the mean value wa meaured. Method In order to tudy the non-mooth pherical lattice pherical diameter, paced row interval, column pacing, and the altitude effect on the wettability. So we can by changing the current intenity, filling pacing, frequency and tep to achieve. The pecific range of choice for the current intenity of 0~80, the filling pacing of 0.5~0.5 mm, frequency 5~0Hz, the tep ize wa 0.~0.5 mm. Study on the influence of the urface wetting property of material by mied orthogonal tet L (8 ). The pecific tet wa divided into group, a total of time. Reult Before the eperiment, the intrinic contact angle of the urface of the mooth tainle teel wa firt determined e 8. From the tet reult, it can be known that the wetting performance of the material urface ha been ignificantly improved. Actual contact angle decreaed by.9degree, 06. The author Publihed by Atlanti Pre 06

2 6th International Conference on Management, Education, Information and Control (MEICI 06) and the ratio wa 8.8%. Analyi and Dicuion Tet reult of tatitical decription were hown in Table. The regreion equation wa a follow: Eq.. The tandard regreion coefficient of the equation how that the factor which influence the actual contact angle were,,,. Filling pacing ( ) wa the mot ignificant influence on the actual contact angle. y () Project Table Fill pacing [mm] Statitical analyi of eperimental reult Electric current [A] Frequency [Hz] Step [mm] Actual contact angle[ ] y Sum Average Ma Min Covariance Number Effect of Element Parameter on the Hydrophilic Property. A hown in Fig., the ample urface wa refined with micron level pherical lattice near regular arrangement. The relationhip between the lattice parameter and the actual contact angle wa hown in Table. In thi eperiment, we tudied the water droplet in the nearly regular non-mooth pherical cap urface wetting behavior. The reult how that the change of laer proceing parameter directly affect the urface morphology of the material, namely, the change of roughne factor (r) or the pore fraction ( ).The eperimental reult wa hown that the wettability of tainle teel urface can be improved by changing the urface morphology. The actual contact angle wa decreaed by.9 degree, and the decreae wa 8.5% compared with the mooth plane. Figure. Morphology of urface (Proceed), bar equal to 500 m Effect of Crown Height on the Actual Contact Angle. Fig. wa the current proceing under different cap height change on the actual contact angle curve. Curve wa hown that regardle of how to adjut the current proceing, the actual contact angle with the cap height increae howed a downward trend, but when the height of the pherical crown more than 0 micron, there tended to be gentle. The Relation Ship between the Line Spacing and the Actual Contact Angle. Fig. were line pacing to the actual contact angle the relation curve and correponding urface morphology, with increae of the pacing, actual contact angle increaing; however, pacing in below, actual contact angle change little. 06. The author Publihed by Atlanti Pre 07

3 6th International Conference on Management, Education, Information and Control (MEICI 06) Figure. Curve of apparent contact angle by pherical crown height Figure. Influence of interval on apparent contact angle The Change Trend of the Actual Contact Angle. According to the tet reult, unit of crown diameter and column pacing change to the actual contact angle doe not have a ignificant impact. Therefore, in the analyi can temporarily doe not conider the unit phere diameter and gap on the actual contact angle effect. From the Fig. and Fig., we can ee that the actual contact angle in the proce of gradually decreaing, there wa a trend of flat. In thi eperiment, on the actual contact angle have ignificant effect of pherical crown height increae rate howed a decreaing trend, leading to low down the water droplet and the urface of the real contact area rate of increae lowed down, the actual contact angle decreaed. Comparion with Wenzel [0] Model. In thi tet, the urface material after laer preciion proceing of the crown. Set pacing for L, column pacing wa B, the pherical diameter pherical crown wa D, and the crown height wa H, then their formula for Eq.. r ( H 0.5D ) LB BD LD ( D D ) ( B D)( L D) ( H 0.5D ) LB BD LD 0.5D ( B D )( L D) () In thi eperiment, the relationhip between the effect of the roughne factor (r) on the actual antenna angle and the calculated value wa hown in Fig.. A can be een from Fig., there wa a big difference between the theoretical value and the oberved value. After calculation the actual contact angle wa 6.55 degree, Roughne factor (r) wa approimately equal to.5, correponding to the crown height wa greater than or equal to 650 micron. In thi eperiment, it wa not recorded. The tatitical relationhip between the oberved value of the actual contact angle and the roughne factor wa Eq.. 58r 877r 96r 66r co / co ~ f (r ) The relationhip After finihing wa Eq.5. () curve wa hown in Fig. 5. It tatitical relationhip wa Eq.. co / co 05.r 7r 575r 55.r 06. The author Publihed by Atlanti Pre 08 ()

4 6th International Conference on Management, Education, Information and Control (MEICI 06) co (05.r 7r 575r 55.r) co (5) Figure. Curve of apparent contact angle by Roughne factor r : Oberved and Calculated Figure 5. Curve of co / co ~ f ( r) Value Comparion with Cai-Bater [] Model. Cai-Bater equation a follow: Eq. 6. co ( co ) (6) c Y ( H 0.5D ) Note: (7) ( L D)( B D) The relationhip between the actual contact angle and the area fraction ( ) wa hown in Fig. 6. In the curve hown in Fig. 5, the relationhip between the area fraction and the actual contact angle wa tatitically ignificant. The relationhip between the coine value and the area fraction wa hown in Fig Note: (8) co. The regreion equation wa a follow: Eq.9. After finihing wa Eq.0. co co f co.566 (9) co ( )(co ) (0) Similarly, the oberved value were till not conitent with the Cai model. Through the above analyi, we can know that under the condition of thi eperiment, that have been compared with the Wenzel model and the Cai model. There were two reaon for thi phenomenon: one wa becaue that the pherical cell body diameter and row pacing or diameter and column pacing ratio wa too large. Another reaon wa that the height and the diameter of pherical element ratio were too mall. The above reaon lead to the Wenzel model in the roughne factor wa too mall and Caie model in the area fraction wa too large, o there wa a large deviation between the theoretical value and the oberved value. The above reaon lead to the value of the Wenzel model wa too mall and the value of the Caie model wa too large, then there wa a large deviation between the theoretical value and the oberved value. 06. The author Publihed by Atlanti Pre 09

5 6th International Conference on Management, Education, Information and Control (MEICI 06) Figure 6. Curve of apparent contact angle by : Oberved and Calculated Value Figure 7. Curve of co co ~ f ( ) Concluion Non-mooth tainle teel bionic urface ha been fabricated by laer preciion proceing and hydrophilic capability ha been increaed 8.8%. The regreion equation wa Eq.. Among the factor that influence factor uch a the pacing, the current, the frequency and the tep ize, the effect of the pacing on the actual contact angle wa the mot ignificant. When the rough factor (r) wa ued a the parameter of the tudy, the formula wa a Eq..When the area fraction ( ) i ued a the reearch parameter, the formula wa a Eq.8 Reference [] K. Tehima, H. Sugimura, Y. Inoue, O. Takai, A. Takano, Wettablity of poly (ethylene terephthalate) ubtrate modified by a two-tep plama proce: ultra water repellent urface fabrication, Chem. Vapor Depo., 00, 0(6): [] A. Nakajima. Deign of a tranparent hydrophobic coating. J. Ceram. Soc. Jpn, 00, : [] R. Furtner, W. Barthlott, C. Neinhui, P. Walzel. Wetting and elf-cleaning propertie of artificial uper-hydrophobic urface. Langniuir, 005, (): [] A.R. Parker, C.R. Lawrence. Water capture a deert beetle. Nature, 00, : -. [5] J.P. Rothtein. Direct velocity meaurement of the flow pat drag-reducing ultrahydrophobic urface. Phy. Fluid, 005, 7(0): [6] Abdelalam, M. E.; Bartlett, P. N.; Kelf, T.; Baumberg, J. Wetting of Regularly Structured Gold Surface. Langmuir; 005; (5);: [7] R.Mohammadi, J. Waink, A. Amirfazli, Effect of urfactant on wetting of uper-hydrophobic urface,langmuir,00,0: [8] M. Niemitz, G. Koβmehl, Wettability of poly (, -bithieny-5,5 -diyl) layer, Angew. Mackromol. Chem, 99, 85: 7-5. [9] S. Veeramauneni, J. Drelich, J.D. Miller, G. Yamauchi, Hydrophobicity of ion-plated coating, Prog. Org. Coat., 997, : [0] Wenzel, R.N. Indutrial and Engeneering Chemitry, 96, 8, [] Caie, A.B.D.; Bater, S. Tranaction of the Faraday Society, 9, 0, The author Publihed by Atlanti Pre 00