Design methodology for nano-engineered surfaces to control adhesion: Application to the anti-adhesion of particles

Kim, Taekyung,Min, Cheongwan,Jung, Myungki,Lee, Jinhyung,Park, Changsu,Kang, Shinill Elsevier 2016 APPLIED SURFACE SCIENCE - Vol.389 No.-

<P><B>Abstract</B></P> <P>With increasing demand for means of controlling surface adhesion in various applications, including the semiconductor industry, optics, micro/nanoelectromechanical systems, and the medical industry, nano-engineered surfaces have attracted much attention. This study suggests a design methodology for nanostructures using the Derjaguin approximation in conjunction with finite element analysis for the control of adhesion forces. The suggested design methodology was applied for designing a nano-engineered surface with low-adhesion properties. To verify this, rectangular and sinusoidal nanostructures were fabricated and analyzed using force-distance curve measurements using atomic force microscopy and centrifugal detachment testing. For force-distance curve measurements, modified cantilevers with tips formed with atypical particles were used. Subsequently, centrifugal detachment tests were also conducted. The surface wettability of rectangular and sinusoidal nanostructures was measured and compared with the measured adhesion force and the number of particles remaining after centrifugal detachment tests.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A design method using the Derjaguin approximation with FEA for low-adhesion surface. </LI> <LI> Fabrication of nanostructures with small adhesion forces by presented design method. </LI> <LI> Characterization of adhesion force <I>via</I> AFM FD-curve with modified atypical tips. </LI> <LI> Verification of low-adhesion of designed surfaces using centrifugal detachment tests. </LI> <LI> Investigation of interdependence of hydrophobicity and anti-adhesion force. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

전자 종이용 하전 입자의 부착력 분석

김승택,김형태,이상호,김종석,Kim, Seung-Taek,Kim, Hyung-Tae,Lee, Sang-Ho,Kim, Jong-Seok 한국반도체디스플레이기술학회 2010 반도체디스플레이기술학회지 Vol.9 No.4

Charged micro-particles are widely used as the key components for many electrical applications such as an e-paper, a touch panel, a printer toner and an electronic ink. Among them, the e-paper is an emerging reflective type display using the charged particles that has the advantages of the extremely low power consumption and sunlight readability. To create images on the e-paper, we confine black positively-charged and white negatively-charged particles between bottom and top electrodes and selectively apply the electric field. When the Coulomb force by an applied electric field is greater than the adhesion force between the charged particle and the electrode, the particles' transition happens resulting in the change of color between black and white. Therefore, the adhesion force is a very important factor for designing and estimating e-paper's operation. In this study, we constructed a basic model for particle's transition and an adhesion force equation describing particle's transition with three different forces: electrostatic image force, Van der Waals force and gravitational force. The simulation results showed that the gravitational force is negligible for the interesting range for the charge and the radius, and the adhesion force can be strongly dependent on the particle's charge and radius.

An investigation into the effect of denture adhesives on incisal bite force of complete denture wearers using pressure transducers : A clinical study

Pawan Kalra,Ramesh Nadiger,Farhan Khalid Shah 대한치과보철학회 2012 The Journal of Advanced Prosthodontics Vol.4 No.2

PURPOSE Study was conducted to determine and assess the effect of different type of denture adhesives on the incisal bite force of complete denture wearers until the dislodgement of upper denture, using pressure transducer. MATERIALS AND METHODS 30 patients out of 100 were included in the study. Based on the Kapur's method of scoring denture retention and stability, these patients were divided into 3 groups- Group A - Clinically good dentures; Group B - Clinically fair dentures; and Group C - Clinically poor dentures. A custom made occlusal force meter was constructed based on the load cell type of pressure transducers. Different adhesives (powder, paste and adhesive strips) were used in the study. Complete denture wearers were asked to bite on the load cell and the readings of incisal bite force were recorded. The readings of incisal bite force were subjected to statistical analysis using Repeated measures ANOVA followed by post-hoc bonferroni test. RESULTS The result suggests that denture adhesives improved the incisal bite force of complete denture wearers significantly The incisal bite force (in kg) in Group A without using adhesives, with powder adhesive, with paste adhesive and with adhesive strips was found to be 2.48 (± 0.16), 3.43 (± 0.11), 6.01 (± 0.11), 3.22 (± 0.09) respectively. The incisal bite force (in kg) in Group B without using adhesives, with powder adhesive, with paste adhesive and with adhesive strips was found to be 1.87 (± 0.18), 3.35 (± 0.14), 5.34 (± 0.18), 3.21 (± 0.12) respectively. The incisal bite force (in kg) in Group C without using adhesives, with powder adhesive, with paste adhesive and with adhesive strips was found to be 1.00 (± 0.17), 3.07 (± 0.14), 4.37 (± 0.26), 2.99 (± 0.14) respectively. CONCLUSION Within the limitations of the study, it was concluded that the use of denture adhesive was found to be significantly effective in improving the incisal bite force of complete dentures until the dislodgement of upper denture. Fittydent paste adhesive was found to be more effective than the powder and strips adhesives. The improvement in incisal bite force was found to be higher in Group C in comparison to that of Group A and Group B.

Adhesion Force Measurements of Urea-Formaldehyde Resins on Wood and Cellulose Films

( Eko Setio Wibowo ),( Byung-dae Park ) 한국목재공학회 2020 한국목재공학회 학술발표논문집 Vol.2020 No.1

The development on wood adhesive research in the recent years mainly focuses on the modification of the resins to increase their cohesion force and resulted in the improvement of wood-adhesion. However, the interaction between adhesive and wood biopolymers itself remains unclear. This study aims to understand adhesion between wood biopolymer such as cellulose and urea-formaldehyde (UF) resins. The cellulose films were made by spin-coating of cellulose nanofibrils (CNFs) onto the silicon wafer and then compared with wood (Pinus densiflora) film for adhesive force analysis. Two methods are employed to calculate the adhesive force: van Oss-Chaudhury-Good (OCG) method and direct measurement using DCAT25 instrument. For OCG method, three liquids such as water, ethylene glycol, and diiodomethane were used for contact angle measurement of the films sample: CNFs, wood, and UF resins. In addition, the maximum adhesion force between UF resins droplet and sample films is obtained using DCAT25 instrument.

고탄성 고분해능을 갖는 응착력 측정장치의 개발

김규성(Gyu Sung Kim),윤준호(Jun Ho Yoon) Korean Society for Precision Engineering 2007 한국정밀공학회지 Vol.24 No.3

To understand adhesive phenomena, we need to get force curve between two surfaces. And it is said that high stiffness force analysis system is needed to get precise force curve and more information of the surfaces. Usually the stiffness of the force measurement system is under the order of 10N/m. The stiffer force measurement system, however, results in more information on the surface, because higher stiffness lead to the wider range of force curves, secondly because the force curve obtained through the stiffer one describes more precise relationship between relative tip-sample separation and interaction force. In this paper, considering for stiffness and resolution, the cantilever was designed and we made adhesion force measurement apparatus with high stiffness and high resolution, so we measured adhesive force between Ag-ball and wafer.

정점 기반 접착력 모델을 활용한 젖은 옷감 애니메이션

박민주,변혜원 (사)한국컴퓨터그래픽스학회 2019 컴퓨터그래픽스학회논문지 Vol.25 No.1

More force must be applied when dragging a wet compared with a dry cloth lying on the table. Increased force is needed because the fluid between the cloth and the surface of the table produces an adhesion force. In this paper, we study the adhesion force between a wet cloth and the surface of an object. To compute the adhesion force, we used the adhesion force model used in textile research based on real-world experiments and also considered the effect of wrinkles, which, to our knowledge, has not been investigated in previous work. Furthermore, we studied the phenomenon in which a wet cloth adheres to the surface of an object and that in which a wet cloth adheres to itself when undergoing self-collision. 책상 위에 놓인 젖은 옷감을 움직이기 위해서는 마른 옷감을 움직일 때와 비교하여 더 많은 힘이 필요하게 되는데, 그 이유는 젖은 옷감과 책상의 표면 사이의 위치한 유체가 접착력을 만들어내기 때문이다. 본 논문은 젖은 옷감이 물체의 표면에 달라 붙는 현상에 집중하여 젖은 옷감을 표현한다. 접착력을 계산하기 위해서 우리는 섬유 관련 연구 분야에서 실제 실험을 기반으로 모델링한 접착력 모델을 활용하였고, 기존 연구와 다르게 젖은 옷감이 물체와 닿아있는 부분에서도 자연스럽게 주름이 만들어지는 모습을 표현한다. 젖은 옷감이 물체에 달라 붙는 현상과 더불어 젖은 옷감끼리도 서로에게 달라 붙는 현상을 표현함으로써 보다 실제의 젖은 옷감과 유사한 결과를 보인다.

Interaction forces between spores and planar surfaces in aqueous solutions

Chung, E.,Yiacoumi, S.,Tsouris, C. Elsevier 2014 Colloids and surfaces. A, Physicochemical and engi Vol.443 No.-

Bacterial spore interactions with planar surfaces in aquatic environments, including adhesive forces and force-distance profiles, are influenced by the geometry and physicochemical properties of the system. The characteristics of spores of Bacillus thuringiensis (Bt) are determined using electron microscopy and electrokinetic measurements. The average size of the spores is 1.57μm long and 0.86μm wide, and the zeta potential values are negative for the solutions used in this work. The zeta potentials of the spores and mica surfaces used in the experiments are measured as a function of pH and ionic strength. The Derjaguin, Landau, Verwey and Overbeek (DLVO) theory is employed to predict the interaction force between the spores and planar surfaces as a function of the separation distance, and a force balance is used to explain the adhesive force. Theoretical estimations are compared to experimental measurements obtained from atomic force microscopy (AFM). The DLVO-based calculations are consistent with AFM force measurements, while the calculated adhesive force shows some deviations from the measurements. The deviations can be minimized by considering the roughness of the Bt spore and substrate surfaces. Results are important in the understanding of spore interactions with environmental surfaces in aquatic systems.

Measurement of Adhesive Force of Urea-Formaldehyde Resins at Softwood Surface

( Minjeong Kim ),( Byung-dae Park ) 한국목재공학회 2021 한국목재공학회 학술발표논문집 Vol.2021 No.1

This study aims to demonstrate a way of measuring the surface adhesion between softwood and urea-formaldehyde (UF) resin adhesives, using a tensiometer. It is necessary to understand the surface adhesion of UF resins on wood because the interfacial adhesion between UF resin adhesives and heterogeneous wood is very complex. The surface adhesion force was measured on the surface of a glossy paper at different moving speeds such as 0.5, 7.5, and 1 mm/s. The speed of 0.75 mm/s provided consistent measurements, which was used for the measurement of the surface adhesion of UF resin adhesives on the surface of early-wood and late-wood of the sapwood or heartwood of Radiata pine. The surface adhesion force of UF resin droplets were measured using the tensiometer on the surface of different woods such as early-wood and late-wood of the sapwood or heartwood of Radiata pine. For a measurement, a liquid resin droplet placed on an RG 2 Du Nouy ring was contacted onto the wood surface. The liquid droplet was pulled off to record a force-distance curve during this procedure. The surface of a wood sample was moved up toward the UF resin droplet at a speed of 0.75 mm/s. Then, the wood sample was retracted until the resin droplet was detached from the surface of wood sample. The maximum surface adhesive force was obtained by the peak of a force-distance plot.

Nanoscale adhesion between Pt nanoparticles and carbon support and its influence on the durability of fuel cells

Kim, J.H.,Yuk, Y.,Joo, H.S.,Cheon, J.Y.,Choi, H.S.,Joo, S.H.,Park, J.Y. Elsevier 2015 Current Applied Physics Vol.15 No.suppl2

We report an atomic force microscopy (AFM) based method to characterize the adhesion between metal nanoparticles and carbon support that plays an important role in determining the durability of fuel cells. This adhesion is related to the electrochemical active surface area (ECSA). Force-distance curves measured with a Pt-coated AFM tip on the surface of the support allows us to probe the adhesion between a Pt nanoparticle and the support because an asperity between a Pt-coated AFM tip and carbon support can mimic the nanoscale interface between Pt nanoparticles and carbon. We found that acid-based surface treatment of the carbon support increases the adhesion force by a factor of 4, compared with the as-received carbon support. Meanwhile, surface treatment using acid on the carbon support can lead to a higher ECSA, which is consistent with the higher adhesion force probed with AFM. We attribute the higher adhesion between the Pt probe and the acid-treated carbon to stronger chemical interaction by the C/O functional groups.

Effect of sputtering parameters on the adhesion force of copper/molybdenum metal on polymer substrate

Lee, Sang-Hyuk,Park, In-Sun,Seo, Bo-Hyun,Seo, Jong Hyun,Choe, Heehwan,Jeon, Jae-Hong,Lee, Yong Uk,Hong, Munpyo Elsevier 2011 Current Applied Physics Vol.11 No.5

<P><B>Abstract</B></P><P>A pure molybdenum was selected as a copper barrier layer on top of the polyimide substrate because of its good etchability with copper and high thermal stability. The adhesion forces were measured by using a micro-scratch tester and an adhesion improvement mechanism is suggested in terms of thin film microstructure and polymer surface modification. The adhesion force of thin copper film on the polymer substrate is greatly enhanced by variation of deposition conditions such as argon pressure, DC power voltage oxygen plasma pretreatment and annealing treatment. As the sputter dc voltage increased from 500 V to 640 V, the critical adhesion force of the molybdenum on the polyimide film increased from 420 mN to 900 mN. As the argon pressure increased from 5 mTorr to 30 mTorr, the adhesion force slightly decreased from 860 mN to 660 mN. The post-annealing process after the film deposition also yielded an enhanced adhesion force.</P>