纺织工业中单纤维接触角检测方案(接触角测量仪)

Contact information attension APPLICATIONNOTE 1 Contact angle measurements onsingle fibers This application note illustrates how the Attension Tensiometers canbe used to study fiber wettability. Contact angle measurements on single fibers are used in dif-ferent industrial areas to characterize the adhesion and wettingbehavior of the fibers. Wetting properties of fluids on fibers canalso be studied by measuring the contact angle formed by theliquids on the fibers. It can be important for example in textileindustry when studying water repellency of textiles. In addition，treatments of human hair (e.g. with shampoos， coloring etc.)require knowledge on the wettability of the hair.Fibers are alsoused as reinforcement material in composites and material prop-erties can be assessed by measuring contact angles with givenliquids. Wettability of fibers can be studied with both optical andtorce tensiometry. In force tensiometry， the fiber sample is hung on the balanceof the tensiometer and brought in contact with the test liquid.The tensiometer measures advancing and receding contactangles formed by the liquid on the fiber. When the fiber comesin contact with the liquid， the change in forces acting on thefiber is detected and the tensiometer registers this elevation aszero depth of immersion. As the solid is pushed into the liquid，the changes in mass are recorded and forces acting on the solidcan be measured. The tensiometer calculates and automaticallysubtracts the effects of the buoyancy force and the weight of theprobe. The only remaining force measured by the balance is thewetting force. The graph shows wetting force versus depth of im-mersion as the data is obtained. In optical tensiometry， a drop is placed onto the surface of thesolid with a dispenser. With standard dispensers the drop volumeis typically a few microliters and therefore the diameter of thedroplet is several millimeters. This kind of drop is too large to beplaced on a thin fiber. To create smaller drops， a dispenser thatis able to create nano and picoliter sized drops is required (e.g.Attension Theta picoliter dispenser). Taylor et al.1 showed thatcontact angles measured from picoliter volume drops of waterare equivalent to contact angles measured from microliter sizeddrops on six common polymers，opening the way for furtherresearch in the field. AttensionBiolin ScientificTietajantie 2FIN-02130 Espoo， Finland Case Study 1： Fiber wettability withforce tensiometry Fu et al.2 studied the influence of oxidation of carbon fibers withozone for reinforcing cement. The filament diameter of these fib-ers was 15±3 um. Among other properties， wettability of the fiberwith water was measured with a Sigma 70 force tensiometer fromAttension (former KSVInstruments) before and after treatment.An example of this kind of measurement is shown in Figure 1. Fuet al. untreated carbon fiber gave an advancing angle of 84，7°whereas the receding angle was 29，0°. After the treatment， thereceding and advancing contact angles decreased to zero. Thiswas due to the fact that the oxygen containing functional groupsimproved the wettability on the fiber surface. Since the cementpaste used is a water based mixture， the wettability between fiberand water can be used to estimate the wettability between fibersand cement paste. Case study 2： PTFE coated wire contactangle measurement with opticaltensiometry Theta optical tensiometer combined with picoliter dispenserwas used to measure contact angles between water and a PTFEcoated wire. The wire had a diameter of 0.18mm and the volumeof the drop placed on its surface was 180pl. Pictures were takenwith a high speed camera (1550fps) and the drop shape was fit-ted with the Young-Laplace method. Figure 2 shows the drop onthe surface of the wire. Water contact angles obtained from the coated wire are shown inFigure 3. As it appears， the coating of the wire can be defined ashydrophilic， as the contact angles are less than 90°. This methodallows the characterization of different coatings used for fibersand wires. Conclusion The surface properties of single fibers are relevant in many fieldssuch as in the textile and construction industries. Contact anglemeasurement is a suitable method to characterize the surfaceand adhesion properties of a fiber. Fiber contact angles can bemeasured with either a force tensiometer by immersing the fiberin a liquid or with an optical tensiometer by placing a liquid droponto the fiber. References [1] M.Taylor，A. J. Urquhart， M. Zelzer， M.C. Davies and M.R. Alex-ander， Picoliter Water Contact Angle Measurement on Polymers，Langmuir 23 (2007)，6875-6878. [2]X. Fu， W. Lu and D.D.L. Chung， Ozone Treatment of CarbonFiber for Reinforcing Cement， Carbon 36， 9(1998)，1337-1345. TEL +358 9 5497 3300FAX +3589 5497 3333info@attension.comwww.attension.com Figure 1. Wetting force per unit length of fiber versus immersiondepth measured by Sigma force tensiometer. Figure 2. A picosized drop on a PTFE coated wire. Time，s Figure 3. Water contact angle of PTFE coated wire measured withTheta optical tensiometer combined with a picoliter dispenser. Availability Attension products and services are provided to customers all over theworld through Biolin Scientific in co-operation with a highly competentnetwork of Distribution Partners. For a list of relevant contact details，please visit www.attension.com 瑞典百欧林科技有限公司是一家先进科研仪器生产商，在北欧的瑞典，丹麦和芬兰都有主要产品的研发和生产基地。我们为用户提供高科技、高精度的科研设备，可用于表界面、材料科学、生物科学、药物开发与诊断等研究领域。