棉表面的疏水性能

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1、Imparting Waterproof Properties to Cotton SurfaceAbstractMethods are suggested and compositions are selected to endow the surfaces of textile goods made of cotton fabrics with waterproof properties. The wetting angles are measured that water drops form with the coatings, made of fluorosilanes of dif

2、ferent structures, on the surfaces of cover glasses and fabric. It is shown that, if the aggregation of fluorosilane molecules takes place in the treated solution, then it is possible to achieve the superhydrophobicity of the cotton surface.摘要采用的方 法和选用的成分都是为了使棉织物表面具有疏水性能。润湿角是测量盖玻片和织物表面涂层上水珠的形态，该涂层是由

3、不同结构的氟化硅烷制成的。结果表明：若氟化硅烷的集合体经过一定的溶液处理，那么棉织物的表面就有可能实现超疏水性。INTRODUCTIONIn recent years, interest in the investigation and production of highly hydrophobic and superhydrophobic surfaces has increased. Thus, a survey of the literature using the database of the Institute of Statistical Information (http:/

4、 showed that the number of papers in this field published within two last years is almost twice that of the total number of publications over the entire previous period, 最近几年，调查和生产高疏水性和超疏水性表面的兴趣大大增加。通过对统计信息研究所数据库里的文献调查，结果表明：最近两年在这个领域发表的文献的数量几乎是以前所有出版物数量的两倍， which is mainly connected with the high de

5、mand in the obtained scientific results from most diverse industrial fields 15. One of the applied trends under current development that uses the achievements in the field of production of superhydrophobic surfaces is the creation of waterproof fabrics68. Waterproof properties are important for mate

6、rials of different purposes, ranging from fabrics used to prepare tents, protective clothing, coats, and umbrellas to linen used to sew clothing for operation personnel. 这主要是与最多样化工业领域中对科学的高需求有关1-5。在目前发展状况下的一个应用趋势是：运用超疏水表面生产领域中所取得的成就是织物疏水方面的创举6-8。对不同目的的材料来说，如从帐篷、保护性布料、外套、伞用的织物到手术缝线用的麻织物，疏水性能都是非常重要的，

7、An important advantage of imparting waterproof properties to a material by applying coatings is the opportunity to retain the texture, properties, density, and coloring of the basic fabric. At present, there are an insufficient number of methods and a restricted number of hydrophobic compounds that

8、can be efficiently applied for textile goods. This work is intended to partially fill this gap.赋予涂层材料疏水性的一个重大的好处是有机会保留原织物的组织、性能、密度和色泽。目前，可以有效的应用于纺织品疏水性的试验方法和疏水成分是有限的。该文献在一定程度上填补了这空缺。MATERIALSThe experiments were conducted with samples of cotton fabric with a twill weave and a weight of130g/m2 and di

9、mensions of 10 10 cm. The pretreatment of the specimens involved mercerization in a solution of sodium hydroxide, neutralization in acetic acid, and rinsing with distilled water. Depending on the method of further processing, we used either wet samples or samples dried for 24 h in a room with 5575%

10、humidity.Samples ：cotton fabricPretreatment： mercerization（丝光处理） neutralization （中合作用） rinsing （水洗）used samplesTo estimate the role of the roughness conditioned by the structure of a fabric weave and the effect of different hydrophobic agents on the wetting angles, as reference samples, we used cove

11、r glasses of Russian production ( Klin Glass Manufacturing Plant) with a roughness that did not exceed 0.1 m (GOST State Standard 6672-75). The pretreatment of these glasses included washing in a chromic mixture, rinsing with distilled water, and drying in a vacuum oven at 150.wetting anglespretreat

12、ment of glassesdistilled water（蒸馏水）FABRIC PROCESSINGTwo different methods were used to process the fabric. In the first procedure, to treat wet fabric and impart waterproof properties to its surface, the commercial sole of fluorofunctionalized siloxane of Degussa production (Germany) (hydrophobic ag

13、ent No. 1) was used. The fabric sample was placed into a sole for 20 min and dried at 120 for an hour. Then, the coating was cured for 1 min at 150. ProcessThe first procedurehydrophobic agent No. 1(憎水剂1号） In the second procedure, the preliminary dried samples were immersed for different periods of

14、time into 1% solution of CF3(CF2)5(C=O)NH(CH2)3Si(C2H5OH) in toluene (hydrophobic agent No. 2). Fluorosilane was granted by Prof. S. Lee (SKL, China). After solvent evaporation, the samples were dried in a vacuum oven at 110. Both of the mentioned compositions were applied to glass plates by the pou

15、ring method.The second proceduretoluene(甲苯）hydrophobic agent No. 2（憎水剂2号）solvent evaporation(蒸发溶剂）MEASUREMENT OF CONTACT ANGLESOne of the main characteristics of the waterproof properties of a fabric is its wetting. Wetting of both the glass samples and fabric surface after the application of the co

16、atings was studied by measuring the contact angles of a sessile drop. on a special unit constructed at the Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences 9. An image of the sessile drop, 2009, vol. 45, no. 6, p. 713.whose volume was, as a rule, 4060 l, was

17、obtained using a PL-B621MU monochrome digital video camera. a sessile drop(静滴） monochrome（单色的） To analyze the data, three samples of each type were used; the average value of the angle for each sample was determined by five different points. Wetting of separate fabric fibers with solutions bearing a

18、 hydrophobizing substance was studied on the same unit using the method of a drop on a fiber 10. This method enables the simultaneous determination from a single experiment of both the outflow and inflow angles as the angles formed with the fiber surface by the receding and advancing angles of the d

19、rop hanging on a fiber. This method is described in detail in 10.This method enables the simultaneous determination from a single experiment of both the outflow and inflow angles as the angles formed with the fiber surface by the receding and advancing angles of the drop hanging on a fiber.通过对纤维的悬滴的

20、后退和前进的角度，从一个单一的实验方法就能够同时测定流出和流入的角度和纤维表面形成的角度。RESULTS AND DISCUSSIONTo date, it has been theoretically shown and experimentally proven (for reviews on this problem, see 15, 11, 12) that an efficient contact angle on a rough surface is determined by the chemical composition of the surface and peculiar

21、ities of its relief. In order for the fabric to possess considerable waterproof properties that are stable over time, the fiber surface must be hydrophobic. At the same time, most natural fabrics used in textile industry are hydrophilic and rapidly absorb water drops falling on their surfaces (see F

22、ig. 1). (a) complete wetting of an untreated fabric,Fig. 1. Wetting of the fabric samples In the present work, to impart hydrophobic properties, we used the two different hydrophobic agents described above. To estimate their hydrophobizing ability, we first studied the wetting angles of the smooth c

23、over glasses processed via the abovementioned procedures of applying a hydrophobic coating. Table 1 lists the values of wetting angles measured on the glasses after the coating was applied. The presented data indicate that both of the chosen hydrophobic agents have good hydrophobizing ability. The f

24、act that, after treatment with fluorofunctionalized siloxane of the Degussa Corporation, the contact angle on the smooth cover glass exceeds 120 implies that the coating does not represent a smooth film. Based on the analysis performed in 2, one may suppose that the coating formed on the glass repre

25、sents a layer with an expressed relief. This is confirmed by the data of atomic-force microscopy of the surface of the glass with a coating. The relief visible in the ASM image (Fig. 2) is mainly associated with the formation of nanosized aggregates of hydrophobic agent molecules. The considerable d

26、ispersion in the wetting angles substantiates this conclusion. atomic-force microscopy（微粒子能）dispersion（分散作用） substantiates（证实、证明） The coating applied by pouring a toluene solution of the second hydrophobic agent also yields a relatively high contact angle, which indicates good hydrophobizing ability

27、. The small scatter of the measured angles along the sample surface allows one to consider an applied coating as rather uniform. The data on the contact angles that water drops form on the surface of a cotton fabric after treatment with both solutions are presented in Table 1. Water drops on fabric

28、treated with both solutions are depicted in Figs. 1b, 1c. The measured wetting angles and small roll-off angles, which do not exceed 15。,unambiguously indicate the achievement of a superhydrophobic state of the fabric treated with the hydrophobizing agent no. 1. At the same time, although fabric tre

29、ated with the agent no. 2 is characterized by good water -resistance, it cannot be considered to be a fabric that possesses superhydrophobic properties. First of all, this is explained by a large wetting hysteresis, which can be judged by the roll-off angles that, in some fragments of the fabric sam

30、ple, reach 80. In addition, the fact that the contact angle for hydrophobizing agent no. 2 at small times of storage in solution depends on time and achieves a constant value at long times indicates the importance of achieving adsorption equilibrium between hydrophobizing agent molecules on the fibe

31、r surface for the hydrophobization process. wetting hysteresis (润湿滞后） adsorption equilibrium（平衡吸收作用） A comparison of the results on the hydrophobizing treatment of both the reference samples, which are smooth glasses, and the fabric samples allows one to connect the difference in the observed contac

32、t angles with the roughness of a hydrophobic covering. Thus, there are several literature references 15, 1113 that indicate that, to reach a superhydrophobic state, the roughness with a number of typical sizes of the relief elements, e.g., bimodal texture, is required . In our case, the typical reli

33、ef parameters are the fiber diameter and interfiber space, which is determined by the weave density. bimodal texture（双峰组织） These parameters are the same for the samples that were treated with different hydrophobic agents. At the same time, in the case of the treatment with an aqueous solution of flu

34、orofunctionalized siloxane of Degussa production, a third typical parameter emerges in connection with the aggregation of the molecules in the sole and yields an angle of greater than 120, even on smooth cover glass. Apparently, as a result of a combination of these three characteristic sizes of rou

35、ghness, one can aqueous solution（水溶液） achieve a hydrophobic state on fabric treated with hydrophobizing agent no. 1. Because the quality of the resulting covering can be determined to a great extent by the wettability of the fabric fibers by the hydrophibizing solution, in the present work, using th

36、e method of a drop on a fiber, we measured the angles that are formed on the fiber surface by drops of the corresponding solutions. The data obtained is presented in Table 2 and allows one to conclude that the difference in the results of the hydrophobic treatment of the fabric cannot relate the to

37、the different conditions of the contact of the cotton fabric and treating solution.CONCLUSIONS In the present study, we suggested simple methods for treating a cotton-based fabric using both commercial and easily synthesized hydrophobic agents that provide a stable water-resistant effect. The analys

38、is of the wetting of the treated fabrics showed that the greatest effect that leads to a superhydrophobic state of the surface is achieved in the case when the surface relief of the fabric with a coating is determined, not only by the structure and weave of the material itself, but also by additiona

39、l 在目前的研究中，我们利用简单的试验方法对以棉为主的面料采用了商业和容易合成的憎水剂基团进行处理，结果使棉面料具有了稳定的抗水性能。通过对处理的棉织物的润湿性分析，结果表明：在表面涂层面料确定的情况下，面料的表面获得了超疏水性状态的显著效果，不仅取决于材料本身的结构和组织，还取决于形成疏水性化合物的集合体的粗糙度方面。 REFERENCE1. Blossey, R., Nature Mater, 2003, vol. 2, p. 301.2. Boinovich, L.B. and Emelyanenko, A.M., Usp. Khim.,2008, vol. 77, no. 7, p.

40、619. 3. Ma, M.L. and Hill, R.M., Curr. Opin. Colloid InterfaceSci., 2006, vol. 11, p. 193. elements of the roughness that are formed by the aggregates of hydrophobic compounds. The complement of the surface microroughness conditioned by the fiber weave with the nanosized roughness of the aggregates

41、allows one to achieve the level of roughness required to obtain small roll-off angles and wetting angles above 150.聚合的纳米纤维组织粗糙度表面微粗糙度的补充，可以实现要求的小卷曲角和润湿角在150。以上粗糙度的水平。4. Extrand, C., Encyclopedia of Surface, Colloid Science,Somasundaran, P., Ed., New York: Taylor and Francis, 2006, p. 5854.5. Nakajim

42、a, A., Hashimoto, K., and Watanabe, T.,Monatsh. Chem., 2001, vol. 132, p. 31.6. Wang, T., Hu, X., and Dong, Sh., Chem. Commun.,2007, p. 1849.7. Tomsic, B., Simoncic, B., Orel, B., et al., J. Sol-Gel.Sci. Technol., 2008, vol. 47, p. 44.8. Lee, H.J. and Michielsen, S., J. Textile Inst., 2006,vol. 97,

43、p. 455.9. Emelyanenko, A.M. and Boinovich, L.B., Kolloidn.Zh., 2001, vol. 63, no. 2, p. 178 Colloid J. (Engl. Transl.), 2001, vol. 63, no. 2, p. 159.10. Emelyanenko, A.M., Ermolenko, N.V., and Boinov ich, L.B., Colloids and Surfaces A, 2004, vol. 239,nos. 13, p. 25.11. Quere, D., Rep. Progr. Phys.,

44、2005, vol. 68, p. 2495.12. Roach, P., Shirtcliffe, N.J., and Newton, M.I., Soft Matter, 2008, vol. 4, p. 224.13. Boinovich, L. and Emelyanenko, A., Langmuir, 2009,vol. 25, p. 2907. 谢谢Fig. 2. Atomic-force image of 2 2 area of surface of cover glass with covering based on hydrophobic agent no. 1. Aggr

45、egates with dimensions of about 0.050.2 m can be clearly defined. Image was created with a Nanoscope IIIAtomic-force microscope (Veeco, Unted States).Fig. 1. Wetting of the fabric samples: (b) water drop on the fabric surface after treatment with a hydrophobic agent No. 2, (c) water drop on the supe

46、rhydrophobized fabric surface after treatment with a hydrophobic agent no. 1. Length of scale segment in all images is 1 mm.Fig. 1. Wetting of the fabric samples(a)complete wetting of an untreated fabric,(b) water drop on the fabric surface after treat ment with a hydrophobic agent No. 2, (c) water drop on the superhydrophobized fabric surface after treatment with a hydrophobic agent no. 1. Length of scale segment in all images is 1 mm.