高分子界面吸附的单分子力谱研究
摘要
高分子界面科学是专门研究高分子材料表面与界面的现象、组成、结构、形态与性能，以及当其与外在环境接触时，物质与能量相互作用的一门新兴边缘学科。界面科学及其应用被认为是当代科学技术发展的生长点之一。随着原子力显微镜的诞生，使高分子单链的界面研究成为可能。本论文即以基于原子力显微镜技术的单分子力谱方法为主要表征手段，尝试直接观测高分子单链的界面信息。
在本论文第一章，总结了高分子界面科学的基本概况，列举了研究高分子界面问题的基本表征方法；详细地介绍了基于原子力显微镜技术的单分子力谱方法，并讨论了其作为高分子单链界面吸附研究手段的可行性。
在本论文第二章，研究了聚4-乙烯基吡啶的单分子力谱。聚4-乙烯基吡啶的力曲线为锯齿形，可能对应着链圈的吸附形态。通过统计分析，发现其单个吸附位点的界面脱附／吸附力约为180pN。这一数值远大于单个氢键的强度，暗示着氢键并非其全部的界面吸附推动力。
在本论文第三章，我们利用一种两亲性多嵌段高分子—PNIPAM-seg-PS，研究了高分子每个链段甚至每个重复单元对界面吸附的贡献。它在不同的基
2004
官林大学俘士拳位论文
底上表现出不同的吸附性质:在疏水基底上是疏水的PS嵌段吸附，而在亲
水基底上则是亲水的PNIP叭M嵌段吸附.在疏水基底上，我们得到了规则的
多峰力曲线，每个峰对应着单个PS嵌段的界面脱附力。我们还发现，PS脱
附力与拉伸速率的对数成正比，这表明PS在界面的吸附/脱附是个较慢的动
态过程。我们推测，平均每个PS重复单元对界面脱附力的贡献为1.3一2.1 pN。
在本论文第四章，研究了含有间隔基团的强聚电解质PAMPS的界面吸附
性质。我们发现，离子强度和主链电荷线密度均不影响PAMPS单链的界面
脱附力，只影响其抗拉强度。这清楚地表明，即使是强聚电解质也有明显的
疏水性。我们将这一性质归因于引入的间隔基团。
由于高分子的缠结特性以及表面富集作用，单分子力谱实验样品制备上
的困难一直困扰着相关的研究人员。在本论文第五章，我们针对这个问题，
提出了一种简易的新型样品制备方法，有效地克服了这个难题。此方法利用
自组装单层膜的缺陷，成功地将一种高分子分散在基底表面，并探测了其单
链界面脱附力。
在本论文最后一章，总结了全部论文的工作并探讨了高分子的界面吸附
问题。
The science of macromolecules at interfaces is an interdisciplinary field that deals with the phenomena, composition, structure, morphology, properties and the energy of macromolecular materials at interfaces. It is regarded as one of the growth points in the modern science and technology. With the emersion of atomic force microscope (AFM), the study of single macromolecular chain at interfaces becomes possible. Utilizing the AFM based technique, single molecule force spectroscopy (SMFS), this dissertation attempted to detect directly the information of single macromolecular chain at interfaces.
In Chapter 1, the science of macromolecules at interfaces is reviewed. Some common characterization methods are summarized. The AFM as well SMFS are specially introduced. The feasibility of SMFS on the study of single chain properties at interfaces is discussed.
In Chapter 2, the SMFS of poly(4-vinylpyridine) (P4VP) is studied. The typical force curve of P4VP presents a saw-tooth pattern, which may correspond
to the loop conformation of P4VP at interface. A statistical analysis finds that the desorption force of a single anchor point is ~180 pN, which is much larger than the s trength o f a s ingle H-bond. T his finding i ndicates t hat b esides H -bonding, other interactions also contribute to the interaction at interface.
In Chapter 3, we used a novel amphiphilic segmented polymer -PNIPAM-seg-PS to study t he contribution of a m onomer unit on the interfacial interaction. This polymer behaves differently on various substrates, depending on the hydrophobicity of the substrate. On hydrophilic substrate, the PNIPAM segments anchor, while on hydrophobic substrate, the PS segments adsorb. The SMFS of PNIPAM-seg-PS on a hydrophobic substrate presents regular saw-tooth pattern, each peak corresponds to the desorption of an individual PS segment from the substrate. The desorption force increase with the rise of stretching velocity implies that the adsorption/desorption progress of PS segment at interface is a slow, dynamic one. We estimate that each styrene monomer contributes 1.3~2.1 pN to the desorption force.
In Chapter 4, the SMFS of a strong polyelectrolyte (PAMPS) is studied, in terms of desorption and elongation. We find that the ionic strength and the linear charge density do not affect the interfacial force between the single PAMPS chain. This result implies that hydrophobic interaction dominates the adhesion force between polymer and substrate, even if strong polyelectrolyte is used. We attribute the phenomena to the introduced spacer between the polymer backbone and the charged groups.
The preparation of a "single-molecule" sample is a key issue in SMFS. Due to the entanglement of polymer chains and the effect of surface concentration enrichment, the sample preparation of SMFS feazes the research community. In Chapter 5, we propose a novel method for the sample preparation by utilizing the
IV
defects of the self-assembly monolayers. With this method, the polymer chains are separated individually at the surface, and the desorption force of single chain from substrate is successfully measured.
In Chapter 6, the whole dissertation is summarized and discussed.
在本论文第一章，总结了高分子界面科学的基本概况，列举了研究高分子界面问题的基本表征方法；详细地介绍了基于原子力显微镜技术的单分子力谱方法，并讨论了其作为高分子单链界面吸附研究手段的可行性。
在本论文第二章，研究了聚4-乙烯基吡啶的单分子力谱。聚4-乙烯基吡啶的力曲线为锯齿形，可能对应着链圈的吸附形态。通过统计分析，发现其单个吸附位点的界面脱附／吸附力约为180pN。这一数值远大于单个氢键的强度，暗示着氢键并非其全部的界面吸附推动力。
在本论文第三章，我们利用一种两亲性多嵌段高分子—PNIPAM-seg-PS，研究了高分子每个链段甚至每个重复单元对界面吸附的贡献。它在不同的基
2004
官林大学俘士拳位论文
底上表现出不同的吸附性质:在疏水基底上是疏水的PS嵌段吸附，而在亲
水基底上则是亲水的PNIP叭M嵌段吸附.在疏水基底上，我们得到了规则的
多峰力曲线，每个峰对应着单个PS嵌段的界面脱附力。我们还发现，PS脱
附力与拉伸速率的对数成正比，这表明PS在界面的吸附/脱附是个较慢的动
态过程。我们推测，平均每个PS重复单元对界面脱附力的贡献为1.3一2.1 pN。
在本论文第四章，研究了含有间隔基团的强聚电解质PAMPS的界面吸附
性质。我们发现，离子强度和主链电荷线密度均不影响PAMPS单链的界面
脱附力，只影响其抗拉强度。这清楚地表明，即使是强聚电解质也有明显的
疏水性。我们将这一性质归因于引入的间隔基团。
由于高分子的缠结特性以及表面富集作用，单分子力谱实验样品制备上
的困难一直困扰着相关的研究人员。在本论文第五章，我们针对这个问题，
提出了一种简易的新型样品制备方法，有效地克服了这个难题。此方法利用
自组装单层膜的缺陷，成功地将一种高分子分散在基底表面，并探测了其单
链界面脱附力。
在本论文最后一章，总结了全部论文的工作并探讨了高分子的界面吸附
问题。
The science of macromolecules at interfaces is an interdisciplinary field that deals with the phenomena, composition, structure, morphology, properties and the energy of macromolecular materials at interfaces. It is regarded as one of the growth points in the modern science and technology. With the emersion of atomic force microscope (AFM), the study of single macromolecular chain at interfaces becomes possible. Utilizing the AFM based technique, single molecule force spectroscopy (SMFS), this dissertation attempted to detect directly the information of single macromolecular chain at interfaces.
In Chapter 1, the science of macromolecules at interfaces is reviewed. Some common characterization methods are summarized. The AFM as well SMFS are specially introduced. The feasibility of SMFS on the study of single chain properties at interfaces is discussed.
In Chapter 2, the SMFS of poly(4-vinylpyridine) (P4VP) is studied. The typical force curve of P4VP presents a saw-tooth pattern, which may correspond
to the loop conformation of P4VP at interface. A statistical analysis finds that the desorption force of a single anchor point is ~180 pN, which is much larger than the s trength o f a s ingle H-bond. T his finding i ndicates t hat b esides H -bonding, other interactions also contribute to the interaction at interface.
In Chapter 3, we used a novel amphiphilic segmented polymer -PNIPAM-seg-PS to study t he contribution of a m onomer unit on the interfacial interaction. This polymer behaves differently on various substrates, depending on the hydrophobicity of the substrate. On hydrophilic substrate, the PNIPAM segments anchor, while on hydrophobic substrate, the PS segments adsorb. The SMFS of PNIPAM-seg-PS on a hydrophobic substrate presents regular saw-tooth pattern, each peak corresponds to the desorption of an individual PS segment from the substrate. The desorption force increase with the rise of stretching velocity implies that the adsorption/desorption progress of PS segment at interface is a slow, dynamic one. We estimate that each styrene monomer contributes 1.3~2.1 pN to the desorption force.
In Chapter 4, the SMFS of a strong polyelectrolyte (PAMPS) is studied, in terms of desorption and elongation. We find that the ionic strength and the linear charge density do not affect the interfacial force between the single PAMPS chain. This result implies that hydrophobic interaction dominates the adhesion force between polymer and substrate, even if strong polyelectrolyte is used. We attribute the phenomena to the introduced spacer between the polymer backbone and the charged groups.
The preparation of a "single-molecule" sample is a key issue in SMFS. Due to the entanglement of polymer chains and the effect of surface concentration enrichment, the sample preparation of SMFS feazes the research community. In Chapter 5, we propose a novel method for the sample preparation by utilizing the
IV
defects of the self-assembly monolayers. With this method, the polymer chains are separated individually at the surface, and the desorption force of single chain from substrate is successfully measured.
In Chapter 6, the whole dissertation is summarized and discussed.
引文
1．Adamson，A．著，顾惕人译，《表面的物理化学》，第三版，科学出版社，北京，1984．
2．段世铎，谭逸玲，《界面化学》，高等教育出版社，北京，1990．
3．张开，《高分子界面科学》，中国石化出版社，北京，1997．
4．沈钟，王果庭，《胶体与表面化学》，化学工业出版社，北京，1991．
5. Stromberg, R; et al J. Phys. Chem 1965, 69, 3955.
6. Baijal, M. Plastic Polymer Science and Technology, Chap 9, John Wiley, New York, 1982.
7. Peterson, C.; Kwei, T. J. Phys. Chem. 1961, 65, 1330.
8. Elias, H. Macromolecule, V. 1, Plenum Press, New York, 1977.
9．张开，《高分子物理学》，化学工业出版社，北京，1992．
10. Jenckel, E; Rumbach, B. Z. Elektrochem. 1951, 55, 612.
11. Sun, J.; Wu, T.; Zhang, X. et al Chem. Commun. 1998, 1853.
12. Bertrand, P.; Jonas, A.; Laschewsky, A.; Legras, R. Macromol. Rapid Commun. 2000, 21, 319.
13. Wang, L.; Cui, S.; Zhang, X. et al Langmuir 2000, 16, 10490.
14. Fu, Y.; Zhang, X. et al Macromolecules 2002, 35, 9451.
15. Binnig, G.; Quate, C.; Gerber, C. Phys. Rev. Lett. 1986, 56, 930.
16．博士学位论文，邹勃，吉林大学，2002．
17. Drummond, C.; Senden, T. Colloids Surfaces A: Physicochem. Eng. Aspects, 1994, 87, 217.
18. Radmacher, M. IEEE Engr. Med. Biol. 1997, 16, 47.
19. Noy, A.; Vezenov, D.; Lieber, C. Annu. Rev. Mater. Sci. 1997, 27, 381.
20. Hinterdorfer, P.; Baumgartner, W.; Gruber, H.; Schilcher, K.; S chindler, H.
Proc. Natl. Acad. Sci. USA 1996, 93, 3477.
21. Ludwig, M.; Dettmann, W.; Gaub, H. Biophys. J. 1997, 72, 445.
22. Butt, H. Biophys. J. 1991, 60, 1438.
23. Butt, H. Biophys. J. 1992, 63, 578.
24. Heinz, W.; Hoh, J. Biophys. J. 1999, 76, 528.
25. Baker, A.; Helbert, W.; Sugiyama, J.; Miles, M. Biophys. J. 2000, 79, 1139.
26. Winkel, H.; Miles, M.-Polymer 2000, 41, 2313.
27. Butt, H.; Wolff, E.; Gould, S.; Dixon-Northern, B.; Peterson, C.; Hansma, P. J. Struct. Biol. 1990, 105, 54.
28. Radmacher, M.; Tillmann, R.; Fritz., M.; Gaub, H. Science 1992, 257, 1900.
29. Schabert, F.; Henn, C.; Engel, A. Science 1995, 268, 92.
30. Hansma, H.; Pietrasanta, L.; Auerbach, I.; Sorenson, C.; Golan, R.; Holden, P. J Biomater. Sci., Polym. Ed. 2000, 11,675.
31. Hansma, H.; Hoh, H. Annu. Rev. Biophys. Biomol. Struct. 1994, 23, 115.
32. Janshoff, A.; Neitzert, M.; Oberd6rfer, Y.; Fuchs, H. Angew. Chem. 2000, 11:2 3346; Angew. Chem. Int. Ed. 2000, 38, 3212.
33. Oberhauser, A.; Marszalek, P.; Erickson, H.; Fernandez, J. Nature 1998, 393, 181.
34. Oesterhelt, F.; Rief, M.; Gaub, H. New J. Phys. 1999, 1, 6.1.
35. Li, H.; Liu, B.; Zhang, X.; Gao, C.; Shen, J.; Zou, G. Langmuir 1999, 15, 2120.
36. Rief, M.; Oesterhelt, F.; Heymann, B.; Gaub, H. Science 1997, 275, 1295.
37. Hugel, T.; Grosholz, M.; Clausen-Schaumarm, H.; Pfau, A.; Gaub, H.; Seitz, M. Macromolecules 2001, 34, 1039.
38．博士学位论文，张文科，吉林大学，2002．
39. Hugel, T.; Seitz, M. Macromol. Rapid Commun. 2001, 22, 989.
2．段世铎，谭逸玲，《界面化学》，高等教育出版社，北京，1990．
3．张开，《高分子界面科学》，中国石化出版社，北京，1997．
4．沈钟，王果庭，《胶体与表面化学》，化学工业出版社，北京，1991．
5. Stromberg, R; et al J. Phys. Chem 1965, 69, 3955.
6. Baijal, M. Plastic Polymer Science and Technology, Chap 9, John Wiley, New York, 1982.
7. Peterson, C.; Kwei, T. J. Phys. Chem. 1961, 65, 1330.
8. Elias, H. Macromolecule, V. 1, Plenum Press, New York, 1977.
9．张开，《高分子物理学》，化学工业出版社，北京，1992．
10. Jenckel, E; Rumbach, B. Z. Elektrochem. 1951, 55, 612.
11. Sun, J.; Wu, T.; Zhang, X. et al Chem. Commun. 1998, 1853.
12. Bertrand, P.; Jonas, A.; Laschewsky, A.; Legras, R. Macromol. Rapid Commun. 2000, 21, 319.
13. Wang, L.; Cui, S.; Zhang, X. et al Langmuir 2000, 16, 10490.
14. Fu, Y.; Zhang, X. et al Macromolecules 2002, 35, 9451.
15. Binnig, G.; Quate, C.; Gerber, C. Phys. Rev. Lett. 1986, 56, 930.
16．博士学位论文，邹勃，吉林大学，2002．
17. Drummond, C.; Senden, T. Colloids Surfaces A: Physicochem. Eng. Aspects, 1994, 87, 217.
18. Radmacher, M. IEEE Engr. Med. Biol. 1997, 16, 47.
19. Noy, A.; Vezenov, D.; Lieber, C. Annu. Rev. Mater. Sci. 1997, 27, 381.
20. Hinterdorfer, P.; Baumgartner, W.; Gruber, H.; Schilcher, K.; S chindler, H.
Proc. Natl. Acad. Sci. USA 1996, 93, 3477.
21. Ludwig, M.; Dettmann, W.; Gaub, H. Biophys. J. 1997, 72, 445.
22. Butt, H. Biophys. J. 1991, 60, 1438.
23. Butt, H. Biophys. J. 1992, 63, 578.
24. Heinz, W.; Hoh, J. Biophys. J. 1999, 76, 528.
25. Baker, A.; Helbert, W.; Sugiyama, J.; Miles, M. Biophys. J. 2000, 79, 1139.
26. Winkel, H.; Miles, M.-Polymer 2000, 41, 2313.
27. Butt, H.; Wolff, E.; Gould, S.; Dixon-Northern, B.; Peterson, C.; Hansma, P. J. Struct. Biol. 1990, 105, 54.
28. Radmacher, M.; Tillmann, R.; Fritz., M.; Gaub, H. Science 1992, 257, 1900.
29. Schabert, F.; Henn, C.; Engel, A. Science 1995, 268, 92.
30. Hansma, H.; Pietrasanta, L.; Auerbach, I.; Sorenson, C.; Golan, R.; Holden, P. J Biomater. Sci., Polym. Ed. 2000, 11,675.
31. Hansma, H.; Hoh, H. Annu. Rev. Biophys. Biomol. Struct. 1994, 23, 115.
32. Janshoff, A.; Neitzert, M.; Oberd6rfer, Y.; Fuchs, H. Angew. Chem. 2000, 11:2 3346; Angew. Chem. Int. Ed. 2000, 38, 3212.
33. Oberhauser, A.; Marszalek, P.; Erickson, H.; Fernandez, J. Nature 1998, 393, 181.
34. Oesterhelt, F.; Rief, M.; Gaub, H. New J. Phys. 1999, 1, 6.1.
35. Li, H.; Liu, B.; Zhang, X.; Gao, C.; Shen, J.; Zou, G. Langmuir 1999, 15, 2120.
36. Rief, M.; Oesterhelt, F.; Heymann, B.; Gaub, H. Science 1997, 275, 1295.
37. Hugel, T.; Grosholz, M.; Clausen-Schaumarm, H.; Pfau, A.; Gaub, H.; Seitz, M. Macromolecules 2001, 34, 1039.
38．博士学位论文，张文科，吉林大学，2002．
39. Hugel, T.; Seitz, M. Macromol. Rapid Commun. 2001, 22, 989.