This presentation is about the application of Atomic Force Microscopy in Polymer Science and Composites

1. Atomic Force Microscope By Vimal Kumar

2. Outline: History of AFM Principle of AFM Instrumentation of AFM Modes of operation of AFM Forces & Force Distance curve Applications of AFM in Polymers

3. History of AFM Development of Scanning tunneling microscopy (STM) in 1981 earned its inventors, GerdBinng and Heinrich Rohrer (at IBM Zürich), the Nobel Prize in Physics in 1986 Based on the above work Binnig, Quate and Gerber invented the first AFM in 1986 Heinrich Rohrer Gerd Binnig http://en.wikipedia.org/wiki/AFM

4. Outline: History of AFM Principle of AFM Instrumentation of AFM Modes of operation Forces & Force Distance curve Applications of AFM

5. Principle of AFM:

6. Outline: History of AFM Principle of AFM Instrumentation of AFM Modes of operation Forces & Force Distance curve Applications of AFM

7. Block diagram of AFM: http://www.farmfak.uu.se/farm/farmfyskem-web/instrumentation/images/afm.gif

8. Ref: Synthetic Polymeric Membranes Characterization by Atomic Force Microscopy Page.26

9. Piezoelectric Scanner: http://nanohub.org/resources/520/play

10. The Beam Deflection method Courtesy- J. Gomez-Herrero, UAM, Spain

11. Micro Cantilever of AFM Tip is made up of Silicon Nitride or Silicon Tip radius ranges from 10nm to 200nm,Normal radius is 50 nm Spring constant is 0.1 to 100 N/m Nowadays CNT tips were used for special applications. In this case radius will be 15nm to 10 nm

12. The Microcantilever – the force sensor

13. Needle AFM Tip Needle is fabricated with Ag2Ga material It is manufactured by Nano science Instruments It is available in varying lengths, diameters, and attachment angles Needle AFM tips are available in standard lengths of 1, 5, or 10 µm with a diameter of 50 nm. The simple geometry and high conductivity of the Needle probes provides a wide range of enhanced sensing and manipulation capabilities http://www.nanoscience.com/news/2009-Mar24.html

14. MWCNT AFM Tip: Ref: Appl. Phys. Lett., Vol. 82, No. 23, 9 June 2003

15. CNT V/S Conventional Image:

16. Thermocouple Tip: Here thermocouple probes were used for scanning the surface. It maps the local temperature and thermal conductivity of an interface. It can be used to detect phase changes in polymer blends Measuring material variations in Conducting Polymers. Hot-spots in integrated circuits http://en.wikipedia.org/wiki/Scanning_thermal_microscopy

17. Outline: History of AFM Principle of AFM Instrumentation of AFM Modes of operation Forces & Force Distance curve Applications of AFM

18. Modes of operation: AFM Can be operated in 3 modes 1)Contact Mode AFM 2)Non-Contact Mode AFM 3)Taping Mode AFM

20. Outline: History of AFM Principle of AFM Instrumentation of AFM Modes of operation Forces & Force Distance curve Applications of AFM

22. Force Distance Curve:

23. Other SPM Techniques: STM – Scanning Tunneling Microscopy LFM – Lateral Force Microscopy EFM – Electric Force Microscopy MFM – Magnetic Force Microscopy SCM – Scanning Capacitance Microscopy FMM – Force Modulation Microscopy SNOM – Scanning Near Field Optical Microscopy

24. Outline: History of AFM Principle of AFM Instrumentation of AFM Modes of operation Forces & Force Distance curve Applications of AFM in Polymer Science

25. AFM for morphology of polymers:

26. Dendrites of iPP: Ref: Microsc Microanal 9 (Suppl 2).2003

27. Spherulites: Ref: Microsc Microanal 9 (Suppl 2).2003

28. Crystallization(or)Spherulites formation: This AFM tapping/phase mode image series shows the crystallization of a polylactide spherulite, crystallized from the melt at 95°C http://www.polymermicroscopy.com/eng_afm_lacti1.htm

29. Some nano fillers have a nucleation effect on the crystallization of polymers, i.e. the number of nuclei is increased and the crystallization time of the sample reduced. Additionally the size of the crystalline superstructures, e.g. spherulites, decreases and the transparency of the sample might be improved. The example shows isotactic polypropylene with different amounts of the nano filler "Disperal® 20" (Sasol). With increasing filler content the size of the crystalline superstructures is clearly reduced. 1% Disperal® 0% Disperal 2% Disperal® 10% Disperal® Nano fillers Nucleation: Macromolecular Materials and Engineering (2008), 293(3), 218-227.

30. Block copolymer-Morphology The tapping/phase mode image shows the bulk-morphology of a poly(styrene-b-ethylene/butylene/styrene-b-styrene) tri-block-copolymer. http://www.polymermicroscopy.com/eng_afm_block.htm

31. Polymer Blends: This AFM tapping/phase mode image shows the bulk-morphology of a partially miscible blend of isotactic polypropylene (matrix) and of a non-crystalline polyethylene copolymer. Within the polyethylene phases single i-PP lamellae are visible. Phase dispersion in polymer blends Phase dispersion of ethylene propylene rubber (EPR) in impact copolymers (ICP) Ref: Microsc Microanal 9 (Suppl 2).2003 Miscibility of Branched Ethene Homopolymers with Iso- and Syndiotactic Polypropenes. Jürgen Marquardt, Ralf Thomann, Yi Thomann, Johannes Heinemann and Rolf Mülhaupt Macromolecules, 2001, 34, (25), 8669-8674

32. NanoFibre investigation Ref: Microsc Microanal 10(Suppl 2), 2004

33. NANOFIBRE BLEND INVESTIGATION Ref: Microsc Microanal 10(Suppl 2), 2004

34. NANOINDENDATION BY AFM

36. hc Depth of the residual indentation

37. Β Constant

38. ErMdulus

39. S stiffness (The slope of the curve, dP / dh)Where: Pmax = maximum presure applied Ar = area of the bore H= Harness http://en.wikipedia.org/wiki/Nanoindentation

40. NANO INDENTATION-I AFM is operated in force mode a diamond-tipped stainless steel cantilever probe is used and the dents from left to right were taken using compensation angles of 0, 10, 20, 30, 35, 40, 45, and 50 degrees Ref : M. R. VanLandingham, "The Effect of Instrumental Uncertainties on AFM Indentation Measurements," Microscopy Today, Issue No. 97-10, December 1997, pp. 12-15.

41. Nano pull out technique

42. Nano Pull Out Technique: Carbon nanotube(MWCNT) is used as tip for AFM Here Polyethylene-butene thin film(~300 nm) In this Polymer CNT interaction Force is found In this single CNT is Introduced then detached from the polymer . This test is very important when we reinforce CNT in the polymer in the process of Composite manufacturing. MWCNT AFM Tip: Ref: Appl. Phys. Lett., Vol. 82, No. 23, 9 June 2003

43. Exit Hole Exit hole length Ref: Appl. Phys. Lett., Vol. 82, No. 23, 9 June 2003

44. Pull out force is found to be 47 Mpa The normal force of conventional fibers is 10Mpa From it we can conclude that CNTs are better materials for composites then the fibers. Ref: Appl. Phys. Lett., Vol. 82, No. 23, 9 June 2003

45. AFM for polymer membranes

46. AFM for Membranes Pore size by TEM, SEM are very small when compared to AFM By Using AFM we can find the Pore Size, Density, Size Distribution, Pore Connectivity, Surface Roughness can be calculated. From above data we can calculate the Mean pore size ,Median pore size…etc The above date is very impotent when we want to design a good filtration equipment. AFM is a good Quality Control tool for the membrane process engineers

50. References: Polymer Microscopy By Linda C. Sawyer, David T.Grubb Synthetic Polymeric Membranes By K.C.Khulbe, C.Y.Feng, T.Matsuura Atomic Force Microscopy in Cell Biology By Bhanu P.Jena, J.K.heinrich Horber, American Society for Cell Biology Atomic Force Microscopy By Pier Carlo Braga, Davide Ricci Ref: Appl. Phys. Lett., Vol. 82, No. 23, 9 June 2003 M. R. VanLandingham, J. S. Villarrubia, W. F. Guthrie, G. F. Meyers, "Nanoindentation of Polymers: An Overview," in Macromolecular Symposia, 167, Advances in Scanning Probe Microscopy of Polymers, V. V. Tsukruk and N. D. Spencer, eds. (2001) 15-44. Miscibility of Branched EtheneHomopolymers with Iso- and SyndiotacticPolypropenes. Jürgen Marquardt, Ralf Thomann, Yi Thomann, Johannes Heinemann and Rolf Mülhaupt Macromolecules, 2001, 34, (25), 8669-8674 Macromolecular Materials and Engineering (2008), 293(3), 218-227. MicroscMicroanal 10(Suppl 2), 2004 Appl. Phys. Lett., Vol. 82, No. 23, 9 June 2003 www.nanoscience.com/news www.wikipedia.org www.google.com www.nanohub.com/online_onlinelectures

51. Questions?