1. Methods Micro-contact printing Monolayer UV mask Micro-lithography Limited by wavelength X ~  m ~ 10nm Nano-writing Phase separated Langmuir-Blodgett Films Oriented block co-polymers Intermolecular interaction X~ nm

2. Nanoisland matrix Chemical Functionalities Differing in size and type Examples: CH 3 -, NH 2 -, CF 3 -, COOH-, halide, ethylene oxide Island Surfaces are Formed By Using SAMs with Two Different Functional Groups

3. Temp : 22 0 C OTS Dehydrated Substrate In 1.1 mM APhMS 60 sec rinse in toluene In 1.1 mM OTS soln 60 min CHCl 3 rinse 15 min 8 Å Recessed Islands of APhMS In OTS Background by Backfilling P-Aminophenyltrimethoxy silane mm Silicon wafer OH

4. OTS Ht difference :15 Å Temp : 22 0 C Dehydrated Substrate In 1.1 mM APhMS 60 sec rinse in toluene In 1.1 mM OTS soln 60 min CHCl 3 rinse 15 min Recessed Islands of APhMS In OTS Background by Backfilling octadecyltrichlorosilane mm Silicon wafer

5. Method B: Co-Adsorption Mixed monolayer of OTS and APS(NH 2 C 3 H 6 SiCl 3 ) Silicon wafer CH 3 23Å 6.5Å 30nm amine APhMS OTS octadecyltrichlorosilanes (OTS) P-aminophenyltrimethoxysilanes (APhMS)

6. Island Formation of Co-Adsorbed Self-assembling Surfactants APhMS islands in OTS Matrix 35 islands/µm 2, average diameter: 28 nm, distribution width: 10 nm 3:1 OTS:APhMS; Chloroform 2mM total concentration of silane

7. Effect of Composition 2 mM CHCl 3 solution, deposition time; 2 hrs OTS/APMS=1:3 OTS Pillars OTS/APMS=3:1 APhMS islands OTS/APMS=1:1 OTS Pillars

8. Contact Angles: 80 Contact Angles: 41 Solvent Effect 2 mM solution (OTS/APhMS=1:1), deposition time: 2 hrs, CHCl 3 Toluene CCl 4 THF Contact Angles: 103 Contact Angles: 98

9. Effect of Solvent on Composition Monolayer Composition in Mixed Adsorption is a balance between relative affinity of surfactants to the depositing solvent interfacial energy between the film formed and the depositing solution

10. Sequential Adsorption for Mixed Monolayers Partial OTS monolayers with desired islands Low density surrounding OTS islands at10 0 C. SOLVENT SUBSTRATE OTS SOLUTION SUBSTRATE SECOND SILANE SOLUTION Rinse Fill surrounding with second silane

11. Temperature Effect 10 0 C ~22 0 C Reduced Secondary growth at low temperatures

12. Control of Morphology and Chemical Functionality at Nanometer Scale Mixed monolayer of OTS and BrUTS(BrC 11 H 22 SiCl 3 ) Silicon wafer CH 3 23Å 15Å 30nm to 10 µmBr 10  22 Height Friction

13. Control of Morphology at Angstrom Scale Mixed monolayer of OTS and DTS(C 10 H 21 SiCl 3 ) Silicon wafer CH 3 23Å 14Å 30nm to 10 µm 10  Height Friction

14. Nano-dots 55 Low OTS concentration & low deposition time

15. pH 8... Imaging at loads of ~ 1.5 GPa (70 nN)... 3 scans unworn worn... leads to rapid pit formation and facile dissolution

16. pH 5... Imaging at loads of ~ 0.7 GPa (58 nN)...10 scans... friction appears to be decreasing... surface roughens by ~ 0.5 Å

17. ... charging followed by surface atom abstraction is observed native In wear pH 5... Imaging at loads of ~ 1.6 GPa (96 nN)... 10 scans

18. pH 3... Imaging at loads of ~ 0.7 GPa (56 nN)...83 scans!... no wear to be found, even with increased loads!... no charging due to low [OH - ].

19. Studies of Lubricant Films: Functionalization of AFM tip and Particle Surface CH 3 (CH 2 ) 17 -Si(OCH 2 CH 3 ) 3 (OTE) Functionalization with organosilanes: Si(100) Contact angle with water on OTE modified particle films - Forms self-assembled monolayers on silica. - Have been used in MEMS devices. AFM Tip

20. Thiols on Au… Salmeron and Liu

21. Nanopatterning of Surfaces

22. AFM STM

23. Liu et al, Acc. Chem. Res. 33 (2000) 457. C 18 S/Au C 18 S implanted in a C 10 S/Au

24. Mirkin dip-pen lithography Allows fab in air! Amro et al, Langmuir 16 (2000) 3006.