Growth and Characterization of Solution Based Self-Assembled Metal-Organic Nanofibers
M. E. Salmon*, P.E.
Russell* and E.B.
Troughton Jr.**
Self-assembled structures are of increasing interest today due to the rapid progression of nano-scale engineering applications. In past years much attention has been placed on understanding the formation and properties of monomolecular thin films, also known as self-assembled monolayers (SAMS) and more recently the investigation of 3-dimensional self-assembled structures such as quantum dots, nanotubes, and nanofibers.
A film of evaporated Aluminum metal is deposited onto glass and is then immersed in a sealed container containing a solution of 0.1 wt% Methylphosphonic acid (MPA) in absolute Ethanol. Atomic Force Microscopy (AFM) is used to examine the Aluminum surface over time. It is observed that over a period of 30 days, often highly branched, fibrous structures, ranging in size from 5nm – 50nm wide and sometimes eventually as long as 10 um, will grow and cover the entire surface of the Aluminum forming what resembles a non-woven fabric. Using a tube furnace, previously grown fiber samples were heated in succession from 50 oC to 500 oC in 50 oC steps for 1 hour under both ambient and Nitrogen atmospheres then quenched to room temperature upon removal and imaged with AFM. It was found that no morphology changes occur until ~ 425 oC and what appears to be melting of the fibers occurs at ~ 450 oC. Various nanoindentation and scratching experiments have been done to better understand the mechanical properties of of both the individual fibers as well as the entire mat. In addition to AFM, both Scanning Electron Microscopy (SEM) and Scanning Transmission Electron Microscopy (STEM) in conjunction with Energy Dispersive Spectroscopy (EDS) are used to corroborate AFM results as well as show there is a localization of the Al and P to the fiber structure. Fibers are also observed when bulk Gallium is subjected to the same 0.1 wt% MPA solution. The corresponding STEM/EDS of the fibers also show a localization of Ga and P to the fibers.
Industrial Applications of Scanned Probe-Based
Nanomechanical Testing
Louis T. Germinario
Global Polymers & Research Analytical Services
Eastman Chemical Company
Kingsport, TN 37662
SPM has rapidly evolved into an indispensable tool for characterization of
mechanical properties of nanostructured materials. AFM-based nanoindentation
provides an excellent means for both imaging and measuring mechanical
properties from very small volumes. The ability to selectively position
the testing probe on features of interest and both apply a load and record the
displacement of the indenter during the indentation process provides a useful
tool for manipulating the structural, mechanical and chemical makeup of
nanomaterials. Advances in applications of SPM-based nanomechanical testing
will be reviewed with an emphasis on examples drawn from industrial problem
solving.
Roll-Your-Own Microscopy Program
Dr. Dennis B. Barr
Senior Research Associate
Eastman Chemical Company
With the ease of programming provided by software
such as Microsoft Visual Basic and Borland’s Delphi and with the availability
of “drop-in” components supplied by various third-part vendors, it has become
much simpler to write your own specialized computer program for microscopy
applications. Today there are many good
programs available for microscopy applications, but you may find that none of
them meet your specific needs. This
talk is designed to demonstrate the ease with which microscopy programs may be
written and encourage the audience to “roll their own”.