Nanotechnology Learning Modules and Atomic Force Microscopy of Neanderthal Stone Tools

This thesis uses a Veeco Icon Atomic Force Microscope (AFM) to educate undergraduate students about the nanoscale world and to perform archaeological research. In chapter 2, an educational resource is developed to provide hands-on nanotechnology experience for undergraduate students. With the rapid growth of atomic force microscopy at many levels of industry and academia, it is important to expose the next generation to this technique. This learning module attempts to provide an experimental approach to learning about AFM phase imaging and its many applications. In chapters 3 and 4, AFM is used as one of several techniques for classifying the use of Neanderthal flint tools from Weasel Cave, Russia. These stone tools were identified as being used for tasks such as wood working, hide scraping, and meat cutting. Depending on the type of flint and the task involved, various degrees of abrasion occurred, leaving behind microwear polishes. These microwear traces are localized regions where the degree of polish is strongly influenced by the task being performed. The research presented in this thesis attempts to advance the study of microwear analysis using both qualitative and quantitative techniques: incident light microscopy, AFM, scanning electron microscopy, and optical interferometry

Investigations of Structure / Property Interrelationships of Organic Thin Films Using Scanning Probe Microscopy and Nanolithography

Studies of the surface assembly and molecular organization of organic thin films were studied using scanning probe microscopy (SPM) and scanning probe lithography (SPL). Systems of organic thin films such as n-alkanethiols and pyridyl functionalized porphyrins were characterized at the molecular level, and measurements of the conductive properties of polythiophenes containing in-chain cobaltabisdicarbollides were accomplished. Understanding the self-organization and mechanisms of self-assembly of organic molecules provides fundamental insight for structure/property interrelationships. Investigations of the surface assembly of 5,10-diphenyl-15,20-di-pyridin-4-yl-porphyrin (DPP) on Au(111) were done using SPL methods of nanoshaving and nanografting. Automated computer designs were developed for nanofabrication to provide local characterizations of the thickness of DPP films and nanostructures. Nanolithography was accomplished using DPP films as either matrix self-assembled monolayers (SAMs) or as molecules for nanofabrication. Results presented in this dissertation demonstrate that DPP forms compact layers on Au(111), which can be used for inscribing nanopatterns of n-alkanethiols. Arrays of DPP nanopatterns with precise geometries and alignment were fabricated within n-alkanethiols by nanografting, demonstrating nanoscale lithography with pyridyl porphyrins can be accomplished to produce an upright surface orientation on Au(111) mediated by nitrogen-gold chemisorption. Beyond research investigations, the applicability of atomic force microscopy (AFM) and advancements with automated SPL were applied for teaching undergraduate chemistry laboratories to introduce the fundamentals of surface chemistry and molecular manipulation. New classroom activities were developed for the Chemistry 3493 Physical Chemistry laboratory to give students “hands-on” training with AFM. Undergraduates were trained to prepare nanopatterns of n-alkanethiols using software to control the position, force and speed of the AFM tip for nanolithography experiments. The sensitivity and nanoscale resolution of current sensing AFM was applied for studies of the conductive properties of electropolymerized thin films of polythiophenes with cobaltabisdicarbollide moieties. Images acquired with AFM furnished views of the morphology of different polymers prepared on gold surfaces. Surface maps of the conductivity of electropolymerized films were acquired with AFM current images. These studies provide new insight of the effects of the bound cobaltabisdicarbollide moiety and coordinated metal centers for the electronic properties of the resulting conducting materials