SGER: Breaking the Size-Threshold for Thermal Analysis of Polmer Thin-films: NanoDSC

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

TECHNICAL SUMMARY: Polymers have unusual properties when confined to very small nanometer-scale dimensions. Spatial confinement of materials in the form of thin films, small pores, or islands can have a dramatic effect on their thermodynamic properties. Recently, some experiments have shown that spatial confinement can have a large effect on the glass transition temperature Tg for polymers. Spatial confinement is also important for thin films consisting of self-assembled monolayers (SAM). In addition, processing polymers at very fast heating/cooling rates also has a dramatic effect of the material properties. Commercial differential scanning calorimeters (DSC) are the tools often used for analysis investigations of polymer material. Unfortunately, conventional DSC instruments can not be used for these type of experiments because they lack sensitivity and have scan rates which are too slow. However recently a new calorimetry technique Nanocalorimetry has been developed which has the capability of measuring extremely small samples at extremely fast cooling/heating rates. This proposal focuses on using the NanoDSC to investigate spatial confinement of the glass transition temperature of thin film polymers and the thermodynamic properties of SAMs. This research will develop methods to measure heat capacity during the cooling cycle of a scan and bridge the gap between the slow scan rates of conventional DSC and the fast rates of Nanocalorimetry. NON-TECHNICAL SUMMARY: This research is important because much of the advances in materials technology in the next generation are expected to be made by fabricating and manipulating materials at the nanometer scale dimensions. The research will provide the fundamental tools needed to examine materials at such small microscopic levels and thus allowing analysis of material that is now inaccessible when using conventional techniques. The impact of this research is to add to the infrastructure of the country for basic science as well as for technology in a critical research area. Nanocalorimetry will be especially useful in a wide range of characterization needs in nanotechnology and will be particularly important in the polymer, microelectronic, and biomedical industries. The broad impact of this research will include the education and training of graduate students in the field of nano-technology. Nanocalorimetry has already generated international collaborations and this research will increase this effort.