In this paper, we report differential scanning calorimetry studies of the temperature and molar mass dependences for the primary and secondary crystallization behavior of bisphenol A polycarbonate (BAPC). The molar mass dependence of the crystallization rate is found to be much stronger during primary than during secondary crystallization, confirming our earlier claims that primary and secondary processes occur by significantly different mechanisms. Investigations of the secondary crystallization process suggest the existence of a crossover phenomenon from secondary crystal formation at low temperatures to isothermal lamellar thickening at high temperatures. While the results of our low-temperature studies of BAPC provide further support for the model developed in a previous publication on poly(arylene ether ether ketone), evidences from atomic force microscopy and calorimetry of isothermal lamellar thickening above the crossover temperature lead us to anticipate a more unified view of polymer crystallization.

This article describes a set of demonstrations and experiments involving a polymer product that can be used in a polymer chemistry lab course or incorporated into more traditional type chemistry courses (e.g., general chemistry and instrumental analysis). Through thermal analyses of poly(ethylene terephthlate) (PET) bottles, students are introduced to the relationships between processing, morphology, and physical properties of polymer materials. Although the complete set of exercises incorporates differential scanning calorimetry, important relationships can be demonstrated with just PET bottles and a laboratory oven. A "real-world" problem-solving experience is provided through a multi-week lab project in which students assume the roles of analytical chemists for a hypothetical PET bottle manufacturer.

An environmental chemistry service-learning project was implemented by Greenville University in coordination with the local county health department to test the quality of well water for residents in a five-county region of southern Illinois. Well owners attended a student run well water testing "kickoff meeting", received testing kits, collected their water samples as instructed, and returned the kits to the health department on a predetermined date. Student investigators analyzed the water samples for a range of contaminants, including the concentrations of eight different metals (including lead and arsenic), nitrate ion, and the presence of coliform and Escherichia coli bacteria. Values for pH and water hardness were also determined. The results were communicated to well owners through well water testing reports and at an "interpretation meeting", where students met with the well owners to help them understand and interpret their results. To date, over 130 wells have been tested. The project provided student investigators positive service-learning experiences while delivering many southern Illinois well owners important water quality information.

This sequence of three guided-inquiry labs is designed for a secondsemester general chemistry course and challenges students to discover basic theoretical principles associated with 13 C NMR, 1 H NMR, and IR spectroscopy. Students learn to identify and explain basic concepts of magnetic resonance and vibrational spectroscopy; collect and interpret sets of 13 C NMR, 1 H NMR, and IR spectra; and correctly identify functional groups and chemical structures for a variety of simple organic compounds. Student survey data, along with in-lab observations of student interactions, lead to the conclusion that these lab experiences enhance student interest, increase communication between students, and improve their ability to explain and correct their own misconceptions.

Gas chromatographic analysis of many surfactants has been limited due to tailing and adsorption of the analyte on the stationary phase of the column by polar groups such as hydroxyl and amine functionalities. Silylation of these surfactants reduces these unfavorable interactions by replacement of the active hydrogen with a silyl group Si-(CHah. Although silylation generally is avoided in aqueous solutions, some surfactants have been silylated successfully in aqueous solutions. These include fatty acids and their hydroxamine soaps, fatty and other alcohols, fatty amines, and some inorganic acids. Quantitative results have been confirmed by stoichiometric, gas chromatographic and infrared data.