The reductive and oxidative desorption of a BODIPY labeled alkylthiol self-assembled monolayer (SAM) on Au was studied using electrochemical methods coupled with fluorescence microscopy and image analysis procedures to monitor the removal of the adsorbed layer. Two SAMs were formed using two lengths of the alkyl chain (C10 and C16). The BODIPY fluorescent moiety used is known to form dimers which through donor-acceptor energy transfer results in red-shifted fluorescence. Fluorescence from the monomer and dimer were used to study the nature of the desorbed molecules during cyclic step changes in potential. The reductive desorption was observed to occur over a small potential window (0.15 V) signified by an increase in capacitance and in fluorescence. Oxidative readsorption was also observed through a decrease in capacitance and a lack of total removal of the fluorescent layer. Removal by oxidative desorption occurred at positive potentials over a broad potential range near the oxidation of the bare Au. The resulting fluorescence showed that the desorbed molecules remained near the electrode surface and were not dispersed over the 20 s waiting time. The rate of change of the fluorescence for oxidative desorption was much slower than the reductive desorption. Comparing monomer and dimer fluorescence intensities indicated that the dimer was formed on the Au surface and desorbed as a dimer, rather than forming from desorbed monomers near the electrode surface. The dimer fluorescence can only be observed through energy transfer from the excited monomer suggesting that the monomers and dimers must be in close proximity in aggregates near the electrode. The fluorescence yield for longer alkyl chain was always lower presumably due to its decreased solubility in the interfacial region resulting in a more efficient fluorescence quenching. The oxidative desorption process results in a significantly etched or roughened electrode surface suggesting the coupling of thiol oxidative removal and Au oxide formation which results in the removal of Au from the electrode.

The introduction of polymer chemistry in undergraduate science courses is becoming more popular in recent years, introducing content into the relationships between polymer structure and physical properties in a variety of contexts. However, active learning techniques, outside of laboratory experience, for teaching polymer chemistry are extremely limited. The ChemEscape project has successfully integrated escape-room type puzzle design and course specific learning objectives into an interactive learning experience. The novel battle box design, a self-contained puzzle unit, allows for puzzles to be easily transported and applied as a teaching tool in large postsecondary classrooms as well as an outreach tool. Herein, we describe the design and application of a series of new polymer puzzles, focusing on tacticity, elasticity, and hydrophobicity, into the battle box design as well as an all-in-one backdrop design. Puzzles are scaffolded to allow for all learning to be combined in the final puzzle solution as well as a workbook provided for participants to record observations and learning during the puzzles’ solutions.

The potential-controlled incorporation of DOPC liposomes (100 nm diameter) into an adsorbed octadecanol layer on Au(111) was studied using electrochemical and in situ fluorescence microscopy. The adsorbed layer of octadecanol included a small amount of a lipophilic fluorophore-octadecanol modified with BODIPY-to enable fluorescence imaging. The deposited octadecanol layer was found not to allow liposomes to interact unless the potential was less than -0.4 V/SCE, which introduces defects into the adsorbed layer. Small increases in the capacitance of the adsorbed layer were measured after introducing the defects, allowing the liposomes to interact with the defects and then annealing the defects at 0 V/SCE. A change in the adsorbed layer was also signified by a more positive desorption potential for the liposome-modified adsorbed layer as compared to that for an adsorbed layer that was porated in a similar fashion but without liposomes present in the electrolyte. These subtle changes in capacitance are difficult to interpret, so an in situ spectroscopic study was performed to provide a more direct measure of the interaction. The incorporation of liposomes should result in an increase in the fluorescence measured because the fluorophore should become further separated from the gold surface, reducing the efficiency of fluorescence quenching. No significant increase in the fluorescence of the adsorbed layer was observed during the potential pulses used in the poration procedure in the absence of liposomes. In the presence of liposomes, the fluorescence intensity was found to depend on the potential and time used for poration. At 0 V/SCE, no significant change in the fluorescence was observed for defect-free adsorbed layers. Changing the poration potential to -0.4 V/SCE caused significant increases in the fluorescence and the appearance of new structural features in the adsorbed layers that were more easily observed during the desorption procedure. The extent of fluorescence changes was found to be strongly dependent on the nature of the adsorbed layer under investigation, which suggests that the poration and liposome interaction are dependent on the quality of the adsorbed layer and its ease of poration through changes in the electrode potential.

Educational games and experiential learning experiences are integral alternative learning tools, growing in popularity in postsecondary classrooms. As the introduction of green chemistry concepts, and by extension polymer chemistry, continues to grow, the need for alternative learning tools describing the synthesis, function, and design of polymers is increasing. In response, we describe a series of functional group and polymer chemistry games and hands-on activities including a card game, boardgame, and bioplastic synthesis activity. A unique group molecule building quiz is also described as a related assessment method. The activities were introduced over two years in a second-year Materials Chemistry for Engineers course, approximately 170 students per year. Overall, the activities were well received by students and provided them with an entertaining way to review first-year chemistry concepts, introduce polymer properties, and apply their own design skills to an application. Students reported the games and activities as being enjoyable as well as helpful in understanding material and polymer chemistry concepts.