Research Interests

Dr. R. Larsen’s research efforts focus on the use of research proven pedagogies to incorporate cutting edge chemistry into large enrollment introductory chemistry courses and on the assessment of the designed instructional materials at meeting their educational objectives.  His most recent work has involved the development and implementation of activities involving nanotechnology within large enrollment introductory chemistry courses.

Nanotechnology has been selected as a focus area due to the broad and significant impact it is having on many areas including electronics, the environment, chemical and pharmaceutical industries, biotechnology, and consumer products.  The far-reaching and diverse applications that are being realized for nanotechnology underscore the importance of education that supports future development at this important scientific frontier. 

For making the greatest impact, the lower-division courses within the curriculum represent important targets.  These lower-division courses are at the crossroads of several different career paths.  Among the diverse audience served by introductory courses, at least three target groups can be identified that are relevant to the future development of technology (and nanotechnology) in our society: (1) a large portion of the nation’s future political and business leaders,  (2) future K-12 teaching professionals, and (3) future career scientists, engineers, and medical professionals.  For example, at the University of Iowa three first year chemistry courses (004:005, 004:007, and 004:011) together have a cumulative enrollment of over 2800 annually.  This represents a large fraction of the Universities undergraduate student population, which has recently maintained a freshman class size of approximately 5000 students.  Many among the population served by these courses will impact future social and economic development, regionally, nationally and beyond.

The applications that are being impacted by nanotechnology offer a rich spectrum spanning a vast intellectual range.  However, to students in undergraduate chemistry courses, a large fraction of the intellectual bandwidth of nanotechnology is simply mismatched to the students’ current scientific knowledge. For this reason, students cannot internalize much of the new information.  Therefore, one of the primary tasks of science educators is to filter the vast information and to find the key ideas and concepts within nanotechnology that will resonate with other ideas within the students’ minds and within the curriculum and thereby achieve deep learning. 

In tuning nanoscience to resonate with other ideas that are present in introductory chemistry courses, we have developed and implemented course activities in which students synthesis and characterize colloidal quantum dots of cadmium selenide (CdSe) and cadmium selenide sulfide (CdSe_xS_1-x) alloys.  One of the principal motivating factors in selecting these systems is that they visually display colorful trends that are correlated to the physical size of nanosized crystallites. This visual trend vividly illustrates one of the central themes in nanoscience: physical properties often depend on physical size within the nanoregime and is compatible with the active pedagogical style used to present the materials.

Fig. 1- Student synthesized samples of colloidal quantum dots irradiated with white light (top) and long wave ultraviolet (bottom).

Additional Link: Nanotechnology and Nanoscience Institute at The University of Iowa (NNI@UI)