Research And Education - Increasing Student Participation In Research At Internationally Recognized

User Facilities Tabbetha Dobbins, Louisiana Tech University

DMR 0508560

The motivation for this study is to develop self-assembly of polyelectrolytes under non-aqueous conditions– so that polyelectrolyte films may be deposited over the surface of hygroscopic metal hydrides (used for hydrogen storage). Self-assembly was accomplished using non-aqueous conditions with formamide as a working solvent. This is a key step in developing new catalysis schemes for metal hydrides because few LbL self assembly studies using nonaqueous solvents have been reported Polystyrene-sulfonate (PSS) and polyallylamine hydrochloride (PAH) polyelectrolyte films were deposited onto planar substrates and colloidal hydride particles. Figure 1 shows quartz crystal microbalance tracking of film growth from formamide. Figure 2 shows surface charge associated with alternately depositing positive (polycations) and negative (polycations) layers. Figure 3 shows surface coverage of hydrides– the scanning microscopy image (left) may be compared with the carbon x-ray image (right) to show conformal coverage of the polyelectrolytes.

5m5mFigure 1. Thickness of the nanofilms determined using QCM measurements taken for 5 minutes and 10 minutes self-assembly time from formamide as a working solvent.

Figure 2. Surface charge (mV) measured to show the reversal of charges with each oppositely charged layer.

Figure 3. Energy Dispersive X-ray mapping of NaAlH4 (bilayer of

PSS/PAH) showing the conformal step coverage of carbon

Kamineni V., Lvov Y.M., Dobbins T.A., “Layer-by-Layer Nanoassembly Using Formamide as a Working Solvent”, Langmuir (2007) in press, 10.1021/la700465n S0743-7463(70)00465-1.

For NMA workshop info, visit http://www2.latech.edu/~tdobbins/

The Nanoscale Measurement and Analysis (NMA) workshop is an NSF sponsored outreach program targeted towards junior and senior level high school students with the goal of introducing nanotechnology to the students using hands-on laboratory modules.  The workshop is presented by Asst. Prof. Dobbins and undergraduate students from Louisiana Tech University and Grambling State University (where Dobbins holds a joint faculty appointment) in the high school classroom. During the Spring of 2006, the workshop was presented at two rural high schools in Northern Louisiana (Choudrant High and Simsboro High)—impacting approximately 50 students in total.  During the spring of 2007, the workshop was presented at two additional high schools, Carroll High School (located in the urban community of Monroe, LA) and The Louisiana School for Math, Sciences and Arts (LSMSA) (a private high school located in Nachitoches, LA)– impacting approximately 25 students. The workshop is performed during the 1 hour 15 minute high school class periods with an optional follow-up tour of the IfM taking place at a later date.  The NMA workshop covered:• Surface Area per Unit Volume• Top Down/Bottom Up Nano- Manipulation• Ball Milling (with optical microscopy and image analysis)• Creating Carbon Nanotube Suspensions• UV/Vis Spectroscopy • Nanotechnology TimelineIn 2007, a assessment survey was administered in the form of a 10 question exam. The assessment showed an average increase of 26 points on the post-test relative to the pre-test.

GSU students Kristan Moore and Nicholas Dailey preparing the demonstration units at Carroll High School.

Research And Education - Increasing Student Participation In Research At Internationally

Recognized User Facilities Tabbetha Dobbins, Louisiana Tech University

DMR 0508560

GSU student Dailey works with Carroll High student at the UV/Vis spectrometer.

High School teacher Nyoka Freeman (2nd from left) acted as a workshop participant along-side her students.

Four LSMSA students report their findings from the workshop to their classmates using posters drawn on newsprint.

In 2006, LaTech studentRichard Chevious demonstrates the “create your own suspension” module at Choudrant High.