With support from the Chemistry Research Instrumentation and Facilities: Multiuser program (CRIF:MU), the Department of Chemistry at the University of North Dakota will acquire a cyber-enabled high resolution scanning electron microscope (SEM). The University has designated nanotechnology as a focus for research and the microscope will be used by investigators at the University of North Dakota and at North Dakota tribal colleges to enhance nanochemistry research and education. Research activities that will be enabled by the new instrumentation include the design of new nanomaterials, such as nanotubes, nanowires, fluorescent nanoparticles, metal-modified silica nanoparticles and polymer-based nanocatalysts, and the characterization of these nanomaterials. Fundamental studies on the formation and characterization of secondary organic aerosols will provide significant information regarding the role of these substances in environmental pollution.
A scanning electron microscope probes a material by scanning it with a beam of electrons that interact with surface atoms to produce signals that contain high resolution images of the surface structure. Since the nanoparticles to be investigated in these studies can be as small as several nanometers in diameter, a high resolution SEM is an important tool for investigating their structures. This level of detail is indispensable in designing and characterizing new nanomaterials. The infrastructure made available with this grant will be used in teaching and training a broad range of young scientists, including significant numbers of Native American scientists, in important, cutting-edge, experimental methods.
We purchased a Hitachi SU-8010 scanning electron microscope (SEM). This new Hitachi SEM was released to the US market on April 2011. As a matter of fact, we are the first customer of this model in the US. Most importantly, the SEM includes an integrated EDS analysis system with a liquid nitrogen free Aztec 250 Oxford X-Max 80 mm2 Silicon Drift Detector. When Hitachi made the offer, the Aztec 250 was just announced by Oxford in the preceding week. The 80mm2 detector is the best EDS detector so far. The large solid angle provided by this detector can characterize beam sensitive materials and biological samples with high accuracy. In addition, the Aztec 250 software provides fast and accurate signal collection. This function greatly enhances our ability to detect small biological samples, which might not be possible by traditional SEM detectors. The SEM was installed and then used by a number of graduate students, undergraduate students, postdocs and high school students for research. Students and faculty members from other departments, such as Chemical Engineering, have also used this SEM. Site preparation for the lab in which the SEM was installed was supported by the vice-president for research at UND and the Chemistry Department. The obtained images are of high quality, and have been appeared in three journal publications and a number of conference presentations. Using the SEM, we performed a wide variety of educational and outreach activities: We designed a SEM lecture and lab for undergraduate students in Analytical Chemistry (Chem 333) and Analytical Chemistry Lab (Chem 333L). Following the lecture in Chem 333, we had a 3-hour lab in the Chem 333L. The lab manual has been published. There were about 60 undergraduate students in this class conducting experiments using the SEM. This hand-on experience significantly enhanced the student learning ability and knowledge about nanoscience and nanotechnology. We designed a SEM lab for Chem 541 and Chem 441. Chem 541 is a graduate course, Spectroscopy Analysis. Chem 441 is the Instrumental Analysis for senior undergraduate students. This is the second time for us to offer the SEM lab in these two courses. The hands-on experience significantly benefited students in the area of advanced instrumentation and nanoscience and nanotechnology. UND Chemistry and Chemical Engineering has an NSF REU program. In the summer of 2011, all REU students participated in the demonstration of the SEM. We instructed the students of the principle of SEM and then demonstrated the imaging of gold nanoparticles using SEM. Finally, the students had a discussion about the SEM and nanoscience and nanotechnology. They showed strong interest in this powerful imaging technique. Under the 'Tribal College Freshmen Initial Research Experience' summer program for Tribally Controlled College students, we provided a section on SEM. The Native American students really benefited from the hands-on experience. We have hosted a number of groups of high school students from different towns in North Dakota. This is the first time that most students had the experience of seeing a high resolution electron microscope. They were very excited to see the large images of the tiny materials under the microscope. For instance, on April 26 2012, a group of 15 juniors from a high school in Hope-Page came to our SEM lab. These high school students were introduced to SEM and nanotechnology and nanoscience. We demonstrated nanosicence and nanotechnology using this SEM instrument to the broader public. For example, we hosted groups of students who attended the North Dakota Science Fair on March 28, 2012. Two high school students from one of our local high schools participated in a nanoscience research projects in the summer of 2012. They were trained how to use the SEM. As a result, they were able to independably characterize the nanomaterials they developed using the SEM. A number of beginnning UND students were introduced to the SEM. In one special section of General Chemistry (Chem 122), we demonstrated the usage of the SEM to image gold nanoparticles using a SEM in the College of Engineering at UND. Although this SEM is of much lower level than the Hitachi SEM, the principle of SEM was clearly demonstrated to the students. We developed a nanoscience and nanotechnology website with a focus on imaging technology at UND. The address is www.und.edu/researc/nano. This website is the first nano website at UND. It focuses on introduction of new developments in nanoscience and nanotechnology. The imaging technology, including SEM, is an important part of this website. Overall, based on our experience, various levels of students could master the skills of using SEM if the appropriate training and instruction are given. Specifically, we have demonstrated that high school students, beginning undergraduate students at tribally controlled colleges and at UND, and graduate students all could apply this technique well after suitable instruction and training were provided.
