Conventional methods use liquid nitrogen to cool the protein crystals (with cryoprotectants) so that low-density amorphous (LDA) ice, rather than crystalline ice, forms. Kim et al. developed a procedure known as high-pressure cryo-cooling that uses high-pressure on protein crystals to form high-density amorphous (HDA) ice instead [1].
While the foundational physics of scattering is common to all application areas, individual fields have diverged over the years to develop many specialized tools appropriate to the type of matter under investigation. As science advances, however, areas like structural biology, materials science, and engineering have greater overlap. We organized a dual-track workshop this year aimed at getting soft-matter scientists and biologists in one room to promote exchange.
In a new article published in Advanced Functional Materials (http://dx.doi.org/10.1002/adfm.201502412), Princeton Ph.D. candidate Geoff Purdum in Lynn Loo’s group in the Chemical and Biological Engineering Department at Princeton and his co-authors shed new light on this issue. In particular, they report reversible access of two polymorphs exhibited by core-chlorinated naphthalene tetracarboxylic diimide (NTCDI-1), an organic semiconductor developed by BASF.
CHESS is a high-intensity x-ray source funded by the National Science Foundation that is operated and managed by the University, driving research in fields spanning from electron behavior in a superconductor to arsenic poisoning in shrimp.
Nine educators and 85 students grades 3-8th from Syracuse, Tully, South Seneca, Interlaken and Ithaca were engaged in science learning through experience and exploration. Awesome!!!
Both the instrumental and analytical developments were led by Staff scientist Zhongwu Wang at Cornell High Energy Synchrotron Source (CHESS). This first-of-the-kind X-ray approach together with the growth of single supercrystal and detailed structural analysis and simulation from atomic to mesoscale level was reported in Issue September 09, 2015 at Nano Letters [1].
Dichtel, an associate professor in the Department of Chemistry and Chemical Biology at Cornell University, has made continuous use of CHESS over the past few years to aid his group’s studies of covalent organic frameworks (COFs). The group regularly relies on the G2 station at CHESS to characterize the crystalline and orientational order of different COFs and under different conditions [1-3], including different substrates such as single-layer graphene. Those results have contributed to the group’s development of COFs for various applications, such as vapor detection [4].
Josh and his students have already performed first x-ray scattering experiments related to this project at D1 station in the summer run 2015.
The NASA Program aims to support “early stage technologies that will address high-priority needs of America's space program” (see NASA Press Release). Eight projects were selected out of a national competition which will be funded for $200K per year up to three years.
We congratulate Josh and are looking forward to more exciting experiments of his group at CHESS!
The x-ray pulses have many longitudinal modes, so energy fluctuates over a finite bandwidth. Longitudinally coherent x-ray pulses can be made by sending longitudinally coherent radiation along with electrons through the undulator. This so-called “self-seeding” is done between long undulator sections by separating electron from x-ray beams using a magnetic chicane, monochromatizing the x-rays, and finally recombining beams as indicated in Figure 1.
The current CHESS award supports undergraduate students through both formal and informal programs. One of our newest efforts is a summer program for upstate community college students is named “Summer Research for Community College Students”, or SRCCS, and is modeled after the very successful REU program supported by NSF. Under this program, four to five students interested in STEM careers are invited to participate in cutting-edge research at the CLASSE.