2017 March 15 - April 24
2017 May 17 - June 29
2017 BTR deadline: 04/17/17
2017 October 11 - December 21
2017 Proposal deadline: 08/01/17
2017 BTR deadline: 09/10/17
In last month’s eNewsletter, CHESS Director Joel Brock gave an overview of the CHESS-U project and how important the six summer science workshops were to help define the science frontiers an upgraded CHESS will serve. The project relocates five experimental stations and gives each of the new stations an independently tunable high-flux undulator source. This workshop shared the goal of identifying pressing and important scientific needs for a future high-energy x-ray source utilizing unique capabilities of the Cornell accelerator and special types of organization and user support.
The “nano to meso” workshop was held on June 13th and 14th and involved 12 invited speakers and 28 attendees. 25 remote viewers asked questions and participated in discussions through an on-line YouTube stream. The organizing committee consisted of Ruipeng Li, Detlef Smilgies and Zhongwu Wang (CHESS), helped by outside organizers Ou Chen (Brown University) and Kevin Yager (Brookhaven Center for Functional Materials). This workshop sought to bring together scientists seeking to build and understand new materials achieving exceptional properties through assemblies of either organic or inorganic building blocks or both at all length scales. Through mimicking the nature-enabled materials growth, they seek to discover, design and fabricate novel materials by control and assembly of nanocrystals into periodic ordered supercrystals through fine tuning of particle size, shape, composition and modification of surface molecular decoration in lab. Invited speakers and participants were asked to consider CHESS strengths (e.g. faster detector, friendly collaborative environments, etc.) together with expertise and scientific vision, to identify important science applications and major developments of unique technique which falls into one category of materials design and processing from nano to mesoscale.
The theme of in-situ processing of functional soft materials was introduced by speakers Kevin Yager (BNL) and Joshua Choi (UVa), who discussed photo-thermal assembly of block copolymers and self-assembly of metal halide perovskite thin films, respectively. Future high-performance applications will require sophisticated functional soft materials, including conjugated molecules and polymers, nanoparticle composites, and block copolymers. With the ability to self-assemble, these materials have direct functionality — chemical, electronic, optical, or magnetic — relevant to areas of organic electronics (OLED, OFET, OPV) and nanotechnology (e.g. directed self-assembly, ultrafiltration and desalination membranes). Many industrial processing methods can be studied in-situ with x-ray scattering to help understand and fine-tune the quality of the devices, including thermal annealing, solvent vapor annealing, blade coating and laser annealing.
A second theme revolved around in-situ discovery and processing of designer materials. Speakers Ou Chen (Brown) and Yugang Sun (Temple) introduced self-assembly of multicomponent nanocrystal building blocks. Recent advance of wet synthetic chemistry enable exquisite control of nanocrystals (NCs) not only with great monodispersity, size, shape and composition, but also with desired molecular decorations on NC surfaces. As it is increasingly clear, these tunable and fully-customizable NCs building blocks can act as “super-atoms” having ability to form either random or periodically ordered superlattices. Examples given included using DNA-mediated Au supercrystal to mimick bio-inspired structures, or using magnetic/luminescence to image and sense biological cell activities in a controlled way. Also mentioned were using in-situ processing with pressure, temperature or solvent extraction to develop mechanically stable architectures with size-dependent and collective properties for device purpose, such as creating solar cells by printing 3D porous nanostructured catalysts or 2D semiconductor nanowire arrays.
After the meeting, CHESS scientists, organizers and participants joined forces to summarize notes and compose “white papers”, capturing the scientific need and opportunities for innovative work using an upgraded CHESS source. CHESS scientists are now working with members of the CHESS External Advisory Committee and members of the CHESS Users’ Executive Committee to refine, combine, reduce and/or sharpen the ideas captured from the workshops. The CHESS staff is enormously grateful to members of the user community and beyond who’ve helped shape the future of CHESS.
Stay tuned to the CHESS eNewsletter to hear exciting updates on the CHESS-U upgrade.
Some of the participants at Workshop 4 in the Physical Sciences Building.
Ernest Fontes, CHESS, Cornell University