Paddy University engineers have produced a container that has the potential to prevent volatile organic compounds (VOCs) from accumulating on the surface of deposited nanomaterials. The study is published in the journal of the American Chemical Society Nano Letters.
Low-cost, portable storage technologies highlight common concerns faced by nanotechnologists and materials scientists.
VOCs are in the air that surrounds us every day. They adhere to surfaces and form layers, mainly of carbon. You can’t see these layers with the naked eye, but they form, often within minutes, on nearly any surface exposed to air..
Daniel Preston, Corresponding Author of the Study and Assistant Professor, Department of Mechanical Engineering, Rice University
VOCs are carbon-based molecules that are released from several common products, such as paint, cleaning fluids, and office and craft supplies. In very high concentrations, they accumulate indoors. In addition, the thin layer of carbon gunk they deposit on the surface can hinder industrial nano-fabrication processes, limit the precision of microfluidic assay kits, and create confusion for researchers conducting fundamental research on surfaces.
To solve this problem, Ph.D. student and lead author of the study Zhen Liu, along with Preston and others from his lab, created a new type of storage container that keeps things clean. Experiments proved that his method efficiently limited surface contamination for a minimum of six weeks and could even clean VOC deposited layers from previously contaminated surfaces.
The technology relies on the ultraclean walls that are inside the container. The surface of the inner wall is reinforced with small projections and divots that range in size from one millionth to one millionth of a meter. Nanoscopic and microscopic imperfections increase the surface area of the walls, which makes their metal atoms available to airborne VOCs present in the container when sealed.
“Texture allows internal container walls to act as a ‘sacrificial’ material,” Liu said. “VOCs are drawn to the surface of the container walls, which allows other objects stored inside to remain clean.”
He stated that using large, pre-cleaned surfaces to accumulate pollutants was suggested 50 years earlier but was largely ignored. He and his co-workers refined the idea with advanced surface cleaning methods and nanotexturing. Through a series of experiments, they demonstrated that their method did a better job of removing VOCs from coating the surface of deposited materials than other methods, which include advanced vacuum desiccators and sealed Petri dishes.
Preston’s group built on their experiments, coming up with a theoretical model that precisely defines what happens inside the container. Preston said the model will let them refine their design and optimize system performance in the coming days.
This study was financially supported by Rice’s Shared Equipment Authority, Rice University Academy of Fellows, United States Coast Guard Advanced Education Program, and the Department of Energy’s Innovation in Buildings scholarship (DE-SC0014664).
Liu, Z., et al. (2023) Reducing Contamination with Nano Structure Activated Ultraclean Storage. Nano Letters. doi.org/10.1021/acs.nanolett.3c00626.