Sorption Kinetics on Open Carbon Nanohorn Aggregates: The Effect of Molecular Diameter

Abstract

Abstract:We present the results of a study of the kinetics of adsorption on aggregates of open carbon nanohorns using argon and CF 4 sorbates. We measured the equilibration times for each value of the sorbent loading along eight adsorption isotherms (four isotherms for each sorbate species). We found that: the equilibration times decrease as the sorbent loading (and the equilibrium pressure of the coexisting gas) increases, for a given temperature; and, that, for a given value of the sorbent loading, the equilibration times decrease with increasing temperature. When considering the effect of scaling of the temperatures by the respective critical temperatures we found that, at the same scaled temperature and at comparable loadings, the equilibration times for CF 4 were longer than those for argon. We discuss a possible explanation for this result.

Multidimensional heuristic process for high-yield production of astaxanthin and fragrance molecules in Escherichia coli

“…Nerolidol is a fragrant ingredient widely used in cosmetics (e.g., shampoos and perfumes) and in non-cosmetic products (e.g., detergents and household cleaners). Recent studies indicate nerolidol has many pharmacological and biological activities (antioxidant, anti-microbial, anti-biofilm, anti-parasitic, anti-inflammatory etc) 35 . Linalool is another industrially important fragrant ingredient used in most cosmetic products (body lotions, shampoos, soaps, etc) and has biological activities such as sedative, anxiolytic, and analgesic effects 36 .…”

Block Copolymers as Dispersants for Single-Walled Carbon Nanotubes: Modes of Surface Attachment and Role of Block Polydispersity

“…In contrast to SWNTs, nanohorns present both inner and outer surfaces for adsorbing molecules although it remains unclear (despite frequent sketches in the literature that suggest open access) to which extent in which medium those internal surfaces may become available. As another structural aspect, nanohorns often appear as “dahlia-shaped” aggregates with a multitude of narrow holes and crevices between the constituting horns. − Irrespective whether surfaces are internal to nanohorns or at crevices between aggregated nanohorns, if anchoring groups (such as alkyl chains in PEG-ylated lipids) attach to those surfaces, then the PEO blocks oriented away from the anchoring surface face a situation very different from that experienced by molecules attached to convex surfaces of individual nanotubes or their bundles. Namely, the chains will be pointed toward the limited inner volumes (either in a crevice or within a nanohorn) that must be crowded at high coverage.…”