Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Engineering
Order-Disorder Transition Of Aragonite Nanoparticles In Nacre, Zaiwang Huang, Xiaodong Li
Order-Disorder Transition Of Aragonite Nanoparticles In Nacre, Zaiwang Huang, Xiaodong Li
Faculty Publications
Understanding nacre’s bottom-up biomineralization mechanism, particularly, how individual aragonite platelets are formed, has long remained elusive due to its crystallographic peculiarity and structural complexity. Here we report that crystallographic order-disorder transition can be triggered within individual aragonite platelets in pristine nacre by means of heat treatment and/or inelastic deformation, offering a unique opportunity to discriminate mysterious aragonite nanoparticles in transmission electron microscopy. Our findings unambiguously uncover why aragonite nanoparticles in pristine nacre have long been inaccessible under TEM observation, which is attributed to the monocrystal-polycrystal duality of the aragonite platelet. The underlying physical mechanism for why an individual aragonite platelet …
Hot-Melt Mixing Of Partially Miscible Active Pharmaceutical Ingredient-Polymer Mixtures, Min Yang
Hot-Melt Mixing Of Partially Miscible Active Pharmaceutical Ingredient-Polymer Mixtures, Min Yang
Dissertations
Solid dispersion/solution processes for producing pharmaceutical oral dosages such as hot-met extrusion (HME) have received increasing attention by industry and academe because they can enhance drugs’ solubility and even bioavailability to a great extent by converting drugs from crystalline to amorphous form. HME can be carried out at two process temperature regimes: one where Tprocess > Tm of the drug and the Tg of the polymer (or the Tm for the case of semi-crystalline polymers); the other at Tm > Tprocess > Tg (Tm for the case of semi-crystalline polymer). Processing below the drug’s …
A Thermodynamic Framework For The Modeling And Optimization Of Crystallization Processes, David John Widenski
A Thermodynamic Framework For The Modeling And Optimization Of Crystallization Processes, David John Widenski
LSU Doctoral Dissertations
Crystallization is a widely used chemical engineering separation unit operation process. Since this technique can produce high purity products it is used for the industrial production of many chemical compounds, such as pharmaceuticals, agrochemicals, and fine chemicals. The production of these products is a multi-million dollar industry. Any methods to improve the production of these products would be highly valued. Thus, the main objective of this work is to target model-based optimal strategies for crystallization operations specifically targeting crystal size and crystal size distribution (CSD). In particular, take the knowledge gained and translate it into an economically and practically feasible …