Joseph J. McCarthy

To demonstrate a facile method to control capillary condensation via the design of confined geometric structures, we use a particle self-assembly technique to fabricate porous materials with well-defined pore sizes. Four groups of silica particles were synthesized using the modified Stober method, and these groups of particles were then arranged in closely packed structures. Quantitative predictions of capillary condensation were made based on the Kelvin equation and an approximation of the geometric structures of our closely packed samples. Experimental observations revealed that water uptake at 100% relative humidity reached 40%–50% relative to particle mass across sizes, closely aligning with theoretical predictions for small-particle systems, even though the geometry of some of the confined spaces corresponds to distances smaller than 10 nm. Despite deviation from theoretical predictions that are observed in larger particle systems, and which can be attributed primarily to practical limitations of attainable ordered structures at these scales, this fabrication method shows great potential for the creation of devices that allow facile control of capillary condensation in relevant applications such as vapor capture and humidity control.

An abundant supply of fresh water is one of the leading challenges of the 21st century (UNESCO. The United Nations World Water Development Report 2018: Nature-Based Solutions for Water;UNESCO: Paris, France, 2018; p 154). Here we describe a new approach to scavenge atmospheric water that employs a hierarchically ordered porous material with embedded particles (Lash, M. H.; Jordan, J. C.; Blevins, L. C.; Fedorchak, M. V.; Little, S. R.; McCarthy, J. J.Non-Brownian Particle-Based Materials with Microscale and Nanoscale Hierarchy. Ang. Chem. Int. Ed.201554, 5854-5858). This composite uses structure to amplify native material performance to realize synergy between the capture and storage and to ultimately qualitatively change the adsorption behavior of the hydrogel (from unfavorable to favorable). In this way we can capture moisture at significantly lower relative humidities than would otherwise be feasible with the native materials. Not only does this approach pose the potential for a cheap and low-energy source of clean water but it could also be modified for application across a variety of condensable vapor reclamations.

Evaluation and Results for an Integrated Curriculum in Chemical Engineering October 8, 2010 Increasing knowledge integration has gained wide-spread support as an important goal in engi-neering education. The Chemical Engineering Pillars curriculum is one of the first fully integratedcurricula in engineering, and is specifically designed to facilitate knowledge integration. This cur-riculum, in use for just over 5 years, is unique for its use of block scheduling. Block scheduling,in its simplest form, is transforming multi-semester courses into a single-semester course via ex-tended, concentrated contact time. Among other things, the flexibility afforded by extended andmore frequent contact time allows (and encourages) greater opportunity for active and collabora-tive learning. The specific adaption of this technique to chemical engineering has resulted in acurriculum comprised of 6 “Pillar” courses which are taken individually in 6 consecutive under-graduate semesters and are accompanied by vertically integrated laboratory experiences. In this paper, we present the basics of implementing a pillars-style curriculum and report onour ongoing assessment of student learning and knowledge integration using this framework. Theassessment is “ongoing”, in part, because the new curriculum has been evolving with time. Also,and more importantly, as this curriculum is one of the first of its kind, our somewhat unique as-sessment requirements necessitate development of new tools as we go. Specifically, it is criticalthat our curriculum be evaluated not only for its effectiveness in enhancing the ability of studentsto engage in systems thinking (knowledge integration), but also to specifically assess the impact ofthis type of curriculum on students’ performance in conceptualizing (chemical) engineering princi-ples. We will report results from a variety of assessment vehicles in use toward these ends: conceptmapping exercises, surveys, and concept inventories both from existing sources as well as thosebeing developed within our program. Finally, based on our current assessment results, we will present a few adaption strategies thatmay be fruitful for cohort institutions to use to enhance knowledge integration in similar (chemical)engineering curricula. This adaption can be facilitated by our web-based courseware which willalso be introduced. 1

Filtration is the separation of solid–liquid mixtures. In this study, we assess the predictive power of Kozeny–Carman model for systems operated at low Reynolds numbers and relatively high pressure drops. We find substantial agreement between the K‐C model and experiment only for systems that exhibit tight void size distribution. Dramatic disagreement is observed for particle beds that exhibit wide void size distributions. We propose a modified modeling approach, based on a bimodal void distribution, by introducing two quantities: the fraction of expanded voids and the ratio of void sizes. The simulation results are found to be much more similar to the experimental flow rates than those calculated using the K‐C model. The modified model is deemed reliable at predicting the flow behavior, provided that an accurate representation of the void size distribution is available.

One significant hindrance to the development of granular segregation rate models is the inherent difficulty of performing the dynamic experiments required for validation. Here, we seek to overcome this experimental hurdle by establishing an “equilibrium” between segregation and flow perturbation in free surface granular flows and use steady‐state—rather than dynamic—measurements for validation. That is, we combine the segregation rate expressions to be tested with a segregation control framework such that the perturbation rate enables us to infer the segregation rate by measuring simply the steady state extent of segregation. We use periodic flow inversions via an axially located baffle in a tumbler‐type mixer to provide the perturbations that ultimately alter the steady‐state distribution of particles. This work examines the efficacy of existing models for binary segregation driven by either size or density differences. For completeness, we test our model validation framework both computationally and experimentally. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3756–3763, 2017

The passive separation of a binary mixture of spherical particles is accomplished using a laboratory scale quasi‐two‐dimensional inclined board such that gravity alone drives the flow of the mixture through a static array of obstacles. Experimental results compare well with simulations both qualitatively and quantitatively. An increase in separation is observed for increasing board length, whereas a decrease in separation is observed as the solid fraction (area coverage) of particles increases. The possibility of designing green technology for solid‐solid separations by taking advantage of particle properties that aid naturally occurring segregation is demonstrated. A probability‐based model is suggested as a way to predict the viability of separation between particle types as a function of particle size and coefficient of restitution. It should be noted that size separation is achieved despite peg spacings that are larger than both particles in a mixture. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3717–3727, 2017