No abstract

Dispersions of titanium dioxide nanoparticles with terephthalic acid, isophthalic acid, salicylic acid, benzoic acid, and pyridine-2,5-dicarboxylic acid were prepared by aqueous grinding. The pH of the dispersions was adjusted by adding either HCl or NaOH, and the viscosity of the dispersions was measured. It was found that the viscosity of the system depends strongly on pH. The qualitative interpretation of the results based on the DLVO theory is presented. The evidence of the effect of bridging interactions on the viscosity of titanium dioxide-dicarboxylic acid dispersions is discussed.

Green chemistry and sustainability concepts have been woven into the University of Toronto undergraduate curriculum for almost two decades. This has been achieved through (i) development of expository, discovery-based, and student-directed laboratory experiments; (ii) evolution of several upper-year courses; and (iii) strategic integration of these components into two academic programs. In conjunction with the establishment of a graduate student-run organization known as the Green Chemistry Initiative who assists with curricular redesign, a committed departmental attitude has developed toward sustainability education. The notion of systems thinking (where links are forged between varying systemic components which affect each other in different ways, and separate components are considered as a whole) influences both specific green instructional practices and the broader Department of Chemistry approach to sustainable education and research. This article outlines the departmental mindset in relation to green chemistry, and how systems thinking has inherently informed the progress made. The connection between systems thinking and green chemistry is solidified through discussion of the Green Chemistry Commitment (GCC) learning objectives. The GCC is a voluntary initiative designed by a nonprofit organization (Beyond Benign) to assist in the preparation of chemists whose skills are aligned with the needs of the planet and its inhabitants in the 21st century.

The field of crystal engineering is rapidly expanding. As our understanding of the mechanism of construction and relationship between structure and function of molecular crystals increases, it is important to recognize that this field offers significant toxicological and environmental benefits. The processes of molecular recognition and self-assembly are inherently benign in terms of its impact on human health and the environment. These benefits must be articulated and exploited.

Green chemistry provides unique opportunities for student engagement through K−12 and community outreach. As a platform for safe, engaging outreach, green chemistry activities allow for hands-on approaches to introducing science and chemistry concepts in informal settings. Green chemistry outreach also is a means for American Chemical Society (ACS) student chapters to earn recognition as a green chemistry student chapter through the ACS student chapter awards. Beyond Benign's College Student Fellows program is highlighted as an example of training college students in green chemistry outreach to promote K−12 and college student engagement. The University of New England (UNE) and Colby College provide examples of college student engagement through different outreach settings. This article outlines the many benefits of utilizing green chemistry activities through K−12 and community outreach, including creating a safe environment for student engagement, creating habits-of-mind for college students, and engaging K−12 students in safer, greener chemistry experiments and activities.