title: Synthesis and characterization of polymer-protected rhodium and palladium sols in mixed media

authors: Jaine, Jacob E.

subjects: Sol

abstract: A series of polymer-protectedrhodium and palladiumsols were generated in mixed (organic/aqueous) dispersion media. Protecting polymers used were PAA, PVP, PVA and an oligosaccharide-based protecting agent, arabinogalactan. This is the first systematic study of colloids generated in mixed solvent dispersion media with these protecting agents. The sols were characterized by TEM, UV/Vis spectrophotometry and Photon Correlation Spectroscopy (PCS). In general, the macroscopic stability of the sols depended on the protecting agent/organic cosolvent combination used, with a nonlinear dependence on cosolvent concentration. Observed sol stabilities correlated well with pre-existing hydrodynamic data for the protective polymers, e.g. radius of gyration data. Average particle size and polydispersity of all sols examined decreased as cosolvent concentration increased, with actual cosolvent concentration, protecting agent and reducing agent used influencing the extent of decrease. Sol particle sizes ranged from 0.8 nm to 6.0 nm with sol turbidities decreasing in parallel with the particle sizes. Hydrodynamic sizes (from PCS) tended to reflect the sols’ macroscopic stabilities. FTIR studies using adsorbed CO as a spectroscopic surface probe indicated decreases in the ν(CO)ads stretching frequency with an increase in cosolvent concentration due to competitive adsorption of CO with the cosolvent molecules on the metal colloid surfaces.

text: Synthesis and characterization of polymer-protected rhodium and palladium sols in mixed media A series of polymer-protectedrhodium and palladiumsols were generated in mixed (organic/aqueous) dispersion media. Protecting polymers used were PAA, PVP, PVA and an oligosaccharide-based protecting agent, arabinogalactan. This is the first systematic study of colloids generated in mixed solvent dispersion media with these protecting agents. The sols were characterized by TEM, UV/Vis spectrophotometry and Photon Correlation Spectroscopy (PCS). In general, the macroscopic stability of the sols depended on the protecting agent/organic cosolvent combination used, with a nonlinear dependence on cosolvent concentration. Observed sol stabilities correlated well with pre-existing hydrodynamic data for the protective polymers, e.g. radius of gyration data. Average particle size and polydispersity of all sols examined decreased as cosolvent concentration increased, with actual cosolvent concentration, protecting agent and reducing agent used influencing the extent of decrease. Sol particle sizes ranged from 0.8 nm to 6.0 nm with sol turbidities decreasing in parallel with the particle sizes. Hydrodynamic sizes (from PCS) tended to reflect the sols’ macroscopic stabilities. FTIR studies using adsorbed CO as a spectroscopic surface probe indicated decreases in the ν(CO)ads stretching frequency with an increase in cosolvent concentration due to competitive adsorption of CO with the cosolvent molecules on the metal colloid surfaces.

year: 2012

title: Searching for satisfaction

authors: Grant, Bevan C.

subjects: leisure

abstract: Consumerism is the way of life in the 21st century. Everything is for sale, principally to those with the resources – which is where the profit lies. But it's a competitive market so people from all walks of life are being coerced to part with their discretionary dollars. Leisure is like most other aspects of life - a commodity, a range of goods and services for sale - so it is no surprise that economic viability attracts more attention than social capital.

text: Searching for satisfaction Consumerism is the way of life in the 21st century. Everything is for sale, principally to those with the resources – which is where the profit lies. But it's a competitive market so people from all walks of life are being coerced to part with their discretionary dollars. Leisure is like most other aspects of life - a commodity, a range of goods and services for sale - so it is no surprise that economic viability attracts more attention than social capital.

year: 2007

title: Still standing, still here, still dancing.

authors: Clendon-Tau, Iwa

subjects: first person narrative

abstract: A personal narrative is presented which explores the author's experiences on teaching-learning process and her insights on language, culture and learning.

text: Still standing, still here, still dancing. A personal narrative is presented which explores the author's experiences on teaching-learning process and her insights on language, culture and learning.

year: 2002