Increasing surface hydrophilicity with biopolymers: a combined single bubble collision, QCM-D and AFM study.

Hypothesis: Naturally extracted polysaccharides, such as guar gum, are promising candidates for environmentally friendly flotation reagents. It is hypothesized that the kinetics of collision of sub- to millimeter gas bubbles with a hydrophobic graphite surface, and the stability of thin liquid film formed between the bubble and surface is affected by an adsorbed layer of guar gum.

Experiments: A combination of gravimetric (quartz crystal microbalance with dissipation) and imaging (atomic force microscopy) techniques was used to investigate the adsorption of guar gum on graphite surface, while high-speed camera imaging allowed for direct observation of the bubble collision process with guar gum-modified graphite surfaces with millisecond resolution.

The relationship between Empathy and listening styles is complex: implications for doctors in training.

Background: Effective communication is the key to a successful relationship between doctors and their patients. Empathy facilitates effective communication, but physicians vary in their ability to empathize with patients. Listening styles are a potential source of this difference.

Macroscale superlubricity induced by film-forming polymer brush-grafted colloidal additives.

Hypothesis: Modifying surfaces with concentrated polymer brushes (CPBs) is an effective way to reduce friction of tribo-pairs lubricated with liquids. We investigate the hypothesis that colloids grafted with CPBs (hybrid colloids) can deposit onto tribo-substrates by varying the solvent quality with respect to the polymer, in order to obtain ultra-low coefficients of friction (CoFs), so-called superlubricity.

Experiments: Hybrid colloids are synthesized and characterized, and a dynamic light scattering compares their swellings in aqueous solutions of glycerol or polyethylene glycol.