https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19915 Sat 24 Mar 2018 08:03:46 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19916 Sat 24 Mar 2018 08:03:45 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20856 a, the PDEA brush exhibited a critical conformational change in the range 0.5-1 mM electrolyte, a range much narrower than predicted by the theory of the osmotic brush regime. This behavior is attributed to the hydrophobicity of the collapsed brush. The swelling and collapse kinetics for this salt-induced transition are nearly identical. This is in contrast to the asymmetry in the rate of the pH-induced response, suggesting an alternative mechanism for the two processes dependent on the nature of the environmental trigger.]]> Sat 24 Mar 2018 08:02:52 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:25268 Sat 24 Mar 2018 07:38:20 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27182 in situ ellipsometry and a quartz crystal microbalance with dissipation (QCM-D). At low pH the tertiary amine groups of the three polymers are protonated and all three brushes are significantly solvated and swell by adopting an extended conformation. As the pH is increased the weak polybasic brushes become increasingly deprotonated and collapse via solvent expulsion. By employing high temporal resolution measurements we have found that monomer hydrophobicity has a direct influence on the dynamics of this pH-response. The most hydrophobic poly(2-diisopropylamino)ethyl methacrylate (poly(DPA)) brush exhibits the fastest maximum swelling rate. This maximum swelling rate is reduced with decreasing monomer hydrophobicity for the 2-diethylamino, and even further for the 2-dimethylamino analogues. For all three brushes, the corresponding collapse transition is slower and compounded by an induction time that decreases with monomer hydrophobicity. Here also, the maximum collapse rate is greatest for the most hydrophobic polymer. This domination of the pH-response kinetics by monomer hydrophobicity is attributed to attractive hydrophobic forces between polymer segments overcoming the repulsive electrostatic forces between the tertiary amine residues.]]> Sat 24 Mar 2018 07:31:40 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:25103 Sat 24 Mar 2018 07:15:01 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:23138 Sat 24 Mar 2018 07:10:25 AEDT ]]>