On page 1373, scientists from The Dow Chemical Company discuss their finding that surfactant-free acrylic emulsion polymerization in the presence of a self-assembled polyurea macromer (PUM) nanodispersion resulted in hybrid acrylic-polyurea particles. This hybrid emulsion formed films resembling a composite closed cell foam structure. The cover art shows the TEM of a representative film at two different magnifications. The interfacial volume between particles is illustrated to show the hypothesized polymer interaction between the acrylic phase and polyurea phase. Some intermixing at this phase boundary is expected to enable film formation, given that the PUM is not capable of forming a film on its own.

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Synthesis of a new functionalized pillar[4]­arene[1]­quinone and its host–guest complexation with a bis-imidazolium dication was demonstrated. 1D/2D NMR spectroscopic analyses and high-resolution mass spectrometric analyses showed the formation of the pseudo[3]­rotaxane assembly upon host–guest complexation. 1H NMR titration experiments revealed the role of hydrogen bonding motifs in bringing positive cooperativity by comparing the binding constants for the host–guest complexation of pillar[4]­arene[1]­quinone with a bis-imidazolium guest. Anion-responsiveness of the pseudo[3]­rotaxane assembly was also demonstrated.

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