Transporting protons is essential in several biological processes as well as in renewable energy devices, such as fuel cells. Although biological systems exhibit precise supramolecular organization of chemical functionalities on the nanoscale to effect highly efficient proton conduction, to achieve similar organization in artificial systems remains a daunting challenge. Here, we are concerned with transporting protons on a micron scale under anhydrous conditions, that is proton transfer unassisted by any solvent, especially water. We report that proton-conducting systems derived from facially amphiphilic polymers that exhibit organized supramolecular assemblies show a dramatic enhancement in anhydrous conductivity relative to analogous materials that lack the capacity for self-organization. We describe the design, synthesis and characterization of these macromolecules, and suggest that nanoscale organization of proton-conducting functionalities is a key consideration in obtaining efficient anhydrous proton transport.

Amphiphilic homopolymer films have been immobilized onto substrates to study the interactions of these polymers with proteins. X-ray photoelectron spectroscopy (XPS) was utilized to measure the amount of protein adsorption. Amphiphilic homopolymers have been shown to reduce protein adsorption, despite the high affinity of the hydrophobic or hydrophilic functional groups by themselves toward proteins. This protein resistant property seems to arise from the unique molecular scale alternation of incompatible functionalities. The combination of incompatible functionalities with a pre-defined alternating pattern within monomer could provide a potential design for non-fouling materials.

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Facially amphiphilic dendrimers have been shown to provide significant difference in surface behavior due to subtle changes in structure. The monodendrons are capable of providing hydrophobic surfaces, while the didendrons provide superhydrophobic surfaces. This provides an example of how a molecular level change could result in significant changes in surface behavior. This difference is attributed to the conformational differences exhibited by these dendrimers on surfaces.Amphiphilic dendrimers have attracted tremendous interest for both fundamental and applied research, since these molecules have the potential to form well-controlled and stable selfassembled structures. 1 On solid surfaces, these molecules have been of interest for a variety of reasons, including in applications such as sensors. 2 The amphiphilicity in these molecules is brought about by the difference in polarity of the focal point of the dendron (or core of a dendrimer) vs. the peripheral functionalities. We have recently reported on a new class of amphiphilic dendrimers, in which every repeat unit within the macromolecule contains hydrophilic and hydrophobic functionalities on opposite faces of dendritic backbone. 3 These dendrimers have been shown to form micelle-type or inverse micelle-type assemblies, depending on the solvent environment. 4 Considering these are rather unique self-assemblies, it is interesting to ask: what would be the nature of the self-assembled structures obtained from these facially amphiphilic dendrimers, when presented to two-dimensional surfaces? This question is interesting because, while the solution self-assembly of an amphiphile is driven by the need to minimize the interaction between the incompatible functionalities in the amphiphile with the three-dimensional surface of the bulk solvent, interaction with the solid surface is twodimensional. Would the interaction be such that these facially amphiphilic dendrimers could modify polar surfaces to apolar surfaces and vice versa? How does the surface behavior of these dendrimers differ from the corresponding polymers? Also, note that investigating both solution and solid-surface assemblies could provide information on the limiting conformers that these dendrimers are capable of adapting. Upon investigating the molecules 1-7 (Chart 1) on solid surfaces, we were surprised to realize how sensitive the surface assemblies are to structure of the dendrimer. We disclose these findings in this communication.DMF was chosen as solvent for coating the silica surfaces, since the dendrimers do not preaggregate in DMF, as determined by dynamic light scattering. 5 The modified surfaces were studied using dynamic water contact angle (CA) measurements, where both advancing (θ a ) and receding (θ r ) CAs are measured. 6 The CAs (θ a /θ r ) for the silica itself was determined to be 18°/8°. Upon coating the small molecule model compound 1, the CAs changed to 65°/9°. Although there is a large change in the advancing angle, the receding angle is essentially unchanged resultin...