Aqueous surfaces and interfaces are important in many physical, chemical, and biological processes in our world. The adsorption, dissolution, and reaction of atmospheric gases at the surfaces of atmospheric aerosols and oceanic waters play a key role in the composition of our atmosphere and the sustainability of plant and animal species in land waters. The transport and exchange of ions and solutes across the interface between an aqueous phase and hydrophobic biomolecular assemblies underlies some of the most important processes in living plants and animals. Membrane formation, protein folding, and micelle formation all involve, and are often controlled by, bonding interactions with water molecules at their surfaces. The unique physical, chemical, and biological properties of aqueous surfaces arise from the strong hydrogen bonding that occurs between water molecules and the asymmetry in this otherwise tetrahedral bonding coordination that results from the termination of the bulk water phase. Although there has been increased experimental and theoretical effort in recent years focused on developing a molecular picture of the structure and bonding of water layers to other solid, liquid, and gaseous media, consensus on the details of interfacial bonding has been slow or nonexistent in many areas. The adsorption of ions, surfactants, and solute molecules at these interfaces adds a level of complexity to the Geraldine Richmond holds the Richard M. and Patricia H. Noyes Professor of Chemistry position at the University of Oregon. She received her Ph.D. degree under the mentorship of George Pimentel at the University of California, Berkeley, in 1980. From 1980 to 1985 she was on the faculty at Bryn Mawr College and moved to the University of Oregon in 1985 as an associate professor. Richmond is recognized for her fundamental studies of the structure, dynamics, and bonding characteristics of surfaces and interfaces. Her research group uses a combination of linear and nonlinear optical methods, thermodynamic measurements, and theory to characterize interactions at aqueous surfaces, metal and semiconductor surfaces in contact with liquids and adsorbates, and liquid/liquid interfaces. Richmond has received several recent honors for these studies including the 2002 ACS Spectrochemical Analysis Award, the 2001 Oregon Scientist of the Year, and the 1996 Olin-Garvan Medal of the ACS and has been a Fellow of the American Physical Society since 1993. 2693 Chem. Rev. 2002, 102, 2693−2724

Molecular bonding and interactions at aqueous surfaces as probed by vibrational sum frequency spectroscopy.

A wide variety of two- and three-dimensional physical-chemical systems display domain patterns in equilibrium. The phenomenology of these patterns, and of the shapes of their constituent domains, is reviewed here from a point of view that interprets these patterns as a manifestation of modulated phases. These phases are stabilized by competing interactions and are characterized by periodic spatial variations of the pertinent order parameter, the corresponding modulation period generally displaying a dependence on temperature and other external fields. This simple picture provides a unifying framework to account for striking and substantial similarities revealed in the prevalent "stripe" and "bubble" morphologies as well as in commonly observed, characteristic domain-shape instabilities. Several areas of particular current interest are discussed.

https://science.sciencemag.org/content/sci/267/5197/476.full.pdf

Domain shapes and patterns: the phenomenology of modulated phases.

The Colloid Chemical Approach to Nanostructured Materials

We propose coating spherical particles or droplets with anisotropic nano-sized objects to allow micron-scale colloids to link or functionalize with a four-fold valence, similar to the sp3 hybridized chemical bonds associated with, e.g., carbon, silicon and germanium. Candidates for such coatings include triblock copolymers, gemini lipids, metallic or semiconducting nanorods and conventional liquid crystal compounds. We estimate the size of the relevant nematic Frank constants, discuss how to obtain other valences and analyze the thermal distortions of ground state configurations of defects on the sphere.

Towards a Tetravalent Chemistry of Colloids

We propose coating spherical particles or droplets with anisotropic nanosized objects to allow micron-scale colloids to link or functionalize with a 4-fold valence, similar to the sp3 hybridized chemical bonds associated with, e.g., carbon, silicon, and germanium. Candidates for such coatings include triblock copolymers, gemini lipids, metallic or semiconducting nanorods, and conventional liquid crystal compounds. We estimate the size of the relevant nematic Frank constants, discuss how to obtain other valences and analyze the thermal distortions of ground-state configurations of defects on the sphere.

Toward a Tetravalent Chemistry of Colloids

When we began this review, we intended to write a chapter entitled, "Phase transitions in two-dimensional systems" It soon became evident, however, that it was impossible to cover so broad a topic within the imposed size limitation Even with the restriction to monolayers, it is difficult to provide a complete overview of this lively and growing field Fortunately, recent reviews by M6hwald (1) and McConnell (2) dealt with Langmuir monolayers Because they did not focus on phase transitions, our chapter complements, rather than duplicates, this work New experimental tech­ niques that have been applied to the study of monolayers have also been described recently (3); two Annual Review of Materials Science articles are also relevant (4, 5) And, Wortis (6) has evaluated the state of the art (as of 1990) in the study of surface films of small molecules in a brief and entertaining review We have divided this chapter into four main sections The first deals with structure and is primarily a review of experiments Recent Monte Carlo (MC) and molecular dynamics (MD) simulations are discussed next The kinetics of monolayer phase transitions are then described, and we

C. M. Knobler

Papers

Phase Transitions in Monolayers