Daniel K. Beaman

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Additional resources and features associated with this article are available within the HTML version: • Supporting Information • Access to high resolution figures • Links to articles and content related to this article • Copyright permission to reproduce figures and/or text from this article With Benjamin Franklin's oil on water experiments as a historical(More)
Polyelectrolytes (PEs) are widely used in applications such as water purification, wastewater treatment, and mineral recovery. Although much has been learned in past decades about the behavior of PEs in bulk aqueous solutions, their molecular behavior at a surface, and particularly an oil-water interface where many of their applications are most relevant,(More)
Since ancient Babylonian times when soap-like materials were created for “washing the stones for servant girls”, carboxylate containing surfactants derived from the hydrolysis of fatty acids continue to be important today in industrial, commercial, and personal hygiene applications. In addition to being important in surfactant applications, carboxylate(More)
Divalent metal ions play numerous roles in biological, technological, and environmental systems. This study examines the role of a variety of ions, Mg(2+), Ca(2+), Mn(2+), Ni(2+), Cu(2+), and Zn(2+), in the adsorption of sodium decanoate at the carbon tetrachloride-water interface. For all ions studied, the ions drive the adsorption of the surfactant to the(More)
Nonlinear vibrational spectroscopies such as visible-infrared sum-frequency spectroscopy may serve as powerful probes of interfacial structure. Obtaining quantitative orientation information, however, has been limited by the required knowledge of the corresponding molecular-level nonlinear optical properties. We provide a general scheme for calculating the(More)
Understanding the interfacial adsorption of polymers has become increasingly important because a wide range of scientific disciplines utilize these macromolecular structures to facilitate processes such as nanoparticle assembly, environmental remediation, electrical multilayer assembly, and surfactant adsorption. Structure and adsorption characteristics for(More)
We report on the design and operation of a cryogenic ultra-high vacuum (UHV) scanning tunneling microscope (STM) coupled to a closed-cycle cryostat (CCC). The STM is thermally linked to the CCC through helium exchange gas confined inside a volume enclosed by highly flexible rubber bellows. The STM is thus mechanically decoupled from the CCC, which results(More)
We have used vibrational sum-frequency spectroscopy to provide the first measurement of the spectrum and orientation of the polar headgroup of a charged alkyl surfactant at the air/water interface. Sum-frequency spectra of sodium dodecyl sulfate (SDS) are used to arrive at all participating elements of the second-order susceptibility tensor. We use these(More)
The accumulation of polyelectrolytes at the interface between water and nonpolar fluids is an important process in both environmental and biological systems. For instance, polyelectrolytes such as humic acids are highly charged molecules that play a role in the remediation of water contaminated by oil, and the adsorption of other polyelectrolytes such as(More)
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