We use small-angle x-ray scattering (SAXS) as a tool to study the binding of proteins to spherical polyelectrolyte brushes (SPB) in situ. The SPB consists of a solid core of approximately 100 nm diam onto which long polyelectrolyte chains [poly(styrene sulfonic acid, PSS) and poly(acrylic acid, PAA)] have been densely grafted. The proteins used in this investigation, Bovine Serum Albumine (BSA)...

To describe adsorption of globular protein molecules in a polyelectrolyte brush we use the strong-stretching approximation of the Edwards self-consistent field equation, combined with corrections for a non-Gaussian brush. To describe chemical potentials in this mixture of (globular) species of widely varying sizes (ions, brush polyelectrolyte segments, globular protein molecules), we use the Bo...

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 poly(acrylic acid) at the oil-water i...

‘‘Adsorption of Polyelectrolytes on Mica’’ sounds like a very specific title and it may be difficult to envision, upon first reflection, why mica deserves a separate chapter in the study of adsorption of polymers on solid substrates. What makes mica such a special substrate? What are the driving forces involved in the adsorption of macromolecules on mica? What mechanisms participate in the adso...

The behavior of a polyelectrolyte adsorbed on a charged substrate of high-dielectric constant is studied by both Monte-Carlo simulation and analytical methods. It is found that in a low enough ionic strength medium, the adsorption transition is first-order where the substrate surface charge still keeps repulsive. The monomer density at the adsorbed surface is identified as the order parameter. ...

Integration of living cells with novel microdevices requires the development of innovative technologies for manipulating cells. Chemical surface patterning has been proven as an effective method to control the attachment and growth of diverse cell populations. Patterning polyelectrolyte multilayers through the combination of layer-bylayer self-assembly technique and photolithography offers a si...

We discuss the interaction of proteins dissolved in aqueous solution with spherical polyelectrolyte brushes (SPB). The SPB consist of a solid core particle of colloidal dimensions (ca. 100 nm in diameter) onto which long polyelectrolyte chains have been grafted. Immersed in aqueous solution of proteins these SPB will take up high amounts of protein if the ionic strength is low. At high ionic st...

Polyelectrolytes are polymers carrying either positively or negatively charged ionizable groups. The properties of these polymers in solutions and at charged surfaces depend on the fraction of dissociated ionic groups, solvent quality for polymer backbone, solution dielectric constant, salt concentration, and polymer–substrate interactions. In this review, we summarize the current development o...

Large macromolecules with hydrophobic backbones are known to assemble at the interface between immiscible liquids. This assembly is often unpredictable because of the subtle interplay among hydrophobic interactions, hydrophilic solvation, structural constraints, and the thermodynamics of adsorption. In these studies, we employ vibrational sum frequency spectroscopy and interfacial tension measu...

Weak polyelectrolytes have found extensive practical applications owing to their rich pH-responsive properties. In contrast, strong polyelectrolytes have long been regarded as pH-insensitive based on the well-established fact that the average degree of charging of strong polyelectrolyte chains is independent of pH. The possible applications of strong polyelectrolytes in smart materials have, th...