Meso- and Microscopic Behavior of Spherical Polymer Particles Assembling at the Air−Water Interface

Abstract

Using the Langmuir Blodgett (LB) technique, monolayers of spherical polymer particles were investigated at the air-water interface. In this study, LB methods were used to examine particle interactions, packing, morphology, and viscosity of polymer films. Films composed of polymer microgels (diameters of 113-427 nm) having a block-copolymer dispersant were investigated through isotherm, atomic force microscopy imaging, and two-dimensional (2D) viscosity studies. During monolayer formation, the effect of the dispersant and particle size on the behavior of the isotherms was examined. The contact cross-sectional area of the isotherms for these spheres was compared to the ideal hexagonal close packing (hcp) model. Initial investigations concerning the flow properties of the particles in 2D slurries were also performed. In addition, spherical hyperbranched polymer particles (≈60 nm) with and without a modified hydrophilic surface were also studied using isotherm and hysteresis experiments and the hcp model. Both of these studies may show the influence of surface composition and particle size on the interaction of polymer particles at the airwater interface.

The adsorption and unfolding kinetics determines the folding state of proteins at the air–water interface and thereby the equation of state

“…In the equation of state model of Fainerman et al [13,14], the decrease in apparent size of the adsorbed protein with increasing surface pressure is described as desorption of segments of the protein chain. However, from studies performed with non-unfolding particles (such as Stöber silica particles [15], glass microspheres [16], gelled polymer microbeads [17], latex particles [18], and colloidal silver particles [19]) surface pressure-surface area relations are found that are remarkably similar to those typical for proteins. Another observed phenomenon that has been related to protein unfolding after adsorption is the increase in surface pressure at longer time-scales, while little or no increase in adsorbed amount is measured [2,7,20].…”

Composite interfacial layers containing micro-size and nano-size particles

“…It is noted in [63] that the monolayer behaviour by compression and expansion is possibly affected by the contact angle hysteresis and dynamics of wetting. Further surface pressure/area isotherms of particle monolayers at fluid interfaces were studied also by other authors, such as [64][65][66][67][68][69][70][71].…”

“…3. Surface pressure Π as a function of monolayer coverage for polymeric particles 113 nm (Δ), data according to [71]; theoretical curve calculated from Eq. (3), (for details see [102]).…”

“…The Π(A)-isotherm (note, here A is the area per unit of particle mass) for polymeric spherical particles of 113 nm in diameter [71] is shown in Fig. 3, together with the theoretical curve as calculated from Eq.…”

Ring and Disk‐Like CdSe Nanoparticles Stabilized with Copolymers

“…Block copolymers have been used extensively as a surrounding and stabilizing matrix of the nanoparticles due to their possible bipolar nature and dedicated phase behavior. [10][11][12] The use of the Langmuir-Blodgett (LB) technique to produce monoparticular layers [13] has been demonstrated, too. Ring structures on the mm scale were found by several authors including those prepared with the LB technique.…”