Dissolution of Lamellar Phases

Abstract

Dissolution of surfactant liquid crystals is an important process both at the manufacturing stage of surfactant based formulated products and during their use. Dissipative particle dynamics simulations were employed to study the production of surfactant-oil-water systems under both temperature and water quenches. Upon the dissolution of a high concentration lamellar phase surfactant, wormlike micelles are formed, which differ from the spherical micelles produced at the same concentration with a temperature quench. The surfactant molecules have a tendency to remain within their initially formed lamellar phase sheets and just rearrange into wormlike micelles. When a hydrophobic additive (oil) is added to the initial system, longer cylindrical micelles are formed, with the creation of some spherical micelles under dissolution. These micelles detach from the long cylinders as a result of their natural oscillations.

Investigating the morphological transitions in an associative surfactant ternary system

“…The first step in simulations is to determine the representation of each molecule type (i.e., the architecture of molecules). There have been simulation studies on ternary phase behavior of systems composed of surfactant-oil-water 38,58,69,70 where the oil components are composed of a chain of hydrophobic beads, but there has not been much focus on systems where the oil is polar and has surface activity. For amphiphilic systems, molecules have been mostly represented as simple models such as dimers composed of a hydrophilic head and a hydrophobic tail.…”

“…5, together with their mapping onto the coarse-grained DPD model. Following another work where the headgroup of ionic surfactants is represented with two beads, 58 the headgroup of CPCl is represented here with two bead types, ''N'' and ''M'', where ''M'' type bead represents the repulsion arising from the bulky, charged pyridinium group, while ''N'' captures the hydrophilicity of the overall headgroup. A ''C1'' bead type is distinguished from other ''C'' type beads in order to include bending stiffness for representation of OA double bond in the simulation.…”

“…For constructing a mesoscopic model, we first determine the volume of the simulation beads and then determine the length scale. Three to four carbon atoms with an equivalent volume of 120 Å 3 are taken together 58 and grouped into one bead, and thus each bead represents liquid volume of 120 Å 3 . Given a water molecule volume of 30 Å 3 , 57 each water bead (“W”) represents four water molecules.…”

Dissolution of anionic surfactant mesophases

“…Surfactant dissolution has mainly been studied using solvent penetration experiments [8][9][10][11] and by simulations [12][13][14] . In a solvent penetration experiment, a concentrated surfactant solution is brought into contact with its solvent.…”

Fabricating Robust Constructs with Internal Phase Nanostructures via Liquid‐in‐Liquid 3D Printing

“…Last, composition V exhibits a broad peak at low q, demonstrating possibly jammed micelles that later undergo a phase transition into LAM morphology which is preserved upon photopolymerization (Figure 3a). The process of self-assembly and the morphological pathway associated with the self-assemblies has previously been studied using computational modeling and mesoscale simulation techniques, [41,42] which is the focus of our future work.…”