# softmatter:Lamella

### From NSDL Materials Digital Library Wiki

Block Copolymers (BCPs) and surfactants are known to phase separate into complex morphologies including Cubically Ordered Spherical Micelles, Hexagonally Packed Cylindrical Micelles, Double Gyroid, Perforated Lamella, and **Lamella**. Recent simulation results have shown that Tethered building blocks also can exhibit similar phases as a result of microphase separation.

## Contents |

## Block Copolymers

Melts of BCPs, with block fractions of ~0.35-0.65 have been shown to form cylindrical micelles that order into hexagonal arrangements [1]. Here block fraction is defined as (*length of the A block*)/(*total length of polymer*).

- An example using Brownian Dynamics showing the final morphology of a phase separated block copolymer into lamella:

## Surfactants

Simulations of symmetric surfactants in selective solvent have also yielded lamella for volume fractions of approximately 0.4 - 0.5 [2].

## Tethered Particles

Tether-aggregating tethered nanospheres (TNS) were found to exhibit lamella for a range of volume fractions and various excluded volume ratio, F_{v}, values (ratio of the nanoparticle to tether) [2].

- Specifically, for F
_{v}=1, at volume fractions ~0.4-0.55, tether-aggregating tethered nanospheres yielded lamella bilayers [2]. - Head-aggregating tethered nanospheres (TNS) with F
_{v}=1, were found to exhibit lamella behavior at volume fractions ~0.35-0.5.- An example can be viewed MATDL Repository.
- The full reference can be found at: MATDL Repository.

## Examples

- Brownian Dynamics simulation of a nanoparticle aggregating tethered nanosphere: lamellar bilayers
- Dissipative Particle Dynamics simulation of a diblock Block Copolymer: Lamella
- Brownian Dynamics simulation of a diblock Block Copolymer: Lamella