| Author/Editor | Božič, Bojan | |
| Title | Vpliv zunanjih sil na obliko fosfolipidnega mehurčka | |
| Type | monografija | |
| Place | Ljubljana | |
| Publisher | Fakulteta za matematiko in fiziko | |
| Publication year | 1999 | |
| Volume | str. 113 | |
| Language | slo | |
| Abstract | The effect of external forces was analyzed by a theoretical study of the shape changes of a phospholipid vesicles for the some tipical examples by considering mechanical properties of the laterally homogeneous phospholipid membrane. The membrane is taken to consist of two leaflets which are in close contact but unconnected since there are no shear forces between leaflets. The volume of the vesicle is constant and the membrane meterial is inextensible. The shape of the vesicles is axisymmetric in all treated examples. We analyse the following examples: an axial load that pulls or pushes the poles of the vesicles apart, the squeeze of the vesicle between the two parallel walls where the walls are perpendicular to the vesicle symmetry axis, the squeeze of the vesicle by a ring, and the squeeze of the vesicle by two parallel rings of constant radii where their symmetry axis cioncide with the vesicle rotational symmetry axis. The shape of the vesicle is obtained by solving the difFerential equation that is derived on varying the thermodynamic potential of the system. The thermodynamic potential is sum of the membrane elastic energy and the potential energies of the external forces. The elastic energy of the closed bilayer is given by the sum of the relative expansivity energy because of the expansion and compression of the two membrane layers, and the bending energy. The relative expansivity energy depends on nonlocal bending modulus that is related to the relative expansivity modulus. The bending energy depends on the bending modulus of the membrane. For the chosen values of the ratio between the nonlocal bending modulus and the bending modulus we found out how the tensions in the membrane and the difference between the external pressure and the pressure in the vesicle depend on external forces. (Abstract truncated at 2000 characters) | |
| Descriptors | MEMBRANES, ARTIFICIAL PHOSPHOLIPIDS LIPID BILAYERS THERMODYNAMICS ELASTICITY MODELS, THEORETICAL |