Introduction
The study investigates the mechanical properties of diphenylalanine microtubes (MNTFF), self-assembled peptide structures with promising applications in nanotechnology. Due to its tubular and chemical nature, the presence of water in its internal hydrophilic channel is a determining factor for its stability. This work employs finite element simulation (FEM) to assess how internal hydration modifies the mechanical response and rigidity of these nanomaterials.
Objectives
The main objective is to quantify the impact of internal water (in dry, partial and fully full states) on the force-elongation behavior and elastic constants of MNTFF. The fluid-structure interaction is modeled to understand the reinforcing role of water confined under axial loads.
Methodology
Gmsh software was used to generate 3D meshes with a scale parameter of 17.0 ?m, internal radii of 0.400 ?m and external 0,804 ?m. Three models were compared:
MNTFF Dry: hollow tube (9,516 knots).
MNTFF Partial: With discontinuous water volumes (12.671 knots). MNTFF Full: With the canal completely occupied by water (12.813 knots).
The simulation was performed in ELMER FEM using the ElasticSolver module based on the Saint Venant-Kirchhoff elasticity model. External forces of 10 to 160 ?N were applied. Contour conditions were established using the BC Mortar to project forces and friction (coefficient 0.1) between the inner surface of the tube and the volume of water.
Results
The simulations revealed a drastic difference in load capacity depending on hydration level:
-Dry Tube: Presented higher maximum elongation (1.12 ?m at 160 ?N), indicating lower rigidity due to its hollow nature and lack of internal support.
-Hydrated systems: They presented a significant hardening. The tube with total filling l achieved an elongation of only 0.068 ?m, while the partial one recorded 0.063 ?m.
-Elastic Constants: The theoretical Young module (ET ) increased from 15.91 GPa (dry) to 28.13 GPa (total filling). The value obtained for partial filling (26.32 GPa) showed an excellent correlation with the experimental values reported of 27 4 GPa. Water provides a hydrostatic support that suppresses radial deformation and improves axial load transfer. The friction in active contact between water and inner wall acts opposite to displacement, increasing mechanical strength.
Conclusion
The FEM simulation demonstrates that the inner water is not a passive component, but rather a critical reinforcing agent that transforms microtubes into supramolecular compounds of high rigidity. The results validate that hydration strengthens the hydrogen bond network and aromatic stacking (? ?), allowing the system to withstand significantly higher loads than in the dry state. This continuity model coincides with descriptions of molecular dynamics, confirming that the stability of MNFTs is intrinsically dependent on their water content.
Comissão Organizadora
Pedro Alves da Silva Autreto
Comissão Científica
Ferramenta completa de submissão, avaliação e publicação de anais para eventos científicos.
