Thermodynamics and Energy

Osmotic Pressure as Momentum Counteraction: A Kinetic Theory and its Application in Energy Conversion

Authors: Weigang Li
Comments: 9 Pages. (Note by ai.viXra.org Admin: For the last time, please cite listed scientific references)

The van’t Hoff formula for osmotic pressure (Π = icRT) bears a striking mathematical resemblance to the ideal gas law (P = nkT). Conventionally, its microscopic origin is attributed to entropy or chemical potential gradients. This paper proposes a novel, purely kinetic theory based on momentum transfer: osmotic pressure arises from the instantaneous reversal of the perpendicular momentum component of impermeable soluteparticles during elastic collisions with a semi-permeable membrane while undergoing Brownian motion. This reversal directly counteracts the momentum flux of water molecules impinging on the membrane from the solution side. To compensate for this momentum flux deficit, a macroscopic static pressure must be applied to the solution side, which is the osmotic pressure. We thereby rigorously derive the van’t Hoff law from first principles. Based on this theory, we further conceptualized and experimentally validated an energy conversion system. This system utilizes an electrostatic field to create asymmetric local ionconcentrations near two semi-permeable membranes, generating differential solutemomentum counteraction that ultimately induces a sustained water level difference between pure water columns, allowing for the extraction of gravitational work. Improved experiments observed a water level difference of up to 2.8 meters, indicating the system's ability to absorb ambient heat and convert it into mechanical work, posing a challenge tothe universal applicability of the second law of thermodynamics under specific conditions.However, the consistent contradiction between the observed flow direction and theoreticalpredictions remains a central puzzle to be solved.
Category: Thermodynamics and Energy