Membrantest

Membrantest refers broadly to experiments and procedures used to evaluate the properties and performance of membranes, including synthetic polymeric filtration membranes and biological membranes. It is not a single standardized protocol but a family of tests designed to quantify permeability, selectivity, mechanical integrity, and compatibility with feeds and cleaning agents.

Key properties commonly assessed include permeability (flux under defined driving force), selectivity or rejection of solutes, pore size distribution or molecular weight cut-off, mechanical strength and durability, fouling resistance, chemical compatibility, and thermal stability.

Common testing methods include: pure-water permeability tests to measure baseline flux; solute-rejection tests using representative feeds (for example, NaCl for desalination or bovine serum albumin for protein separations); gas permeation tests for gas separation membranes; pore-size characterization by porometry or MWCO determination; fouling studies with model foulants; long-term aging and chemical-compatibility tests; and mechanical tests such as burst pressure or tensile strength.

Standards and practice are provided by international bodies such as ISO and ASTM, with specific membrane testing standards for different applications.

Applications span water treatment, food and beverage processing, biotechnology, gas separation, and medical devices.

Results are typically reported as flux and rejection or selectivity curves, often illustrating the trade-off between permeability and selectivity. Data interpretation may include pore-structure analysis and lifetime projections.

Limitations include dependence on test conditions, lab-scale versus module-scale results, and differences between model feeds and real feeds.