Cellulose, a homopolymer consisting of glucose units joined by β-1,4 bonds. These are strongly attached through inter and intramolecular hydrogen bonds and van der Waals forces resulting in microfibrils which together form fibers. They are arranged in parallel reducing ends of adjacent glucan chains. Cellulose is widely used as sorbent in TLC. On a cellulose coated TLC Alu foil, the substances are partitioned between the developing solvent and water coating the cellulose particles.