A thermal atomic layer deposition (ALD) process for depositing titanium phosphate onto bundles of carbon fibers as well as flat silicon and germanium substrates using titanium tetrachloride and triethyl phosphate as precursors is presented. This process yields conformal coatings on all substrates used while having a growth per cycle of 0.22 nm cycle−1, which is relatively high compared to other metal phosphate ALD processes. The reactions of the precursors with the surface are shown to be self‐limiting at 200 °C. Compositional analysis of the coating is performed using energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy, and Fourier‐transform infrared spectroscopy. It is shown that the as‐deposited coating has a chemical composition of Ti3.0PO8.2 and a residual carbon content of 7%. Upon thermal annealing in air, residual triethyl phosphate and water is lost from the coating and phosphate can be identified up to 1000 °C. At temperatures exceeding 1000 °C, the coating starts to decompose. Thermogravimetric analysis of coated carbon fibers shows that the coating increases the onset temperature of the carbon fiber oxidation, thus providing an oxidation protection to the fibers.

This article shows a new way to produce hierarchical microsieves by layering three types of float-cast microsieves, differing from each other in their pore diameters (approximately 68 μm, 7 μm, and 0.24 μm) on top of each other. The unsupported microsieves with 7 and 0.24 μm pore sizes are mechanically fragile. The complete hierarchical sieve composed of all three layers, however, can be handled manually without special precaution. This article further investigates the flow through the hierarchical sieve and filtration via experiment, theory (Hagen–Poiseuille’s and Sampson–Roscoe’s law), and simulation (numerically solving the Navier–Stokes equations for a predefined set of discrete volumetric elements). The experimental, theoretical, and simulated permeances of the microsieves and the hierarchical sieves are in reasonable agreement with each other and are significantly higher than the permeances of conventional filtration media. In filtration experiments, the hierarchical sieves show the expected sharp size cut-off, retaining particles of diameters exceeding the pore diameter.