Layered sorbent structures
A shaped sorbent is described comprising a plurality of layers of photopolymerised resin containing particles of a sorbent material. The shaped sorbent may be used as a getter for use in gettering one or more contaminants in a sealed enclosure.
1. A shaped sorbent comprising a plurality of layers of photopolymerised resin containing particles of a sorbent material, wherein the sorbent material comprises alumina, silica, carbon or a molecular sieve and the shaped sorbent is formed by additive layer photopolymerisation comprising digital light processing or continuous liquid interface production of a mixture of the sorbent material and a photopolymerisable resin, wherein each layer has a thickness in a range of from 10 to 300 μm and wherein the maximum particle size (Dv100) of the sorbent material in the shaped sorbent is less than the layer thickness.
2. The shaped sorbent according to claim 1 wherein the sorbent material comprises a reactive sorbent material.
3. The shaped sorbent according to claim 1 comprising a molecular sieve sorbent material and a reactive sorbent material.
4. The shaped sorbent according to claim 1 wherein the photopolymerised resin is derived from a photopolymer comprising a mixture of multifunctional monomers and oligomers functionalized by an acrylate.
5. The shaped sorbent according to claim 1 comprising from 1 to 70% by volume of sorbent material.
6. The shaped sorbent according to claim 1 comprising 5 to 5000 layers.
7. The shaped sorbent according to claim 1 wherein the shaped sorbent has a cross-sectional length width or height, in a range of from 0.3 mm to 100 mm.
8. The shaped sorbent according to claim 1 wherein the shaped sorbent is in the form of an open-ended cylinder containing a lattice structure or layers of spaced parallel struts or meshes.
9. A process for gettering by placing the shaped sorbent according to claim 1 in a sealed container.
10. The shaped sorbent according to claim 1 wherein the sorbent material comprises a zeolite material.
11. A method for making a shaped sorbent unit comprising the steps of (i) combining a sorbent material with a liquid photopolymer comprising a mixture of monomers, oligomers and photoinitiators to form a sorbent mixture, and (ii) using photopolymerisation to form a shaped sorbent comprising a plurality of layers of photopolymerised resin containing particles of the sorbent material, wherein the shaped sorbent is formed by additive layer photopolymerisation comprising digital light processing or continuous liquid interface production of a mixture of the sorbent material and a photopolymerisable resin, each layer has a thickness in the range of from 10 to 300 μm and the maximum particle size (Dv100) of the sorbent material in the shaped sorbent is less than the layer thickness.
12. The method according to claim 11 wherein the photopolymer has a viscosity in a range of from 1 to 500 mPa·s at 20° C.
13. The method according to claim 11 wherein the sorbent mixture comprises from 1 to 70% by volume of the sorbent material.
14. The method according to claim 11 wherein the sorbent mixture comprises a dispersant.
15. The method according to claim 11 , wherein the sorbent material comprises alumina, silica, carbon or a molecular sieve.