PHOTO-RESPONSIVE LAYER AND LAYER ASSEMBLY

• US 20120223248A1
• Filed: 10/06/2010
• Published: 09/06/2012
• Est. Priority Date: 10/16/2009
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Broer, Dirk Jan, Peeters, Emiel
• Granted Patent: US 8,921,806 B2
• Time in Patent Office: Days
• US Class Current: 250/435
• CPC Class Codes: C02F 1/325 Irradiation devices or lamp constructions
• CPC Class Codes: C02F 2201/326 Lamp control systems
• CPC Class Codes: C02F 2209/40 Liquid flow rate
• CPC Class Codes: C09K 19/2007 the chain containing -COO- or -OCO- groups
• CPC Class Codes: C09K 19/24 linked by a chain containing nitrogen-to-nitrogen bonds
• CPC Class Codes: C09K 19/54 Additives having no specific mesophase characterised by their chemical composition
• CPC Class Codes: C09K 19/588 Heterocyclic compounds
• CPC Class Codes: C09K 2019/0448 the end chain group being a polymerizable end group, e.g. -Sp-P or acrylate
• CPC Class Codes: C09K 2219/03 in the form of films, e.g. films after polymerisation of LC precursor

Abstract

The present invention relates to a photo-responsive layer and layer assembly which can be used for controlling a flow of liquid for example in a water-purification device. The photo-responsive layer according to the invention comprises a first domain comprising a first material comprising molecules having a photo-responsive moiety, wherein the first domain of the photo-responsive layer is capable of undergoing a reversible geometrical change when said photo-responsive moiety is exposed to photo-activating illumination, such as UV-radiation. The photo-responsive layer is useful in UV controlled membranes e.g. for water purification.

Claims

1. A photo-responsive layer comprising a first domain comprising a first material comprising molecules having a photo-responsive moiety, wherein said first domain of said photo-responsive layer is capable of undergoing a reversible geometrical change when said photo-responsive moiety is exposed to photo-activating illumination.

2. A photo-responsive layer according to claim 1, wherein said first material comprises a first molecularly ordered phase.

3. A photo-responsive layer according to claim 1, wherein said geometrical change provides a topographic change of said photo-responsive layer.

4. A photo-responsive layer according to claim 1, wherein said first domain is capable of undergoing a reverse geometrical change when said photo-responsive moiety is not under exposure to photo-activating illumination.

5. A photo-responsive layer according to claim 1, wherein said first material is a liquid crystal polymer material.

6. A photo-responsive layer according to claim 1, wherein said first molecularly ordered phase is a nematic phase.

7. A photo-responsive layer according to claim 1, wherein said photo-responsive moiety is a moiety capable of photo-isomerization.

8. A photo-responsive layer according to claim 1, further comprising a second domain comprising a second material which is capable of undergoing a reversible geometrical change when exposed to photo-activating illumination.

9. A photo-responsive layer according to claim 8, wherein said second domain comprises a second material which has a second molecularly ordered phase, different from said first molecularly ordered phase, comprising molecules having a photo-responsive moiety, wherein said second domain is capable of undergoing a geometrical change when said photo-responsive moiety of said second domain is exposed to photo-activating illumination, wherein the geometrical change is different from the geometrical change of said first domain.

10. A photo-responsive layer according to claim 8, wherein said second material is a liquid crystal polymer material.

11. A photo-responsive layer assembly comprising

a fluid transmissive layer, and

a photo-responsive layer according to claim 1, arranged in contact with said transmissive layer,

wherein under photo-activating illumination, said photo-responsive layer is capable of a topographic change allowing for opening of at least one fluid path passing by said photo-responsive layer and said transmissive layer allowing for flow, or increased flow, of a fluid through said photo-responsive layer assembly.

12. A method for controlling a photo-responsive layer assembly according to claim 11, comprising exposing said photo-responsive layer to photo-activating illumination, such that said photo-responsive layer undergoes a topographical change in response to photo-activating illumination, whereby the photo-responsive layer shifts from a state of fluid-tight arrangement or low flow arrangement with the fluid transmissive layer to a state of fluid transmissive arrangement or high flow arrangement with the fluid transmissive layer, the fluid transmissive arrangement comprising at least one fluid path passing by the photo-responsive layer to the transmissive layer, wherein flow through said photo-responsive layer assembly is allowed or increased.

13. A fluid purification device comprising a UV-radiation chamber having a fluid inlet and a fluid outlet, and a flow control device arranged in said fluid inlet or fluid outlet, wherein said flow control device includes a photo-responsive layer according to claim 1 or a photo-responsive layer assembly.

14. A method for producing a photo-responsive layer according to claim 1 comprising:

providing a substrate,

applying a composition to said substrate forming a layer on the substrate, wherein said composition comprises monomers being both UV-radiation responsive and capable of forming an molecularly ordered phase, and/or monomers being UV-radiation responsive and monomers capable of forming a molecular ordered phase, and a photo-initiator,

selectively polymerizing a first domain of said layer by photo-polymerization;

rearranging said monomers in said second domain by heating, applying an electrical field or an external magnetic field; and

allowing said second domain to polymerize by photo-polymerization.

15. A method for producing a photo-responsive layer according to claim 1 comprising:

providing a discontinuous layer on a substrate,

applying a composition comprising a monomer being photo-responsive and optionally a photo-initiator on at least one region of said substrate not covered by said discontinuous layer, thus forming said first domain, and

polymerizing/allowing the monomers of a first domain to polymerize, optionally by photo-polymerization.