Antifouling Coating for Sensor Transducers Used for Monitoring Fluid Properties

Abstract

A coating for sensor transducers that transmit a signal to—and/or receive a signal from—a fluid, either liquid or gas, in contact with the transducer. In particular the coating minimizes or eliminates fouling of the transducer surface by the fluid, reducing the need for transducer maintenance, while not interfering with the transducer's ability to send and/or receive signals.

1 . A coating comprising at least one chloro-terminated-silicone-oligomer which is a coating on a transducer of a sensor used to measure a fluid property. 
     
     
         2 . The coating of  claim 1  wherein the chloro-terminated-silicane-oligomers bond to reactive sites on the transducer surface to form a coating and wherein the chloro-terminated-silicone-oligomers are selected from the group so as to (1) minimize or eliminate reaction with—or wetting by—fluids in contact with the transducer while in use; (2) minimize or eliminate absorption or blocking of signals between the transducer and the fluid in contact with the transducer when in use or (3) combinations thereof. 
     
     
         3 . The coating of  claim 1  wherein the transducer has reactive hydroxyl groups on the surface for binding with the coating selected from the group consisting of functionalized chloro-terminated-silicone-oligomers. 
     
     
         4 . The coating of  claim 1  wherein the transducer's surface is selected from the group consisting of metal, semi-conductor, polymer, crystalline, amorphous materials, hydroxyl sites and combinations thereof. 
     
     
         5 . (canceled) 
     
     
         6 . The coating of  claim 1  wherein the functional chloro-terminated-silicone-oligomer are selected from the group consisting of
 a. the chemical as represented by the formula:   
       
         
           
           
               
               
           
         
       
       wherein the repeat group is 
       
         
           
           
               
               
           
         
       
       and wherein x is in the range of 0 to about 25 and H 3 C are non-hydrolysable side-chains,
 b. the chemical as represented by the formula: 
 
       
         
           
           
               
               
           
         
       
       wherein x is in the range of 0 to about 25 and wherein the repeat group is 
       
         
           
           
               
               
           
         
       
       and H 3 C and F 3 CH 2 CH 2 C are non-hydrolysable side-chains. 
     
     
         7 . The coating of  claim 1  wherein the coating contains molecules bonded to the transducer surface and other molecules by a means selected from the group consisting of at least one reactive site bonded to the transducer surface and no molecule-molecule bonding; at least one reactive site bonded to the transducer surface and molecules with at least one reactive site and molecule-molecule bonding; molecules with at least one reactive site bonded to the transducer surface and molecules bonded to the surface bonded molecules; or combinations thereof. 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . The coating of  claim 1  wherein the chloro-terminated-silicone-oligomer is a short silicon oligomer selected from the groups consisting of short silicon oligomers having at least one reactive chloro group at one end, short silicon oligomers having at least one reactive chloro group at both ends, short silicon oligomers having at least one reactive chloro group on at least one internal silicon or combinations thereof. 
     
     
         11 . The coating of  claim 1  wherein the chloro-terminated-silicone-oligomers can be functionalized with alkyl or aryl groups and contains groups selected from the group consisting of fluorine, chlorine and combinations thereof. 
     
     
         12 . A process to make a sensor transducer antifouling coating comprising (a) cleaning a transducer surface; (b) immersing the transducer into a solution selected from the group consisting of chloro-terminated-silicone-oligomers; (c) rinsing the transducer with solvent; (d) drying the transducer to remove the solvent and to minimize remaining reactive sites of the coating resulting in antifouling coating on the transducer of the sensor. 
     
     
         13 . The process of  claim 12  wherein the solution for immersing the transducer has a concentration in the range of about 0.1% to about 10%. 
     
     
         14 . The process of  claim 12  wherein a cleaning material is used to clean to transducer surface and is selected from the group consisting of solvents, detergents, oxidizers, physical agitation, scrubbing, and combinations thereof resulting in cleaning and modifying the surface of the transducer. 
     
     
         15 . The process of  claim 12  wherein the immersion time is in the range of about 1 minute to about 60 minutes at a temperature in the range of ambient temperature to elevated temperature. 
     
     
         16 . The process of  claim 12  wherein the drying temperature occurs at about ambient temperature to about 60° C. so as to not damage the substrate on the coating. 
     
     
         17 . The process of  claim 12  wherein the coating has anti-fouling properties that do not substantially interfere with the transducer's ability to transmit or receive signals from a fluid. 
     
     
         18 . A process to make a sensor transducer antifouling coating comprising (a) cleaning a transducer surface; (b) immersing the transducer into a solution selected from the group consisting of chloro-terminated-silicone-oligomers; (c) rinsing the transducer with solvent; (d) drying the transducer to remove the solvent but not to minimize remaining reactive sites of the coating; (e) repeating steps (b), (c), and (d) until the desired coating porosity and thickness is achieved; and (f) drying the transducer to minimize remaining reactive sites of the coating resulting in antifouling coating on the transducer of the sensor. 
     
     
         19 . The process of  claim 18  wherein the coating has anti-fouling properties that do not substantially interfering with the transducer's ability to transmit or receive signals from a fluid.