Photocatalytic surfacing agents with varying oxides for inhibiting algae growth

• US 5,994,268 A
• Filed: 03/05/1999
• Issued: 11/30/1999
• Est. Priority Date: 05/20/1997
• Status: Expired due to Term

• Current Assignee: University of Central Florida (State University System of Florida)
• Original Assignee: University of Central Florida (State University System of Florida)
• Inventors: Linkous, Clovis A.
• Primary Examiner(s): Dees, Jose' G.
• Assistant Examiner(s): PRYOR, ALTON NATHANIEL
• Application Number:
  US09/263,309
• Time in Patent Office: 270 Days
• Field of Search: 504/120, 504/151, 504/152, 424/646
• US Class Current: 504/120
• CPC Class Codes: A01N 2300/00 Combinations or mixtures of active ingredients covered by classes A01N27/00 - A01N65/48 with other active or formulation relevant ingredients, e.g. specific carrier materials or surfactants, covered by classes A01N25/00 - A01N65/48
• CPC Class Codes: A01N 59/16 Heavy metals; Compounds thereof
• CPC Class Codes: C09D 5/14 Paints containing biocides, e.g. fungicides, insecticides or pesticides C09D5/16 takes precedence
• CPC Class Codes: C09D 5/1618 inorganic

Abstract

Self cleaning mixtures that use photoactive agents with varying oxides, along with mixing the photoactive agents with carbon, noble metals and cobalt phosphide that inhibit the growth of algae are disclosed. The agents include concentrations of approximately at least 5% to approximately 50% TiO_n1, WO_n2, X--WO_n2, or X--TiO_n1, where 1.8≦n1≦2, and where 2.2≦n2≦3, and where X can be one of carbon, a noble metal, and cobalt phosphide. The agents can be combined together, and/or each agent can be combined with various coatings such as but not limited to a cement or a polymer binder. The coatings and agents can be applied to surfaces that are exposed to water such as but not limited to an aquarium, liners on the inner walls of swimming pools, drinking water tanks and the like. Further, applications can include using the novel surfacing agent as part of a solar water heater for both a home and a pool, wherein in the latter application the heater is connected between pool pumps and the pool so that when light is absorbed inside the heater, the surfacing agent becomes active for inhibiting the growth of algae. The photoactive agent can also be applied as a non-toxic algae-retardant marine paint. The invention can be used to inhibit the growth of other undesirable substances such as fungus, bacteria and mold.

Claims

1. A method of inhibiting the growth of nuisance organisms including algae, bacteria, fungus and mold, on surfaces that are exposed to water using a photoactive coating comprising the steps of:

(a) applying a coating combined with a photoactive agent having a Co₂ P compound to a water exposed surface;

(b) applying light to the coating and the agent which inhibits the growth of nuisance organisms on the surface.

2. The method of inhibiting the growth of nuisance organisms of claim 1, wherein the photoactive agent includes:

TiO_n, wherein n≦

2.

3. The method of inhibiting the growth of nuisance organisms of claim 2, wherein n includes:

1.8≦

n≦

2.

4. The method of inhibiting the growth of nuisance organisms of claim 1, wherein the photoactive agent includes:

WO_n to a water exposed surface, wherein n≦

3.

5. The method of inhibiting the growth of nuisance organisms of claim 4, wherein n includes:

2.5≦

n≦

3.

6. The method of inhibiting the growth of nuisance organisms of claim 5, wherein the Co₂ P includes:

approximately 1% Co₂ P.