PRODUCTION PROCESS OF NANOPARTICLES OF ORGANIC EXTRACT OF CURCUMA SP. FOR THE MANUFACTURE OF A BIODEGRADABLE ANTI-FOULING ADDITIVE

Description

1 / 16 PROCESS FOR THE PRODUCTION OF NANOPARTICLES OF ORGANIC CURCUMA sp. EXTRACT FOR THE MANUFACTURE OF A BIODEGRADABLE ANTI-FOULING ADDITIVE FIELD OF APPLICATION

[001] The present invention relates to the technical field of antifouling coatings, more specifically, to the development of nanoencapsulated additives based on natural extracts for the production of environmentally friendly antifouling paints. Such additives are applicable to vessels, offshore platforms, submerged structures, and other equipment exposed to aqueous environments to prevent biological fouling. FUNDAMENTALS OF THE INVENTION

[002] Biofouling, that is, the unwanted attachment of marine organisms such as algae, barnacles and other sessile invertebrates, has generated challenges for industries involved with the marine environment, causing economic, social and environmental impacts.

[003] For the marine transport sector, biofouling on vessels increases frictional drag and hydrodynamic weight, decreasing transport speed and maneuverability, resulting in increased fuel consumption and the emission of substances harmful to the environment.

[004] In the offshore sector, such as oil and gas platforms, biofouling increases the diameter of tubular structures and the surface roughness of coatings, leading to an increase in the hydrodynamic load on the structures. Fouling can impede inspection and Petition 870240111146, dated 12 / 30 / 2024, page 11 / 33 2 / 16 Maintenance of these structures, carried out by divers or remotely operated vehicles (ROVs), makes it difficult to locate damage reference marks on the coating, affecting the safety of these structures.

[005] In the energy sector, production costs increase by 20% due to expenses related to the removal of encrusted organisms from water pipelines. In the marine renewable energy sector, such as offshore wind energy and ocean wave and tidal technologies, equipment (e.g., sensors and devices) submerged for long periods suffers from loss of structural integrity and performance, increased weight, thickness, and roughness, all caused by biological fouling.

[006] Marine biofouling is also associated with biocorrosion of submerged metallic structures. Bacteria present in marine biofilms promote corrosion through the oxidation (aerobic) or reduction (anaerobic) of sulfur compounds, by a process known as microbiologically influenced corrosion (MIC). Macrofouling organisms, such as barnacles and polychaetes, can accelerate corrosion by synthesizing adhesive substances to attach to or perforate the substrate.

[007] Submerged artificial structures, such as ship hulls and offshore structures, can serve as surfaces for colonization by marine organisms, including non-native species. These structures can act as "stepping stones" for exotic species, contributing to the spread of these organisms. Exotic species can Petition 870240111146, dated 12 / 30 / 2024, page 12 / 33 3 / 16 impact ecosystems, causing loss of biodiversity, threatening native and commercially important species, and causing changes in the function and structure of communities, presenting an ecological and economic threat.

[008] Several attempts to combat this unwanted fouling have been used, such as the use of paints containing heavy metals, such as copper, and the use of organotin compounds such as tributyltin (TBT) (Ferreira-Vançato YCS, Dantas FML, Fleury BG. 2020. Nanobiocides against marine biofouling. In: Stud Nat Prod Chem. 67: 463-514. https: / / linkinghub.elsevier.com / retrieve / pii / S1572599503800 200). TBT has been banned by the International Maritime Organization since 2008 (IMO 2002) due to its toxicity and accumulation in the marine environment and in non-target organisms, such as fish and mammals. This substance affects essential enzymatic functions, causing the death of these organisms. The use of TBT is also associated with the induction of imposex, which is an alteration of sexual characteristics in female marine mollusks. Furthermore, it also causes an obesogenic effect in animals and humans.

[009] Currently, other biocides have been formulated into antifouling paints, such as copper oxide, Irgarol 1051, and diuron. However, these substances are toxic in small concentrations and are not biodegradable.

[0010] These persistent organic pollutants (POPs) used in marine paints contaminate marine organisms, bioaccumulating and potentially reaching humans through food.

[0011] The marine paint industry has an urgent need to replace conventional toxic paints. Petition 870240111146, dated 12 / 30 / 2024, page 13 / 33 4 / 16 for new formulations that combine antifouling properties with environmental compatibility.

[0012] The present invention seeks to solve and reduce fouling by organisms such as barnacles, mussels and algae, on vessels, offshore platforms and other submerged structures, through the use of a biodegradable, efficient and sustainable formulation. STATE OF THE ART

[0013] Document CN106221353 (D1) describes an antifouling additive for paints, a method for preparing it, and an antifouling paint. In the antifouling agent, components with anti-biofouling effects, such as capsaicin, curcumin, garlic powder, and vulgarin, are compounded for use; in addition, auxiliary components are added, such as a controlled-release agent and an oily solvent. In said document D1, with the further adjustment and optimization of the raw materials, the use of the active ingredient is mentioned without showing the method of obtaining or producing this compound. Additionally, no more sophisticated forms of protection and release control of the antifouling actives were observed, especially for those of natural origin, which are widely known in the state of the art to be unstable under conditions of physical exposure to radiation and temperature common in outdoor or open environments, such as the marine environment.

[0014] Patent CN106221353 (D2) appears to describe a simple mixture of components for paint formulation. As for applications, the additive is mixed into anti-corrosive paints for ships, which may be epoxy, acrylic or Petition 870240111146, dated 12 / 30 / 2024, page 14 / 33 5 / 16 inorganic. The document does not mention applications in water-based paints.

[0015] Document CN106868441 (D3) also describes a polymer compound coating, a method of preparation and its application. The document discloses a coating comprising 50 to 90% by weight of polymer and 10 to 50% by weight of an antifouling agent, said polymer being polyethylene, polypropylene or polytetrafluoroethylene, and the antifouling agent being at least one of the following: allicin, capsaicin, curcumin, chitin, tannic acid and enzyme. This work does not clearly describe how the active ingredients are released; from what is described, the formulated paint appears to act conventionally with the polymers acting as a dispersion matrix from the formation of the post-drying film. Therefore, it is a conventional paint formulation and does not mention applications in water-based paints.

[0016] Document WO2008033112 (D4) refers to polymer coatings; UHMW polyethylene, VHMW polyethylene and latex compounds incorporating biocidal phytochemicals. This document provides compositions of polyethylene and latex compounds that may include at least one environmentally benign phytochemical suitable for use in preventing biofouling. The compositions in this document may also include controlled release agents, such as microencapsulation of the phytochemicals to maintain sustained and prolonged release of the biocidal agents on the treated surface.

[0017] However, document WO2008033112 (D4) addresses the microencapsulation of phytochemical biocides, including the Petition 870240111146, dated 12 / 30 / 2024, page 15 / 33 6 / 16 The document discusses the use of *Curcuma longa*, without detailing the specific microencapsulation process. It only mentions the combined or sequential addition of phytochemicals, antioxidants, and release agents to polymeric coatings, followed by mixing until the phytochemicals are uniformly dispersed, suggesting a simple mixture of components. The document cites the use of citric acid, zinc oxide, iron oxide, or vitamin E as agents for the sustained release of biocides on the treated surface, suggesting a release of active ingredients with little control. The document also does not mention applications in water-based paints. SUMMARY OF THE INVENTION

[0018] The present invention seeks to solve / reduce fouling by organisms such as barnacles, mussels, and algae on vessels, offshore platforms, and other submerged structures, through the use of a biodegradable and sustainable formulation. The presented technology consists of a process for producing nanocapsules of preferential organic extract of Curcuma sp., comprising steps of (a) extraction of Curcuma sp. and (b) nanoencapsulation of Curcuma sp.; the application of this encapsulated extract in biodegradable polymers as nanoadditives in antifouling paints; and its application in the production of sustainable antifouling paint. Laboratory and natural environment studies have demonstrated its efficiency in inhibiting the attachment of the main fouling species, such as biofilm, mussels, and polychaetes.

[0019] Paints containing tributyltin (TBT) and other heavy metals such as copper have been used to prevent fouling. However, these compounds are toxic to Petition 870240111146, dated 12 / 30 / 2024, page 16 / 33 7 / 16 marine organisms and humans accumulate in the environment. The marine paint industry has an urgent need to replace conventional toxic paints with new formulations that combine antifouling properties with environmental compatibility. Therefore, the present invention sought to develop an efficient and high-tech solution through the application of nanotechnology. BRIEF DESCRIPTION OF THE FIGURES

[0020] The invention can be better understood through the brief description in the following figures: Figure 1 presents the flowchart of the paint production process with the addition of nanoencapsulated Curcuma longa extract. Figures 2A-D show images of polyhydroxybutyrate (PHB) nanocapsules containing Curcuma longa extract. Caption: Magnifications of 100,000x (Figure A), 200,000x (Figure B), 300,000x (Figure C) and 400,000x (Figure D). Highlight on a 43nm nanoparticle (D). Figure 3 presents the graph for the antifouling activity and standard deviation (±) of the Curcuma longa extract against the attachment of the mussel Perna perna. Legend: CN - negative control, CP - positive control, CL - free Curcuma longa extract. Figure 4 presents the randomized phytagel plate methodology - Static raft. Legend: Colored circles represent treatments. Figure 5 presents the graph of the average percentage of coverage and standard deviation (±) of total biofouling in the different treatments evaluated in the field bioassay. Legend: CN - negative control, CP - positive control, CL Petition 870240111146, dated 12 / 30 / 2024, page 17 / 33 8 / 16 free — free Curcuma longa extract and CL nano — nanoencapsulated Curcuma longa extract. Figures 6A-C present graphs of the average biofouling coverage percentages in relation to exposure time for biofilm (Figure 6A), Serpulidae (Figure 6B), and Amphibalanus amphitrite (Figure 6C). DETAILED DESCRIPTION OF THE INVENTION

[0021] The invention can be better understood through the following detailed description:

[0022] The present invention describes the application of nanotechnology for the control of biofouling in marine environments and can also be used for the control of fouling in freshwater or biofilm control in humid environments. The technology presented consists of the process for producing nanocapsules of preferred organic extract of Curcuma longa, as well as the extract of the following species: Curcuma aeruginosa, Curcuma amada, Curcuma amaríssima, Curcuma angustifolia, Curcuma aromatica, Curcuma attenuata, Curcuma caesia, Curcuma ecalcarata, Curcuma elata, Curcuma glans, Curcuma haritha, Curcuma inodora, Curcuma kwangsiensis, Curcuma leucorhiza, Curcuma mangga, Curcuma petiolata, Curcuma zedoaria, Curcuma neilgherrensis, Curcuma nankunshanensis, Curcuma cf.xantorriza, Curcuma thorelii, Curcuma rhabdota, Curcuma pseudomontana, Curcuma phaeocaulis; in the application of nanocapsules as nanoadditives in antifouling paints and in the production of sustainable antifouling paint for application in submerged coatings in order to prevent the attachment of marine organisms. Petition 870240111146, dated 12 / 30 / 2024, page 18 / 33 9 / 16

[0023] The process of the present invention occurs through the steps of (a) extraction of Curcuma sp. and (b) nanoencapsulation of Curcuma sp.

[0024] Organic extracts can be made with the main non-chlorinated organic solvents such as isoamyl alcohol, isoamyl acetate, ethyl acetate, acetone, methanol, ethanol, 95% ethanol, 90% methanol in water, ethyl ether, ethyl formate, heptane, pentane, 1-propanol, 2-propanol, propyl acetate, isobutyl acetate, hexane, petroleum ether, acetonitrile, methoxybenzene, 1-butanol, 2-butanol, butyl acetate, cumene, and mixtures thereof according to the nature of the turmeric. Also, extraction can be done with chlorinated solvents, preferably those approved by the Food and Drug Administration (FDA) or other health surveillance agencies as safe; in this case, dichloromethane is one of the most suitable. Therefore, extraction can be done with polyethylene glycol, tetrachloromethane, chlorobenzene, trichloromethane, 1,2-dichloroethane, 1,1-dichloroethene, 1,2-dichloroethene, methyl chloroform, and 1,1,2-trichloroethene.Extraction is preferably done from macerated or finely divided rhizomes, and the active ingredient / solvent ratio will depend on the chemical nature of the turmeric and the solvent.

[0025] Regarding techniques for recovering the concentrated extract, it can first be obtained by dispersing the macerated or powdered rhizome of Curcuma sp. in a suitable solvent, and the concentration can vary from 1 to 50% mass by volume in a vessel with mechanical agitation. Then, the system can be concentrated by rotary evaporator or direct evaporation. The dispersion can also be previously subjected to treatment with ultrasound or an enzymatic system to... Petition 870240111146, dated 12 / 30 / 2024, page 19 / 33 10 / 16 destruction or separation of plant fibers through cell lysis, which facilitates solvent extraction efficiency.

[0026] Another technique is extraction with the Soxhlet system, in which the macerated or powdered rhizome of Curcuma sp. is continuously extracted by circulating refluxed solvent over the sample until the material is exhausted. The extract of the Curcuma sp. rhizome can also be obtained by supercritical fluid extraction, and this technique is preferred due to its low environmental impact. The extraction residue can be subjected to 3 or more extraction cycles, preferably 3 cycles.

[0027] The biopolymer preferably used as an encapsulating agent is polyvinylpyrrolidone (PVP), poly(3-hydroxybutyrate), as well as the entire series of polyhydroxyalkanoates (PHAs), such as polyhydroxybutyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), polyhydroxyoctanoate, among others. Other biodegradable polymers can also be used, such as alpha-hydroxy acids, such as L, D and DL isomers of poly(lactic acid), isomers of poly(lactic-co-glycolic acid), polycaprolactone; also polysaccharides, such as chitosan, alginate, amylose, methylpropylcellulose, ethylcellulose and agarose; and proteins, such as casein, gelatin A and gelatin B.

[0028] The nanoparticles or nanocapsules should have a size between 10 and 150nm, preferably between 20 and 70nm.Turmeric extracts are composed of various active ingredients, including curcumin, demethoxycurcumin, and bisdemethoxycurcumin, as well as essential oils, which also exhibit biological activity. Therefore, their use... Petition 870240111146, dated 12 / 30 / 2024, page 20 / 33 11 / 16 of nanoencapsulated Curcuma extracts, and not only isolated components of the extract (possibly in nano form), have greater anti-fouling bioactive potential due to the synergistic effect of the original compounds.

[0029] The present invention utilizes a nanoencapsulation technique based on the traditional emulsion / evaporation system, modified and optimized by means of rotor / stator type dispersion elements, which drastically reduces particle size and offers process yields exceeding 90% and high morphological homogeneity. The stator should operate with between 4 and 20 blades, preferably 12, and the rotor should operate with between 2 and 16 blades, preferably 8. The rotation speed can vary between 5,000 and 20,000 RPM, preferably 15,000 RPM. The dispersion time can vary between 1 and 20 minutes, preferably 5 minutes. The dispersion system can operate with 1 to 4 dispersers, preferably 1 disperser. The injection system of one of the phases can be done using single or multi-point injection. Single-point injection, i.e., one injection needle, is used for volumes up to 2 liters.Multipoint injection, that is, multiple injection needles, is used for volumes greater than 2 liters. Multipoint systems can be individually constructed and distributed along the mixing vessel or mounted in the form of a shower or needle bundle.

[0030] To prevent agglomeration of nanoparticles, nonionic surfactants formed by polyoxyethylene, such as the PEG 1000 to PEG 8000 series, polyols, such as ethylene glycol, glycerol, sorbitan, sucrose, alkyl glycosides, such as mono- and diesters of, are added. Petition 870240111146, dated 12 / 30 / 2024, page 21 / 33 12 / 16 sucrose stearyl, mono- and diesters of glucose stearyl, sorbitan monolaurate, among others.

[0031] The embodiments of the process of the present invention described in examples 1 and 2 below can be evaluated as described in Figure 1. EXAMPLE 1:

[0032] In one embodiment of the invention, in step (a) the extraction process of Curcuma longa can be carried out according to the steps described below: 1st: Grind approximately 5 to 200 g, preferably 100 g, of C. longa rhizome or use the dry powder directly. Mix with 500 ml of dichloromethane at a temperature of 0 to 15°C, preferably 5°C, in a suitably sized vessel with mechanical stirring and homogenize for 5 minutes. 2nd: Using an ultrasound probe, induce cell lysis for 5 to 30 minutes, preferably 20 minutes. Turn the agitation back on and leave the dispersion under agitation for 1 to 12 hours (preferably 6 hours). 3rd: Next, filter the dispersion, preferably under vacuum. The material retained in the filter (the cake) should be saved for 2 more extraction cycles. 4th: The filtered liquid should be concentrated in a rotary evaporator at 20 to 60°C (preferably 50°C) and stored for step (b) of nanoencapsulation.

[0033] In step (b), the production process of C. longa extract nanocapsules can be carried out according to the steps described below: 1st: Weigh between 0.1 g and 0.7 g of C. longa extract, preferably 0.5 g. Weigh 0.5 g of PHB. The C. longa / PHB mass ratio can vary from 0.2% to 140%, 50% is preferred. Petition 870240111146, dated 12 / 30 / 2024, page 22 / 33 13 / 16 Prepare a mixture containing between 10ml and 200ml of dichloromethane, preferably 50ml, and sorbitan monolaurate between 1% and 10%, preferably 2%. 2nd: Mix the compounds and the mixture mentioned above until completely homogenized. Then, subject the mixture to ultrasound for 5 to 15 minutes, preferably 10 minutes. In another container, add 30g to 100g, preferably 50g, of polyvinylpyrrolidone (PVP) to 300ml of water, resulting in a PVP solution. Maintain the PVP solution under ultrasound for 5 to 15 minutes, preferably 10 minutes, and then under mechanical agitation for 12 hours at 80°C. 3rd: Transfer the PVP solution to a 500 ml beaker and subject said solution to ultradispersion at 10,000 to 20,000 rpm, preferably 14,000 rpm. Slowly inject the C. longa solution in dichloromethane solvent into the vortex of the agitation. Maintain the system under ultradispersion for 1 to 10 min, preferably 5 min, resulting in a solution containing encapsulated C. longa nanoparticles.

[0034] The nanoparticles obtained are spherical in shape with homogeneous sizes ranging from 20 to 50 nm (Figures 2AD).

[0035] The product can be used in solution / dispersion form as obtained from the process or dried by freeze-drying or spray drying.

[0036] The product was subjected to an in vitro study of mussel attachment inhibition by Perna perna, Figure 3. Mussel attachment via byssus filaments (attachment structures) was reduced by 31% on the plates. Petition 870240111146, dated 12 / 30 / 2024, page 23 / 33 14 / 16 containing C. longa extract, compared to the negative control. Demonstrating the product's efficiency in inhibiting the mollusk. Also, a field study was conducted according to the design described in Figure 4, where reductions of 10% in total fouling (Figure 5), up to 90% in marine biofilm (15 days), up to 40% in snakes (15 days), and up to 90% in barnacles (A. amphitrite) in 22 days (Figure 6) were observed on plates containing nanoencapsulated C. longa extract compared to negative controls. This also demonstrated great efficiency in inhibiting biofouling by different marine organisms. EXAMPLE 2:

[0037] In another embodiment of the invention, in step (a), the extraction process of attenuated Curcuma can be carried out according to the steps described below: 1st: Grind approximately 5 to 200 g, preferably 100 g, of the rhizome of C. attenuated, or use the dry powder directly and mix with 500 ml of isoamyl acetate at a temperature of 50 to 80°C, preferably 65°C, in a suitably sized vessel with mechanical agitation and homogenize for 5 minutes. 2nd: Using an ultrasound probe, induce cell lysis for 5 to 30 minutes, preferably 20 minutes. Turn the agitation back on and leave the dispersion under agitation for 1 to 12 hours (preferably 6 hours). 3rd: Next, filter the dispersion, preferably under vacuum. The material retained in the filter (the cake) should be saved for 2 more extraction cycles. 4th: The filtered liquid should be concentrated in a rotary evaporator at 20 to 60°C (preferably 50°C) and stored for the nanoencapsulation step. Petition 870240111146, dated 12 / 30 / 2024, page 24 / 33 15 / 16

[0038] In step (b), the production process of C. longa extract nanocapsules can be carried out according to the steps described below: 1st: Weigh between 0.1g and 0.7g of attenuated C. extract, preferably 0.5g. Weigh 0.5g of Poly(lactic acid) (PLA). The mass ratio of attenuated C. / PLA can vary from 0.2% to 140%, 50% is preferred. Prepare a mixture containing between 10ml and 200ml of dichloromethane, preferably 50ml, and 1 to 10% of sorbitan monolaurate, preferably 2%. 2nd: Mix the compounds until completely homogenized. Then, subject the mixture to ultrasound for 5 to 15 minutes, preferably 10 minutes. In another container, add 30 g to 100 g, preferably 50 g of polyethylene glycol to 300 ml of water, resulting in a polyethylene glycol solution. 3. Transfer the polyethylene glycol solution to a 500 ml beaker and subject said solution to ultradispersion at 10,000 to 20,000 rpm, preferably 14,000 rpm. Slowly inject the attenuated C. longa solution in dichloromethane solvent into the agitation vortex. Maintain the system under ultradispersion for 1 to 10 min, preferably 5 min, resulting in a solution containing encapsulated C. longa nanoparticles.

[0039] Nanoparticles are spherical in shape with homogeneous sizes ranging from 20 to 100 nm.

[0040] The product can be used in solution / dispersion form as obtained from the process or dried by freeze-drying or spray drying. Petition 870240111146, dated 12 / 30 / 2024, page 25 / 33 16 / 16

[0041] The present invention has been disclosed in this descriptive report in terms of its preferred embodiment. However, other modifications and variations are possible from the present description, and are still within the scope of the invention disclosed herein. Petition 870240111146, dated 12 / 30 / 2024, pp. 26 / 33

Claims

1 / 3 CLAIMS 1. Process for producing nanocapsules of organic extract of Curcuma sp. CHARACTERIZED by comprising the following steps: (a) extraction of Curcuma sp.; and (b) nanoencapsulation of Curcuma sp.

2. Process, according to claim 1, CHARACTERIZED in that in step (a) 5 to 200 g of Curcuma sp. rhizome is ground and mixed with 500 ml of solvent at a temperature of 0 to 15°C with mechanical stirring and homogenized for 5 minutes; whereupon cell lysis is then promoted for 5 to 30 min, with dispersion under stirring for 1 to 12 h; and whereupon the dispersion is then vacuum filtered; and whereupon the filtered liquid is concentrated in a rotary evaporator at 20 to 60°C and stored for step (b) of nanoencapsulation.

3. Process according to claim 1 or 2, CHARACTERIZED in that in step (b) between 0.1g and 0.7g of Curcuma sp. extract and 0.5g of biopolymer are weighed; wherein a mixture containing between 10ml and 200ml of solvent with surfactant between 1% and 10% is further prepared; wherein the compounds and the mixture are mixed until complete homogenization, and then the mixture is subjected to ultrasound for 5 min to 15 min; and in another container between 30g and 100g of an encapsulating agent is added to 300ml of water, resulting in a solution of encapsulating agent, which is maintained under ultrasound for 5 min to 15 min and under mechanical agitation; and then said solution is subjected to ultradispersion at 10,000 to 20,000 rpm, and the Curcuma sp. solution is slowly injected. in Petition 870240111146, dated 12 / 30 / 2024, page 27 / 33 2 / 3 solvent to the vortex of agitation, for 1 to 10 min, resulting in a solution containing encapsulated Curcuma sp. nanoparticles.

4. Process, according to any one of claims 1 to 3, CHARACTERIZED in that, in step (b), the mass ratio of Curcuma sp. / biopolymer can vary from 0.2% to 140%.

5. Process, according to any one of claims 1 to 4, CHARACTERIZED by the fact that organic extract of Curcuma longa, Curcuma attenuata, Curcuma aeruginosa, Curcuma amada, Curcuma amaríssima, Curcuma angustifolia, Curcuma aromatica, Curcuma caesia, Curcuma ecalcarata, Curcuma elata, Curcuma glans, Curcuma haritha, Curcuma inodora, Curcuma kwangsiensis, Curcuma leucorhiza, Curcuma mangga, Curcuma petiolata, Curcuma zedoaria, Curcuma neilgherrensis, Curcuma nankunshanensis, Curcuma cf. xantorriza, Curcuma thorelii, Curcuma rhabdota, Curcuma pseudomontana or Curcuma phaeocaulis is used.

6. Process, according to any one of claims 1 to 5, CHARACTERIZED in that in step (a) non-chlorinated organic solvent or chlorinated solvent is used, wherein: the non-chlorinated organic solvent is selected from a group comprising isoamyl alcohol, isoamyl acetate, ethyl acetate, acetone, methanol, ethanol, 95% ethanol, 90% methanol in water, ethyl ether, ethyl formate, heptane, pentane, 1-propanol, 2-propanol, propyl acetate, isobutyl acetate, hexane, petroleum ether, acetonitrile, methoxybenzene, 1-butanol, 2-butanol, butyl acetate, cumene, and mixtures thereof according to the nature of the turmeric; and Petition 870240111146, dated 12 / 30 / 2024, p. 28 / 33 3 / 3 The chlorinated solvent is selected from a group comprising polyethylene glycol, dichloromethane, tetrachloromethane, chlorobenzene, trichloromethane, 1,2-dichloroethane, 1,1-dichloroethene, 1,2-dichloroethene, methyl chloroform, 1,1,2-trichloroethene.

7. Process, according to any one of claims 1 to 6, CHARACTERIZED in that in step (b) the biopolymer used as an encapsulating agent is selected from a group comprising Poly(lactic acid (PLA), polyvinylpyrrolidone (PVP), polyhydroxyalkanoates (PHAs), alpha-hydroxy acids, proteins and polysaccharides.

8. Process, according to any one of claims 1 to 7, CHARACTERIZED in that nonionic surfactants selected from a group comprising polyoxyethylene, polyols such as ethylene glycol, glycerol, sorbitan, sucrose, alkyl glycosides such as mono- and diesters of sucrose stearyl, mono- and diesters of glucose stearyl, sorbitan monolaurate are further added.

9. A process, according to any one of claims 1 to 8, characterized by the fact that spherical nanoparticles with homogeneous sizes ranging from 20 to 100 nm are obtained.

10. Use of Curcuma sp. nanocapsules, obtained as defined in claims 1 to 9, CHARACTERIZED by their application as nano-additives in antifouling paints and in the production of sustainable antifouling paint for application in coatings to be submerged. Petition 870240111146, dated 12 / 30 / 2024, pp. 29 / 33

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