A process for the preparation of essential oil modified nanocellulose wherein the steps comprising: a) treating cotton rag with a base at a temperature in the range of 70-90 degree C for a time period in the range of 2 to 4 hours to form alkali treated cotton rag; b) subjecting bleaching treatment on the cotton rag of step (a) by using acetate buffer and sodium hypochlorite or hydrogen peroxide at a temperature in the range of 70-90 degree C for a period of 2 hours; repeating the process for 2 to 3 times to make the fibers white and washing with distilled water until pH becomes neutral to form washed bleached pulp; c) grinding the pulp obtained in step (b) to form cellulose nanofibers; d) dispersing the cellulose nanofibers obtained in step (c) in water to form suspension; e) adding 2,2,6,6 tetramethyl-1-piperidinyloxy (TEMPO), sodium bromide (NaBr) and sodium hypochlorite into suspension of step (d), adjusting the pH of the reaction mixture to 10-11 followed by stirring at a temperature of 30 degree C for the time period of 4 to 5 hours to obtain TEMPO oxidized cellulose nanofibers (TO-CNF); f) adding borane dimethylsulfide (BH3-SMe2) or BH3 into essential oil solution in solvent preferably tetrahydrofuran; stirring the resulting mixture at a temperature of 0 to minus 5 degree C for a period of 1 to 2 hours and further stirring the reaction mixture at a temperature of 25 to 30 degree C for a period ranging from 1 to 2 hours to form reaction mixture; g) cooling the reaction mixture of step (f) to a temperature in the range of 0 to minus 5 degree C, adding the base sodium hydroxide (NaOH) and H2O2 into reaction mixture followed by stirring the reaction mixture at a temperature in the range of 0 to minus 5 degree C for a period of 30 min to 1 hour and stirring at a temperature of 25 to 30 degree C for a period ranging from 1 to 2 hours to obtain 4-(3-hydroxypropyl)-2-methoxyphenol; h) adding 4-Dimethylaminopyridine (DMAP) or triethyl amine or diisopropylethyl 5 amine and 4-(3-hydroxypropyl)-2-methoxyphenol into solution of TO-CNF as obtained in step (e) in solvent dimethyl formamide followed by cooling the mixture at a temperature in the range of 0 to minus 5 degree C to form reaction mixture; i) adding the coupling reagent Dicyclohexylcarbodiimide to the reaction mixture obtained in step (h) followed by stirring at a temperature of 0 to minus 5 degree C for a period of 30 min to 1 hour and further stirring at a temperature in the range of 25 to 30 degree C for a period ranging from 24 to 26 hours to obtain the desired essential oil modified nanocellulose. a) treating cotton rag with a base at a temperature in the range of 70-90 degree C for a time period in the range of 2 to 4 hours to form alkali treated cotton rag; b) subjecting bleaching treatment on the cotton rag of step (a) by using acetate buffer and sodium hypochlorite or hydrogen peroxide at a temperature in the range of 70-90 degree C for a period of 2 hours; repeating the process for 2 to 3 times to make the fibers white and washing with distilled water until pH becomes neutral to form washed bleached pulp; c) grinding the pulp obtained in step (b) to form cellulose nanofibers; d) dispersing the cellulose nanofibers obtained in step (c) in water to form suspension; e) adding 2,2,6,6 tetramethyl-1-piperidinyloxy (TEMPO), sodium bromide (NaBr) and sodium hypochlorite into suspension of step (d), adjusting the pH of the reaction mixture to 10-11 followed by stirring at a temperature of 30 degree C for the time period of 4 to 5 hours to obtain TEMPO oxidized cellulose nanofibers (TO-CNF); f) adding borane dimethylsulfide (BH3-SMe2) or BH3 into essential oil solution in solvent preferably tetrahydrofuran; stirring the resulting mixture at a temperature of 0 to minus 5 degree C for a period of 1 to 2 hours and further stirring the reaction mixture at a temperature of 25 to 30 degree C for a period ranging from 1 to 2 hours to form reaction mixture; g) cooling the reaction mixture of step (f) to a temperature in the range of 0 to minus 5 degree C, adding the base sodium hydroxide (NaOH) and H2O2 into reaction mixture followed by stirring the reaction mixture at a temperature in the range of 0 to minus 5 degree C for a period of 30 min to 1 hour and stirring at a temperature of 25 to 30 degree C for a period ranging from 1 to 2 hours to obtain 4-(3-hydroxypropyl)-2-methoxyphenol; h) adding 4-Dimethylaminopyridine (DMAP) or triethyl amine or diisopropylethyl 5 amine and 4-(3-hydroxypropyl)-2-methoxyphenol into solution of TO-CNF as obtained in step (e) in solvent dimethyl formamide followed by cooling the mixture at a temperature in the range of 0 to minus 5 degree C to form reaction mixture; i) adding the coupling reagent Dicyclohexylcarbodiimide to the reaction mixture obtained in step (h) followed by stirring at a temperature of 0 to minus 5 degree C for a period of 30 min to 1 hour and further stirring at a temperature in the range of 25 to 30 degree C for a period ranging from 24 to 26 hours to obtain the desired essential oil modified nanocellulose.