DESC:FIELD
The present disclosure relates to a superhydrophobic and a superoleophillic material and a process for its preparation.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which it is used indicates otherwise.
Hydrophobicity- refers to a tendency of material/surface to repel water.
Superhydrophobic-refers to a material/surface which is highly hydrophobic, i.e., extremely difficult to wet. The contact angle of a water droplet on such material/surface exceeds 150°.
Oleophilic- refers to a tendency of a material/ surface to have an affinity for oils.
Superoleophilic – refers to a material/surface that has a strong affinity for oils. The contact angle of oil on such materials is extremely low and closer to 0o.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Spillage of crude oil is a major environmental hazard. The challenge is further compounded by the difficulty of separation of spilled oil from water. Generally, spillage of oil occurs during the process of production, transportation, or storage of oil.
The separation of the oil and water or separation of spilled oil from water is known in the art. The various processes/material/devices used for the separation of oil from the water include:
• mechanical devices like booms and skimmers can separate oil slick from water and prevent contamination. However, the efficiency of the separation of oil and water depends upon the technical features of the booms and skimmers, oil properties, and weather conditions;
• in-situ burning of crude oil is a time-effective technique used for removal of oil slick, however, the resultant air pollution and inability to recover the spilled resource are major disadvantages of this technique;
• various types of chemicals like emulsion breakers, inhibitors, solidifiers, sinking agents, and dispersants are also known for the removal of oil spills. However, these chemicals have disadvantages like environmental toxicity;
• membrane separation processes, though economical, lack improved membrane separation material that can be used in a wide array of industrial processes;
• introduction of oil degrading micro-organisms in an oil spill is also known in the art for the separation of oil from water. However, the process requires specific environmental conditions and longer time of action;
• some absorbents like perlite, silica, zeolites and the like can absorb oil but their capacity is limited to 4-20 times their weight. Synthetic organic products like polyurethane, polyethylene, polypropylene have higher absorption capacity than natural absorbents but they degrade slowly and are expensive to manufacture. Further, these absorbents are not superhydrophobic or superoleophilic.
There is, therefore, felt a need for superhydrophobic and superoleophilic material that mitigates the drawbacks mentioned hereinabove. There is also felt a need for a process for the preparation of such types of material.

OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
Another object of the present disclosure is to provide a hydrophobic and an oleophilic material.
Still another object of the present disclosure is to provide a superhydrophobic and a superoleophilic material.
Another object of the present disclosure is to provide a superhydrophobic and a superoleophilic material that exhibits excellent selectivity towards oil sorption and excellent re-usability over repeated sorption-squeeze cycles.
Yet another object of the present disclosure is to provide a simple and economic process for the preparation of a superhydrophobic and a superoleophilic material.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure relates to a process for preparing a superhydrophobic and a superoleophilic material having a water contact angle >150°.The process comprises the step of dissolving a pre-determined amount of a chloroalkylsilane in a first fluid medium to obtain a solution. A pre-determined amount of silica nanoparticles is added to the solution under stirring to obtain a suspension. A cellulosic material is immersed in the suspension for a first predetermined time period to obtain a soaked material. The soaked material is separated/removed from the suspension followed by washing by using a second fluid medium to obtain a washed material. The washed material is dried at a predetermined temperature for a second predetermined time period to obtain the superhydrophobic and the superoleophilic material.
The superhydrophobic and the superoleophilic material comprising a cellulosic material impregnated with a suspension containing chloroalkylsilane and silica nanoparticles is characterized by having a sorption capacity in the range of 80 to 170 times of the material’s weight and the sorption capacity of at least 94% after 100 sorption-squeezing cycles.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The present disclosure will now be described with reference to accompanying non-limiting drawings, wherein:
Figure 1illustrates a reaction mechanism of chloroalkylsilane with the melamine sponge and cotton (as cellulosic materials) in accordance with the present disclosure;
Figure 2a illustrates a digital image of a beaded water droplet on the surface of an ordinary melamine sponge, and Figure 2b illustrates a digital image of a beaded water droplet on the surface of the superhydrophobic and the superoleophilic melamine sponge in accordance with the present disclosure;
Figure 3aillustrates a digital image of a beaded water droplet on the surface of ordinary cotton, and Figure 3b illustrates a digital image of a beaded water droplet on the surface of the superhydrophobic and the superoleophilic cotton in accordance with the present disclosure; and
Figure 4a illustrates a digital image of a beaded water droplet on the surface of ordinary cotton fabric, and Figure 4b illustrates a digital image of a beaded water droplet on the surface of the superhydrophobic and the superoleophilic cotton fabric in accordance with the present disclosure.
DETAILED DESCRIPTION
Embodiments of the present disclosure will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
Spillage of crude oil is a major environmental hazard. The challenge is further compounded by the difficulty of separating spilled oil from water. Generally, spillage of oil occurs during the process of production, transportation, or storage of oil.
Conventionally, there are many methods for the separation of oil from water. However, the conventional methods/materials have drawbacks such as lower absorption capacity of the material, requires longer time, environmentally unfriendly, and is not cost-effective.
The present disclosure relates to a superhydrophobic and a superoleophilic material for the separation of oil from water and a process for its preparation.
First aspect of the present disclosure relates to a process for preparing a superhydrophobic and a superoleophilic material having a water contact angle>150o.The process is described in detail as follows:
The process comprises the step of dissolving a pre-determined amount of a chloroalkylsilane in a first fluid medium to obtain a solution.
In accordance with the embodiments of the present disclosure, the chloroalkylsilane is selected from the group consisting of octadecyltrichlorosilane, hexadecyltrichlorosilane and heptadecyltrichlorosilane. In an exemplary embodiment of the present disclosure, the chloroalkylsilane is octadecyltrichlorosilane.
In accordance with the embodiments of the present disclosure, the pre-determined amount of chloroalkylsilane is in the range of 0.5 wt.% to 0.7wt.%. In an exemplary embodiment, the pre-determined amount of chloroalkylsilane is 0.5 wt.%.
In accordance with the embodiments of the present disclosure, the first fluid medium is selected from an aromatic rich side stream of a refinery. The aromatic rich side stream of a refinery consists of toluene, xylene, C7 aromatic stream, C8aromatic stream, and heavy isomerate from isomerization unit. The composition of the fluid medium is provided below in Table 1.

Table 1
Parameters/
Composition Toluene C7aromatic stream from MX unit C8aromatic stream from MX unit Heavy isomerate from isomerization unit
Paraffins (Vol%) 1.0 31-35 2-3 65-70
Napthenes (Vol%) Nil 3-4 Nil 30-35
C7 Aromatics (Vol%) 99.0 58-64 Nil Nil
C8 Aromatics (Vol%) Nil 2-3 97-98 Nil

In an exemplary embodiment, the first fluid medium is C7aromatic stream. In another exemplary embodiment, the first fluid medium is toluene. In yet another exemplary embodiment, the first fluid medium is C8aromatic stream. In still another exemplary embodiment, the first fluid medium is heavy isomerate from isomerization unit.
A pre-determined amount of silica nanoparticles is mixed with the solution under stirring to obtain a suspension.
In accordance with the embodiments of the present disclosure, the particle size of silica nanoparticles is in the range of 200 to300 nm. In an exemplary embodiment, the particle size of silica nanoparticles is250 nm.
In accordance with the embodiments of the present disclosure, the pre-determined amount of the silica nanoparticles is in the range of 0.001 to 0.01% (w/v). In an exemplary embodiment, the pre-determined amount of silica nanoparticles is 0.005 % (w/v). The addition of more than 0.01wt% of silica nanoparticles is not recommended to avoid the scaling of silica nanoparticles on the surface of the material.
A cellulosic material is immersed in the suspension for a first predetermined time period to obtain a soaked material.
In accordance with the embodiments of the present disclosure, the cellulosic material is at least one selected from the group consisting of cotton, cotton fabric, and melamine sponge. In an exemplary embodiment, the cellulosic material is cotton. In another exemplary embodiment, the cellulosic material is cotton fabric. In still another exemplary embodiment, the cellulosic material is melamine sponge.
In accordance with the embodiments of the present disclosure, the first predetermined time period is in the range of 30 to 40 minutes.
The soaked material is separated/removed from the suspension followed by washing by using a second fluid medium to obtain a washed material.
In accordance with the embodiments of the present disclosure, the second fluid medium is selected from an aromatic rich side stream of a refinery. The aromatic rich side stream of the refinery consists of toluene, xylene, C7aromatic stream, C8aromatic stream, and heavy isomerate from isomerization unit. The composition of the fluid medium is provided in Table 1.
The washed material is dried at a predetermined temperature for a second predetermined time period to obtain the superhydrophobic and the superoleophilic material.
In accordance with the embodiments of the present disclosure, the pre-determined temperature is in the range of 70oC to 120oC.In an exemplary embodiment, the pre-determined temperature is 100oC.
In accordance with the embodiment of the present disclosure, the second pre-determined time period is in the range of 30 minutes to 2 hours. In an exemplary embodiment, the second predetermined time period is 1 hour.
The process of the present disclosure is easy and cost-effective for the preparation of superhydrophobic and superoleophillic material. Water contact angle and the absorption efficiency of the superhydrophobic and the superoleophillic material of the present disclosure are better as compared to the conventional materials (absorbents).
The superhydrophobic and the superoleophilic material of the present disclosure is cost-effective, robust, easy to prepare in bulk quantity, and used as promising oil absorbents for potential applications in oil spill recovery and oil-water separation applications.
The second aspect of the present disclosure relates to a superhydrophobic and superoleophilic material. The superhydrophobic and superoleophilic material comprises a cellulosic material impregnated with a suspension of chloroalkylsilane and silica nanoparticles. The superhydrophobic and superoleophilic material of the present disclosure is characterized by having a sorption capacity in the range of 80 to 170 times of the material’s weight and the sorption capacity of at least 94% after 100 sorption-squeezing cycles.
Further, the mechanism of superoleophilicity formation in the melamine sponge or cotton or cotton fabric is illustrated in Figure 1. At the beginning, the free –N-H or –O-H groups of the melamine and the cotton or cotton fabric respectively, forms hydrogen bonding with the hydrolyzed silane i.e, silanol (Si-OH). Finally, during the drying step, dehydration reaction occurs and resulting in the covalent bond between the -N and -Si in the melamine sponge and –O and –Si in cotton or cotton fabric. Long alkyl chain on the –Si atom is giving durable superoleophilicity to the material.
The foregoing description of the embodiments has been provided for purposes of illustration and is not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. The following experiments can be scaled up to industrial/commercial scale and the results obtained can be extrapolated to industrial scale.
EXPERIMENTAL DETAILS
Experiment 1: Preparation of a superhydrophobic and a superoleophilic material in accordance with the present disclosure
5g of octadecyltrichlorosilane was dissolved in 1000 ml of C7 aromatic stream to obtain a solution comprising 0.5 wt% of the silane. To this solution,0.05g of silica nanoparticles (having particle size 250nm) were added under stirring to obtain a suspension. Then the cotton was immersed in the suspension for 30 minutes (reaction time) to obtain soaked cotton. The soaked cotton is separated/removed from the suspension and washed by using C7aromatic stream to obtain washed cotton. The washed cotton was dried at 100°C in a hot air oven for 1 hour to obtain a superhydrophobic and superoleophilic cotton. The water contact angle of the superhydrophobic and the superoleophilic cotton was 156°.
Effect of variation of octadecyltrichlorosilane concentration in C7 Solvent on the contact angle of the superhydrophobic and the superoleophilic material
The effect of silane concentration in the C7 aromatic stream on the superhydrophobic and the superoleophilic properties of the cellulosic material was evaluated by varying the concentration of silane from 0.1 % to 0.7 % wt/v.
The superhydrophobic and the superoelophilic material was prepared similar to Experiment 1 by varying the octadecyltrichlorosilane concentration from 0.1 to 0.7% for various cellulosic materials (sponge, cotton, cotton fabric). The so obtained superhydrophobic and the superoelophilic materials were evaluated for water contact angle (WCA), the results are provided below in Table 2.
Table 2-Effect of variation of the silane concentration on the contact angle
S. No Silane (%) Water Contact Angle
Sponge Cotton Cotton Fabric
1 0.1 132° 133° 134°
2 0.2 138° 137° 140°
3 0.3 142° 140° 141°
4 0.4 148° 149° 148°
5 0.5 154° 156° 152°
6 0.6 154° 156° 152°
7 0.7 155° 156° 153°
It is evident from table 2 that, to obtain superhydrophobic materials with WCA of > 150°, a minimum of 0.5% silane was required. No significant change in WCA for 0.6% and 0.7% silane concentration was observed. Hence, the optimum silane concentration of 0.5% has been considered to carry out further experimentations.
The ordinary sponge, cotton, cotton fabric and superoleophilic sponge, cotton, cotton fabric obtained with 0.5% silane is evaluated by placing a beaded water droplet on the surface, it is observed that the water droplet soaks in the untreated materials, remained as a droplet on superoleophilic sponge, cotton, cotton fabric, as illustrated in Figures 2, 3 to 4 respectively.
Effect of variation of reaction time on the contact angle of the superhydrophobic and the superoleophilic material
The effect of reaction time (immersion time of cellulosic material in the suspension) on the superhydrophobic and superoleophilic properties of the cellulosic material was evaluated by varying the reaction time from 5 min to 40 min.
The superhydrophobic and the superoelophilic material was prepared similar to Experiment 1 by varying the reaction time (immersion time of cellulosic material in the suspension) for various cellulosic materials (sponge, cotton, cotton fabric). The so obtained superhydrophobic and the superoelophilic materials were evaluated for water contact angle (WCA), the results are provided below in Table 3.
Table 3-Effect of the reaction time on the water contact angle.
S. No Reaction Time (at 0.5% silane) Water Contact Angle
Sponge Cotton Cotton Fabric
1 5 143° 140° 141°
2 10 146° 143° 143°
3 15 147° 145° 145°
4 20 149° 147° 146°
5 25 149° 151° 148°
6 30 154° 156° 152°
7 35 154° 156° 153°
8 40 155° 156° 153°
It is evident from the above table that, to obtain superhydrophobic materials with WCA of > 150°, a reaction time of a minimum of 30 min was required. No significant change in WCA for 35 minutes and 40 minutes reaction time was observed. Hence, the optimum reaction time of 30 minutes has been considered to carry out further experimentations.

Effect of fluid medium(solvent) on the contact angle of the superhydrophobic and the superoleophilic material
The effect of a fluid medium (solvent) on the superhydrophobic and the superoleophilic properties of the cellulosic material was evaluated by varying the fluid medium.
The superhydrophobic and the superoelophilic material was prepared similar to Experiment 1 by varying the fluid medium (toluene, C7 stream from MX unit, C8 stream from MX unit, heavy isomerate from isomerisation unit) and cellulosic materials (sponge, cotton, cotton fabric). The so obtained superhydrophobic and the superoelophilic materials were evaluated for water contact angle (WCA), the results are provided below in Table 4.
Table 4- Effect of the variation of the solvent on the water contact angle
Solvent
(at 0.5% silane) Water Contact Angle
Sponge Cotton Cotton Fabric
Toluene 153° 155° 150°
C7 stream from MX unit 154° 156° 152°
C8 stream from MX unit 153° 155° 150°
Heavy isomerate from isomerization unit 152° 153° 151°
From Table 4, it is evident that all the four solvents (toluene, C7 stream from MX unit, C8 stream from MX unit, and heavy isomerate from isomerization unit) were suitable for preparing the hydrophobic/oleophilic material. Amongst these solvents, the hydrophobic/oleophilic materials prepared in the C7 stream showed a comparatively higher water contact angle.
Effect of silica nanoparticles on the contact angle of the superhydrophobic and the superoleophilic material
The effect of silica nanoparticles on the superhydrophobic and superoleophilic properties of the cellulosic material was evaluated by preparing the materials with and without silica nanoparticles.
The superhydrophobic and superoelophilic material was prepared similar to Experiment 1 by immersing the cellulosic material in chloroalkylsilane solution without nanoparticles and by immersing the cellulosic material in the suspension (chloroalkylsilane solution with silica nanoparticles). The so obtained superhydrophobic and the superoelophilic materials (sponge, cotton, cotton fabric) were evaluated for water contact angle (WCA), the results are provided below in Table 5.
Table 5: Effect of the use of the silica nanoparticles on the water contact angle of the hydrophobic and oleophilic material
At0.5% silane WCA
Sponge Cotton Cotton Fabric
With 0.01 wt% silica 154° 156° 152°
Without 0.01 wt% silica 149° 151° 148°
From Table 5, it is evident that the addition of 0.01 wt% of nano-silica into 0.5% silane solution improves the water contact angle of the materials.
The addition of silica nanoparticles provides more active sites on the surface of the material, thus increasing the water contact angle of the material. The addition of more than 0.01wt% of silica nanoparticles is not recommended to avoid the scaling of silica nanoparticles on the surface of the material.
Experiment 2: Sorption capacity
Sorption capacity is the amount of oil/solvent taken up by one/per unit mass of superoelophilic material. 1 g of sponge/cotton/cotton fabric was immersed in the different oil/solvents as mentioned in Table 6. Once the oil/solvent is absorbed by the material, the sponge/cotton/cotton fabric was taken out and weighed again to determine the quantity of oil/solvent absorbed.
The sorption capacity of the superhydrophobic materials (sponge, cotton, cotton fabric) were evaluated by contacting the materials with different oils and solvents, the results are provided below in Table 6.
Table 6: Sorption capacity of superhydrophobic/superoleophilic materials in different oils/solvents
S. No Oil Sorption capacity (g/g)
Sponge Cotton Cotton Fabric
1 Naphtha 80.1 19.4 13.6
2 Kerosene 89.6 20.1 14.8
3 Diesel 94.1 23.5 15.8
4 Crude Oil 96.7 24.3 16.3
5 Mineral Oil 100.9 25.9 17.7
6 Chloroform 165.7 39.4 28.1
7 Toluene 97.5 25.2 16.9
8 n-Heptane 80.5 19.7 13.7

From the above data, it is evident that sorption capacity varies with material and oil/solvent type. The superoeleophilic sponge has a high sorption capacity followed by cotton and cotton fabric.
The durability of the superhydrophobicity/superoleophilicity of materials was evaluated by measuring the sorption capacity after 100 cycles of sorption and squeezing with different oils and solvents. The sorption capacity of superhydrophobic/superoleophilic sponge, cotton, and cotton fabric after 100 cycles of experiments are compiled in Table 7.
Table 7: Sorption capability of hydrophobic/ oleophilic materials after 100 cycles of sorption-squeezing experiments:
S. No Oil Type Sorption capacity (g/g)
Sponge Cotton Cotton Fabric
1 Naphtha 77.3 17.1 12.1
2 Kerosene 85.6 18.2 13.8
3 Diesel 91.8 21.7 13.7
4 Crude Oil 93.2 22.3 15.1
5 Mineral Oil 97.2 23.8 16.7
6 Chloroform 159.8 36.8 25.2
7 Toluene 95.3 22.9 14.9
8 n-Heptane 77.5 17.4 12.2
The hydrophobic/oleophilic materials showed good recyclability with retention of sorption capacity of more than 94% after 100 cycles of sorption-squeezing.
Since these superhydrophobic/superoleophilic materials selectively absorb only oils/solvents and repel water, the sorption capacity of these materials will not change with respect to any oil/solvent when immersed in oil/solvent-water mixture.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of:
- superhydrophobic and superoleophilic material which is environment friendly, inexpensive and has a high absorption capacity and re-usability over repeated cycles; and
- process for preparation of the superhydrophobic and the superoleophilic material which is simple, economical and efficient, one step and does not need expensive reagents for the manufacturing of the material.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising, will be understood to imply the inclusion of a stated element, integer or step,” or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the formulation of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention.
The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
,CLAIMS:WE CLAIM:
1. A process for preparing a superhydrophobic and a superoleophilic material having a water contact angle >150o, said process comprising the following steps:
a) dissolving a pre-determined amount of a chloroalkylsilane in a first fluid medium to obtain a solution;
b) mixing a pre-determined amount of silica nano-particles under stirring to said solution to obtain a suspension;
c) immersing a cellulosic material in said suspension for a first predetermined time period to obtain a soaked material;
d) separating the soaked material followed by washing by using a second fluid medium to obtain a washed material; and
e) drying the washed material at a predetermined temperature for a second predetermined time period to obtain the superhydrophobic and superoleophilic material.
2. The process as claimed in claim 1, wherein said chloroalkyl silane is selected from the group consisting of octadecyltrichlorosilane, heptadecyltricholorosilane and hexadecyltricholorosilane.
3. The process as claimed in claim 1, wherein said pre-determined amount of said chloroalkyl silane is in the range of 0.5 wt.% to 0.7wt.%.
4. The process as claimed in claim 1, wherein said first fluid medium and said second fluid medium are independently selected from an aromatic rich side stream of a refinery.
5. The process as claimed in claim 4, wherein said aromatic rich side stream of a refinery consists of toluene, xylene, C7aromatic stream, C8aromatic stream and heavy isomerate from isomerization unit.
6. The process as claimed in claim 1, wherein the particle size of said silica nanoparticles is in the range of 200 to 300 nm.
7. The process as claimed in claim 1, wherein the pre-determined amount of said silica nanoparticles is in the range of 0.001 to 0.01% w/v.
8. The process as claimed in claim 1, wherein said cellulosic material is at least one selected from the group consisting of cotton, cotton fabric, and melamine sponge.
9. The process as claimed in claim 1, wherein said first pre-determined time period is in the range of 30 to 40 minutes and said second pre-determined time period is in the range of 30 minutes to 2 hours.
10. The process as claimed in claim 1, wherein said pre-determined temperature is in the range of 70 oC to 120 oC.
11. A superhydrophobic and superoleophilic material comprising a cellulosic material impregnated with a suspension of chloroalkylsilane and silica nanoparticles, wherein said material is characterized by having a sorption capacity in the range of 80 to 170 times of the material’s weight and the sorption capacity of at least 94% after 100 sorption-squeezing cycles.

Dated this 23rd Day of February, 2021

MOHAN RAJKUMAR DEWAN, IN/PA-25
of R.K. DEWAN & COMPANY
APPLICANT’S PATENT ATTORNEY

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT CHENNAI