Description:FIELD OF INVENTION:
The present disclosure generally relates to the field of polymer chemistry. More specifically, the present disclosure relates to a polymer composite and method for preparing of polymer composite with metal organic frameworks through emulsion-pooled modified hydrothermal method. The polymer composite described in present application has improved stability, high surface area, and metal ions dispersion, higher porosity and high thermal stability, whereas the method for preparation of said polymer composite is cost effective, simple, efficient, environment friendly and requires less time as compared to other existing methods.

BACKGROUND OF INVENTION:
Metal organic frameworks are a new class of micro porous crystalline materials that possess intrinsic properties like high surface area and tunable porosity. These functional characteristics of MOF play a vital role in wide range of industrial applications, such as gas adsorption, storage, catalysis etc.

In literature, a great variety of MOFs have been synthesized by employing various metal ions and diverse type of ligands. Studies related to MOFs chemical structure, morphologies and properties are well documented. In general, MOFs have been prepared via conventional solvothermal method. However, demerits such as high energy consumption, long reaction time and use of large amount of toxic harmful solvents forces the research towards development of efficient, cost- effective and environmental friendly synthetic methods.

EP 2578593A1, discloses a process for the preparation of a dry crystalline metal organic framework, which comprises: a) spray drying at least one metal ion and at least one organic ligand which is at least bidentate into a spray dryer in the presence of a solvent, wherein the reaction of the at least one metal ion with the at least one organic ligand to yield the metal organic framework and the drying of the obtained metal organic framework take place simultaneously inside the spray dryer, and b) collecting the formed dry crystalline metal organic framework. The synthesized particles have surface area in the range between 1209- 1266 m2/g.

US20090042000, discloses the preparation of Cu-benzene-1,3,5-tricarboxylic acid (1,3,5-BTC) by reacting an admixture of a copper nitrate with 1,3,5-BTC in the liquid phase at atmospheric pressure above 80°C. Long crystallization times between 15 and 96 hours are needed to obtain the crystalline MOF particles with surface area in the range of 2031-2073m2/g and particle size of 20 Å size.

US 7,880,026 B2 discloses a rapid, simple and versatile metal organic framework molecule (MOF) synthesis method particularly adapted to make non-linear MOFs includes heating MOF precursors, such as a metal or metal oxide and an organic ligand, in a microwave oven for a period sufficient to achieve crystallization. Microwave-assisted MOF synthesis yields high quality MOF crystals in a reaction time ranging from about 5 seconds to about 2.5 minutes provide MOF materials with uniform crystal size of 2-7 micron (2000 – 7000nm).

CN 105153204A discloses a CuBTC type mesopore and micropore metal organic framework material under hydrothermal synthesis reactions at 110 - 1200C temperature for 12-16 hrs. The synthesized CuBTC type mesopore and micropore metal organic framework material have specific surface area in the range of 1100-1200 m2/g and pore size of 3.4 nm.

WO 2012/138419 Al discloses synthesis of sub-micron or nano-sized MOF crystals with an average size of 690–796 nm. Ultrasound is combined with low temperature and a morphology control additive (2-propanol, ethanol, methanol, and the like) to obtain smaller more isotropic crystals.

US 2012/0082864 A1 discloses to a process for preparing a porous metal-organic framework comprising at least one metal ion is based on an aluminium ion and the at least one bidentate organic compound is based on fumaric acid, in an alkaline aqueous medium, at a temperature in the range from 20°C to 100°C at an absolute pressure of not more than 2 bar for 0.2 to 4 hours. The synthesized product has surface area in the range of 800 – 1100m2/g.

Cryst. Growth Des. 2016, 16, 7, 3565–3568 discloses the synthesis of highly uniform Fe-MIL-88B particles with shape evolution from hexagonal bipyramids to bipyramidal hexagonal prism were obtained by a surfactant (polyvinylpyrrolidone, PVP) assisted modified solvothermal method. The produced nanosized MOF particles have surface area 209.83 m2/g with an average particle size of 1.78 µm. In order to explore potential performance of MOF in practical applications, substantial progress, particularly in the MOF synthetic strategies is demanded.

Thus, there is a need to develop a cost effective, and environment friendly polymer composite and method for production of polymer composite with improved properties to provide commercial advantages.

SUMMARY OF THE INVENTION:
This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the invention. This summary is neither intended to identify key or essential inventive concepts of the invention and nor is it intended to determine the scope of the invention.

The present invention relates to a polymer composite with metal organic framework with improved stability, surface area, and porosity, said polymer composite comprising:
a) an inorganic compound; and
b) a dual-ligand matrix comprising Ligand-1 and Ligand-2.

In an aspect, the present invention provides the polymer composite, wherein the inorganic compound, Ligand-1 and Ligand-2 are in molar ratio in the range of 1: 1: 0.5 to 2: 2: 0.5.

In another aspect, the present invention provides the polymer composite, wherein the inorganic compound is selected from the group comprising a metal, ionic form of metal, and metal salt.

In another aspect, the present invention provides the polymer composite, wherein the Ligand-1 (L1) is trimesic acid having three specific carboxylate functional moiety and the Ligand-2 (L2) is an azolate compound.

In another aspect, the present invention provides the polymer composite, wherein the azolate compound is 2-Methyl imidazole.

In another aspect, the present invention provides the polymer composite, wherein the inorganic compound is Copper (II) nitrate.
In some of the aspect, the present invention provides the polymer composite, wherein the inorganic compound is Copper (II) nitrate, Ligand-1 is trimesic acid having three specific carboxylate functional moiety and the Ligand-2 is 2-Methyl imidazole, in a molar ratio of 1.8:1:0.5.

In some of the aspect, the present invention provides the polymer composite, wherein the polymer composite is a Cu (II)-based Metal Organic Frameworks (Cu-MOFs) comprising particles having a pore size in the range of 1.68 to 2.37 nm with of tetragonal pyramid morphology and surface area in the range of 1500 m2/g to 2200 m2/g, preferably 2063 m2/g.

In an aspect, the present invention provides a method for preparation of polymer composite with metal organic framework, said method comprising steps of:
(a) preparing homogenized solutions-I, solution-II, and solution-III;
(b) simultaneously adding solution-II and solution-III into solution-I to obtain a reaction mixture;
(c) incubating the reaction mixture obtained in step b) with continuous stirring;
(d) heating the reaction mixture obtained in step c) to obtain precipitates; and
(e) drying the precipitates obtained from step d) to obtain polymer composite,
wherein solution-I is a homogenized solution of a metal salt in water, wherein solution-II is a homogenized solution of Ligand-1, and wherein solution-III is a homogenized solution of Ligand-2.

In another aspect, the present invention provides the method, wherein the metal salt in solution-I is Copper (II) nitrate, wherein the solution of Ligand-1 is a trimesic acid having three specific carboxylate functional moiety and ethoxylated compound in methanol as emulsifier, and wherein the solution of Ligand-2 is 2-Methyl imidazole (IMI) in N, N-Dimethyl Formamide (DMF).

In another aspect, the present invention provides the method, wherein the solutions-I, solution-II, and solution-III are separately homogenized using sonication for 5 to 20 minutes at temperature in the range of 15 to 40°C.

In still another aspect, the present invention provides the method, wherein the addition of solution-II and solution-III, into solution-I in step b) is carried out dropwise with a stirring at a temperature in the range of 30 to 50°C for 20 to 40 minutes, preferably for 10 to 15 minutes and wherein the solution-II, the solution-III and the solution-I are used in equal volumes.

In another aspect, the present invention provides the method, wherein the incubation in step c) is carried out for 15 to 45 minutes, preferably for 30 minutes, wherein the heating of reaction mixture in step d) is carried out for 8 to 10 hours at a temperature in the range of 50 to 70°C, preferably at 60°C, and wherein the drying of precipitates in step e) is carried out in a vacuum for 3 to 5 hours at a temperature in the range of 110 to 130°C, preferably for 4 hours at 120°C.

In another aspect, the present invention provides the method wherein the precipitates obtained in step d) are purified using standard techniques known in the art comprising solvent exchange method, wherein solvent is ethanol.

In another aspect, the present invention provides the method, wherein the solution-I is a 0.2 to 0.35 M solution of copper(II) nitrate in water, wherein the solution-II is a 0.2 to 0.35 M solution of Trimesic acid in methanol mixed with 0.1 to 0.4 gm (0. 5 to 2 %) of ethoxylated compound, and wherein the solution-III is a 0.2 M solution of 2-Methyl imidazole (IMI) in N, N-Dimethyl Formamide (DMF).

DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Figure 1 illustrates SEM images of polymer composite (Cu-MOFs)

Figure 2 illustrates EDAX Image and elemental composition of synthesized polymer composite(Cu-MOF).

Figure 3 illustrates Powder XRD Pattern of polymer composite (Cu-MOFs).

Figure 4 illustrates FTIR Chromatogram of synthesized polymer composite (Cu-MOF Compound).

Figure 5 illustrates TGA Curves of synthesized polymer composite (Cu-MOF).

Figure 6 illustrates BET Plot of synthesized polymer composite (Cu-MOF).

Figure 7 illustrates the nitrogen adsorption/desorption isotherm and pore size distribution curve of polymer composite (Cu-MOF).

Figure 8 illustrates the repeatable XRD and BET plot of synthesized polymer composite (Cu-MOFs).

DETAILED DESCRIPTION OF THE INVENTION:
The present disclosure addresses the drawbacks of the art and provides for a polymer composite with metal organic framework with improved stability, surface area, and porosity. Further, the present invention also provides a method for preparing polymer composite with metal organic framework. A polymer composite with metal organic framework is crystalline in nature. The method is environment friendly and requires less time as compared to other existing methods.
For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the disclosure relates. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skilled in the art to which this disclosure belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.

Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited.

It must be noted that as used herein and in the appended claims, the singular forms "a", "and", and "the" include plural referents unless the context dictates otherwise. Thus, for example, reference to "a compound" includes a plurality of such compounds, and reference to "the step" includes reference to one or more steps and equivalents thereof known to those skilled in the art, and so forth.

The term “some” as used herein is defined as “none, or one, or more than one, or all.” Accordingly, the terms “none,” “one,” “more than one,” “more than one, but not all” or “all” would all fall under the definition of “some.” The term “some embodiments” may refer to no embodiments or to one embodiment or to several embodiments or to all embodiments. Accordingly, the term “some embodiments” is defined as meaning “no embodiment, or one embodiment, or more than one embodiment, or all embodiments.”

The terminology and structure employed herein is for describing, teaching and illuminating some embodiments and their specific features and elements and does not limit, restrict or reduce the spirit and scope of the claims or their equivalents.

More specifically, any terms used herein such as but not limited to “includes”, “comprises”, “has”, “consists” and grammatical variants thereof is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. The specification will be understood to also include embodiments which have the transitional phrase “consisting of” or “consisting essentially of” in place of the transitional phrase “comprising.” The transitional phrase “consisting of” excludes any element, step, or ingredient not specified in the claim, except for impurities associated therewith. The transitional phrase “consisting essentially of” limits the scope of a claim to the specified materials or steps “and those that do not materially affect the basic and novel characteristic(s)” of the claimed disclosure.

Whether or not a certain feature or element was limited to being used only once, either way it may still be referred to as “one or more features” or “one or more elements” or “at least one feature” or “at least one element.” Furthermore, the use of the terms “one or more” or “at least one” feature or element do NOT preclude there being none of that feature or element, unless otherwise specified by limiting language such as “there NEEDS to be one or more. ” or “one or more element is REQUIRED.”

As used herein, the term “about” is used to indicate a degree of variation or tolerance in a numerical or quantitative value. It indicates that the disclosed value is not intended to be strictly limiting, and may vary by plus or minus 5%, without departing from the scope of the invention.
Unless otherwise defined, all terms, and especially any technical and/or scientific terms, used herein may be taken to have the same meaning as commonly understood by one having an ordinary skill in the art.

Reference is made herein to some “embodiments.” It should be understood that an embodiment is an example of a possible implementation of any features and/or elements presented in the attached claims. Some embodiments have been described for the purpose of illuminating one or more of the potential ways in which the specific features and/or elements of the attached claims fulfil the requirements of uniqueness, utility and non-obviousness.

Use of the phrases and/or terms such as but not limited to “a first embodiment,” “a further embodiment,” “an alternate embodiment,” “one embodiment,” “an embodiment,” “multiple embodiments,” “some embodiments,” “other embodiments,” “further embodiment”, “furthermore embodiment”, “additional embodiment” or variants thereof do NOT necessarily refer to the same embodiments. Unless otherwise specified, one or more particular features and/or elements described in connection with one or more embodiments may be found in one embodiment, or may be found in more than one embodiment, or may be found in all embodiments, or may be found in no embodiments. Although one or more features and/or elements may be described herein in the context of only a single embodiment, or alternatively in the context of more than one embodiment, or further alternatively in the context of all embodiments, the features and/or elements may instead be provided separately or in any appropriate combination or not at all. Conversely, any features and/or elements described in the context of separate embodiments may alternatively be realized as existing together in the context of a single embodiment.

As used herein, the term "polymer composite" refers to a multi-phase material in which reinforcing fillers or fibres are integrated with a polymer matrix, resulting in synergistic mechanical properties that is not achieved from either component alone.

As used herein, the term “ligand” is an ion or molecule which donates a pair of electrons to the central metal atom or ion to form a coordination complex.

As used herein the terms “method” and “process” have been used interchangeably.

The present application describes a polymer composite and a method for preparation of said polymer composite with metal organic frameworks through emulsion-pooled modified hydrothermal technique. The method is based on dual ligand ( Ligand 1 and ligand 2). Further, the polymer composite has improved surface area, metal ions dispersion, porosity and thermal stability. A polymer composite with metal organic framework described herein is a nano-sized, porous and crystalline in nature. Even the method for the preparation of said polymer composite is cost effective, simple, efficient, environment friendly and requires less time as compared to other existing methods.

In one of the aspects of the present invention, the method of synthesis of a polymer composite comprising the inorganic compound, dual-ligand matrix consisting of Trimesic acid having three carboxylate functional moiety as ligand 1 (L1)) and N-base azolate compound as ligand 2 (L2) and ethoxylated compound as an emulsifier.

In one of the aspects, the present application describes a method for the preparation of polymer composite, wherein polymer composite is Cu-MOFs, and wherein synthesis of said polymer composite is based on dual-ligand matrix system in an emulsion-pool system, wherein Ligand 1(trimesic acid (TA)) functions as a framework-directing medium and ligand 2 (N-base azolate) functions as a coordination regulator medium.

In one of the aspects, the present invention provides a polymer composite with metal organic framework and having an improved stability, surface area, and porosity, said polymer composite comprising:
a) an inorganic compound; and
b) a dual-ligand matrix comprising Ligand-1 and Ligand-2.

In another aspect, the present invention provides a polymer composite wherein the inorganic compound, Ligand-1 and Ligand-2 are in molar ratio in the range of 1: 1: 0.5 to 2: 2: 0.5.
In another aspect, the present invention provides a polymer composite wherein the inorganic compound, Ligand-1 and Ligand-2 are in molar ratio selected from the group comprising of 0.5:1:0.5, 1:1:0.5, 2:1:0.5 1:2:0.5 or 2:2:0.5.

In yet another aspect, the present invention provides a polymer composite wherein the inorganic compound is selected from the group comprising a metal, ionic form of metal, and metal salt.

In yet another aspect, the present invention provides a polymer composite wherein the Ligand-1 (L1) is trimesic acid having three carboxylate functional moiety and the Ligand-2 (L2) is an azolate compound.

In yet another aspect, the present invention provides a polymer composite wherein the azolate compound is 2-Methyl imidazole.

In yet another aspect, the present invention provides a polymer composite wherein the inorganic compound is Copper (II) nitrate.

In yet another aspect, the present invention provides a polymer composite wherein the inorganic compound is Copper (II) nitrate, Ligand-1 is trimesic acid and the Ligand-2 is 2-Methyl imidazole, present in a molar ratio of 1.8:1:0.5.

In yet another aspect, the present invention provides a polymer composite wherein the polymer composite is a Cu(II)-based metal organic frameworks (Cu-MOFs) comprising particles having a pore size in the range of 1.68 to 2.37 nm with tetragonal pyramid morphology and surface area of in the range of 1500 m2/g to 2200 m2/g, preferably 2063 m2/g.

In yet another aspect, the present invention provides a polymer composite wherein a method for preparation of polymer composite with metal organic framework, said method comprising steps of:
(a) preparing homogenized solutions-I, solution-II, and solution-III;
(b) simultaneously adding solution-II and solution-III into solution-I to obtain a reaction mixture in an emulsion-pool system;
(c) incubating the reaction mixture obtained in step b) with continuous stirring;
(d) heating the reaction mixture obtained in step c) to obtain precipitates; and
(e) drying the precipitates obtained from step d) to obtain polymer composite,
wherein solution-I is a homogenized solution of a metal salt in water, wherein solution-II is a homogenized solution of Ligand-1, and wherein solution-III is a homogenized solution of Ligand-2.

In yet another aspect, the present invention provides a polymer composite wherein the metal salt in solution-I is Copper (II) nitrate, wherein the solution of Ligand-1 is a trimesic acid and ethoxylated compound in methanol as emulsifier, and wherein the solution of Ligand-2 is 2-Methyl imidazole (IMI) in N, N-Dimethyl Formamide (DMF).

In yet another aspect, the present invention provides a polymer composite wherein the solutions-I, solution-II, and solution-III are separately homogenized using sonication for 5 to 20 minutes at temperature in the range of 15 to 40°C.

In yet another aspect, the present invention provides a polymer composite wherein in step (b) solution-II and solution-III, are simultaneously added dropwise into solution-I with a stirring at a temperature in the range of 30 to 50°C for 20 to 40 minutes, preferably for 10 to 15 minutes.
In yet another aspect, the present invention provides a polymer composite wherein the incubation in step (c) is carried out for 15 to 45 minutes, preferably for 30 minutes.
In yet another aspect, the present invention provides a polymer composite wherein the heating of reaction mixture in step (d) is carried out for 8 to 10 hours at a temperature in the range of 50 to 70°C, preferably at 60°C.

In yet another aspect, the present invention provides a polymer composite wherein the precipitates obtained in step (d) are purified using standard techniques known in the art comprising solvent exchange method, and wherein solvent is ethanol.

In yet another aspect, the present invention provides a polymer composite wherein the drying of precipitates in step (e) is carried out in a vacuum for 3 to 5 hours at a temperature in the range of 110 to 130°C, preferably for 4 hours at 120°C.

In yet another aspect, the present invention provides a polymer composite wherein the solution-I is a 0.2 to 0.35M solution of copper(II) nitrate in water, wherein the solution-II is a 0.2 to 0.35M solution of trimesic acid in methanol mixed with 0.1 to 0.4 gm of ethoxylated compound, and wherein the solution-III is a 0.2 M solution of 2-Methyl imidazole (IMI) in N, N-Dimethyl Formamide (DMF).

In some of the aspects, the present invention provides an integrated modified hydrothermal method under the influence of emulsifier, wherein emulsifier provides a superior alternative approach to synthesise or prepare porous nano-sized Cu-MOF materials.

In yet another aspect, the present invention provides a modified solvent system is Water: Methanol: DMF.

In yet some another aspect, the present invention provides a method of synthesizing polymer composite, which is facile, requires a low temperature, and a shorter reaction time. The synthesized MOFs have improved properties like better metal ions dispersion, high surface area and high thermal stability.

The present invention provides an improved and efficient method as compared to existing prior arts for synthesizing nano-sized polymer composite with respect to the reproducible materials (porous Cu-MOF materials) which adds to another commercial advantage. Therefore, the above emulsion-pooled strategy is considered as unified process that combines homogeneous, low temperature, cost effective and environment friendly features.

Further, the method provides a more effective, eco-friendly, and scalable method to create high-quality Cu-MOFs. The present invention also provides a major improvement in the already published conventional prior arts.

Furthermore, the present invention provides the technical contribution in the optimization of the synthesis procedure of Fe-Cu (nanoparticles)NPs functionalized multi-walled carbon nanotubes (MWCNTs).

The present invention provides that the method of preparing of polymer composite, wherein the polymer composite (Cu-MOFs) comprises Cu salt as inorganic ligand and TA (Trimesic acid/ Legand-1), IMI (2-Methyl imidazole/ Legand-2) in a molar ratio in the range from 1: 1: 0.5 to 2: 2: 0.5, preferably at 1.8:1:0.5. The reaction proceeds at low temperature conditions under the influence of emulsion. Herein, ethoxylated compound is used as an emulsifier, as a crystal growth activator and as a surface - active agents.

The present invention provides that the Cu nitrate trihydrate (Cu (NO3)2. 3H2O), ligand- 1(Trimesic acid (C9H606)) and ligand-2(2-methyl Imidazole (C4H6N2)) obtained from sigma aldrich. N, N-Dimethyl Formamide (DMF), Methanol and Ethanol were obtained from S. D. Fine Chemicals. All the chemicals were of analytical grade and used without further purification.

In another aspect, the present invention provides the variable parameters. Variable parameters are molar concentration of Cu-salt (0.2 – 0.35M), TA (0.2 – 0.35M) and IMI (0.2M) and dosage of the ethoxylated compound as an emulsifier (0.1-0.4 gm). The synthesized Cu-MOFs framework has been characterized by powder X-ray diffraction (P-XRD), scanning electron microscope (SEM), Infrared spectroscopy (IR) and Thermo gravimetric analysis (TGA). Synthesized Cu-MOFs physical property like Surface area is measured by BET surface area analyser. Further, the impact of emulsifier on the synthesized Cu-MOF’s surface area was also studied.

The main advantages of this method of preparing polymer composite are:
1) The present invention relates to simple, reliable, energy efficient, low temperature and small duration crystallization reaction as compared to existing reactions involving high temperature, high pressure and long crystallization times.
2) The choice of modified solvent system (water: Methanol: DMF) produces uniformly shaped nano-sized particles through solvent–induced effects preferably in the range of 1.68 to 2.37 nm.
3) The solvent system is less toxic and environment friendly. After reaction, the solution can be stored, dosed and decomposed quite easily.
4) Application of dual-ligand matrix consisting of an organic ligand with –COOH functional moiety and N-base azolate compound to prepare Cu-MOFs under the influence of new kind of emulsifier has not been discussed so far.
5) The merits of present emulsion-pooled system are –
• Emulsifier (EM) used is low cost Emulsogen-M, chemically it is an ethoxylated compound selected from the group comprising compounds (C16-C18) and (C18) unsaturated alkyl alcohol, ethoxylate and is preferably fatty alcohol ethoxylate. Its specific characteristics like non-toxic, biodegradable nature, excellent emulsification property, good solubility in wide range of organic solvents, high hard water tolerance is advantageous to produce Cu-MOFs with improved properties.
• Provides gradual in-situ dissolution of otherwise heterogeneous organic-inorganic moieties and results in uniform homogeneous dispersion.
• Uniform dispersion medium accelerates nucleation/crystallization reaction between MOF precursors that facilitate high ion exchange and better electrostatic interactions which results in porous Cu-MOFs with enhanced surface physical property such as high surface area.
• The presence of emulsifier provides consistency and produce nano-sized MOFs that both exhibit high mono dispersity and stability.
• The presence of emulsifier as surface - active agents provides stability to MOF particles against agglomeration.
6) The main advantages of modified hydrothermal method are –
• The hydrothermal system used in the present invention comprises of a sealed glass tube and metallic steel reactor.
• The present reactor system has specific features such as increased heating rate, more uniform heating, enhancement of the precursor dissolution, high reaction rate, which is advantageous in polymer composite formation in small duration in comparison to proposed prior art.
• CuMOF reaction under the uniform and controlled environment avoids imbalance of critical parameters like temperature and capable of producing consistent reproducible results.
7) Present invention is cost effective in terms of low energy requirement and usage of renewable low-cost water as major solvent medium.
8) The current emulsion-pooled strategy showed potential towards up- scalability of Cu-MOFs for industrial use due to their facile preparation and reproducible crystal growth.

EXAMPLES:
The present disclosure is further illustrated by reference to the following examples which is for illustrative purpose only and does not limit the scope of the disclosure in any way. These examples are not intended to be inclusive of all aspects of the subject matter disclosed herein, but rather to illustrate representative features, methods, compositions, and results. These examples are not intended to exclude equivalents and variations of the present disclosure, which are apparent to one skilled in the art.

Powder X-ray diffractometer (Rigaku, Japan) and FTIR (Perkine Elmer 2000) were used to study crystal structure. Scanning electron microscope (JSM-6610LV, JEOL, Japan) were used to observe microstructures of materials at 10 kV. Thermal stability of prepared MOFs were analysed by Thermogravimetric analysis (TGA) done on TG model 2950 high resolution modulated TGA. The surface area, particle size and pore volume were measured by Microtrac BEL BELSORB-Max PC000668 instrument from adsorption desorption measurements.

Example 1: Preparation of polymer composite with metal organic framework (Cu-MOFs) through emulsion-pooled modified hydrothermal system
Polymer composite with metal organic framework (Cu-MOFs) comprises Cu Nitrate salt as inorganic moiety, trimesic acid having three carboxylate functional moiety (TA) as L1 and IMI as L2. MOF synthesis is carried out by using three steps: (1) homogenization, (2) fabrication of MOF precursors into porous framework, particle growth and (3) purification. The required quantity 20 ml of each of solution I, solution II and solution III is prepared separately. Solution I is 02. To 0.35 M solution of copper salt and distilled water, Solution II is 02. To 0.35 M solution of trimesic acid (TA) and 0.1 to 0.4 gm of ethoxylated compound as an emulsifier in methanol. Solution II acts as ligand and as an emulsifier. Solution III is 0.2 M solution of IMI in DMF solvent. Further, solutions I, II, and III were separately homogenized using sonication for 10-15 minute at room temperature 250C -370C to form a dispersed nano slurry. Further, MOF precursor’s coordination and fabrication was continued by drop-wise addition of solution-II and solution-III into solution-I at 400 C temperature with stirring. The prepared reaction mixture was continuously stirred for 30 minutes. After fabrication, the resultant viscous product was transferred to hydrothermal autoclave reactor and heated at 600C under controlled temperature using a box furnace for 8 to 10 hrs. Subsequently, the thick MOF precipitates were purified using solvent exchange process with fresh ethanol (2 times) in order to remove unreacted products and contamination. Finally, the recovered Cu-MOF product was dried under vacuum for 4 hours at 1200 C. Cu-MOF is obtained in powdered form and the colour of Cu-MOF is sea green. Further, the polymer composite with metal organic framework (Cu-MOFs) wherein the inorganic compound is Copper (II) nitrate, Ligand-1 is trimesic acid with structural formula:
,
and the Ligand-2 is 2-Methyl imidazole, are in a molar ratio of 1.8:1:0.5 respectively. Polymer composite with metal organic framework (Cu-MOFs) with different ratios of inorganic compound: Ligand-1: Ligand-2 were prepared in manner as given above and, wherein the molar ratio of inorganic compound: Ligand-1: Ligand-2 were 0.5:1:0.5, 1:1:0.5, 2:1:0.5, 1:2:0.5, and 2:2:0.5.

Example 2: Characterization of polymer composite with metal organic framework
The synthesized polymer composite with metal organic (Cu-MOFs) framework is characterized by Scanning electron microscope (SEM), powder X-ray diffraction (P-XRD), Infrared spectroscopy (IR) and Thermo gravimetric analysis (TGA).

Scanning electron microscope (SEM): Polymer composite was analysed by SEM. SEM images of polymer composite (Cu-MOFs) using emulsion-pooled hydrothermal method are provided in figure1. SEM image showed the high dispersive tetragonal pyramid shaped nanoparticles in the range of 1.68-2.37nm. The nano particles are randomly dispersed and form continuous pore voids. The presence of small crystals is attributed to the rapid nucleation and growth of Cu+2, TA and IMI precursors. The EDAX image of the synthesized Cu-MOF is shown in figure 2, that represents the compositional map of the elements present in Cu-MOFs. In view of observation, the presence of C, O, N and Cu elements further supports the formation of dual ligands incorporated desired Cu-MOFs. In addition, scan mapping also displays the uniform distribution of Cu, N, C and O indicated the formation of Cu-MOFs.

Powder X-ray diffraction: The powder X-ray diffraction (XRD) technique has been used to study the crystalline phase present on the framework surface. XRD pattern generated by structure ranging between 2O values of 5 and 70° is given in figure 3. The sharp peaks confirmed good crystallinity of the synthesized MOFs. The relative intensities and prominent peak positions having 6.68°, 9.47°, 11.60°, 13.41°, 14.62°, 15.00°, 16.45°, 17.45°, 19.01°, 20.18°, 21.28°, 23.33°, 24.08°, 25.23°, 25.93°, 27.66°, 28.71°, 29.30°, 30.30°, 30.91°, 35.16°, 37.83°, 39.06° are found in good agreement. As shown in Figure 3, the XRD pattern of Cu-TA-IMI exhibited sharp diffraction pattern consistent with the simulated pattern much identical to HKUST-1 material. The XRD pattern was analysed using Rietveld analysis and the crystallographic results of unit cell are given in Table 1.
Table 1; Crystallographic data for synthesized polymer composite

Crystal System Cubic
Space group F M- 3M
a, Å
b, Å
c, Å
?, degree
?, degree
?, degree 26.361(3)
26.361(3)
26.361(3)
90.00
90.00
90.00
V, Å3 18319.08(4.4)
GoF 6.0

Infrared spectroscopy (IR): Fourier-transform infrared spectroscopy (FTIR) technique has been used to study the Cu-MOF crystal structure of polymer composite and the representative IR chromatogram is shown in Figure 4. The presence of characteristic absorption bands showed that the carboxylate group (-OCO) of TA ligand and –NH of IMI ligand are coordinated with Cu+2 metal ions. Some of the absorption bands at 1622, 1439 and 1384 cm-1 (Cu-TA interaction), 1578 cm-1 (-C-N interaction) and 426 cm-1 (Cu-N interaction) supported the crystalline nature of Cu-MOFs. The duplet band at 755 cm-1 are attributed to the benzene groups in TA ligand that are influenced by metal Cu substitution and the band at 1107 cm-1 corresponds to the C–O–Cu stretching.

Thermogravimetric analysis (TGA): The thermal stability of prepared polymer composite (Cu-MOF) was evaluated by Thermogravimetric analysis (TGA) and the curve is shown in Figure 5. The curve indicated that the product (Cu-MOF) underwent three stages of weight reduction at different temperatures. The first stage of reduction in weight occurred at 900C, corresponding to the removal of trapped moisture molecules. The second stage of weight reduction occurred at approximately 1500C which is related to the evaporation of solvent / guest molecules. The third stage of weight reduction occurred at 3700C which showed the stability of Cu-MOF. MOFs TGA graph confirmed that the introduction of surfactants do not impact or degrade the thermal stability.

Example 3: Physical Properties of synthesized polymer composite (Cu-MOF)
The porosity of synthesized Cu-MOFs is measured by N2-adsorbtion-desorbtion method. The adsorption isotherm of the synthesized Cu-MOF and pore size distribution curve is shown in figure 6 and figure 7. The adsorption isotherm shown in Figure 6. showed about the surface area, pore size distribution and pore volume whereas Figure. 7 showed the pore size distribution pattern and also indicated the presence of abundant micropores on the surface of synthesized polymer composite Cu-MOFs. The Type 1 isotherm also supported the microporous nature of the synthesized polymer composite with Cu-MOF. Surface physical properties explained the presence of nano particles having pore size 1.68nm attaining the maximum Surface area (SA) of 2063 m2/g.

Example 4: Effect of Emulsifier Concentration on Surface Area (SA) of Synthesized polymer composite
polymer composite with porous metal organic frameworks, especially Cu-MOFs are successfully synthesized by using a new emulsifier under mild reaction conditions. The surface area is identified as characteristic parameter for porous materials. Porosity of synthesized Cu-MOFs is dependent to the use of concentration of emulsifier. The impact of concentration of emulsifier was studied on surface area of synthesized Cu-MOFs. The concentration of emulsifier used to identify the impact on surface area of synthesized Cu-MOFs was in range of 0.1 gm to 0.4 gm. The results are given in Table 2. Table 2 showed that that the surface area of synthesized polymer composite (Cu-MOF) has increased with the increase in emulsifier concentration (0.1 to 0.2 gm). Further, the addition of the emulsifier has efficiently modified the porous structure of the material by generating nano-sized particles and increased in surface area was observed. On further increasing the emulsifier concentration from 0.2 to 0.4 gm, the surface area (SA) of synthesized Cu-MOFs was decreased from 2063 to 1609 m2/gm and the pore size was increased from 1.68 to 2.37 nm respectively. As increase in pore size led to a decrease of surface area or vice versa under the presence of higher dosage of emulsifier (0.2-0.4g) due to more ionisation resulted in movement of particles away from one another. Thus, a conditional correlation under presence of higher dosage of emulsifier (0.2-0.4g) is that SA is inversely proportional to pore size. The saturation towards degree of ionization resulted in electrostatic repulsion of adjacent emulsion droplets. The observations of the present invention explained the systematic development of porous Cu-MOFs via emulsion-pooled hydrothermal method.

Table 2, Effect of Emulsifier Concentration on Physical Properties Surface area (SA), Pore volume (PV) and pore size diameter (PD) of Synthesized polymer composite

Synthesized
Product Emulsifier
Concentration
(gm) SA
(m2g-1) PV
(cm3g-1) PD
(nm)
Cu-MOF NIL 127 0.44 65.51
Cu-MOF-EM-1 0.1 798 0.65 3.26
Cu-MOF-EM-2 0.2 2063 0.87 1.68
Cu-MOF-EM-3 0.3 1812 1.04 2.31
Cu-MOF-EM-4 0.4 1609 0.95 2.37


Example 5: Reproducibility Study of Synthesized polymer composite (Cu-MOFs)
polymer composite (Cu-MOFs) synthesis under the optimized emulsion-pooled hydrothermal method provides the controlled reaction environment to produce the repeatable metal organic framework (MOF) batches. Prepared MOFs with prospective composition exhibited high surface area and consistent thermal stability. The repeatability results were confirmed by analytical techniques like XRD, and SA analysis. The repeatable XRD and SA BET Plots are shown in figure 8. , Claims:1. A polymer composite with metal organic framework with improved stability, surface area, and porosity, said polymer composite comprising:
a) an inorganic compound; and
b) a dual-ligand matrix comprising Ligand-1 and Ligand-2.

2. The polymer composite as claimed in claim 1, wherein the inorganic compound, Ligand-1 and Ligand-2 are in molar ratio in the range of 1: 1: 0.5 to 2: 2: 0.5.

3. The polymer composite as claimed in claim 1, wherein the inorganic compound is selected from the group comprising a metal, ionic form of metal, and metal salt.

4. The polymer composite as claimed in claim 1, wherein the Ligand-1 (L1) is trimesic acid and the Ligand-2 (L2) is an azolate compound.

5. The polymer composite as claimed in claim 4, wherein the azolate compound is 2-Methyl imidazole.

6. The polymer composite as claimed in claim 1, wherein the inorganic compound is Copper (II) nitrate.

7. The polymer composite as claimed in claim 1, wherein the inorganic compound is Copper (II) nitrate, Ligand-1 is trimesic acid and the Ligand-2 is 2-Methyl imidazole, in a molar ratio of 1.8:1:0.5.

8. The polymer composite as claimed in claim 1, wherein the polymer composite is a Cu (II)-based Metal Organic Frameworks (Cu-MOFs) comprising particles having a pore size in the range of 1.68 to 2.37 nm with of tetragonal pyramid morphology and surface area in the range of 1500 m2/g to 2200 m2/g, preferably 2063 m2/g.

9. A method for preparation of polymer composite with metal organic framework, said method comprising steps of:
(a) preparing homogenized solutions-I, solution-II, and solution-III;
(b) simultaneously adding solution-II and solution-III into solution-I to obtain a reaction mixture;
(c) incubating the reaction mixture obtained from step b) with continuous stirring;
(d) heating the reaction mixture obtained from step c) to obtain precipitates; and
(e) drying the precipitates obtained from step d) to obtain polymer composite,
wherein solution-I is a homogenized solution of a metal salt in water, wherein solution-II is a homogenized solution of Ligand-1, and wherein solution-III is a homogenized solution of Ligand-2.

10. The method as claimed in claim 9, wherein the metal salt in solution-I is Copper (II) nitrate, wherein the solution of Ligand-1 is a trimesic acid and ethoxylated compound in methanol, and wherein the solution of Ligand-2 is 2-Methyl imidazole (IMI) in N, N-Dimethyl Formamide (DMF).

11. The method as claimed in claim 9, wherein the solutions-I, solution-II, and solution-III are separately homogenized using sonication for 5 to 20 minutes at temperature in the range of 15 to 40°C.

12. The method as claimed in claim 9, wherein the addition of solution-II and solution-III into solution-I in step b) is carried out dropwise with a stirring at a temperature in the range of 30 to 50°C for 20 to 40 minutes, preferably for 10 to 15 minutes and wherein the solution-II, the solution-III and the solution-I are used in equal volumes.

13. The method as claimed in claim 9, wherein the incubation in step c) is carried out for 15 to 45 minutes, preferably for 30 minutes, wherein the heating of reaction mixture in step d) is carried out for 8 to 10 hours at a temperature in the range of 50 to 70°C, preferably at 60°C, and wherein the drying of precipitates in step e) is carried out in a vacuum for 3 to 5 hours at a temperature in the range of 110 to 130°C, preferably for 4 hours at 120°C.

14. The method as claimed in claim 9, wherein the precipitates obtained from step d) are purified using standard techniques known in the art comprising solvent exchange method, wherein solvent is ethanol.

15. The method as claimed in claim 9, wherein the solution-I is a 0.2 to 0.35 M solution of copper (II) nitrate in water, wherein the solution-II is a 0.2 to 0.35 M solution of Trimesic acid in methanol mixed with (0. 5 to 2 %) of fatty alcohol ethoxylate as ethoxylated compound, and wherein the solution-III is a 0.2 M solution of 2-Methyl imidazole (IMI) in N, N-Dimethyl Formamide (DMF).