KR101090517B1 - Nanocarbon-polymer composites and method for preparing the same - Google Patents

Abstract

Provided are carbon nanomaterial-polymer composites and methods for their preparation. The carbon nanomaterial-polymer composite includes a polymer matrix. A carbon nanomaterial-polymer nanoparticle complex having polymer nanoparticles introduced thereon is positioned in the polymer matrix. As the polymer nanoparticles are introduced onto the carbon nanomaterial and then dispersed in the polymer matrix, the compatibility between the carbon nanomaterial and the polymer matrix may be improved due to the polymer nanoparticles. As a result, the carbon nano material may be well dispersed in the polymer matrix, and fine phase separation may not occur. Accordingly, the electrical and mechanical properties of the carbon nanomaterial-polymer composite may be improved.

Description

Carbon nanomaterial-polymer composite and its manufacturing method {Nanocarbon-polymer composites and method for preparing the same}

The present invention relates to a polymer composite, and more particularly to a carbon nano material-polymer composite.

Carbon nanotubes (CNT)-polymer composites, which are currently being actively developed among carbon nanomaterials-polymer composites, can have high contact strength with polymers due to the large surface area of CNTs, and thus can exhibit high strength and light weight. In addition, it may have conductivity due to the electrical conductivity of the CNT. Due to the light weight and high strength, the CNT-filled polymer composite may be applied to sporting goods, automobiles, military equipment, aircraft, etc., and may be used as an electrostatic discharge material or an electromagnetic shielding material due to the conductive property.

However, carbon nanomaterials tend to aggregate by van der Waals forces. Therefore, in preparing the carbon nanomaterial-polymer composite, it is important to uniformly disperse the carbon nanomaterial in the polymer.

The problem to be solved by the present invention is to provide a carbon nano-material-polymer composite and a method for producing the carbon nano-material dispersed efficiently.

One aspect of the present invention to achieve the above object provides a carbon nano material-polymer composite. The carbon nanomaterial-polymer composite includes a polymer matrix. A carbon nanomaterial-polymer nanoparticle complex having polymer nanoparticles introduced thereon is positioned in the polymer matrix.

The carbon nano material may be graphene flake or carbon nanotube. As an example, the carbon nano material may be graphene flakes having one to several tens of graphene layers. The graphene flakes may be graphene flakes having 1 to 10 graphene layers.

The polymer nanoparticles and the polymer matrix may be made of the same polymer.

The polymer nanoparticles are polystyrene, polyisoprene, polyvinyl benzyl chloride, polyvinyl chloride, polyvinyl acetate , Polyacrylamide, polyacrylonitrile, polyacrylic acid, poly methacrylates, poly methyl methacrylate (methyl methacrylate), poly (butyl methacrylate), polylauryl methacrylate, poly dodecyl methacrylate, and polyester It may be at least one material selected from the group consisting of aryl methacrylate (poly (stearyl methacrylate)).

The carbon nanomaterial-polymer composite may have a film form. The carbon nanomaterial-polymer composite is several tens of Ω / sq. It can have a sheet resistance of several tens of ㏁ / sq.

Another aspect of the present invention to achieve the above object provides a carbon nano-material-polymer composite manufacturing method. First, polymer nanoparticles are introduced on a carbon nanomaterial to form a carbon nanomaterial-polymer nanoparticle composite. The carbon nanomaterial-polymer nanoparticle composite is introduced into the polymer matrix to form the carbon nanomaterial-polymer composite.

Forming the carbon nanomaterial-polymer nanoparticle composite is prepared by dispersing a carbon nanomaterial dispersion comprising a hydrophilic solvent, a surfactant and a carbon nanomaterial, and adding and dispersing an organic monomer and a polymerization initiator in the carbon nanomaterial dispersion, respectively. After forming the carbon nanomaterial-organic monomer dispersion, the organic monomer in the carbon nanomaterial-organic monomer dispersion may be polymerized to form polymer nanoparticles on the surface of the carbon nanomaterial.

The carbon nano material may be graphene flake or carbon nanotube. The carbon nano material is graphene flake, and the graphene flake may be prepared by heat treating expanded graphite. Heat treatment of the expanded graphite may be performed at a temperature of 700 to 1500 ℃. The heat treatment of the expanded graphite may be carried out at a temperature of 900 to 1100 ℃.

The organic monomer may be a monomer of a polymer forming the polymer matrix. The organic monomers are styrene, isoprene, vinyl benzyl chloride (VBC), vinyl chloride, vinyl acetate, acrylamide, acrylonitrile ), Acrylic acid, methacrylates, methyl methacrylate, butyl methacrylate, lauryl methacrylate, dodecyl methacrylate methacrylate), and stearyl methacrylate (stearyl methacrylate) may be at least one material selected from the group consisting of. Preferably, the organic monomer may be styrene.

The surfactant is sodium dodecyl sulfate (SDS), sodium lauryl sulfate (SLS), sodium dodecylbenzene sulfonate (NaDDBS), cetyltrimethyl ammonium bromide (CTAB), octadecylpyridinium bromide (ODPB), and poly (ethylene oxide) derivatives (poly (ethylene oxide) derivatives). derivatives), NP-40 (nonylphenol polyethoxylate), PVOH (polyvinyl alcohol), and tertitol (tergitol) may be at least one material selected from the group.

The polymerization initiator may be AIBN (azobisisobutyronitrile), LPO (lauroyl peroxide), CUPO (cumyl peroxide), BPO (benzoyl peroxide), NaPS (sodium persulfate) / KPS (potassium persulfate), and V50 (2,2'-azobis (2) -methylpropionamidine) dihydrochloride) may be at least one material selected from the group consisting of.

According to the present invention, as the polymer nanoparticles are introduced onto the carbon nanomaterial and then dispersed in the polymer matrix, the compatibility between the carbon nanomaterial and the polymer matrix may be improved due to the polymer nanoparticles. As a result, the carbon nano material may be well dispersed in the polymer matrix, and fine phase separation may not occur. Accordingly, the electrical and mechanical properties of the carbon nanomaterial-polymer composite may be improved.

The effects of the present invention are not limited to the above-mentioned effects, and other effects that are not mentioned will be clearly understood by those skilled in the art from the following description.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to describe the present invention in more detail. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms.

1 is a schematic view showing a method of manufacturing a carbon nano material-polymer composite according to an embodiment of the present invention, respectively.

Referring to FIG. 1, a carbon nano material 10 is prepared (S100).

The carbon nano material 10 may be a graphene flake or carbon nano tube (CNT). The CNT may be a single-walled carbon nanotube (SWCNT) or a multi-walled carbon nanotube (MWCNT). The graphene flakes may have 1 to several tens of graphene layers. Preferably, the graphene flakes may have graphene layers of 1 to 10. Considering that graphene has a wider surface area and superior electrical conductivity than CNTs, the carbon nanomaterial 10 may be graphene flakes.

When the carbon nano material 10 is graphene flakes, the graphene flakes may be prepared by heat-treating expanded graphite. Expanded graphite generally means that the crystalline graphite is acid treated and then heated to expand to 100 to 700% of the initial volume. The heat treatment of the expanded graphite may be performed under low pressure conditions of about 0.01 to 1.00 torr and temperature conditions of 700 to 1500 ° C. The heat treatment temperature may be 900 to 1100 ℃.

Meanwhile, a hydrophilic solvent 20 and a surfactant 30 are put into the reactor 1 and stirred to prepare a liquid mixture. The carbon nano material 10 is added to the liquid mixture to prepare a carbon nano material mixture (S110). Before the carbon nanomaterial 10 is added, a hydrophobic solvent may be further added to the liquid mixture. This process can proceed at room temperature.

The hydrophilic solvent 20 may be deionized water.

The surfactant 30 has a hydrophilic portion 30b and a hydrophobic portion 30a in its molecule, and includes sodium dodecyl sulfate (SDS), sodium lauryl sulfate (SLS), sodium dodecylbenzene sulfonate (NaDDBS), and cetriylmethyl (CTAB). ammonium bromide), octadecylpyridinium bromide (ODPB), poly (ethylene oxide) derivatives, NP-40 (nonylphenol polyethoxylate), PVOH (polyvinyl alcohol), and tergitol It may be at least one material.

The hydrophobic solvent may contain pentanol, hexadecane, dodecyl alcohol, dotyl alcohol, cetyl alcohol, and Triton X-100.

Dispersing the carbon nano material mixture to prepare a carbon nano material dispersion (S120). At this time, the hydrophobic portion 30a of the surfactant 30 is located on the surface of the carbon nanomaterial 10, and the hydrophilic portion 30b of the surfactant 30 is directed toward the hydrophilic solvent 20. Positioned so that the carbon nanomaterial 10 can be dispersed in the hydrophilic solvent 20. This process can proceed at room temperature.

Thereafter, an organic monomer and a polymerization initiator are added to the carbon nanomaterial dispersion, and then dispersed to form a carbon nanomaterial-organic monomer dispersion (S130). At this time, the organic monomer and the polymerization initiator are hydrophobic to form fine droplets 40 in the hydrophilic solvent 20 by the surfactant. This process may be carried out at a temperature at which the polymerization of the organic monomer may not occur, for example, at 0 ° C.

The organic monomers are styrene, isoprene, vinyl benzyl chloride (VBC), vinyl chloride, vinyl acetate, acrylamide, acrylonitrile ( acrylonitrile, acrylic acid, methacrylates, methyl methacrylate, butyl methacrylate, lauryl methacrylate, dodecyl methacrylate ( dodecyl methacrylate, and stearyl methacrylate (stearyl methacrylate) may be at least one material selected from the group consisting of. The organic monomer is preferably a conjugate system (conjugate system) in the form of alternating single double bond.

The polymerization initiator may be AIBN (azobisisobutyronitrile), LPO (lauroyl peroxide), CUPO (cumyl peroxide), BPO (benzoyl peroxide), NaPS (sodium persulfate) / KPS (potassium persulfate), and V50 (2,2'-azobis (2) -methylpropionamidine) dihydrochloride) may be at least one material selected from the group consisting of.

Thereafter, the organic monomer in the carbon nanomaterial-organic monomer dispersion is polymerized to form the polymer nanoparticles 45 on the surface of the carbon nanomaterial 10 (S140). As a result, carbon nanomaterial-polymer nanoparticle composite is formed. This process can be carried out at a temperature capable of polymerizing the organic monomer. That is, the organic monomer may be polymerized by heating the carbon nano material-organic monomer dispersion.

In this process, the droplets in which the polymerization was initiated in the carbon nanomaterial-organic monomer dispersion, that is, the initial polymer droplet (40 ', juvenile polymer droplet) and the graphene flakes 10 were subjected to brown motion in the hydrophilic solvent 20. Conflict with each other. In this collision process, a site for fixing the initial polymer droplet 40 'on the surface of the graphene flake 10 may be generated. The bond between the initial polymer droplet 40 'and the graphene flakes 10 is further increased by π-π stacking when the polymer in the initial polymer droplet 40' has an aromatic group or a double bond. It can happen easily.

Thereafter, the carbon nanomaterial-polymer nanoparticle composite is introduced into the polymer matrix 50 to form a carbon nanomaterial-polymer composite (S150). The monomer of the polymer constituting the polymer matrix 50 may be the same as the organic monomer. In other words, the polymer nanoparticles 45 and the polymer matrix 50 may be made of the same polymer. The polymer matrix 50 may be prepared by melting polymer beads.

Thereafter, the carbon nanomaterial-polymer composite may be coated on a base substrate using a wet coating method such as casting, and then separated from the base substrate to prepare a free standing film.

As such, as the polymer nanoparticles are introduced onto the carbon nanomaterial and then dispersed in the polymer matrix, the compatibility between the carbon nanomaterial and the polymer matrix may be improved due to the polymer nanoparticles. As a result, the carbon nano material may be well dispersed in the polymer matrix and no fine phase separation may occur. Accordingly, the electrical and mechanical properties of the carbon nanomaterial-polymer composite may be improved.

Hereinafter, preferred examples are provided to aid the understanding of the present invention. However, the following experimental examples are only for helping understanding of the present invention, and the present invention is not limited to the following experimental examples.

Preparation Example 1 Preparation of Graphene Flake

<Production Example 1-1>

50 mg of expanded graphite having a purity of 99.9% or more was placed in a lidded alumina boat into the chamber. A rotary pump connected to the chamber was used to lower the pressure in the chamber below 0.01 Torr. Using a tungsten lamp heater and a programmable heater controller, a ramping rate of 800 ° C./min and a target temperature of 700 ° C. were set, followed by heat treatment of the expanded graphite for 2 minutes at the target temperature to obtain graphene flakes. Got it. Thereafter, the graphene flakes were unloaded after cooling the temperature in the chamber to room temperature.

<Manufacture example 1-2>

Graphene flakes were prepared in the same manner as in Preparation Example 1-1, except that the expanded graphite was heat-treated at 800 ° C.

<Manufacture example 1-3>

Graphene flakes were prepared in the same manner as in Preparation Example 1-1, except that the expanded graphite was heat-treated at 900 ° C.

<Manufacture example 1-4>

Graphene flakes were prepared in the same manner as in Graphene Preparation Example 1-1, except that the expanded graphite was heat-treated at 1000 ° C.

Graphene flakes and expanded graphite according to Preparation Examples 1-1 to 1-4 were observed using a scanning electron microscope (SEM) and a transmission electron microscopy (TEM). SEM used FESEM (field emission transmission electron microscopy) with JEOL model name JSM6700F, and TEM used high resolution transmission electron microscopy (HRTEM) with JEOL 300 kV JEOL model name. In observing the samples using TEM, the samples were dispersed in methanol and then drop coated onto a copper grid and loaded into the TEM equipment.

2a is a photograph of expanded graphite and graphene flakes prepared in Preparation Examples 1-4.

Referring to Figure 2a, it can be seen that the bulk volume of the graphene flakes (GF) prepared by heat-treating the expanded graphite at 1000 ℃ is very large compared to the bulk volume of the expanded graphite powder (EG). In addition, the temperature to heat-treat the expanded graphite is 700 ° C. (Manufacture Example 1-1), 800 ° C. (Manufacture Example 1-2), 900 ° C. (Manufacture Example 1-3), and 1000 ° C. (Manufacturing Example 1-4). As it increased, the bulk volume of the graphene flakes obtained from each of them gradually increased.

2B is an SEM photograph of expanded graphite, FIGS. 2C and 2D are SEM photographs of graphene flakes according to Preparation Example 1-4, and FIGS. 2E and 2F illustrate graphene according to Preparation Example 1-4. SEM pictures of the flakes.

Referring to FIG. 2B, it can be seen that expanded graphite has a structure in which hundreds of unit graphenes are stacked, but an interval therebetween is expanded compared to pure graphite. However, referring to FIGS. 2C, 2D, 2E and 2F, the graphene flakes have one (FIG. 2E) or two (FIG. 2F) graphene layers, folded like paper (FIG. 2C), and edges It can be seen that the part is also folded (FIG. 2D).

In addition, the graphene flakes obtained when the temperature for heat-treating the expanded graphite was 700 ° C. (Preparation Example 1-1) or 800 ° C. (Preparation Example 1-2) were provided with dozens, specifically, up to 35 graphene layers. However, the graphene flakes obtained when the temperature of heat-treating the expanded graphite was 900 ° C. (Preparation Examples 1-3) or 1000 ° C. (Preparation Examples 1-4) provided a single layer of graphene or 2 to 10 graphene layers. .

From these results, the graphene layers which maintained the stack structure of several hundred layers by van der waals force in the expanded graphite were graphene flakes having several to several tens of layers of graphene by heat treatment of 700 ° C. or higher. It can be seen that it can be separated by. In addition, it can be seen that by heat treatment at about 1000 ° C., expanded graphite can be separated into graphene flakes having one or two graphene layers.

Preparation Example 2 Preparation of Graphene-Polystyrene Nanoparticle Composite

<Manufacture example 2-1>

The probe output energy of Sonomaster Model No. ULH-700S, a standard aluminum horn with a replaceable tip with a diameter of 13 mm and an ultrasonic irradiation device with a temperature controller, was set to 300W. 200 ml of deionized water, 4.5 ml of pentanol, and 0.5 gm of SDS were placed in a beaker. About 0.15 gm of the graphene flakes obtained through Preparation Example 1-4 was added thereto, followed by sonication for 1 hour to disperse the graphene flakes to form a graphene dispersion.

The graphene dispersion was then placed in a 500 ml four-necked glass reactor equipped with a condenser, dropping funnel, stirrer and nitrogen inlet, and then placed in an ice bath. Thereafter, 5 mg of styrene as an organic monomer and 0.05 mg of AIBN as a polymerization initiator were added to the reactor using a dropping funnel, respectively. Thereafter, nitrogen gas was bubbled through the nitrogen inlet to remove oxygen in the reactor while maintaining an oxygen-free nitrogen atmosphere for 20 minutes. Thereafter, the mixture was sonicated at 0 ° C. for 4 hours to obtain a homogeneous graphene-styrene dispersion. Thereafter, after the reactor was moved into an oil bath, the temperature of the oil bath was raised to 85 ° C. and allowed to stand for 4 hours to cause polymerization in the reactor. The inside of the reactor was maintained in an inert nitrogen atmosphere during the polymerization process.

After polymerization, the gray emulsion was washed three times with methanol and water to wash the remaining pentanol, SDS, styrene, and AIBN, and then dried in a vacuum at 60 ° C. for 24 hours to contain 3 wt% of graphene. Graphene-polystyrene nanoparticle composites were obtained.

<Manufacture example 2-2>

Except for using the graphene flake 250mg obtained in Preparation Example 1-4 was carried out in the same manner as in Preparation Example 2-1 to obtain a graphene-polystyrene nanoparticle composite containing 5% by weight graphene.

<Manufacture example 2-3>

A graphene-polystyrene nanoparticle composite containing 10 wt% graphene was obtained in the same manner as in Preparation Example 2-1, except that 500 mg of graphene flakes obtained through Preparation Examples 1-4 were used.

<Manufacture example 2-4>

A graphene-polystyrene nanoparticle composite containing 15 wt% of graphene was obtained in the same manner as in Preparation Example 2-1, except that 750 mg of graphene flakes obtained through Preparation Examples 1-4 were used.

<Manufacture example 2-5>

A graphene-polystyrene nanoparticle composite containing 20 wt% of graphene was obtained in the same manner as in Preparation Example 2-1, except that 1000 mg of graphene flakes obtained through Preparation Examples 1-4 were used.

Comparative Example 1

Pure polystyrene nanoparticles were obtained by performing the same method as in Preparation Example 2-1 without using graphene flakes.

Graphene-polystyrene nanoparticle composite according to Preparation Example 2-1 was observed using a scanning electron microscope (SEM) and a transmission electron microscopy (TEM). SEM used FESEM (field emission transmission electron microscopy) with JEOL model name JSM6700F, and TEM used high resolution transmission electron microscopy (HRTEM) with JEOL 300 kV JEOL model name. In observing the samples using TEM, the samples were dispersed in methanol and then drop coated onto a copper grid and loaded into the TEM equipment.

3A to 3C are SEM images of graphene-polystyrene nanoparticle composites according to Preparation Example 2-1 at different resolutions, and FIGS. 3D to 3F are graphene-polystyrene nanoparticles according to Preparation Example 2-1. TEM pictures of the complexes at different resolutions.

3a to 3f, it can be seen that the graphene-polystyrene nanoparticle composite has graphene flakes and polystyrene nanoparticles irregularly positioned on the upper and lower surfaces thereof. The graphene flakes were very thin, irregularly agglomerated and had a size of about 5-10 um.

In addition, there was no charging of the graphene-polystyrene nanoparticle composite during the imaging process using the SEM, which means that the graphene-polystyrene nanoparticle ���polymer has conductivity.

Graphene-polystyrene nanoparticle composites according to Preparation Example 2-1, graphene flakes according to Preparation Examples 1-4, and pure polystyrene nanoparticles according to Comparative Example 1 were subjected to Fourier transform infrared spectrometer (FTIR) and Raman spectroscopy. ) Was observed. FTIR used Nicolet's model name IR 200, and Raman optics used Renishaw's micro Raman optics with Invia Basic's model name, which employs a 640 nm Ar ion laser as the excitation light source.

4A is a graph showing FTIR spectra of graphene-polystyrene nanoparticle composites, graphene flakes, and pure polystyrene nanoparticles.

Referring to FIG. 4A, graphene flakes (GF) showed no peaks. Graphene-polystyrene nanoparticle composites (G / PSNP) and pure polystyrene nanoparticles (PSNP), on the other hand, exhibit vibration modes due to different forms of aliphatic CH stretching, aromatic CH stretching, aliphatic CH ₂ , and polystyrene, respectively. It represents exhibited a peak of 2820-2967cm ^-1, near, around 2994-3043cm ^-1, 1500cm ^-1, near, and near 700-1400cm ^-1. This means that the nanoparticles of the graphene-polystyrene nanoparticle composite are polystyrene. On the other hand, the graphene-polystyrene nanoparticle composite shows a new peak near 3036 cm ⁻¹ due to the CH stretching of the aromatic ring.

In summary, pure polystyrene nanoparticles (PSNP) and graphene-polystyrene nanoparticle composites (G / PSNP) are not significantly different in peak positions except for peak intensity. This means that the pure polystyrene nanoparticles (PSNP) and the polystyrene nanoparticles in the graphene-polystyrene nanoparticle composite (G / PSNP) have the same structural properties. From this, it can be seen that the internal structure of the polystyrene nanoparticles fixed on the graphene flake surface is not modified. However, the graphene flake surface may have been structurally modified.

4B is a graph showing Raman spectra of graphene-polystyrene nanoparticle composites and graphene flakes. Raman spectra are effective in determining the alignment of carbon crystal structures, and typical graphene shows G bands (~ 1580 cm ^-1 ) and 2D bands (~ 2670 cm ^-1 ) in the Raman spectrum.

Referring to FIG. 4B, the 2D bands of the graphene flakes (GF) and the graphene-polystyrene nanoparticle complexes (G / PSNP) were wider than the 2D bands of general graphene. It can be seen that the crystal defects in the graphene in the graphene flake (GF) and the graphene-polystyrene nanoparticle complex (G / PSNP). On the other hand, unlike graphene flakes (GF), the graphene-polystyrene nanoparticle complex (G / PSNP) exhibits a D band of 1354 cm ⁻¹ . This was attributed to the covalent bonding of polystyrene nanoparticles with the opening of the π bond of graphene when the polystyrene nanoparticles were introduced onto the graphene. In addition, the I (D) / I (G) value of the graphene-polystyrene nanoparticle complex (G / PSNP) was significantly increased compared to the graphene flakes (GF), which means that the graphene is doped.

Thermobalance TGA 2050 for graphene-polystyrene nanoparticle composites according to Preparation Examples 2-1 to 2-5, graphene flakes according to Preparation Examples 1-4, and pure polystyrene nanoparticles according to Comparative Example 1 Differential thermogravimetric analysis was carried out using a thermal analyzer, and dynamic differential scanning calorimetry (DSC) analysis was performed using a thermal analyzer DSC 2920. In differential thermal gravimetric analysis, the temperature was increased at a rate of 10 ° C./min from room temperature to 800 ° C. while continuously flowing nitrogen. In dynamic DSC analysis, the temperature was increased at a rate of 5 ° C./min while continuously flowing nitrogen. Raised.

5a shows graphene-polystyrene nanoparticle composites according to Preparation Examples 2-1 to 2-5, graphene flakes according to Preparation Examples 1-4, and pure polystyrene nanoparticles according to Comparative Example 1. A graph showing weight loss.

Referring to FIG. 5A, graphene flakes (GF) showed an initial 8% weight loss below 350 ° C., due to oxidation of amorphous carbon in the sample. Pure polystyrene nanoparticles (PSNP) began to decompose at 380 ° C and completely decomposed at 401 ° C. Pure polystyrene nanoparticles (PSNP) and graphene-polystyrene nanoparticle composites (G / PSNP) exhibited weight loss below 200 ° C due to decomposition of low molecular weight polystyrene and high weight loss above 200 ° C. By decomposition of molecular weight polystyrene. What is unusual is that as the graphene content increases in the graphene-polystyrene nanoparticle composites (G / PSNP), the residual amount is increased at 400 ° C or higher, and the temperature at which the weight loss starts also increases.

5B shows the weight of the graphene-polystyrene nanoparticle composites according to Preparation Examples 2-1 to 2-5, the graphene flakes according to Preparation Examples 1-4, and the temperature of the pure polystyrene nanoparticles according to Comparative Example 1. FIG. A graph showing the first derivative of the loss.

Referring to FIG. 5B, the peaks represent the temperature at which the highest reaction rate occurred. Pure polystyrene nanoparticles (PSNP) exhibit the highest reaction rate at 401 ° C, and as the graphene content increases, the temperature at which the graphene-polystyrene nanoparticle composites (G / PSNP) exhibit the highest reaction rate increases. Specifically, when the graphene content is 20wt%, the temperature indicating the highest reaction rate is increased by about 7 ° C. compared with the pure polystyrene nanoparticles (PSNP). This means that as the graphene content increases, the thermal stability of the graphene-polystyrene nanoparticle complexes (G / PSNP) is improved. Therefore, it can be seen that the graphene-polystyrene nanoparticle complexes can be applied to thermal barriers.

5C is a graph showing glass transition temperatures (T _g ) of graphene-polystyrene nanoparticle composites according to Preparation Examples 2-1 to 2-5 and pure polystyrene nanoparticles according to Comparative Example 1. FIG.

Referring to FIG. 5c, T _g is observed at 96 ° C. for pure polystyrene nanoparticles (PSNP), and T _g of graphene-polystyrene nanoparticle composite (20% G / PSNP) is _obtained when the graphene content is 20 wt%. Observed at 113 ° C. From this, it can be seen that the T _g of the graphene-polystyrene nanoparticle complexes (G / PSNP) increases as the graphene content increases. The increase in T _g with increasing graphene content is attributable to an increase in the motion restriction of the polymer chain at the graphene interface with the polymer nanoparticles in the graphene-polystyrene nanoparticle complexes (G / PSNP). The limit is greater the better the interfacial compatibility between the polymer chain and the graphene. Accordingly, it can be seen that the boundary affinity between the polystyrene nanoparticles and the graphene in the graphene-polystyrene nanoparticle complexes (G / PSNP) is excellent.

Preparation Example 3 Preparation of Graphene-Polystyrene Composite Film

<Manufacture example 3-1>

5 mg of polystyrene beads (Mw: 280,000) were dissolved in 20 ml of THF to prepare a polystyrene matrix. 0.150 gm of the graphene-polystyrene nanoparticle composite (graphene 3 wt%) obtained in Preparation Example 2-1 was stirred in the polystyrene matrix. Thereafter, the resultant was cast on a glass substrate and then dried at room temperature to obtain a graphene-polystyrene composite free standing film having a uniform thickness to 600 um.

<Manufacture example 3-2>

A graphene-polystyrene composite freestanding film was prepared in the same manner as in Preparation Example 3-1, except that 0.250 gm of the graphene-polystyrene nanoparticle composite (5 wt% of graphene) obtained in Preparation Example 2-2 was used. Had.

<Manufacture example 3-3>

A graphene-polystyrene composite freestanding film was prepared in the same manner as in Preparation Example 3-1, except that 0.500 gm of the graphene-polystyrene nanoparticle composite (graphene 10 wt%) obtained in Preparation Example 2-3 was used. Had.

<Manufacture example 3-4>

A graphene-polystyrene composite freestanding film was prepared in the same manner as in Example 3-1, except that 0.750 gm of the graphene-polystyrene nanoparticle composite (graphene 15 wt%) obtained in Preparation Example 2-4 was used. Had.

<Manufacture example 3-5>

A graphene-polystyrene composite freestanding film was prepared in the same manner as in Preparation Example 3-1, except that 1.0 g of the graphene-polystyrene nanoparticle composite (20 wt% of graphene) obtained in Preparation Example 2-5 was used. Had.

Comparative Example 2

5 mg of polystyrene beads (Mw: 280,000) were dissolved in 20 ml of THF to prepare a polystyrene matrix. The polystyrene matrix was cast on a glass substrate and then dried at room temperature to yield a graphene-polystyrene composite free standing film with a uniform thickness of 600 um.

6A is a photograph of a freestanding film prepared through Preparation Examples 3-1 to 3-5, and Comparative Example 2, and FIGS. 6B, 6C, 6D, and 6E are all Preparation Examples 3-5. Pictures showing the flexibility of the freestanding film produced through.

6B-6E, the freestanding film was shown to maintain flexibility regardless of graphene content.

The sheet resistance (Rs) of the graphene-polystyrene composite film according to Preparation Examples 3-1 to 3-5 was measured. Specifically, the sheet resistance was measured using CMT-SR1000 N (AIT Co., Ltd.), which is a 4-point probe resist meter.

7 is a graph showing the sheet resistance (Rs) according to the graphene content of the graphene-polystyrene composite film.

Referring to FIG. 7, the graphene-polystyrene composite film containing 3 wt% of graphene exhibited a sheet resistance of 36.67 μs / sq. However, as the graphene content increased, the sheet resistance rapidly decreased to 20 wt% of graphene. The graphene-polystyrene composite film containing 65 exhibited a sheet resistance of 65.46 dl / sq. When the sheet resistance is converted into electrical conductivity, the graphene-polystyrene composite film containing 3 wt% of graphene has an electrical conductivity of 4.5 × 10 ⁻⁵ S / m, which is 1 × 10 ⁻ , which is a reference conductivity for use as an antistatic film. ^It was about 20 times higher than ⁶ S / m.

This improvement in electrical conductivity means that the graphene is very well dispersed in the polystyrene matrix. This may be due to the introduction of the polystyrene nanoparticles onto the graphene and then dispersing it in the polystyrene matrix, thereby improving the compatibility between the graphene and the polystyrene matrix.

1 is a schematic view showing a method of manufacturing a carbon nano material-polymer composite according to an embodiment of the present invention, respectively.

2a is a photograph of expanded graphite and graphene flakes prepared in Preparation Examples 1-4.

2b is an SEM photograph of expanded graphite.

2C and 2D are SEM photographs of graphene flakes according to Preparation Example 1-4.

2E and 2F are SEM images of graphene flakes according to Preparation Example 1-4.

3A to 3C are SEM images of graphene-polystyrene nanoparticle composites prepared at different resolutions according to Preparation Example 2-1.

3D to 3F are TEM images of graphene-polystyrene nanoparticle composites prepared at different resolutions according to Preparation Example 2-1.

4A is a graph showing FTIR spectra of graphene-polystyrene nanoparticle composites, graphene flakes, and pure polystyrene nanoparticles.

4B is a graph showing Raman spectra of graphene-polystyrene nanoparticle composites and graphene flakes.

5a shows graphene-polystyrene nanoparticle composites according to Preparation Examples 2-1 to 2-5, graphene flakes according to Preparation Examples 1-4, and pure polystyrene nanoparticles according to Comparative Example 1. A graph showing weight loss.

5B shows the weight of the graphene-polystyrene nanoparticle composites according to Preparation Examples 2-1 to 2-5, the graphene flakes according to Preparation Examples 1-4, and the temperature of the pure polystyrene nanoparticles according to Comparative Example 1. FIG. A graph showing the first derivative of the loss.

5C is a graph showing glass transition temperatures (T _g ) of graphene-polystyrene nanoparticle composites according to Preparation Examples 2-1 to 2-5 and pure polystyrene nanoparticles according to Comparative Example 1. FIG.

6A is a photograph of a freestanding film prepared through Preparation Examples 3-1 to 3-5, and Comparative Example 2. FIG.

6B, 6C, 6D and 6E are all photographs showing the flexibility of the freestanding film manufactured through Preparation Example 3-5.

7 is a graph showing the sheet resistance (Rs) according to the graphene content of the graphene-polystyrene composite film.

Claims (19)

Introducing carbon nanoparticles onto graphene flakes to form carbon nanomaterial-polymer nanoparticle composites; And A carbon nanomaterial-polymer composite manufacturing method comprising the step of adding a carbon nanomaterial-polymer nanoparticle composite into a polymer matrix to form a carbon nanomaterial-polymer composite. The method of claim 1, Forming the carbon nanomaterial-polymer nanoparticle complex Preparing a carbon nanomaterial dispersion having a hydrophilic solvent, a surfactant, and graphene flakes; Injecting an organic monomer and a polymerization initiator into the carbon nano material dispersion and then dispersing them to form a carbon nano material-organic monomer dispersion; And A method of producing a carbon nanomaterial-polymer composite comprising polymerizing an organic monomer in the carbon nanomaterial-organic monomer dispersion to form polymer nanoparticles on a surface of the carbon nanomaterial. delete The method according to claim 1 or 2, The graphene flakes are carbon nanomaterial-polymer composite manufacturing method prepared by heat-treating the expanded graphite. 5. The method of claim 4, Heat treating the expanded graphite is carried out at a temperature of 700 to 1500 ℃ carbon nanomaterial-polymer composite manufacturing method. The method of claim 5, Heat treating the expanded graphite is carried out at a temperature of 900 to 1100 ℃ carbon nanomaterial-polymer composite manufacturing method. 3. The method of claim 2, The organic monomer is a carbon nano material-polymer composite manufacturing method of the monomer constituting the polymer matrix. The method according to claim 2 or 7, The organic monomers are styrene, isoprene, vinyl benzyl chloride (VBC), vinyl chloride, vinyl acetate, acrylamide, acrylonitrile ), Acrylic acid, methacrylates, methyl methacrylate, butyl methacrylate, lauryl methacrylate, dodecyl methacrylate methacrylate), and stearyl methacrylate (stearyl methacrylate) at least one material selected from the group consisting of carbon nanomaterials-polymer composite manufacturing method. The method of claim 8, The organic monomer is styrene (styrene) carbon nano material-polymer composite manufacturing method. 3. The method of claim 2, The surfactant is sodium dodecyl sulfate (SDS), sodium lauryl sulfate (SLS), sodium dodecylbenzene sulfonate (NaDDBS), cetyltrimethyl ammonium bromide (CTAB), octadecylpyridinium bromide (ODPB), and poly (ethylene oxide) derivatives (poly (ethylene oxide) derivatives). derivatives), NP-40 (nonylphenol polyethoxylate), PVOH (polyvinyl alcohol), tertitol (tergitol) at least one material selected from the group consisting of carbon nano material-polymer composite. 3. The method of claim 2, The polymerization initiator may be AIBN (azobisisobutyronitrile), LPO (lauroyl peroxide), CUPO (cumyl peroxide), BPO (benzoyl peroxide), NaPS (sodium persulfate) / KPS (potassium persulfate), and V50 (2,2'-azobis (2) -methylpropionamidine) at least one material selected from the group consisting of carbon nanomaterials-polymer composite manufacturing method. Polymer matrix; A carbon nano material-polymer composite having a carbon nano material-polymer nanoparticle complex in which the polymer nanoparticles are introduced on the graphene flakes and positioned in the polymer matrix. delete delete The method of claim 12, The graphene flake is a carbon nano material-polymer composite that is a graphene flake having 1 to 10 graphene layers. The method of claim 12, The polymer nanoparticles and the polymer matrix is a carbon nano-material composite made of the same polymer. The method according to claim 12 or 16, The polymer nanoparticles are polystyrene, polyisoprene, polyvinyl benzyl chloride, polyvinyl chloride, polyvinyl acetate , Polyacrylamide, polyacrylonitrile, polyacrylic acid, poly methacrylates, poly methyl methacrylate (methyl methacrylate), poly (butyl methacrylate), polylauryl methacrylate, poly dodecyl methacrylate, and polyester Carbon nanomaterial-polymer complex, which is at least one material selected from the group consisting of aryl methacrylate (poly (stearyl methacrylate)). The method of claim 12, The carbon nanomaterial-polymer composite is a carbon nanomaterial-polymer composite having a film form. The method according to claim 12 or 18, wherein The carbon nanomaterial-polymer composite is several tens of Ω / sq. Carbon nanomaterial-polymer composite having a sheet resistance of several tens of ㏁ / sq.

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