Field of the invention

The invention relates to the field of electroactive materials, more particularly to a hybrid composite for preparing thin conductive layers, to a method of preparing thereof, and to a thin conductive layer prepared from this hybrid composite.

Background of the Invention

The flexible and organic electronics field has experienced dynamic development over the last 20 years. Electronic devices produced by printing, coating, sputtering or steaming in a continuous mode, so-called roll-to-roll or R2R, feature low production costs and are gradually being applied in various applications. Most of the devices produced in this way use polyethylene-terephthalate film or PET film as a base, on which other functional layers are then gradually applied to create different types of electronic devices. The most common and commercially successful solution is the method where a layer of conductive transparent metal oxides is applied on the PET film by vacuum deposition. These are most commonly tin-doped indium trioxide or ITO and fluorine-doped indium trioxide or FTO. In both cases, the disadvantage is the limiting quantity and availability of indium, which is mostly imported from East Asia. Another disadvantage is that the recyclability thereof is limited, and it is, therefore, a non-renewable resource.

Another widely used solution is the so-called metallic nanowires of silver and copper. The disadvantage of these printing formulations is the tendency of the deposited nanoparticles to oxidation or the low electrochemical stability thereof in humid environments, as well as the necessity of sintering at higher temperatures after the layer preparation. Moreover, it is again a non-renewable resource and recycling the metallic layer is virtually unfeasible.

Another option is preparing thin conductive layers by depositing carbon nanomaterial. Graphene is a very promising material. The carbon nanomaterial deposited in a 2D arrangement allows the preparation of a transparent conductive layer. However, from an industrial point of view, production technology appears problematic. The basic deposition technique is vacuum chemical vapor deposition. This technique does not allow to prepare a homogeneous layer without crystal lattice defects, affecting the conductivity of such prepared layer and resulting in local conductivity problems. The growth of graphene single crystals on a single-crystal catalytic substrate is expensive and inefficient from an industrial point of view. Another disadvantage is that graphene films prepared in a such way are limited by the dimensions thereof, and it is practically impossible to talk about continuous production technology.

This disadvantage is attempted to be eliminated by using a larger film of graphene so that more single crystals are allowed to coalesce on common substrates that may no longer be specifically single crystalline. Under certain conditions, multiple pieces can be linked without creating “seams”, holes and other deformations of the regular structure at the contact points. However, it is still an expensive technology. The use of carbon nanotubes, or CNTs, seems to be a certain concession if the resulting application does not require a completely transparent layer. These materials exhibit high conductivity close to cheaper versions of graphene, especially when it comes to so-called single-walled carbon nanotubes, or SWCNTs. However, the CNT deposition process in thin conductive layers has a major disadvantage in that they are highly prone to agglomeration, and conventional deposition techniques do not allow the preparation of a homogeneous layer of reproducibly uniform thickness. This disadvantage is solved by the addition of dispersing agents, which, however, reduce the conductivity of the final conductive layer at the same time. Another approach is the oxidation of the carbon nanotube surface to form -OH and -COOH groups. Although these improve dispersibility, the conductivity of the prepared layers is significantly reduced.

A new approach has been introduced by US 2012/0326093 and US 2014/0138588, which address the problem of dispersion by surface modification of CNTs. The CNTs are fiberized by agitation in an acidic medium in the presence of sulfuric, chlorosulfonic, trifluoromethanesulfonic or 4-toluenesulfonic acid so that the pH of the medium is less than 1. At the same time, the fiberizing is carried out in the presence of polyaromatic molecules, both substituted and unsubstituted, where the number of aromatic units is at least two, and graphene may also be used. The weight ratio of CNTs to polyaromatic molecules ranges from 1 :3 to 3:1. Under these conditions, the CNT surface can be achieved to be covered with sulfonated polyaromatic derivatives, forming a so-called TT-TT stacking with the CNTs. The bonds are highly stable and allow efficient dispersion to a high degree and limit the risk of CNT agglomeration. However, this modification of CNTs did not provide the desired method of preparing conductive mixtures that could be easily deposited on the support substrate surface such as a film, which then carries limitations, particularly in the case of requirements for the production of thin, highly conductive layers as a basis for the subsequent deposition of flexible electronic devices.

Therefore, the object of the invention is to provide such a hybrid composite for the preparation of thin conductive layers, a method of preparing thereof, and thin conductive layers prepared from this hybrid composite, which method of preparation would be inexpensive, wherein the hybrid composite would be recyclable, stable even in a humid environment, and, furthermore, easily deposited on the support substrate surface such as PET film. The hybrid composite prepared by such a method could be used to produce thin, highly conductive layers as a basis for the deposition of flexible electronic devices.

Summary of the invention

This object is achieved by development of a hybrid composite for the preparation of carbon nanomaterial thin films according to the present invention, which comprises a carbon nanomaterial and a conducting polymer based on poly(3,4-ethylenedioxythiophene). It is the subject matter of the invention that the carbon nanomaterial is at least one material selected from the group consisting of: single-walled carbon nanotubes, multi-walled carbon nanotubes, graphene particles, graphene oxide particles, nanographite particles, globular carbon nanoparticles. The use of these nanoparticles is preferable particularly because of their high strength and excellent electrical conductivity due to their large specific surface area. It allows the formation of a thin, highly conductive layer. The surface of the carbon nanomaterial is modified with a sulfonated polyaromatic compound based on pyrene, which forms strong ionic bonds with a conductive polymer based on poly (3,4-ethylenedioxothiophene) or PEDOT. The whole system is highly stable due to the formation of strong TT - TT stacking between the carbon nanomaterial and the sulfonated pyrene-based polyaromatic compound and at the same time strong ionic bonds between PEDOT and polyaromatic sulfonated compounds, which can only be broken by the action of strong alkalis or reducing agents. The conductivity of this array combines electron conductivity through electron holes and ionic conductivity. The hybrid composite is further in the form of a stable, electrically conductive film-forming dispersion, in which the weight ratio of the carbon nanomaterial to the sulfonated polyaromatic compound ranges from 1 :10 to 10:1 , and the weight ratio of the carbon nanomaterial surface-modified with the sulfonated polyaromatic compound to the conductive polymer poly(3,4- ethylenedioxythiophene) ranges from 1 :10 to 10:1. Such a weight ratio is preferable for formulating the film-forming matrix from the prepared hybrid composite. This ratio produces a stable dispersion in aqueous media suitable for preparing high conductivity thin films.

To describe the present invention, the term “stable dispersion” is understood to mean an electrically conductive dispersion, stability of which consists in the absence of agglomeration and/or settling of the particles contained in the dispersion. Without the addition of further additives, it is thus possible to prepare a stable electrically conductive dispersion having very good film-forming properties.

In a preferred embodiment, the sulfonated polyaromatic compound is formed on the surface of carbon nanomaterials during mixing in the presence of chlorosulfonic acid or sulfuric acid, and the polyaromatic compound is selected from the group: pyrene, 1 -pyrenemethylamine, 1 - acetylpyrene, 1 -methylpyrene, 1 -(bromoacetylpyrene), 1 -(bromomethyl)pyrene, 1 - bromopyrene, 1 -pyrenemethanol, 1 -aminopyrene, 1 -hydroxypyrene, 1 -pyrenebutyric acid, 1 - pyrenecarboxylic acid, 1 -pyrenesulfonic acid, benzo[a]pyrene, benzo[e]pyrene, 7- methylbenzo[a]pyrene, dibenzo[a,e]pyrene, dibenzo[a,h]pyrene, dibenzo[a,l]pyrene.

In a preferred embodiment, the hybrid composite is in the form of a stable aqueous dispersion having a dry solids content of the hybrid composite of from 0.1 to 3.0% by weight. Such a stable aqueous dispersion is also suitable for preparing very thin conductive films with a thickness of from 100 nm to 100 pm.

Further the object of the invention is a preparation method of the hybrid composite for preparing thin conductive layers. In this process, the carbon nanomaterials are firstly surface-modified in presence of sulfuric acid or chlorosulfonic acid with the addition of at least one pyrene-based polyaromatic compound. Subsequently, in the presence of the carbon nanomaterials modified in such a way, polymerization of 3,4-ethylenedioxythiophene is performed by oxidative action of ferric chloride and/or ferric sulfate and/or ferric tosylate and/or mixtures of ferric chloride hexahydrate and ammonium persulfate or sodium persulfate. It will cover the modified carbon nanomaterial with a PEDOT layer. Finally, an aqueous dispersion of a mixture of surface- modified carbon nanomaterials with a polyaromatic compound and a PEDOT conducting polymer in an aqueous medium is prepared.

In a preferred embodiment, the hybrid composite is applied on the supporting substrate using a coating method selected from the group consisting of: slot die, curtain coating, spiral bar coating, spray coating, dip coating, screen printing, gravure printing, flexographic printing, microdispensing, and aerosol jet printing. The use of these deposition techniques is preferable due to the possibility of preparing very thin layers or films having thicknesses of up to 100 pm.

Further the object of the invention is a thin conductive layer made by a method according to the present invention. The thin conductive layer has a conductivity of 500 to 2,000 S/cm and a thickness of 100 nm to 100 pm. The conductivity of this grouping combines electron conductivity through electron holes and ionic conductivity. In addition, the hybrid composite shows excellent film-forming properties so that the entire mixture can be well deposited on the pre-treated surface.

The advantage of the hybrid composite for preparing thin conductive layers and the thin conductive layers prepared from this hybrid composite according to the present invention is that the preparation method is inexpensive, the hybrid composite is recyclable and stable even in a humid environment. Another advantage of the hybrid composite for preparing thin conductive layers is that it can be easily deposited on the supporting substrate surface, such as PET film. Another advantage is that the hybrid composite prepared by such a method can be used to produce thin, highly conductive layers as a basis for the deposition of flexible electronic devices.

Examples of Invention Embodiments

Example 1 : Modification of SWCNT with pyrene at a weight ratio of 1 :5

1 g of SWCNT and 1 ,000 mL of concentrated sulfuric acid were placed in a 1.5L flask fitted with a mechanical stirrer. In another non-displayed exemplary embodiment, graphene particles, graphene oxide particles, globular carbon nanoparticles, multi-walled carbon nanotubes, or MWCNTs, nanographite particles were used. The mixture was stirred for 24 h at laboratory temperature. Then, 5 g of pyrene was added to the reaction mixture. In another non-displayed exemplary embodiment, 1 -acetylpyrene, 1 -methylpyrene, 1 -(bromoacetylpyrene), 1 -(bromomethyl)pyrene, 1 -bromopyrene, 1 -pyrenemethanol, 1 -aminopyrene, 1 -hydroxypyrene, 1 -pyrenebutyric acid, 1 -pyrenecarboxylic acid, 1 -pyrenesulfonic acid, benzo[a]pyrene, benzo[e]pyrene, 7-methylbenzo[a]pyrene, dibenzo[a,e]pyrene, dibenzo[a,h]pyrene, dibenzo[a,l]pyrene were used. The prepared hybrid composite in the form of a mixture was stirred for another 24 hours at laboratory temperature. After the prescribed time had elapsed, the mixture forming the hybrid composite was poured onto 5 kg of crushed ice and stirred for a further 24 hours. The resulting SWCNT dispersion was filtered and washed with distilled water up to the neutral pH of the filtrate. The filtered sulfonated pyrene modified SWCNTs were transferred as a thick paste into a vial, and the dry matter weight was determined.

Example 2: Modification of DWCNT with 1 -pyrenemethylamine at a weight ratio of 1 :1

1 g of double-walled carbon nanotubes, or DWCNT, 1 g of 1 -pyrenemethylamine and 1 ,000 mL of concentrated sulfuric acid were placed in a 1.5L flask fitted with a mechanical stirrer. In another non-displayed exemplary embodiment, graphene particles, graphene oxide particles, globular carbon nanoparticles, MWCNT, SWCNT, nanographite particles were used. In another non-displayed exemplary embodiment, pyrene, 1 -acetylpyrene, 1 -methylpyrene, 1 -(bromoacetylpyrene), 1 -(bromomethyl)pyrene, 1 -bromopyrene, 1 -pyrenemethanol, 1 -aminopyrene, 1 -hydroxypyrene, 1 -pyrenebutyric acid, 1 -pyrenecarboxylic acid, 1 -pyrenesulfonic acid, benzo[a]pyrene, benzo[e]pyrene, 7-methylbenzo[a]pyrene, dibenzo[a,e]pyrene, dibenzo[a,h]pyrene, dibenzo[a,l]pyrene were used. The reaction mixture was stirred for 24 hours at laboratory temperature. Then, 100 ml of chlorosulfonic acid was added to the reaction mixture. The reaction mixture was stirred for a further 24 hours at laboratory temperature. After the prescribed time had elapsed, the mixture forming the hybrid composite was poured onto 7.5 kg of crushed ice and stirred for 24 hours. The mixture was then filtered and washed with distilled water up to the neutral pH of the filtrate. The filtered sulfonated 1 -pyrenemethylamine modified DWCNTs were transferred as a thick paste into a vial, and the dry matter weight was determined. Example 3: Modification of MWCNT with pyrene at a weight ratio of 1 :10

1 g of MWCNT, 10 g of pyrene, 500 mL of chlorosulfonic acid and 500 mL sulfuric acid were placed in a 1.5L flask fitted with a mechanical stirrer. In another non-displayed exemplary embodiment, graphene particles, graphene oxide particles, globular carbon nanoparticles, SWCNT, nanographite particles were used. In another non-displayed exemplary embodiment, 1 -acetylpyrene, 1 -methylpyrene, 1 -(bromoacetylpyrene), 1 -(bromomethyl)pyrene, 1 -bromopyrene, 1 -pyrenemethanol, 1 -aminopyrene, 1 -hydroxypyrene, 1 -pyrenebutyric acid, 1 -pyrenecarboxylic acid, 1 -pyrenesulfonic acid, benzo[a]pyrene, benzo[e]pyrene, 7-methylbenzo[a]pyrene, dibenzo[a,e]pyrene, dibenzo[a,h]pyrene, dibenzo[a,l]pyrene were used. The reaction mixture was stirred for 48 hours at laboratory temperature. After the prescribed time had elapsed, the mixture forming the hybrid composite was poured onto 10 kg of crushed ice and stirred for 24 hours. The resulting MWCNT dispersion was filtered and washed with distilled water up to the neutral pH of the filtrate. The filtered sulfonated pyrene modified MWCNTs were transferred as a thick paste into a vial, and the dry matter weight was determined.

Example 4: Modification of graphite with 1 -pyrenemethylamine at a weight ratio of 10:1

1 g of nanographite particles and 1 ,000 mL of chlorosulfonic acid were placed in a 1 .5L flask fitted with a mechanical stirrer. In another non-displayed exemplary embodiment, graphene particles, graphene oxide particles, globular carbon nanoparticles, MWCNT, SWCNT were used. The mixture was stirred for 24 hours at 80°C. After the prescribed time had elapsed, the mixture was cooled to laboratory temperature and 0.1 g of 1 -pyrenemethylamine was added. In another non-displayed exemplary embodiment, pyrene, 1 -acetylpyrene, 1 -methylpyrene, 1 - (bromoacetylpyrene), 1 -(bromomethyl)pyrene, 1 -bromopyrene, 1 -pyrenemethanol, 1 - aminopyrene, 1 -hydroxypyrene, 1 -pyrenebutyric acid, 1 -pyrenecarboxylic acid, 1 - pyrenesulfonic acid, benzo[a]pyrene, benzo[e]pyrene, 7-methylbenzo[a]pyrene, dibenzo[a,e]pyrene, dibenzo[a,h]pyrene, dibenzo[a,l]pyrene were used. The mixture was stirred for 24 hours at laboratory temperature. Then, the mixture forming the hybrid composite was poured onto 8.5 kg of crushed ice and stirred for further 24 hours. The resulting graphite dispersion was then filtered and washed with distilled water up to the neutral pH of the filtrate. Sulfonated 1 -pyrenemethylamine modified graphite was transferred as a thick paste into a vial, and the dry matter weight was determined. Example 5: Polymerization of PEDOT on modified SWCNT prepared according to Example 1 at a weight ratio of 1 :10

1 ,000 mL of distilled water and 1 g of modified SWCNTs prepared according to Example 1 were placed into a 1 .5L flask fitted with a mechanical stirrer. The flask was placed in an ultrasonic bath and sonicated at laboratory temperature for 12 hours while stirring. Then, 0.1 g of 3,4-ethylenedithiothiophene, or EDOT, and 1 g of anhydrous ferric tosylate were dispensed to the flask. In another example not displayed, ferric sulfate was used. The reaction mixture was polymerized for 24 hours at laboratory temperature while stirring and sonicating. After the prescribed time had elapsed, the product was filtered and washed with distilled water up to the neutral pH of the filtrate. The product was transferred as a thick paste into a vial, and the dry matter weight was determined.

Example 6: Polymerization of PEDOT on modified DWCNT prepared according to Example 2 at a weight ratio of 1 :1

500 mL of distilled water and 1 g of modified DWCNTs prepared according to Example 2 were placed into a 1.5L flask fitted with a mechanical stirrer. The flask content was stirred for 12 hours using ultraturrax dispersing instrument. Then, 4 g of ferric chloride hexahydrate was dispensed to the reaction mixture and 1 g of EDOT was added by drops over 24 hours. The hybrid composite was polymerized for 48 hours at 5°C. After polymerization, the product was filtered and washed with distilled water up to the neutral pH of the filtrate. The washed product was dried in a vacuum oven at 80°C and transferred into a vial.

Example 7: Polymerization of PEDOT on modified MWCNT prepared according to Example 3 at a weight ratio of 10:1

1 ,000 mL of distilled water and 1 g of modified MWCNTs prepared according to Example 3 were placed into a 1 .5L flask fitted with a mechanical stirrer. The mixture was sonicated for 24 hours at 5°C. Then, 17 g of ammonium persulfate and 10 g of EDOT were added to the reaction mixture. The mixture was polymerized for 24 hours at 45°C while mixing simultaneously using a mechanical stirrer and ultraturrax dispersing instrument. After reaction time had elapsed, the product was filtered and washed with distilled water up to the neutral pH of the filtrate. The washed product was dried in a lyophilizer and transferred to a vial. Example 8: Polymerization of PEDOT on modified graphite prepared according to Example 4 at a weight ratio of 5:1

1 ,000 mL of distilled water and 1 g of modified graphite prepared according to Example 4 were placed into a 1 .5L flask fitted with a mechanical stirrer. The mixture was stirred for 24 hours using ultraturrax dispersing instrument. Then 10 g of sodium persulfate and 0.2 g of ferric chloride hexahydrate were added to the reaction mixture. In another non-displayed exemplary embodiment, a mixture of ammonium persulfate and ferric chloride hexahydrate was used. The mixture was sonicated for 12 hours and, then, 5 g of EDOT was added to the reaction mixture. The reaction mixture was polymerized for 48 hours at 10°C. After reaction time had elapsed, the product was filtered and washed with distilled water up to the neutral pH of the filtrate. The washed product was dried in an oven at 130°C.

Example 9: Preparation of aqueous dispersion

The product prepared according to Example 5 was dispersed in 500 mL of distilled water for 12 hours using the ultraturrax. Then, the dispersion was cooled to 5°C and sonicated for 24 hours, while mixing simultaneously using the ultraturrax. After the prescribed time had elapsed, the dry matter weight of the prepared dispersion was determined.

Example 10: Preparation of self-supporting conductive film by drying

The dispersion prepared according to Example 9, containing 200 mg of modified SWCNTs was poured into a petri dish of 20 cm in diameter. The petri dish was placed in a drying oven and dried at 130°C to a constant weight. After drying, the prepared self-supporting film was peeled off the petri dish. The thickness of the prepared film was measured to be 50 pm, and the electrical resistance was determined to be 0.04 Q. From these data, the conductivity was calculated to be 1 ,100 S/cm. In another exemplary embodiment not shown, the thickness of the thin conductive layer was from 100 nm to 100 pm. In another exemplary embodiment not shown, the thin conductive layers exhibited conductivities from 500 to 2,000 S/cm. Example 11 : Preparation of self-supporting conductive film by filtration

The dispersion prepared according to Example 9, containing 200 mg of modified SWCNTs was poured into a filter bed of 20 cm in diameter. After the distilled water was drawn off, the cake of the filter bed was purged with air for 2 hours. The filter bed and the cake were then placed in a drying oven and dried at 130°C to a constant weight. After drying, the filter cake was peeled off the filter bed. The thickness thereof was measured to be 38 pm, and the electrical resistance was determined to be 0.04 Q. From these data, the conductivity was calculated to be 1 ,450 S/cm. In another exemplary embodiment not shown, the thickness of the thin conductive layer was from 100 nm to 100 pm. In another exemplary embodiment not shown, the thin conductive layers exhibited conductivities from 500 to 2,000 S/cm.

Example 12: Preparation of the printing formulation for screen printing I

An ion pair dispersion of poly(3,4-ethylenedithiothiophene) and polystyrene sulfonate, or PEDOT :PSS, with a dry matter content of 3% by weight was used for the printing formulation. In another exemplary embodiment not shown, a dry matter concentration of 0.1 to 3% by weight was used. An aqueous dispersion of the modified SWCNTs of Example 9 in an amount of 14% by weight was added to the above mixture. A bifunctional 30% glycol and a polyether- based surfactant in an amount of 0.5% by weight were also added to the formulation. The printing formulation was then properly homogenized. The printing formulation was used for printing by screen printing technique on the PET substrate. In another exemplary embodiment not shown, a coating method selected from the group consisting of slot die, curtain coating, spiral bar coating, spray coating, dip coating, gravure printing, flexographic printing, microdispensing, aerosol jet printing was used. A stencil with 120 fib./cm mesh was used for printing. After printing, the thin conductive layers were dried for 15 minutes at 120°C. The given thin conductive layer exhibited an area resistance of 550 Q/square at a thickness of 320 nm. In another exemplary embodiment not shown, the thickness of the thin conductive layer was from 100 nm to 100 pm. In another exemplary embodiment not shown, the thin conductive layers exhibited conductivities from 500 to 2,000 S/cm. Example 13: Preparation of the printing formulation for screen printing II

A base polymer solution based on carboxymethylcellulose, or CMC, at a concentration of 2% by weight was used for the printing formulation. An aqueous dispersion of the modified SWCNTs of Example 9 in an amount of 20% by weight was added to the above mixture. In addition, 15% glycol, 10% glycolether and a surfactant based on polyethersiloxane in an amount of 0.25% by weight were added to the said formulation. The printing formulation was then properly homogenized. The printing formulation was used for printing by screen printing technique on the PET substrate. In another exemplary embodiment not shown, a coating method selected from the group consisting of slot die, curtain coating, spiral bar coating, spray coating, dip coating, gravure printing, flexographic printing, microdispensing, aerosol jet printing was used. A stencil with 120 fib./cm mesh was used for printing. After printing, the thin conductive layers were dried for 15 minutes at 120°C. The given thin conductive layer exhibited an area resistance of 430 Q/square at a thickness of 220 nm. In another exemplary embodiment not shown, the thickness of the thin conductive layer was from 100 nm to 100 pm. In another exemplary embodiment not shown, the thin conductive layers exhibited conductivities from 500 to 2,000 S/cm.

Example 14: Preparation of the printing formulation for screen printing III

A base polymer solution based on CMC at a concentration of 1% by weight was used for the printing formulation. An aqueous dispersion of the modified SWCNTs of Example 9 in an amount of 25% by weight was added to the above mixture. 1 % acrylate dispersion, 20% glycol, 10% monofunctional alcohol and a surfactant based on alkoxylated alcohol in the amount of 0.15% by weight were added to the formulation. The printing formulation was then properly homogenized. The printing formulation was used for printing by screen printing technique on the PET substrate. In another exemplary embodiment not shown, a coating method selected from the group consisting of slot die, curtain coating, spiral bar coating, spray coating, dip coating, gravure printing, flexographic printing, microdispensing, aerosol jet printing was used. A stencil with 120 fib./cm mesh was used for printing. After printing, the thin conductive layers were dried for 15 minutes at 120°C. The given thin conductive layer exhibited an area resistance of 400 Q/square at a thickness of 190 nm. In another exemplary embodiment not shown, the thickness of the thin conductive layer was from 100 nm to 100 pm. In another exemplary embodiment not shown, the thin conductive layers exhibited conductivities from 500 to 2,000 S/cm.

Example 15: Preparation of the printing formulation for coating I

An ion pair dispersion of poly(3,4-ethylenedithiothiophene) and polystyrene sulfonate, or PEDOT :PSS, with a dry matter content of 3% by weight was used for the printing formulation. In another exemplary embodiment not shown, a dry matter concentration of 0.1 to 3% by weight was used. An aqueous dispersion of the modified SWCNTs of Example 9 in an amount of 14% by weight was added to the above mixture. A monofunctional 40% glycol and a polyether-based surfactant in an amount of 0.5% by weight were also added to the formulation. A thin conductive layer was stretched with a Bird ruler with a 150-pm slit on the PET substrate. In another exemplary embodiment not shown, a coating method selected from the group consisting of slot die, curtain coating, spiral bar coating, spray coating, dip coating, gravure printing, flexographic printing, microdispensing, aerosol jet printing was used. After coating, the thin conductive layers were dried for 15 minutes at 120°C. The given thin conductive layer exhibited an area resistance of 35 Q/square, at a thickness of 3 pm. In another exemplary embodiment not shown, the thickness of the thin conductive layer was from 100 nm to 100 pm. In another exemplary embodiment not shown, the thin conductive layers exhibited conductivities from 500 to 2,000 S/cm.

Example 16: Preparation of the printing formulation for coating II

An ion pair dispersion of poly(3,4-ethylenedithiothiophene) and polystyrene sulfonate, or PEDOT :PSS, with a dry matter content of 3% by weight was used for the printing formulation. In another exemplary embodiment not shown, a dry matter concentration of 0.1 to 3% by weight was used. An aqueous dispersion of the modified SWCNTs of Example 9 in an amount of 14% by weight was added to the above mixture. A monofunctional 40% glycol and a polyether-based surfactant in an amount of 0.5% by weight were also added to the formulation. A micrometer stretching ruler with a 1 ,5-mm slit was used to apply the coating to a paper substrate deposited in the R2R mode. After coating, the thin conductive layers were dried in a tunnel for 15 minutes in at 120°C. In another exemplary embodiment not shown, a coating method selected from the group consisting of slot die, curtain coating, spiral bar coating, spray coating, dip coating, gravure printing, flexographic printing, microdispensing, aerosol jet printing was used. The given thin conductive layer exhibited an area resistance of 3 Q/square at a thickness of thin conductive layer of 32 pm. In another exemplary embodiment not shown, the thickness of the thin conductive layer was from 100 nm to 100 pm. In another exemplary embodiment not shown, the thin conductive layers exhibited conductivities from 500 to 2,000 S/cm.

Industrial Applicability

The hybrid composite for preparing thin conductive layers, the method of preparing thereof, and the thin conductive layer prepared from the hybrid composite according to the present invention can be used to prepare a transparent thin conductive layer on a flexible or rigid substrate using printing and deposition techniques. The thin conductive layer prepared by such a method can be used as a component of electronic devices.