KR20120031765A - Phase change material nanocapsule immobilized metal nanoparticles inside and outside, and method for preparing the same by using one-step process - Google Patents

Abstract

PURPOSE: A nano composite capsule is provided to improve heat transmission because metal particles are fixed to the inside/outside of the nano capsule through single process polymerizing by adding the metal particles during the nano capsulation of a phase transition material. CONSTITUTION: A nano composite capsule comprises nano capsule in which a polymer shell surrounds a phase transition material. And metal particles are fixed to inside/outside the nano capsule. The polymer shell is one or more selected from a group consisting of polyurethane, polyester, polyamide, a melamine resin, a urea resin, gelatine, and cellulose. A manufacturing method of the nano complex capsule comprises a step of polymerizing by mixing a phase transition material, an emulsion containing monomers and the metal particles, and a chain extender.

Description

Phase change material nanocapsule immobilized metal nanoparticles inside and outside, and method for preparing the same by using one-step process}

The present invention relates to a phase-transfer nanocomposite capsule in which metal particles are fixed inside and outside of a capsule through a single process and a method of manufacturing the same. More specifically, the present invention relates to a single polymerized polymer addition process during the nanoencapsulation process of a phase-transfer material. Regarding the phase-transfer nanocomposite capsules in which metal particles are fixed inside and outside of the capsule through a single process to fix the metal particles inside and outside the nanocapsules through a process to further improve heat transfer ability, and a method of manufacturing the same will be.

A method of encapsulating core-shell structure using a phase-transfer material is disclosed in Korean Patent No. 284,192, which has a spherical diameter of 0.1 to 10 mm, a polymer coating layer of 2.5 to 50 μm, and a micro capsule of 0.1 to 10 mm in diameter. The heat storage capsule is disclosed, but it is not suitable for mass production because it requires a coolant such as liquid nitrogen and drops the inorganic hydrate in a molten state during the manufacturing process. In addition, in order to solidify the molten inorganic hydrate, there is a disadvantage in that the size of the container containing the refrigerant must be long because the drop path must be long.

In addition, a latent heat storage material obtained by microencapsulating a heat storage material by interfacial polymerization of a polymer using wax as a PCM is disclosed in US Patent No. 4,513,053. The latent heat storage material is prepared by forming a heat storage material in a pill shape having a curved edge. The encapsulation of the inorganic salt hydrate and mechanical strength have been improved by encapsulating it with various kinds of polymer materials. However, the surface area per unit volume is small compared to the spherical encapsulation, so that the thermal response is poor and the manufacturing cost is high.

In addition, Korean Patent Publication No. 2003-0018155 discloses a microencapsulation method of a phase change material using an emulsion method, the formation and stabilization of smooth microparticles using a surfactant, and a step 1 microencapsulation step of a phase change material using a co-surfactant. And a two-step process consisting of a two-step microencapsulation process using a tangential spray coater (tangential spray coater) through a more inconvenient process than the one-step process, less efficient in the manufacturing process, and also the size of the capsule produced Since 10 ~ 100㎛, the size was insufficient to increase the structural stability by distributing the force by reducing the size.

Therefore, in order to strengthen the durability of the core-shell capsule made of a phase-transfer material, a material having a strong strength forms a polymer shell, or a capsule size is made in nanometer size to use pressure dispersibility to improve pressure. In order to withstand the need, a method of constructing a polymer shell made of a material having a high strength may be inconvenient in the manufacturing process, and if the strength is high due to the characteristics of a general material, it may interfere with heat transfer of the phase change material in the polymer shell. In addition, it is necessary to further increase the heat transfer rate between the phase change material and the outside. In order to overcome this problem, studies have been conducted to increase the heat transfer rate through the introduction of metal particles with high thermal conductivity, but there is a lack in sensitively controlling the rate of change of phase due to the fixing of metal particles only in the polymer shell. . In addition, there is a manufacturing inconvenience due to the multi-step process in the production of nanocomposite capsules.

An object of the present invention is to introduce the metal particles in order to increase the thermal conductivity of the nanocapsule enclosing the phase-transfer material, the inside of the nanocapsules prepared through a one-step process of introducing the metal particles during nanoencapsulation of the phase-transfer material The present invention provides a phase-transfer nanocomposite capsule in which metal particles are fixed to the outside, and a method of manufacturing the same.

In order to achieve the above object, the present invention

Nanocapsules surrounding the phase change material by the polymer shell; And

Provided are nanocomposite capsules comprising metal particles fixed to the inside and outside of the nanocapsules.

The present invention also provides a method for producing a nanocomposite capsule, which comprises a step of polymerizing a mixture containing an emulsion containing a phase change material, a polymer monomer and metal particles and a chain extender.

The present invention also provides a product comprising any one of a heat storage material, a solar material, an automotive part, or a fiber material comprising the nanocomposite capsule of the present invention.

In the present invention, when introducing the metal particles to increase the thermal conductivity of the nanocapsule surrounded by the polymer shell in the phase-transfer material, the metal inside and outside the nanocapsule through a one-step process of introducing the metal particles during nanoencapsulation of the phase-transfer material Since the particles are fixed, there is an effect of eliminating the inconvenience of the manufacturing process due to the existing multi-step process and shortening the manufacturing time.

In addition, the nanocomposite capsule of the present invention has the effect of improving the heat transfer capacity is fixed to the metal particles inside and outside the capsule.

1 is a SEM photograph of a nanocomposite capsule in which metal particles are fixed inside and outside of a capsule manufactured through a single process of the present invention.
2 is a TEM photograph of nanocomposite capsules in which metal particles are fixed inside and outside of a capsule manufactured through a single process of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention is demonstrated concretely.

The present invention

Nanocapsules surrounding the phase change material by the polymer shell; And

The present invention relates to a nanocomposite capsule including metal particles fixed inside and outside of the nanocapsules.

In the present specification, "phase change material" refers to a material that can be used for the purpose of storing energy or maintaining a constant temperature by using the latent heat absorption and release effect of "latent heat storage material", or " Phase change material. The "latent heat" refers to heat that absorbs or releases heat when a substance phase changes. The latent heat is much larger than heat absorbed or released according to a temperature change without phase transition.

The phase change material constituting the core portion of the nanocomposite capsule of the present invention is not particularly limited, but more specifically, it is preferable to use a material that becomes phase change at room temperature.

The "substance which is phase-changed at room temperature" refers to the phase-transfer substance defined above which is phase-changed at a normal room temperature range including, for example, the body temperature, for example, 20 to 40 ° C. For example, tetradecane, eicosane, Octadecane, hexadecane, propionamide, naphthalene, acetamide, stearic acid, polyglycol, wax, palmitic acid, myristic acid, lignocerate, camphor, 3-heptananecanone, polyethylene glycol, tetradecane, cyanamide , Lauric acid, carpolone, trimyriline, hexadecanone, capric acid, caprylic acid, polyglycol and the like can be used alone or in combination.

In addition, the polymer shell is not particularly limited as long as it is a polymer that can provide excellent mechanical strength of the nanocapsules. For example, polyurethane, polyester, polyamide, melamine resin, urea resin, gelatin, or cellulose may be used alone. Or two or more kinds thereof.

The metal particles serve to increase the heat transfer rate of the phase change material and the external environment of the nanocomposite capsule of the present invention, and the heat transfer is particularly limited as long as the material can be completely fixed by interaction with the polymer shell forming the outer wall. For example, gold, silver, copper, iron, alloys thereof, or the like can be used.

More specifically, in the case where the polymer shell has (+) charges, the metal shell exhibits the (-) charge, and in the case where the polymer shell has the (-) charge, the polymer shell has the positive (+) charge. It is good.

The nano-composite capsule of the core-shell structure may have a diameter of 50 to 1000 nm. More specifically, it may be 100 to 600 nm.

Nanocomposite capsule of the present invention is fixed to the metal particles inside and outside, it is possible to further improve the heat transfer rate due to the temperature difference between the phase change material and the external environment. Accordingly, the nanocomposite capsule may have a value of 80 to 150 J / g in the differential scanning calorie curve.

The present invention also relates to a method for preparing nanocomposite capsules comprising a step of polymerizing a mixture containing an emulsion containing a phase change material, a polymer monomer and metal particles and a chain extender.

The present invention relates to a method for preparing a phase-transfer nanocomposite capsule having a core-shell structure in which metal particles are fixed inside and outside of a capsule, and wherein metal particles are introduced during the nanoencapsulation process of the phase change material, thereby introducing metal particles into and out of the capsule. Since the nanocomposite capsule is manufactured through a one-step process of fixing, the manufacturing process is simple, the manufacturing time is shortened, and metal particles are fixed inside and outside of the capsule, thereby improving the heat storage capacity of the capsule. .

The emulsion may be prepared by mixing a phase change material, a polymer monomer, and metal particles.

More specifically, the emulsion

Homogenizing the solution containing the phase change material and the polymer monomer to nanometer size; And

It is preferable to include the step of forcibly emulsifying the homogenization solution, the emulsifier and the metal particles.

The phase change material is tetradecane, eicosane, octadecane, hexadecane, propionamide, naphthalene, acetamide, stearic acid, polyglycol, wax, palmitic acid, myristic acid, lignocerate, campene, 3-heptane Canon, polyethylene glycol, tetradecane, cyanamide, lauric acid, carpolone, trimyriline, hexadecanone, capric acid, caprylic acid, or polyglycol may be used alone or in combination of two or more thereof. There is no restriction in particular.

The polymer monomer for forming the polymer shell may be used without limitation as long as it is a monomer capable of causing a polymerization reaction, more specifically, a condensation polymerization when preparing a capsule of the core-shell structure by a polymerization reaction in a subsequent step, but more preferably 2 Compounds containing at least two isocyanate groups are preferred.

Compounds containing two or more isocyanate groups include tolylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, or octamethylene diisocyanate, or the like. Two or more kinds can be used.

The phase change material and the polymer monomer may be mixed in a weight ratio of 5: 1 to 1: 1. If within the content range, the physical strength of the polymer shell can be produced firmly.

The physically crushed to the nanometer size to homogenize step is to crush the droplets to nanometer size using a physical device such as a homogenizer (Homogenizer), if the separation method commonly used in the art for this purpose Anything may be used.

The homogenization may be carried out by stirring for 5 to 30 minutes at 5000 to 20,000 rpm, but is not particularly limited thereto.

The emulsion may be prepared by mixing a mixed solution of a phase change material and a polymer monomer crushed to a nanometer size and a dispersion solution of an emulsifier and a polymer.

The emulsifier can be polymerized with the monomer, emulsifies the phase change material to produce stable droplets of small size, and can be used for chemical bonding of the polymer monomer to the reactor for the polymerization reaction.

The emulsifier can be used without limitation so long as it is a reactor having a reactive property with a reactor of a polymer monomer, preferably a compound having a hydroxyl group. For example, a polystyrene sulfonic acid-maleic acid copolymer (Poly (styrene sulfonic acid-co-maleic acid)), or a styrene-maleic anhydride copolymer (styrene-maleic anhydride copolymer) may be used alone or in combination of two or more.

The emulsifier is preferably included in 0.2 to 1 parts by weight based on 100 parts by weight of the emulsion. This is because the dispersion stability of the prepared nanocomposite capsule is the highest when it is within the content range.

In addition, the metal particles may be used without limitation as long as the metal particles have good heat transfer and can be completely fixed by interaction with the polymer shell forming the outer wall. For example, gold, silver, copper, iron particles, or the like can be used. More specifically, when the polymer shell exhibits (+) charges, metal particles with (-) charges are used, and when the polymer shell exhibits (-) charges, metal particles with (+) charges are used. Good to do.

The metal particles may be prepared using a conventional metal nanoparticle manufacturing method, and are not particularly limited.

According to one embodiment of the present invention, the metal particles may be prepared by mixing silver nitrate and sodium citrate in an aqueous solution and stirring for 20 minutes to 2 hours at a temperature of 60 to 90 ℃ nanometer size silver particles.

The metal particles may be included in an amount of 0.01 to 1 part by weight based on 100 parts by weight of the emulsion. It is because heat transfer efficiency is the largest when it is in the said content range.

The emulsion is mixed with a chain extender and condensation polymerization (condensation polymerization) at 60 to 80 ℃ for 3 to 12 hours through the condensation polymerization (condensation polymerization) nano structure of the metal particles fixed inside and outside of the nanocapsule surrounding the polymer shell surrounding the phase transition material Complex capsules can be prepared.

The chain extender may use a compound containing two or more amine groups at its terminals.

Compounds containing two or more amine groups at the terminal may be ethyldiamine, propanediamine, hexanediamine, phenylenediamine, or polyoxyethylene bis-amine. These may be used alone or in combination of two or more.

The chain extender may be included in an amount of 1 to 10 parts by weight based on 100 parts by weight of the emulsion. This is because the physical strength of the polymer shell is maintained within the content range.

In addition, in the method of manufacturing a nanocomposite capsule of the present invention, the process of centrifugally separating the unreacted metal particles not fixed to the inside and outside of the capsule can be further carried out.

The centrifugation is preferably performed for 5 to 10 minutes at 500 to 2000 rpm. If it is less than 500 rpm, it is difficult to separate the metal particles which are not fixed inside and outside of the capsule in the form of pellets. If it exceeds 2000 rpm, the nanocapsules also sink together to separate the metal particles not fixed inside and outside of the capsule. Difficult to separate

The present invention also relates to a product comprising any one of a heat storage material, a solar material, an automobile part, or a fiber material comprising the nanocomposite capsule of the present invention.

The nanocomposite capsule of the present invention has a structure in which metal particles are fixed inside and outside the phase-transfer nanocapsule, and the phase change material and the external environment of the core part compared to the capsule using the phase change material in which the metal particles are fixed only to the outside of the conventional capsule. It is possible to further improve the heat transfer rate due to the temperature difference. Accordingly, the nanocomposite capsule may have a value of 80 to 150 J / g in the differential scanning calorie curve. Therefore, the nanocomposite capsules can be applied to heat storage materials, solar materials, automobile parts, etc., and can be used for biomedical applications such as drug carriers and functional garments because they can absorb, release and store thermal energy at room temperature. Characterized in that it can.

Hereinafter, the present invention will be described in more detail with reference to Examples of the present invention, but the scope of the present invention is not limited by the following Examples.

Example 1 Preparation of Nanocomposite Capsules Using a Single Process

3 g of tolylene diisocyanate [Sigma-Aldrich, USA], which can be polymerized into a capsule membrane material by condensation polymerization, and 9 g of octadecane [Sigma-Aldrich, USA], which is a phase change material as a capsule core material. , 5% of acetone [Duksan Co., Ltd. Korea] was added to 80 g of water, and then agitated at 8000 rpm for about 10 minutes using a homogenizer [T25 basic ULTRA-TURAX, IKA, Germany] to prepare a first solution. It was.

Then, the forced emulsification in a solution in which 0.6 g of polystyrene sulfonic acid-co-maleic acid (Poly) (Sigma-Aldrich, USA) and 0.025 g of silver nanoparticles prepared were dispersed in 60 g of water. The prepared first solution was mixed at 600 rpm to prepare a second solution.

The manufacturing method of the silver nanoparticles is as follows. A solution of 0.3 g of silver nitrate [Sigma-Aldrich, USA] dissolved in 10 g of water, and a solution of 0.1 g of sodium citrate [Sigma-Aldrich, USA] dissolved in 10 g of water, stirred at 70 ° C. for about 1 hour, was about 5 nm in size. The negatively charged silver particles were prepared.

A solution of a polystyrene sulfonic acid-maleic acid (Poly (styrene sulfonic acid-co-maleic acid)) 0.005g, 5g ethyldiamine [Junsei Chemical, Japan] and 5g water was slowly mixed into the second solution. Then, the mixture was reacted at 60 ° C. at 600 rpm for 4 hours to prepare core-shell phase-transfer nanocomposite capsules in which silver particles were fixed inside and outside the capsule (FIGS. 1 and 2).

After preparing nanocomposite capsules, unreacted metal particles, which were not immobilized inside and outside the capsules, were separated through a centrifuge [Hanil Science Industry, MF80] at 1200 rpm for 5 minutes.

DSC was used to evaluate the heat storage capacity of the resulting solid-state nanocomposite capsules. As a result, a value of 86.91 J / g was obtained.

Claims (16)

Nanocapsules surrounding the phase change material by the polymer shell; And
Nanocomposite capsules comprising metal particles fixed to the inside and outside of the nanocapsules.
The method of claim 1,
Phase transfer materials include tetradecane, eicosane, octadecane, hexadecane, propionamide, naphthalene, acetamide, stearic acid, polyglycol, wax, palmitic acid, myristic acid, lignocerate, camphor, 3-heptananecanone Nanocomposite capsules, one or more selected from the group consisting of polyethylene glycol, tetradecane, cyanamide, lauric acid, carpolone, trimyriline, hexadecanone, capric acid, caprylic acid and polyglycol.
The method of claim 1,
The polymer shell is at least one nanocomposite capsule selected from the group consisting of polyurethane, polyester, polyamide, melamine resin, urea resin, gelatin and cellulose.
The method of claim 1,
The metal particles are nanocomposite capsules that are nanoparticles made of gold, silver, copper, iron, or alloys thereof.
The method of claim 1,
Nanocomposite capsules having a diameter of 50 to 1000 nm.
The method of claim 1,
Nanocomposite capsules having a value of 80 to 150 J / g in a differential scanning calorie curve.
A method for preparing a nanocomposite capsule, comprising the step of polymerizing a mixture containing an emulsion containing a phase change material, a polymer monomer and metal particles and a chain extender.
The method of claim 7, wherein
Phase transition material and polymer monomer is a method for producing a nanocomposite capsules are mixed in a weight ratio of 5: 1 to 1: 1.
The method of claim 7, wherein
Polymer monomer is a method for producing a nanocomposite capsule is a compound containing two or more isocyanate groups.
10. The method of claim 9,
The compound containing two or more isocyanate groups is one selected from the group consisting of toylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate and octamethylene diisocyanate Nanocomposite capsules manufacturing method as described above.
The method of claim 7, wherein
Metal particles is a method for producing a nanocomposite capsule containing 0.01 to 1 part by weight with respect to 100 parts by weight of the emulsion.
The method of claim 7, wherein
Chain extender is a method for producing a nanocomposite capsule is a compound containing two or more amine groups at the terminal.
The method of claim 12,
Compounds containing at least two amine groups at the terminal are composed of ethyldiamine, propanediamine, hexanediamine, phenylenediamine and polyoxyethylene bis-amine. Method for producing a nanocomposite capsule is one or more selected from the group.
The method of claim 7, wherein
Chain extender is a method for producing a nanocomposite capsule containing 1 to 10 parts by weight with respect to 100 parts by weight of the emulsion.
The method of claim 7, wherein
Polymerization is a method of producing a nanocomposite capsule is a condensation polymerization (condensation polymerization) for 3 to 12 hours at 60 to 80 ℃ mixed solution.
A product comprising any one of a heat storage material, a solar material, an automotive part, or a fiber material comprising the nanocomposite capsule of claim 1.

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