DE102005035374A1 - Nano hollow capsules - Google Patents

Abstract

Hollow nanocapsules are described which can be obtained by mixing microemulsions, mixed with block copolymers and modified with polymers, and subsequent processing of the hollow nanocapsules formed.

Description

The The invention relates to nano hollow capsules, a process for their preparation as well as uses of the nano hollow capsules.

task The present invention is the production of smallest possible cavities, in the substrates are stored and used as reactor space for nanoparticle formation can serve.

nanoparticles have special properties. The special properties Nanoparticles are achieved, inter alia, by comparing the surface area to the volume is very large. By the size surface can e.g. very good catalytic and optoelectronic properties be achieved. Another property of nanoparticles is that they work well in other materials or composite materials such as paints, Emulsions, films and membranes can be installed.

The Object of the present invention is by nano hollow capsules obtainable by Mixing microemulsions with block copolymers and polymers (e.g., polyelectrolytes) and subsequent work-up solved the formed nano hollow capsules.

Nano hollow capsules are able to store substances. Thus it is possible nano hollow capsules e.g. to use for wastewater treatment. In the wastewater store the Nanohohlkapseln metals in their interior and deprive them so the sewage.

The Nanohohlkapseln preferably have a diameter of 5 nm 1000 nm.

This has the advantage that the nano-hollow capsules are smaller than microcapsules, as in various fields of medicine, pharmacy, in the Food industry and many other areas. As a result, they are for many new applications suitable for the microcapsules not suitable are because they are too big.

The Microemulsion is preferably water, long chain alcohols (e.g., heptanol) and / or an oil component (e.g., toluene) as well as surfactants (e.g., sodium dodecyl sulfate (SDS)).

The Polymers are preferably water-soluble polyelectrolytes and / or oil-soluble polymers.

In a preferred embodiment According to the invention, the polyelectrolytes are water-soluble selected ionic polymers. The polyelectrolytes contribute to the stabilization of the nano-hollow capsules or control the formation of nanoparticles inside the hollow capsules.

The Polyelectrolytes are preferably anionic polyacids, cationic Polybases or neutral polyampholytes or polysalts selected. When Polyelectrolytes become water-soluble ionic Polymers anionically derived from polyacids (e.g., polycarboxylic acids), cationic formed from polybases (e.g., polyvinylamines) or are neutral (Polyampholytes or polysalts).

The Block copolymers preferably consist of at least two or three Blocks. Good results are achieved with the addition of block copolymers scored from three blocks consist.

One Part of the block copolymer is polymerizable.

Preferably show the blocks the block copolymers have different properties, wherein the Properties selected are selected from the group of hydrophilic, polymerizable and / or hydrophobic Properties.

For example, the triblock copolymer SBEO is suitable for the preparation of the nano-hollow capsules. This is a copolymer which is composed of a styrene, a butadiene and an ethylene oxide block and is referred to as S ₄₃ B ₂₁ EO ₃₆ . It has an average molecular weight of about 110,000 g / mol. Due to its structure, the copolymer should be arranged in a W / O microemulsion so that the hydrophobic block in the oil phase and the hydrophilic ethylene oxide block penetrate into the aqueous phase. The Butadienblock then arranges in the region of the interface between water droplets and oil phase. Such a structure opens up the possibility of initializing additional crosslinking via the double bonds of the butadiene block. This leads to a spatial limitation of the water droplet and the particle formation occurring therein.

Prefers are the nano hollow capsules by crosslinking the polymerizable blocks enveloping the block copolymer networked. The block copolymers penetrate with their hydrophilic or hydrophobic block the microemulsion droplets. Due to the fact that the block copolymers additionally have a polymerizable Block is the formation of a covalently sealable polymer layer around the droplet or the nanoparticles formed therein.

In a preferred embodiment of Invention, the nano hollow capsules are pre-filled. By pre-filling the nano hollow capsules, nanoparticles can be formed when mixing two microemulsions, which can be used in a variety of ways.

So Is it possible to pre-fill the nano hollow capsule with various substances and thus To obtain nanoparticles that have a wide variety of properties exhibit.

The nano-hollow capsules are preferably prefilled with metal salts, metal halides, reducing agents, pharmacologically active substances, magnetically and / or optically active reagents or polymers. As magnetic substances, for example, magnetite (Fe ₃ O ₄ ) or ferrites such as CoFe ₂ O ₄ can be used.

In order to this pre-filling is achieved contains the Microemulsion preferably metal salts and / or reducing agents, the then as a precursor for the structure of the pre-filled Serve nano hollow capsule.

Further The object of the present invention is achieved by a method for the production of nano hollow capsules in which, at least two Microemulsions mixed with each other, which one with block copolymers and modified polymers and then the resulting nano hollow capsules worked up.

The stability the shell and the size of the particles can by the concentrations of the individual reaction components and the reaction conditions are controlled. The resulting particles with polymer surface can from the solvent mixture free and in other solvents - a suitable solvent is water - redispersed become.

The covalent cladding The nano hollow capsules offer the advantage that in all subsequent reaction steps changes chemical or physical nature are minimized.

moreover allows the use of the block copolymers it, the surface of the Modify nanoparticles.

Prefers you add inverse microemulsions of water, an oil component, long-chain alcohols and / or surfactants too. As the oil component, e.g. Xylene, toluene, isooctane, heptanol, cyclohexane, hexadecane and / or n-octane can be used.

you adds preference as polymers water-soluble Polyelectrolytes for W / O microemulsions and oil-soluble polymers for O / W microemulsions at. Here, water is the outer and oil is the inner phase, is one O / W emulsion whose basic character is characterized by water. Is oil the outer and Water the inner phase, there is a W / O emulsion before, here the basic character of the oil is determined.

Further prefers adds as polyelectrolytes water-soluble ionic polymers too. By the addition of polyelectrolytes can the stability the nano hollow capsules are controlled.

Preferably you add as polymers anionic from polyacids (e.g., polycarboxylic acids), cationic from polybases (e.g., polyvinylamines) or neutral polyampholytes or polysalts too.

you adds as Polymer preferably oil-soluble polymers and / or oil-in-water Microemulsions too.

Further you add preferably as an oil-in-water Microemulsions electron acceptor and electron donor polymers to.

In a preferred embodiment the invention adds one block polymers of at least two blocks, the blocks have different properties and the properties of the blocks from the group of hydrophilic, hydrophobic or polymerizable properties.

By The choice of block copolymers allows the size of the nano-hollow capsules Taxes. The bigger the Block copolymers, the larger the nano hollow capsules.

The polymerizable blocks The block copolymer is preferably crosslinked, so that the nano hollow capsules polymerumhüllt are. The polymerization can be carried out via the addition of a radical initiator, e.g. of azoisobutyronitrile (AIBN) thermally or else radiation-initiated respectively.

In a preferred embodiment The invention relates to the nano-hollow capsules with pharmacologically active Prefilled substances, magnetically or optically active substances.

It is possible, the nano hollow capsules already during to prefill their education. For this purpose, the desired substances are added to the microemulsion, then as a precursor for the formation of the nano hollow capsules serve.

Prefers mixed metal salts, metal halides and / or the microemulsion Reducing agent at.

In a preferred embodiment of Invention filled in a further step, the nano hollow capsules.

Preferably, the nano hollow capsules are filled with metals, metal halides, metal oxides, metal salts, pharmacologically active substances, magnetic, optical or radioactive substances, color pigments or contrast agents. The pre-filling of the nano-hollow capsules yields nanoparticles with a wide variety of properties. Magnetic nanoparticles can be produced, for example, by prefilling with magnetite Fe ₃ O ₄ or ferrite such as Co-Fe ₂ O ₄ . Optoelectronically interesting nanoparticles can be pre-filled with CdS, CdSe and / or ZnS, for example. Catalytically interesting nanoparticles are, for example, nano hollow capsules prefilled with gold (Au), platinum (Pt) and / or palladium (Pd). In addition, it is possible to produce core-shell particles.

Furthermore, the object of the present invention is achieved by using nano-hollow capsules, for the transport of pharmacologically active substances into the human or animal body. In addition to the transport of pharmacologically active substances, it is also possible to transport other substances (eg metals, metal halides, metal oxides, metal salts, magnetic, optical and / or radioactive substances, X-ray contrast media, eg BaSO ₄ ) into the human or animal body using the nano-hollow capsules ,

Farther The object of the present invention is achieved by the use of nano hollow capsules for the manufacture of medicines for the transport of pharmacologically active substances in human and animal body solved.

Of the Interior of the nano hollow capsules allows pharmacologically effective Absorb substances and thus in the human or animal body contribute. This can cause a delayed release of active ingredients in the body be achieved.

It is also a use of the nano hollow capsules to protect against a Ambient environment, as taste / odor masking, for long-term stabilization, controlled release, dosage and mixing, prevention of contamination and / or to reduce allergenic effects possible.

Farther The object of the present invention is achieved by use pre-filled nano hollow capsules, solved as nanoparticles. It is not only possible to fill the nano-hollow capsules after their production, but also to carry out a pre-filling of the nano hollow capsules immediately during production. On In this way, nanoparticles are obtained which have a polymer coating.

Of Furthermore, the object of the present invention by a Use of pre-filled Nanohohlkapseln, solved for the coating of surfaces.

A another solution The present invention is the use of pre-filled nano hollow capsules for incorporation in polymer membranes.

Possible applications The nano hollow capsules are the textile industry, paint and varnish industry (Flakes, pigments, antifoulings), construction industry (heat storage, Pest control), printing and paper industry, electroplating (installation of, for example, corrosion protection and skimmers) or in the plastics industry.

in the The invention will be described in more detail below with reference to figures and examples. In detail shows

1a a nano hollow capsule consisting of surfactant molecules and diblock copolymers,

1b a nano hollow capsule consisting of surfactant molecules and triblock copolymers,

1c the construction of a triblock copolymer,

2 the particle size distribution according to Example 1,

3 the particle size distribution according to Example 2,

3 the particle size distribution according to Example 3,

4 the particle size distribution according to Example 4,

5 the particle size distribution according to Example 6 and

6 the particle size distribution according to Example 7.

The 1a shows a section through a nano hollow capsule 1 consisting of surfactant molecules 2 and diblock copolymers. The nanoclip 1 is through a scaffold of surfactant molecules 2 educated. Between the surfactant molecules 2 are block copolymers 3 stored in the scaffolding. The block copolymers 3 consist of a hydrophilic part 3a and a hydrophobic part 3b , where the block copolymers 3 are arranged so that they are with the hydrophilic part 3a in the interior 4 the nano hollow capsules 1 rich and with the outer, hydrophobic part 3b the outer layer of the nano hollow capsules 1 form.

The 1b shows an analogous scheme for a triblock copolymer 5 the middle block 3c is polymerizable.

The 1c shows an example of the construction of a triblock polymer 5 consisting of a hydrophilic part 3a , a hydrophobic part 3b and a polymerizable part 3c ,

The 2 to 6 show diagrams of the dynamic light scattering analysis results on the Nano Zetasizer (Malvern Instruments ^® ) for Examples 1 to 4, 6 and 7. In the diagrams, the size of the particles in nm is plotted in relation to the intensity in percent.

2 shows the particle size distribution that was measured in the preparation of nano hollow capsules according to Example 1. The mean particle diameter (Z-average) is 225 nm.

3 shows the particle size distribution according to Example 2. The mean particle diameter (Z-average) is 119 nm here.

4 shows the particle size distribution according to Example 3. The mean particle diameter (Z-average) is here at 224 nm.

5 shows the particle size distribution according to Example 4. The mean particle diameter (Z-average) is 213 nm here.

6 shows the particle size distribution according to Example 6. The average particle diameter (Z-average) is here at 214 nm.

7 shows the particle size distribution according to Example 7. The mean particle diameter (Z-average) is here at 689 nm.

Example 1 (preparation and characterization of nano hollow capsules):

to Preparation of the nano hollow capsules were triblock copolymers consisting from a styrene (S), a butadiene (B) and an ethylene oxide block in xylene / pentanol (1: 1), sodium dodecyl sulfate (SDS) and water. The resulting slightly opaque solutions were then by means of Light scattering characterized.

Composition of the mixture:

• ⇨ 1 g of water;
• 1 g SDS
• 7.92 g of xylene, pentanol (1: 1)
• 0.08 g of block copolymer S ₁₄ B ₄₆ EO ₄₀

The analysis of the dynamic light scattering Zetasizer Nano on (Malvern Instruments ^®) resulted in a mean particle diameter of 225 nm (see 2 ).

Example 2 (preparation and characterization of nano hollow capsules):

to Preparation of the nano hollow capsules were triblock copolymers consisting from a styrene (S), a butadiene (B) and an ethylene oxide block in xylene / pentanol (1: 1), sodium dodecyl sulfate (SDS) and water. The resulting slightly opaque solutions were then by means of Light scattering characterized.

Composition of the mixture:

• ⇨ 1 g of water;
• 1 g SDS
• 7.92 g of xylene, pentanol (1: 1)
• 0.08 g of block copolymer S ₁₈ B ₃₆ EO ₄₆

The analysis of the dynamic light scattering Zetasizer Nano on (Malvern Instruments ^®) gave a mean particle diameter of 119 nm (see 3 ).

Example 3 (with barium sulfate filled Nano hollow capsules):

Two nanosound capsule mixtures were each prefilled with a 2 mmol BaCl ₂ solution or with a 2 mmol Na ₂ SO ₄ solution. After addition of adequate amounts of both mixtures (2 ml each), scattered light photometric investigations were carried out on the barium sulphate-containing nano-hollow capsules:

Composition of the mixture 1:

• ⇨ 1 g (2 mmol) BaCl ₂ solution;
• 1 g SDS
• 7.92 g of xylene, pentanol (1: 1)
• 0.08 g of block copolymer S ₁₄ B ₄₆ EO ₄₀

Composition of the mixture 2:

• ⇨ 1 g (2 mmol) of Na ₂ SO ₄ solution;
• 1 g SDS
• 7.92 g of xylene, pentanol (1: 1)
• 0.08 g of block copolymer S ₁₄ B ₄₆ EO ₄₀

The analysis of the dynamic light scattering Zetasizer Nano on (Malvern Instruments ^®) gave a mean particle diameter of 224 nm (see 4 ).

Example 4 (crosslinking of barium sulfate filled nano hollow capsules):

In the presence of a crosslinker (azoisobutyronitrile (AIBN)), in analogy to Example 3, two nanosound capsule mixtures were each prefilled with BaCl ₂ or Na ₂ SO ₄ . After addition of adequate amounts of both mixtures (2 ml each) and nanoparticle formation, the mixture was heated to 60 ° C to initiate radical crosslinking of the butadiene blocks of the block copolymer. Following crosslinking, scattered-light photometric investigations were again carried out:

Composition of AIBN-containing Mixture 1:

• ⇨ 1 g (2 mmol) BaCl ₂ solution;
• 1 g SDS
• 7.92 g of xylene, pentanol (1: 1) (0.03% AIBN)
• 0.08 g of block copolymer S ₁₄ B ₄₆ EO ₄₀

Composition of AIBN-containing Mix 2:

• ⇨ 1 g (2 mmol) of Na ₂ SO ₄ solution;
• 1 g SDS
• 7.92 g of xylene, pentanol (1: 1) (0.03% AIBN)
• 0.08 g of block copolymer S ₁₄ B ₄₆ EO ₄₀

The analysis of the dynamic light scattering Zetasizer Nano on (Malvern Instruments ^®) resulted in a mean particle diameter of 213 nm (see 5 ).

Example 5 (Gold filled nano capsules):

Two nano-capsule mixtures were each prefilled with a 2 mmol HAuCl ₄ solution or with a 40 mmol NaBH ₄ solution. After combining both mixtures in a ratio of 1: 2, scattered light photometric investigations were carried out on the gold-containing nano-hollow capsules:

Composition of the mixture 1:

• ⇨ 1 g (2 mmol) HAuCl ₄ solution;
• 1 g SDS
• 7.92 g of xylene, pentanol (1: 1)
• 0.08 g of block copolymer S ₄₃ B ₂₁ EO ₃₆

Composition of the mixture 2:

• ⇨ 1 g (40 mmol) of NaBH ₄ solution;
• 1 g SDS
• 7.92 g of xylene, pentanol (1: 1)
• 0.08 g of block copolymer S ₄₃ B ₂₁ EO ₃₆

The analysis of the dynamic light scattering Zetasizer Nano on (Malvern Instruments ^®) gave a mean particle diameter of 336 nm.

Example 6 (crosslinking of gold filled Nano hollow capsules):

In the presence of a crosslinker (azoisobutyronitrile (AIBN)), in analogy to Example 5, two nanosound capsule mixtures were each prefilled with a 2 mmol HAuCl ₄ solution or with a 40 mmol NaBH ₄ solution. After combining both mixtures in a 1: 2 ratio and nanoparticle formation, the mixture was heated to 60 ° C to initiate radical crosslinking of the butadiene blocks of the block copolymer. Following crosslinking, scattered-light photometric investigations were again carried out:

Composition of AIBN-containing Mixture 1:

• ⇨ 1 g (2 mmol) HAuCl ₄ solution;
• 1 g SDS
• 7.92 g of xylene, pentanol (1: 1) (0.03% AIBN)
• 0.08 g of block copolymer S ₄₃ B ₂₁ EO ₃₆

Composition of AIBN-containing Mix 2:

• ⇨ 1 g (40 mmol) of NaBH ₄ solution;
• 1 g SDS
• 7.92 g of xylene, pentanol (1: 1) (0.03% AIBN)
• 0.08 g of block copolymer S ₄₃ B ₂₁ EO ₃₆

The analysis of the dynamic light scattering Zetasizer Nano on (Malvern Instruments ^®) resulted in a mean particle diameter of 214 nm (see 6 ).

Example 7 (redispersion of gold filled nano capsules):

The resulting mixture from Example 6 was in a vacuum oven at a temperature of 35 ° C Dried for 2 days. The residue was redispersed in toluene and then scattered light photometrically examined.

The analysis of the dynamic light scattering Zetasizer Nano on (Malvern Instruments ^®) gave a mean particle diameter (z-average) of 689 nm (see 7 ).

Claims (30)

Nano hollow capsules obtainable by mixing Microemulsions modified with block copolymers and polymers are and subsequent Work-up of the formed nano-hollow capsules. Nanohohlkapseln according to claim 1, characterized characterized in that the nano hollow capsules have a diameter of 5 nm to 1000 nm. Nanohohlkapseln according to one of claims 1 or 2, characterized in that the microemulsion of water, long-chain Alcohols and / or an oil component and surfactants. Nanohohlkapseln according to one of claims 1 to 3, characterized in that the polymers are water-soluble polyelectrolytes and / or oil-soluble polymers are. Nanocarbon capsules according to claim 4, characterized in that that the polyelectrolytes of water-soluble ionic polymers selected are. Nanohohlkapseln according to claim 4 or 5, characterized that the polyelectrolytes from anionic polyacids, cationic polybases or neutral polyampholytes or polysalts are selected. Nanohohlkapseln according to one of claims 1 to 6, characterized in that the block copolymers of at least two blocks consist. Nanohohlkapseln according to claim 7, characterized in that that the blocks the block copolymers hydrophilic, polymerizable and / or hydrophobic Have properties. Nanohohlkapseln according to one of claims 1 to 8, characterized in that by crosslinking the polymerizable blocks the block copolymers are networked enveloping the nano hollow capsules. Nanohohlkapseln according to one of claims 1 to 9, characterized in that the nano hollow capsules are pre-filled. Nanohohlkapseln according to claim 10, characterized in that that the nano hollow capsules with metal salts, metal halides, reducing agents, pharmacological active substances, magnetically and / or optically active reagents or polymers prefilled are. Nanohohlkapseln according to claim 10 or 11, characterized in that the microemulsion comprises metal salts and / or reducing agents contains. Process for the preparation of nano hollow capsules, according to one of the preceding claims, characterized marked that at least two microemulsions are mixed together, which are modified with block copolymers and polymers and then the processed nano hollow capsules worked up. Method according to claim 13, characterized in that that inverse microemulsions of water, an oil component and / or long-chain alcohols and surfactants. Method according to claim 13 or 14, characterized that as polymers water-soluble Polyelectrolytes for W / O microemulsions and oil-soluble polymers for O / W microemulsions. Method according to claim 15, characterized in that that is added as polyelectrolytes water-soluble ionic polymers. Method according to claim 15, characterized in that that as polymers anionic from polyacids, cationic from polybases or neutral polyampholytes or polysalts. Method according to claim 13, characterized in that that as polymers oil-soluble polymers and / or oil-in-water Microemulsions inflicts. Method according to claim 18, characterized that as an oil-in-water Microemulsions electron acceptor and electron-donor polymers. Method according to one of claims 13 to 19, characterized adding block polymers of at least two blocks, the blocks being hydrophilic, have hydrophobic and / or polymerizable properties. Method according to one of claims 13 to 20, characterized that the polymerizable blocks of the block copolymers are crosslinked, so that the nano hollow capsules are wrapped in polymer. Method according to one of claims 13 to 21, characterized that the nano-hollow capsules with pharmacologically active substances, prefilled with magnetically or optically active substances. Method according to one of claims 13 to 22, characterized that the microemulsion metal salts, metal halides and / or Reducing agent admixed. Method according to one of claims 13 to 23, characterized that you fill in a further step, the nano hollow capsules. A method according to claim 24, characterized in that nano hollow capsules with metal len, metal halides, metal oxides, metal salts, pharmacologically active substances, magnetic, optical or radioactive substances, color pigments or contrast agents filled. Use of nano hollow capsules, according to one of claims 1 to 12, for the transport of pharmacologically active substances in the human or animal body. Use of nano hollow capsules, according to one of claims 1 to 12, for the production of pharmaceuticals for the transport of pharmacological effective substances in the human and animal body. Use of pre-filled nano hollow capsules, after one of the claims 1 to 12, as nanoparticles. Use of pre-filled nano hollow capsules, after one of the claims 1 to 12, for coating surfaces. Use of pre-filled nano hollow capsules, after one of the claims 1 to 12, for incorporation in polymer membranes.