CN109776843B - Double-ligand Janus nanoparticle and preparation method and application thereof - Google Patents
Double-ligand Janus nanoparticle and preparation method and application thereof Download PDFInfo
- Publication number
- CN109776843B CN109776843B CN201910067210.5A CN201910067210A CN109776843B CN 109776843 B CN109776843 B CN 109776843B CN 201910067210 A CN201910067210 A CN 201910067210A CN 109776843 B CN109776843 B CN 109776843B
- Authority
- CN
- China
- Prior art keywords
- polymer
- ligand
- nanoparticles
- etching
- nanoparticle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Graft Or Block Polymers (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
Abstract
The invention discloses a dual-ligand Janus nanoparticle and a preparation method and application thereof, belonging to the field of polymers and inorganic nanocomposite materials. Firstly, preparing a single-layer film by self-assembly of inorganic nanoparticles modified by a first polymer, then etching, removing part of the first polymer, and then grafting a second polymer to the exposed part of the surface of the nanoparticles to obtain the Janus structure nanoparticles. The two different polymers on the surface of the Janus structure nanoparticle are respectively grafted in a first area and a second area, and the first area and the second area are respectively one area and are not crossed with each other; the first region and the second region constitute the entire surface of the inorganic nanoparticles. The preparation method of the invention has simple operation and can control the proportion of two polymer ligands on the surface of the nanoparticle. The Janus structure nano particle can be used for preparing solid surfactants, emulsifiers, hydrophilic-hydrophobic conversion materials, asymmetric catalysts, drug targeting carriers or optical biosensors.
Description
Technical Field
The invention belongs to the field of polymers and inorganic nano composite materials, and particularly relates to a dual-ligand Janus nano particle and a preparation method and application thereof.
Background
Janus nanoparticles refer to a type of non-centrosymmetric heterojunction nanoparticles, which have two clearly separated sides, and the components of the two sides have obvious difference in chemical or physical properties. Janus nano particles can be divided into dumbbell type, snowman type, semi-basin type, rubber type, double-ligand particles and the like according to the shapes of the Janus nano particles. Wherein, two sides of the double-ligand Janus nano particle are respectively modified with different types of ligands. Compared with common Janus nanoparticles, the nanoparticles not only have the properties of the nanoparticles and two ligands, but also have wider application value due to the asymmetry caused by the Janus structure. According to the physicochemical property of the ligand, the ligand can be used for solid surface active agents, hydrophilic-hydrophobic conversion materials, catalysts, optical biosensors and the like.
At present, the research on the preparation technology of dual-ligand Janus nanoparticles is less, and the reported methods are as follows: the reaction between the special functional group on the surface of the polymer monocrystal substrate and the nano-particles is utilized to induce the nano-particles to deposit on the surface of the substrate, then the other surface is grafted with a second ligand, and finally the double-ligand Janus nano-particles (J.Am.chem.Soc.2008,130,11594) are obtained after the polymer monocrystal is disassembled and assembled. Or a special phase structure is formed by utilizing the self-assembly of the triblock copolymer, then metal salt or a precursor is added, the metal salt or the precursor is subjected to complexation with the midblock and then reduced to form the nano particle, and then the assembly is disassembled and assembled to obtain the Janus nano particle (J.Am.chem.Soc.2012,134, 13850). The preparation process of the method is complicated, and the proportion of the two ligands is difficult to effectively control, which affects the large-scale production and the practical application of the dual-ligand Janus nano-particles. The preparation method in the prior art has the disadvantages of complicated process, difficult effective control of ligand proportion and low grafting density of Janus structure nano particles prepared by the method.
Disclosure of Invention
The invention solves the technical problems that the ligand proportion of the Janus structure nano particles prepared in the prior art is difficult to effectively control, the preparation process is complicated, and the grafting density of the prepared Janus structure nano particles is low.
According to the first aspect of the invention, a method for preparing dual-ligand Janus structure nanoparticles by etching re-modification is provided, which comprises the following steps:
(1) grafting and modifying the inorganic nanoparticles by a first polymer terminated by a functional group through a ligand exchange method, and dispersing in a solvent to obtain a dispersion liquid of the first polymer grafted inorganic nanoparticles;
(2) self-assembling the dispersion liquid obtained in the step (1) by using an oil-water interface assembly method, an L B film assembly method, a solvent volatilization assembly method or a pulling assembly method to prepare a first polymer grafted inorganic nanoparticle single-layer film, and transferring the single-layer film to the surface of a substrate;
(3) etching the single-layer film to remove the first polymer on the surface of each first polymer grafted inorganic nano particle on the single-layer film in a partial area, wherein the partial area is any area on the surface of each first polymer grafted inorganic nano particle; soaking the substrate in a second polymer terminated by functional groups after etching, and modifying the second polymer to the exposed part on the surface of each inorganic nanoparticle through a ligand exchange method, wherein the exposed part is the etched part of the first polymer; the repeating structural units of the first polymer and the second polymer are different; and soaking the single-layer film in a solvent for dispersion, and disassembling the single-layer film to form single dispersed dual-ligand Janus structure nanoparticles.
Preferably, the etching of step (3) is plasma etching.
Preferably, the etching power in the step (3) is 1W-20W, and the etching time in the step (3) is 1s-10 min.
Preferably, the solvent in step (1) and step (3) is, independently, chloroform, toluene, benzene, ethyl acetate, acetone, tetrahydrofuran, N-dimethylformamide, dioxane, dichloromethane ethanol, methanol, propanol or water.
Preferably, the inorganic nanoparticles of step (1) are quantum dots, inorganic metal nanoparticles or metal oxide nanoparticles; the diameter of the inorganic nano particles is 3.5nm-100 nm;
preferably, the inorganic metal nanoparticles are gold nanoparticles or silver nanoparticles, the metal oxide nanoparticles are ferroferric oxide nanoparticles, and the quantum dots are cadmium selenide quantum dots or zinc sulfide quantum dots.
Preferably, the functional groups in step (1) and step (3) are groups containing sulfhydryl, disulfide, thioester, carboxyl or amino groups, respectively.
Preferably, the dispersion of step (3) is ultrasonic dispersion or stirring dispersion.
Preferably, the first polymer and the second polymer are oil-soluble polymers with different repeating structural units, or the first polymer and the second polymer are water-soluble polymers with different repeating structural units, or one of the first polymer and the second polymer is an oil-soluble polymer and the other is a water-soluble polymer;
the oil-soluble polymer is polystyrene, polyethylene, polymethyl methacrylate or poly (4-vinylpyridine), and the water-soluble polymer is polyethylene oxide, polyacrylic acid or poly (N-isopropylacrylamide).
According to another aspect of the invention, the dual-ligand Janus structure nanoparticle prepared by any one of the methods is provided, wherein the dual-ligand Janus structure nanoparticle is an inorganic nanoparticle with two different polymers grafted on the surface, and the two different polymers are connected with the inorganic nanoparticle through a covalent bond; the two different polymers are respectively grafted on a first region and a second region on the surface of the inorganic nano particle to form a dual-ligand Janus structure; the first area and the second area are respectively one area and are not intersected with each other; the first and second regions constitute the entire surface of the inorganic nanoparticles; the diameter of the dual-ligand Janus structure nano particle is 3.5nm-100 nm.
According to another aspect of the invention, the application of the dual-ligand Janus structure nano-particle in preparing a solid surfactant, an emulsifier, a hydrophilic-hydrophobic switching material, an asymmetric catalyst, a drug targeting carrier or an optical biosensor is provided.
In general, the above technical solutions contemplated by the present invention can achieve the following advantageous effects compared to the prior art.
(1) The invention provides a dual-ligand Janus structure nano particle prepared by an etching re-modification technology. The method comprises the steps of preparing a single-layer film by using nanoparticles modified by polymer ligands through a self-assembly technology, removing the polymer ligands of partial areas on the surface of the nanoparticles by using an etching method, wherein the partial areas are areas, grafting second polymer ligands to exposed positions on the surface of the nanoparticles, and finally adding a solvent to disassemble and assemble the single-layer film, thereby obtaining the nanoparticles with the dual-ligand Janus structure. Two sides of the obtained Janus structure nano particle are respectively modified with different polymer ligands. The etching is preferably plasma etching, the proportion of two polymer ligands on the surfaces of the nanoparticles can be controlled by controlling the plasma etching time and power, the preparation method disclosed by the invention is short in time, simple to operate, strong in repeatability and convenient for large-scale preparation, and the technical problems that the existing method for preparing double-ligand Janus nanoparticles is complex in process, the proportion of the ligands is difficult to effectively regulate and control and the like are solved.
(2) The invention preferably uses a plasma etching method to prepare the dual-ligand Janus structure nano-particles, can be suitable for various polymer ligands, and can be used for preparing not only amphiphilic Janus structure nano-particles but also dual-hydrophilic ligand or dual-hydrophobic ligand Janus structure nano-particles.
(3) According to the invention, the dual-ligand Janus structure nano-particle is preferably prepared by using a plasma etching method, and the etching degree of the upper surface of the nano-particle can be controlled by controlling parameters such as etching time, etching power and the like, so that the grafting proportion of two ligands on the surface of the Janus structure nano-particle is controlled.
(4) The double-ligand Janus structure nano particle provided by the invention has the properties of the nano particle and two ligands, has special performance brought by the Janus structure, and has wider application value. According to the physicochemical property of the ligand, the ligand can be used for preparing solid surfactants, emulsifiers, hydrophilic-hydrophobic conversion materials, catalysts, drug targeting carriers, optical biosensors and the like.
(5) Compared with the same type of nano particles prepared in the prior art, the nano particles modified by the polymer ligand are used for preparing a single-layer film by a self-assembly technology, then the polymer ligand in partial areas on the surface of the nano particles is removed by using an etching method, a second polymer ligand is grafted to the exposed parts on the surface of the nano particles, and the second ligand can completely cover the exposed parts, so that the grafting density of the ligand on the surface of the nano particles is improved.
Drawings
FIG. 1 is a schematic diagram of a process for preparing a dual-ligand Janus structure nanoparticle by etching and modifying according to the invention.
FIG. 2a is a schematic diagram of the complexation process of the polystyrene and poly (4-vinylpyridine) dual-ligand Janus structure gold nanoparticles obtained in example 1 with cadmium selenide quantum dots; FIG. 2b is a transmission electron microscope picture of polystyrene and poly (4-vinylpyridine) dual-ligand Janus structure gold nanoparticles obtained in example 1 complexed with cadmium selenide quantum dots.
Fig. 3a, fig. 3b and fig. 3c are schematic diagrams of the process of controlling the grafting ratio of two ligands on the surface of the nanoparticles with Janus structure by controlling different etching powers in example 1, example 2 and example 3, respectively, and transmission electron microscope pictures.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
The invention provides a plasma etching re-modification technical method for preparing dual-ligand Janus nano particles, which comprises the following steps:
(1) preparation of dispersion solution of polymer grafted inorganic nanoparticles: grafting modification is carried out on the surface of the inorganic nanoparticles by using a first polymer terminated by a functional group through a ligand exchange method, and then the inorganic nanoparticles are dispersed in a good solvent to obtain a dispersion solution of the first polymer grafted inorganic nanoparticles; the inorganic nanoparticles comprise gold, silver and ferric oxide nanoparticles and one of quantum dots such as cadmium selenide and zinc sulfide, and the diameter of the inorganic nanoparticles is 3.5-100 nm; the first polymer is selected from at least one of polystyrene, polyethylene, polymethyl methacrylate, poly (4-vinylpyridine), polyethylene oxide, polyacrylic acid and poly (N-isopropylacrylamide); the functional group of the polymer end capping is sulfydryl (-SH), disulfide bond (-S-S-), sulfatide (-CO-S-), carboxyl (-COOH) or amino (-NH)2) A group of (a); the molecular weight of the first polymer is 500-100,000 g/mol; the good solvent is selected from chloroform, toluene, benzene, acetic acidEthyl ester, acetone, tetrahydrofuran, N-dimethylformamide, dioxane, dichloromethane, ethanol, methanol, propanol or water can effectively prevent the polymer grafted nanoparticles from agglomerating. The nanoparticles are prepared or purchased according to current state-of-the-art methods.
The ligand exchange method is a process of replacing original weak ligands on the surfaces of the nanoparticles by ligands (small molecular compounds, polymers, DNA chains and the like) which have strong interaction with the surfaces of the nanoparticles under the action of ultrasonic or mechanical stirring. The preparation method comprises the following steps: dissolving 3mg of the first polymer end-capped with functional groups in a solvent; under the ultrasonic condition, dropwise adding the inorganic nanoparticle solution into the first polymer solution, continuously carrying out ultrasonic treatment for 30 minutes, and standing for 1 hour; the ungrafted free first polymer and displaced weak ligand are removed by centrifugation.
(2) Preparing a first polymer grafted inorganic nanoparticle single-layer film by using the first polymer grafted inorganic nanoparticle dispersion solution in the step (1) through a self-assembly technology, and transferring the first polymer grafted inorganic nanoparticle single-layer film to the surface of a substrate, wherein the self-assembly technology is L B film technology, a solvent volatilization method, a pulling method or an oil-water interface rapid assembly method.
(3) Etching and modifying the first polymer grafted inorganic nano particle single-layer film: the surface etching is carried out on the first polymer grafted inorganic nanoparticle single-layer film, the polymer part on the surface of each nanoparticle is removed, the surface part is exposed, after the etching is finished, the substrate is soaked in another polymer solution with a terminal end of a functional group, another polymer is modified to the surface of the exposed nanoparticle through a ligand exchange method, the single-layer film is soaked in a good solvent for ultrasonic treatment, and the single-layer film is disassembled to form the double-ligand Janus structure nanoparticle. The etching is preferably plasma etching, the exciting gas used by the plasma etching is at least one of air, argon, helium and nitrogen, the plasma etching time is 1 second to 10 minutes, and the used etching power range is 1W to 20W; the second polymer ligand is selected from polystyrene and polyethyleneOne of alkene, polymethyl methacrylate, poly (4-vinylpyridine), polyethylene oxide, polyacrylic acid and poly (N-isopropyl acrylamide), wherein the second polymer is different from the first polymer, and the molecular weight of the second polymer is 500-100,000 g/mol; the functional group of the end capping of the second polymer ligand is a group containing sulfydryl (-SH), disulfide bond (-S-S-), thioester (-CO-S-), carboxyl (-COOH), amino (-NH)2) The molecular weight of the second polymer is 500-100,000 g/mol; the good solvent is at least one selected from chloroform, toluene, benzene, ethyl acetate, acetone, tetrahydrofuran, N-dimethylformamide, dioxane, dichloromethane ethanol, methanol, propanol and water.
The dual-ligand Janus structure nano particle provided by the invention comprises a nano particle and two kinds of ligand polymers, wherein the dual-ligand Janus structure nano particle is an inorganic nano particle with two different polymers grafted on the surface, and the two different polymers are connected with the inorganic nano particle through covalent bonds; the two different polymers are respectively grafted on a first region and a second region on the surface of the inorganic nano particle to form a dual-ligand Janus structure; the first area and the second area are respectively one area and are not intersected with each other; the first and second regions constitute the entire surface of the inorganic nanoparticles; the diameter of the dual-ligand Janus structure nano particle is 3.5nm-100 nm. The nano particle is one of gold, silver and ferric oxide nano particles and quantum dots such as cadmium selenide, zinc sulfide and the like. The double-ligand Janus structure nano particle can be applied to preparation of solid surfactants, emulsifiers, hydrophilic-hydrophobic conversion materials, asymmetric catalysts, drug targeting carriers or optical biosensors.
The invention can prepare double-ligand Janus structure nano particles, a polymer grafted nano particle single-layer film is prepared by the self-assembly method in the step (2), and the time and the power of plasma etching in the step (3) are controlled according to the parameters of the molecular weight, the chemical property and the like of the first polymer ligand in the step (1), so that part of the first polymer on the upper surface of the nano particles is etched and removed, the upper surface of the nano particles is exposed, the steric hindrance encountered in the modification process of the second polymer is greatly reduced, and the second polymer is grafted on the exposed surface conveniently. And (3) completely etching and removing the polymer ligand on the surface of the nanoparticle in the step (1) due to too large etching degree, or not removing the polymer ligand on the upper surface of the nanoparticle in the step (1) due to too small etching degree, so that the double-ligand Janus structure nanoparticle cannot be obtained.
The double-ligand Janus structure nano particle can be successfully prepared according to the method, the operation is simple, the repeatability is strong, the method is suitable for nano particles with different sizes and different materials and different polymer ligands, the proportion of the two polymer ligands on the surface of the nano particle can be controlled by controlling the plasma etching time and power, and the large-scale preparation is facilitated.
Example 1
A dual-ligand Janus structure nanoparticle is prepared according to the following method:
(1) preparation of dispersion solution of polymer-grafted nanoparticles: using polystyrene with mercapto-terminated molecular weight of 20,000g/mol, the surface of gold nanoparticles with diameter of 20nm was grafted by ligand exchange method and then dispersed in tetrahydrofuran.
(2) Preparation of polymer grafted nanoparticle monolayer film: the polymer grafted nano particle single-layer film is prepared by an oil-water interface rapid assembly method by using the polymer grafted nano particles and is transferred to the surface of a substrate.
(3) Etching and modifying the polymer grafted nano particle single-layer film: using a plasma cleaning machine, taking argon as plasma excitation gas, carrying out surface etching on the polymer grafted nanoparticle single-layer film to remove the polymer on the upper surface of the nanoparticle, exposing the upper surface, wherein the etching time is 5 minutes, the etching power is 10.5W, and after the etching is finished, soaking the substrate in a poly (4-vinylpyridine) solution with the molecular weight of 100,000g/mol and containing a mercapto group, so that the polymer is modified to the exposed upper surface of the nanoparticle through a ligand exchange method; and soaking the single-layer film in chloroform for ultrasonic treatment, and disassembling the single-layer film to form the gold nanoparticles with the polystyrene-poly (4-vinylpyridine) double-ligand Janus structure. FIG. 2 is a schematic diagram of the process of complexing gold nanoparticles with CdSe quantum dots by using a dual ligand Janus structure of polystyrene and poly (4-vinylpyridine) obtained in example 1 (FIG. 2a) and a transmission electron microscope picture (FIG. 2 b). FIG. 3b is a schematic diagram of a process of complexing gold nanoparticles with cadmium selenide quantum dots, wherein the gold nanoparticles are obtained in example 1 and are double ligands of polystyrene and poly (4-vinylpyridine), and a transmission electron microscope picture. Because the cadmium selenide quantum dots can generate coordination with N atoms in the poly (4-vinylpyridine), the cadmium selenide can be seen to be only distributed on one side of the gold nanoparticles after complexation, which indicates that the obtained nanoparticles are of Janus structures, namely, polystyrene ligands and poly (4-vinylpyridine) ligands are respectively grafted on two sides of the nanoparticles. The grafting density of the ligands was 1.3 per square nanometer.
Example 2
A dual-ligand Janus structure nanoparticle is prepared according to the following method:
(1) preparation of dispersion solution of polymer-grafted nanoparticles: using polystyrene with mercapto-terminated molecular weight of 20,000g/mol, the surface of gold nanoparticles with diameter of 20nm was grafted by ligand exchange method and then dispersed in tetrahydrofuran.
(2) Preparation of polymer grafted nanoparticle monolayer film: the polymer grafted nano particle single-layer film is prepared by an oil-water interface rapid assembly method by using the polymer grafted nano particles and is transferred to the surface of a substrate.
(3) Etching and modifying the polymer grafted nano particle single-layer film: using a plasma cleaning machine, taking argon as plasma excitation gas, carrying out surface etching on the polymer grafted nanoparticle single-layer film to remove the polymer on the upper surface of the nanoparticle, exposing the upper surface, wherein the etching time is 5 minutes, the etching power is 6.8W, and after the etching is finished, soaking the substrate in a poly (4-vinylpyridine) solution with the molecular weight of 100,000g/mol and containing a mercapto group, so that the polymer is modified to the exposed upper surface of the nanoparticle through a ligand exchange method; and soaking the single-layer film in chloroform for ultrasonic treatment, and disassembling the single-layer film to form the gold nanoparticles with the polystyrene-poly (4-vinylpyridine) double-ligand Janus structure. FIG. 2 is a schematic diagram of the process of complexing gold nanoparticles with CdSe quantum dots by using a dual ligand Janus structure of polystyrene and poly (4-vinylpyridine) obtained in example 1 (FIG. 2a) and a transmission electron microscope picture (FIG. 2 b). Because the cadmium selenide quantum dots can generate coordination with N atoms in the poly (4-vinylpyridine), the cadmium selenide can be seen to be only distributed on one side of the gold nanoparticles after complexation, which indicates that the obtained nanoparticles are of Janus structures, namely, polystyrene ligands and poly (4-vinylpyridine) ligands are respectively grafted on two sides of the nanoparticles. FIG. 3a is a schematic diagram of a process of complexing gold nanoparticles with cadmium selenide quantum dots in a Janus structure by using polystyrene and poly (4-vinylpyridine) obtained in example 2, and a transmission electron microscope picture. As the cadmium selenide quantum dots can be subjected to coordination with N atoms in the poly (4-vinylpyridine), the distribution area of the cadmium selenide can be only one third of the area around the gold nanoparticles after complexation, which indicates that the obtained nanoparticles are of Janus structures, and the grafting ratio of the polystyrene ligand to the poly (4-vinylpyridine) ligand is about 2: 1. The grafting density of the ligands was 2.1 per square nanometer.
Example 3
A dual-ligand Janus structure nanoparticle is prepared according to the following method:
(1) preparation of dispersion solution of polymer-grafted nanoparticles: using polystyrene with mercapto-terminated molecular weight of 20,000g/mol, the surface of gold nanoparticles with diameter of 20nm was grafted by ligand exchange method and then dispersed in tetrahydrofuran.
(2) Preparation of polymer grafted nanoparticle monolayer film: the polymer grafted nano particle single-layer film is prepared by an oil-water interface rapid assembly method by using the polymer grafted nano particles and is transferred to the surface of a substrate.
(3) Etching and modifying the polymer grafted nano particle single-layer film: using a plasma cleaning machine, taking argon as plasma excitation gas, carrying out surface etching on the polymer grafted nanoparticle single-layer film to remove the polymer on the upper surface of the nanoparticle, exposing the upper surface, wherein the etching time is 5 minutes, the etching power is 18W, and after the etching is finished, soaking the substrate in a poly (4-vinylpyridine) solution with the molecular weight of 100,000g/mol and containing a mercapto group, so that the polymer is modified to the exposed upper surface of the nanoparticle by a ligand exchange method; and soaking the single-layer film in chloroform for ultrasonic treatment, and disassembling the single-layer film to form the gold nanoparticles with the polystyrene-poly (4-vinylpyridine) double-ligand Janus structure. FIG. 2 is a schematic diagram of the process of complexing gold nanoparticles with CdSe quantum dots by using a dual ligand Janus structure of polystyrene and poly (4-vinylpyridine) obtained in example 1 (FIG. 2a) and a transmission electron microscope picture (FIG. 2 b). Because the cadmium selenide quantum dots can generate coordination with N atoms in the poly (4-vinylpyridine), the cadmium selenide can be seen to be only distributed on one side of the gold nanoparticles after complexation, which indicates that the obtained nanoparticles are of Janus structures, namely, polystyrene ligands and poly (4-vinylpyridine) ligands are respectively grafted on two sides of the nanoparticles. FIG. 3c is a schematic diagram of the complexing process of the polystyrene and poly (4-vinylpyridine) double-ligand Janus structure gold nanoparticles obtained in example 2 and cadmium selenide quantum dots, and a transmission electron microscope picture. As the cadmium selenide quantum dots can be subjected to coordination with N atoms in the poly (4-vinylpyridine), the distribution area of the cadmium selenide can only occupy two thirds of the area around the gold nanoparticles after complexation, which indicates that the obtained nanoparticles are of Janus structures, and the grafting ratio of the polystyrene ligand to the poly (4-vinylpyridine) ligand is about 1: 2. The grafting density of the ligands was 1.7 per square nanometer.
Example 4
A dual-ligand Janus structure nanoparticle is prepared according to the following method:
(1) preparation of dispersion solution of polymer-grafted nanoparticles: polystyrene with mercapto-terminated molecular weight of 500g/mol is used, the surface of gold nano particles with the diameter of 3.5nm is grafted through a ligand exchange method, and then the gold nano particles are dispersed in trichloromethane.
(2) Preparing a polymer grafted nanoparticle single-layer film, namely preparing the polymer grafted nanoparticle single-layer film by self-assembling polymer grafted nanoparticles through L B film technology and transferring the film to the surface of a substrate.
(3) Etching and modifying the polymer grafted nano particle single-layer film: using a plasma cleaning machine, taking air as plasma excitation gas, carrying out surface etching on the polymer grafted nanoparticle single-layer film to remove the polymer on the upper surface of the nanoparticle, exposing the upper surface, wherein the etching time is 1 second, the etching power is 1W, and after the etching is finished, soaking the substrate in polyethylene oxide solution with the molecular weight of 10,000g/mol and containing disulfide bond groups, so that the polymer is modified to the exposed upper surface of the nanoparticle by a ligand exchange method; and soaking the single-layer film in dichloromethane for ultrasonic treatment, and disassembling the single-layer film to form the polystyrene-polyethylene oxide double-ligand Janus structure gold nanoparticles, wherein the grafting density of the surface ligands is 2.4 per square nanometer.
Example 5
A dual-ligand Janus structure nanoparticle is prepared according to the following method:
(1) preparation of dispersion solution of polymer-grafted nanoparticles: the surface of silver nanoparticles having a diameter of 100nm was grafted by a ligand exchange method using polymethyl methacrylate having an amino-terminated molecular weight of 100,000g/mol, and then dispersed in methylene chloride.
(2) Preparation of polymer grafted nanoparticle monolayer film: the polymer grafted nano particle single-layer film is prepared by self-assembly of the polymer grafted nano particles through a pulling method and is transferred to the surface of a substrate.
(3) Etching and modifying the polymer grafted nano particle single-layer film: using a plasma cleaning machine, taking argon as plasma excitation gas, carrying out surface etching on the polymer grafted nanoparticle single-layer film to remove the polymer on the upper surface of the nanoparticle, exposing the upper surface, wherein the etching time is 10 minutes, the etching power is 20W, and after the etching is finished, soaking the substrate in a polyethylene solution with the molecular weight of 50,000g/mol and containing amino groups, so that the polymer is modified to the exposed upper surface of the nanoparticle by a ligand exchange method; and soaking the single-layer film in N, N-dimethylformamide for ultrasonic treatment, and disassembling the single-layer film to form the polymethyl methacrylate-polyethylene double-ligand Janus-structure silver nanoparticles, wherein the grafting density of the surface ligands is 1.5 per square nanometer.
Example 6
A dual-ligand Janus structure nanoparticle is prepared according to the following method:
(1) preparation of dispersion solution of polymer-grafted nanoparticles: the surface of iron oxide nanoparticles having a diameter of 20nm was grafted by ligand exchange using polyacrylic acid having a carboxyl-terminated molecular weight of 5,000g/mol, and then dispersed in water.
(2) Preparation of polymer grafted nanoparticle monolayer film: the polymer grafted nano particle single-layer film is prepared by self-assembly of the polymer grafted nano particles through a solvent volatilization method and is transferred to the surface of a substrate.
(3) Etching and modifying the polymer grafted nano particle single-layer film: using a plasma cleaning machine, taking helium as plasma excitation gas, carrying out surface etching on the polymer grafted nanoparticle single-layer film to remove the polymer on the upper surface of the nanoparticle, exposing the upper surface, wherein the etching time is 1 minute, the etching power is 5W, and after the etching is finished, soaking the substrate in a carboxyl-containing poly (N-isopropylacrylamide) solution with the molecular weight of 10,000g/mol, so that the polymer is modified to the exposed upper surface of the nanoparticle by a ligand exchange method; and soaking the single-layer film in ethanol for ultrasonic treatment, so that the single-layer film is disassembled and assembled to form the polyacrylic acid-poly (N-isopropylacrylamide) double-ligand Janus structure iron oxide nano particles, wherein the grafting density of the surface ligands is 0.9 per square nanometer.
Example 7
A dual-ligand Janus structure nanoparticle is prepared according to the following method:
(1) preparation of dispersion solution of polymer-grafted nanoparticles: the surface of cadmium selenide nano-particles with the diameter of 10nm is grafted by a ligand exchange method by using poly (4-vinylpyridine) with the mercapto-terminated molecular weight of 50,000g/mol, and then the nano-particles are dispersed in ethanol.
(2) Preparation of polymer grafted nanoparticle monolayer film: and preparing a polymer grafted nanoparticle single-layer film by using the polymer grafted nanoparticles through a pulling method, and transferring the film to the surface of the substrate.
(3) Etching and modifying the polymer grafted nano particle single-layer film: using a plasma cleaning machine, taking nitrogen as plasma excitation gas, carrying out surface etching on the polymer grafted nanoparticle single-layer film to remove the polymer on the upper surface of the nanoparticle, exposing the upper surface, wherein the etching time is 8 minutes, the etching power is 15W, and after the etching is finished, soaking the substrate in a polystyrene solution with the molecular weight of 5,000g/mol and containing sulfydryl, so that the polymer is modified to the exposed upper surface of the nanoparticle by a ligand exchange method; and soaking the single-layer film in tetrahydrofuran for ultrasonic treatment, and disassembling the single-layer film to form the poly (4-vinylpyridine) -polystyrene double-ligand Janus-structure cadmium selenide nano-particle.
Example 8
A dual-ligand Janus structure nanoparticle is prepared according to the following method:
(1) preparation of dispersion solution of polymer-grafted nanoparticles: the surface of zinc sulfide nanoparticles 15nm in diameter was grafted by ligand exchange using a mercapto-terminated polyethylene having a molecular weight of 2,000g/mol and then dispersed in toluene.
(2) Preparation of polymer grafted nanoparticle monolayer film: the polymer grafted nano particle single-layer film is prepared by an oil-water interface rapid assembly method by using the polymer grafted nano particles and is transferred to the surface of a substrate.
(3) Etching and modifying the polymer grafted nano particle single-layer film: using a plasma cleaning machine, taking air as plasma excitation gas, carrying out surface etching on the polymer grafted nanoparticle single-layer film to remove the polymer on the upper surface of the nanoparticle, exposing the upper surface, wherein the etching time is 15 seconds, the etching power is 3W, and after the etching is finished, soaking the substrate in a polyethylene oxide solution with the molecular weight of 20,000g/mol and containing a sulpholipid group, so that the polymer is modified to the exposed upper surface of the nanoparticle by a ligand exchange method; and soaking the single-layer film in dichloromethane for ultrasonic treatment to disassemble and assemble the single-layer film to form the polystyrene-polyethylene oxide double-ligand Janus structure zinc sulfide nano particles, wherein the grafting density of the surface ligands is 1.4 per square nanometer.
Example 9
A dual-ligand Janus structure nanoparticle is prepared according to the following method:
(1) preparation of dispersion solution of polymer-grafted nanoparticles: the surface of cadmium selenide nanoparticles having a diameter of 20nm was grafted by a ligand exchange method using poly (4-vinylpyridine) having an amino-terminated molecular weight of 12,000g/mol, and then dispersed in methanol.
(2) Preparing a polymer grafted nanoparticle single-layer film, namely preparing the polymer grafted nanoparticle single-layer film by self-assembling polymer grafted nanoparticles through L B film technology and transferring the film to the surface of a substrate.
(3) Etching and modifying the polymer grafted nano particle single-layer film: using a plasma cleaning machine, taking argon as plasma excitation gas, carrying out surface etching on the polymer grafted nanoparticle single-layer film to remove the polymer on the upper surface of the nanoparticle, exposing the upper surface, wherein the etching time is 3 minutes, the etching power is 15W, and after the etching is finished, soaking the substrate in polyacrylic acid solution with the molecular weight of 30,000g/mol and containing sulfhydryl groups, so that the polymer is modified to the exposed upper surface of the nanoparticle through a ligand exchange method; and soaking the single-layer film in tetrahydrofuran for ultrasonic treatment, and disassembling the single-layer film to form the poly (4-vinylpyridine) -polyacrylic acid double-ligand Janus-structure cadmium selenide nano-particles, wherein the grafting density of the surface ligands is 1.9 per square nanometer.
Example 10
A dual-ligand Janus structure nanoparticle is prepared according to the following method:
(1) preparation of dispersion solution of polymer-grafted nanoparticles: the surface of iron oxide nanoparticles having a diameter of 50nm was grafted by ligand exchange using polystyrene having a carboxyl-terminated molecular weight of 80,000g/mol, and then dispersed in dioxane.
(2) Preparation of polymer grafted nanoparticle monolayer film: the polymer grafted nano particle single-layer film is prepared by self-assembly of the polymer grafted nano particles through an oil-water interface assembly method and is transferred to the surface of a substrate.
(3) Etching and modifying the polymer grafted nano particle single-layer film: using a plasma cleaning machine, taking air as plasma excitation gas, carrying out surface etching on the polymer grafted nanoparticle single-layer film to remove the polymer on the upper surface of the nanoparticle, exposing the upper surface, wherein the etching time is 8 minutes, the etching power is 15W, and after the etching is finished, soaking the substrate in a poly (N-isopropyl acrylamide) solution which has the molecular weight of 80,000g/mol and contains carboxyl groups, so that the polymer is modified to the exposed upper surface of the nanoparticle through a ligand exchange method; and soaking the single-layer film in chloroform for ultrasonic treatment to disassemble and assemble the single-layer film to form the polystyrene-poly (N-isopropylacrylamide) double-ligand Janus structure iron oxide nano particles, wherein the grafting density of the surface ligands is 1.0 per square nanometer. FIG. 1 is a schematic diagram of a process for preparing a dual-ligand Janus structure nanoparticle by using the plasma etching re-modification technology. Firstly, preparing a polymer grafted nanoparticle single-layer film by a self-assembly technology, transferring the polymer grafted nanoparticle single-layer film to the surface of a substrate, removing a polymer on the upper surface of the nanoparticle by a plasma etching method, grafting a second polymer on the upper surface of the bare nanoparticle, and finally adding a good solvent for disassembly and assembly to obtain the dual-ligand Janus structure nanoparticle.
Tables 1, 2 and 3 are pictures of the surface contact angle change of nanoparticles in the process of preparing polystyrene and polyethylene oxide dual-ligand Janus structure nanoparticles by using polystyrene modified gold nanoparticles with different molecular weights, gold nanoparticles with the diameter of 8 nanometers, gold nanoparticles with the diameter of 15 nanometers and gold nanoparticles with the diameter of 24 nanometers through a plasma etching re-modification method. It can be seen that the contact angle of the monolayer film formed by gold nanoparticles modified by hydrophobic polymer polystyrene is about 80 °, which indicates that the upper surface of the nanoparticles is mainly covered by polystyrene. After plasma etching is adopted, the contact angle is reduced to about 10 degrees, which shows that the polystyrene on the upper surface of the nano particles is removed, the upper surface is in a naked state, and the contact angle is reduced because the gold has good hydrophilicity. After the hydrophilic polymer polyethylene oxide is modified, the contact angle is about 10-20 degrees, a small increase occurs, and the small increase occurs because the hydrophilicity of the polyethylene oxide is weaker than that of gold although the polyethylene oxide is a hydrophilic polymer, and the phenomenon also proves that the polyethylene oxide is successfully grafted to the upper surface of the gold nano-particles. The series of data in fig. 3 illustrates that for nanoparticles of different sizes and different molecular weights of surface ligands, dual ligand Janus nanoparticles can be successfully prepared by the method.
TABLE 1
TABLE 2
TABLE 3
Fig. 3a, fig. 3b and fig. 3c are schematic diagrams of the process of controlling the grafting ratio of two ligands on the surface of the nanoparticles with Janus structure by controlling different etching powers in example 1, example 2 and example 3, respectively, and transmission electron microscope pictures. It can be seen that at the same etch time (5 minutes), etching with low power (6.8w) removed only about one third of the polystyrene, so that the resulting Janus nanoparticles, with a polystyrene to poly (4-vinylpyridine) ratio of about 2:1 (example 2); etching with moderate power (10.5w) removed about half of the polystyrene, thus producing the final Janus nanoparticles with a polystyrene to poly (4-vinylpyridine) ratio of about 1: 1 (example 1); etching with high power (18w) removes only about two thirds of the polystyrene, thus resulting in the final Janus nanoparticle prepared, with a polystyrene to poly (4-vinylpyridine) ratio of about 1:2 (example 3). Therefore, the etching degree is changed by controlling the etching power, the removal amount of the polymer on the upper surface of the nano particles and the exposed area of the upper surface of the nano particles can be effectively controlled, and the grafting proportion of the two ligands on the surfaces of the nano particles with the Janus structures is realized.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (8)
1. A method for preparing dual-ligand Janus structure nanoparticles by etching and re-modification is characterized by comprising the following steps:
(1) grafting and modifying the inorganic nanoparticles by a first polymer terminated by a functional group through a ligand exchange method, and dispersing in a solvent to obtain a dispersion liquid of the first polymer grafted inorganic nanoparticles;
(2) self-assembling the dispersion liquid obtained in the step (1) by using an oil-water interface assembly method, an L B film assembly method, a solvent volatilization assembly method or a pulling assembly method to prepare a first polymer grafted inorganic nanoparticle single-layer film, and transferring the single-layer film to the surface of a substrate;
(3) etching the single-layer film to remove the first polymer on the surface of each first polymer grafted inorganic nano particle on the single-layer film in a partial area, wherein the partial area is any area on the surface of each first polymer grafted inorganic nano particle; soaking the substrate in a second polymer terminated by functional groups after etching, and modifying the second polymer to the exposed part on the surface of each inorganic nanoparticle through a ligand exchange method, wherein the exposed part is the etched part of the first polymer; the repeating structural units of the first polymer and the second polymer are different; soaking the single-layer film in a solvent for dispersion, and disassembling the single-layer film to form single dispersed dual-ligand Janus structure nanoparticles;
the etching is plasma etching, and the proportion of two polymer ligands on the surface of the inorganic nano-particle can be controlled by controlling the plasma etching time and power; the method comprises the steps of preparing a single-layer film by adopting inorganic nanoparticles modified by a first polymer ligand through a self-assembly technology, removing the first polymer ligand in partial surface area of the inorganic nanoparticles by using an etching method, grafting a second polymer ligand to the exposed part of the surface of the inorganic nanoparticles, wherein the second polymer ligand can completely cover the exposed part, and the grafting density of the inorganic nanoparticle surface ligand is improved.
2. The method for preparing the dual-ligand Janus structure nanoparticle through etching re-modification according to claim 1, wherein the etching power in the step (3) is 1W-20W, and the etching time in the step (3) is 1s-10 min.
3. The method for preparing dual-ligand Janus structure nanoparticles through etching re-modification as claimed in claim 1, wherein the solvent in step (1) and the solvent in step (3) are each independently chloroform, toluene, benzene, ethyl acetate, acetone, tetrahydrofuran, N-dimethylformamide, dioxane, dichloromethane ethanol, methanol, propanol or water.
4. The method for preparing dual-ligand Janus structure nanoparticles through etching re-modification according to claim 1, wherein the inorganic nanoparticles in the step (1) are quantum dots, inorganic metal nanoparticles or metal oxide nanoparticles; the diameter of the inorganic nano-particles is 3.5nm-100 nm.
5. The method for preparing dual-ligand Janus structure nanoparticles through etching re-modification according to claim 4, wherein the inorganic metal nanoparticles are gold nanoparticles or silver nanoparticles, the metal oxide nanoparticles are ferroferric oxide nanoparticles, and the quantum dots are cadmium selenide quantum dots or zinc sulfide quantum dots.
6. The method for preparing dual-ligand Janus structure nanoparticles through etching re-modification according to claim 1, wherein the functional groups in the step (1) and the step (3) are groups containing sulfydryl, disulfide bonds, thioester bonds, carboxyl groups or amino groups respectively.
7. The method for preparing dual-ligand Janus structure nanoparticles through etching re-modification according to claim 1, wherein the dispersion in the step (3) is ultrasonic dispersion or stirring dispersion.
8. The method for preparing dual-ligand Janus structure nanoparticles through etching re-modification according to claim 1, wherein the first polymer and the second polymer are oil-soluble polymers with different repeating structural units, or the first polymer and the second polymer are water-soluble polymers with different repeating structural units, or one of the first polymer and the second polymer is an oil-soluble polymer and the other is a water-soluble polymer;
the oil-soluble polymer is polystyrene, polyethylene, polymethyl methacrylate or poly (4-vinylpyridine), and the water-soluble polymer is polyethylene oxide, polyacrylic acid or poly (N-isopropylacrylamide).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910067210.5A CN109776843B (en) | 2019-01-24 | 2019-01-24 | Double-ligand Janus nanoparticle and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910067210.5A CN109776843B (en) | 2019-01-24 | 2019-01-24 | Double-ligand Janus nanoparticle and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109776843A CN109776843A (en) | 2019-05-21 |
| CN109776843B true CN109776843B (en) | 2020-07-10 |
Family
ID=66502370
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910067210.5A Active CN109776843B (en) | 2019-01-24 | 2019-01-24 | Double-ligand Janus nanoparticle and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109776843B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112342013B (en) * | 2019-12-30 | 2022-03-29 | 广东聚华印刷显示技术有限公司 | Quantum dot film and preparation method and application thereof |
| CN114057961B (en) * | 2020-07-29 | 2022-11-18 | 清华大学 | Polymer double-chain/inorganic nanoparticle composite Janus material and preparation method thereof |
| CN114057962B (en) * | 2020-07-29 | 2023-05-05 | 清华大学 | Polymer double-chain/inorganic nano particle asymmetric compound and preparation method thereof |
| CN113500200B (en) * | 2021-06-24 | 2022-05-17 | 北京航空航天大学 | Surface modification method for gold nanorod water-phase-oil-phase conversion by using seed growth method |
| CN114058353B (en) * | 2021-12-02 | 2022-08-09 | 中国石油大学(北京) | Janus modified molybdenum disulfide nano-particles, preparation method thereof and oil displacement material |
| CN115561846B (en) * | 2022-09-27 | 2024-10-18 | 华中科技大学 | Surface plasmon-based response pattern, preparation method and application thereof |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101733052B (en) * | 2010-01-25 | 2011-09-28 | 吉林大学 | Preparation method of heterogeneous binary asymmetric particles |
| CN102527304B (en) * | 2011-12-21 | 2013-10-30 | 吉林大学 | Preparation method for multi-element heterogeneous asymmetric particles |
| CN107082889B (en) * | 2017-04-26 | 2019-06-18 | 华中科技大学 | A kind of Centimeter Level, grain polymer grafting gold nanoparticle composite single layer film adjustable in pitch and preparation method thereof |
-
2019
- 2019-01-24 CN CN201910067210.5A patent/CN109776843B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109776843A (en) | 2019-05-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109776843B (en) | Double-ligand Janus nanoparticle and preparation method and application thereof | |
| Wu et al. | Janus nanoarchitectures: From structural design to catalytic applications | |
| Rozenberg et al. | Polymer-assisted fabrication of nanoparticles and nanocomposites | |
| Han et al. | Conducting polymer-noble metal nanoparticle hybrids: Synthesis mechanism application | |
| Liu et al. | Recent advances in scalable synthesis and performance of Janus polymer/inorganic nanocomposites | |
| Mahouche-Chergui et al. | Polymer-immobilized nanoparticles | |
| Zhu et al. | Engineering ordered and nonordered porous noble metal nanostructures: synthesis, assembly, and their applications in electrochemistry | |
| Wu et al. | Surface-initiated controlled radical polymerizations from silica nanoparticles, gold nanocrystals, and bionanoparticles | |
| Yuan et al. | One-dimensional organic–inorganic hybrid nanomaterials | |
| Beija et al. | RAFT/MADIX polymers for the preparation of polymer/inorganic nanohybrids | |
| Aizawa et al. | Nanoscale patterning of two metals on silicon surfaces using an ABC triblock copolymer template | |
| Misner et al. | Directed deposition of nanoparticles using diblock copolymer templates | |
| Loget et al. | Bulk synthesis of Janus objects and asymmetric patchy particles | |
| Lohmüller et al. | Nanopatterning by block copolymer micelle nanolithography and bioinspired applications | |
| Tang et al. | Poly (N-vinyl-2-pyrrolidone)(PVP)-capped dendritic gold nanoparticles by a one-step hydrothermal route and their high SERS effect | |
| Fahmi et al. | Functional hybrid materials | |
| Liang et al. | Controllable AuPt bimetallic hollow nanostructures | |
| Kaltenpoth et al. | Conductive Core–Shell Particles: An Approach to Self‐Assembled Mesoscopic Wires | |
| Dai et al. | Formation of gold nanoparticles in the presence of o-anisidine and the dependence of the structure of poly (o-anisidine) on synthetic conditions | |
| Yan et al. | Poly (acrylic acid)-Lined Nanotubes of Poly (butyl methacrylate)-b lock-poly (2-cinnamoyloxyethyl methacrylate) | |
| Zhang et al. | High-yield preparation of vertically aligned gold nanorod arrays via a controlled evaporation-induced self-assembly method | |
| Zhou et al. | Janus hybrid hairy nanoparticles | |
| Xu et al. | Immobilization of gold nanoparticles on poly (4-vinylpyridine)-grafted carbon nanotubes as heterogeneous catalysts for hydrogenation of 4-nitrophenol | |
| Chen et al. | Preparation and applications of freestanding Janus nanosheets | |
| Beyou et al. | Organic–inorganic hybrid functional materials by nitroxide-mediated polymerization |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |