CN106632774B - Dendritic alkoxy ether polymer, its modified gold nanosphere and its preparation method - Google Patents

Abstract

The present invention relates to a kind of poplar bundles alcoxyl ether polymers, its modification gold nano microballoon and preparation method thereof.The gold nano microballoon is that the poplar bundles alcoxyl ether polymer and gold nanoparticle surface action by end with three thioesters form golden sulfide linkage and be prepared.Temperature sensitive poplar bundles gold nano microballoon of the invention has the characteristics that nanoscale and good monodispersity, and in certain temperature section, single microballoon, which can express, increases the temperature sensitive behavior that rapid dehydration is collapsed with temperature, and the size of microballoon becomes smaller therewith, and the process is reversible.Since this temperature sensitive poplar bundles gold nano microsphere surface contains large-sized tree-like alcoxyl ether polymer, ability and good biocompatibility with higher load small molecule compound, to have potential application value in fields such as bio-medical material, intelligent opto-electrical material, nano containers.

Description

Dendritic alkoxy ether polymer, its modified gold nanosphere and its preparation method

technical field

The invention relates to an alkoxy ether branched polymer with temperature-sensitive behavior, its modified gold nano-microsphere and a preparation method thereof.

Background technique

Gold nanoparticles have obvious surface effects, volume effects, quantum effects, small size effects and macroscopic quantum tunneling effects. Their optical, electronic, sensing and biochemical properties have become research hotspots. and other technical fields have broad application prospects. In particular, gold nanoparticles have special stability due to their weakly charged ligand binding layer, and the surface is easy to be improved, and can generate non-covalent electrostatic bonds with amino groups, sulfur groups, proteins (certain antibodies, antigens), etc. Adsorption, the complexes labeled with gold nanoparticles were obtained, and still have similar spectral properties to gold nanoparticles, which provides a basis for its application in biological detection. However, gold nanoparticles are prone to agglomeration in solution, which affects their performance. The use of polymers to modify the surface of gold particles to prepare hybrid polymer gold nanospheres has attracted widespread attention. In this type of composite materials, gold nanoparticles are used as the core, and a polymer that can stabilize the gold nanoparticles is used as the shell, which is the most common and most widely studied composite method. The use of polymers as stabilizers generally has the following advantages: the stability of gold nanoparticles is enhanced; the hydrophilicity, lipophilicity, solubility, compatibility, and processability of gold nanoparticles can be adjusted by adjusting the polymer composition and structure; to the surface functionalization of gold nanoparticles, etc. Introducing smart polymers to the surface of gold nanoparticles can not only improve their stability but also endow them with intelligent response behaviors that change with the environment. Among them, temperature-sensitive gold nanospheres have become a research hotspot in recent years. This kind of microspheres combines the temperature response behavior of temperature-sensitive polymers and the excellent characteristics of gold particles, and has great potential application value in the fields of smart optoelectronic devices, smart catalysis, analysis and detection, switch control, and nano-containers. The surface of temperature-sensitive gold nanoparticles reported so far is generally grafted with linear or hyperbranched temperature-sensitive polymers, see Cyrille Boyer, et al. Macromolecules, 2009.42, 6917-6926; Yi Shen, et al. , 2227-2230. Due to the small size of the polymers, they cannot be directly observed, and most of them contain amide bonds, which have the problems of slow thermosensitive recovery process and poor biocompatibility. Dendritic polymer is a new type of nonlinear polymer developed in the past two decades. It is composed of a linear polymer main chain and a branched base as a side group. This construction method makes the dendritic polymer have many Excellent features include high packing density, large single-molecule size, nanoscale, easy-to-adjust structure, rich internal holes for efficient loading of small guest molecules, second-dimensional tunable diameter, and easy functionalization. Zhang Afang and others have prepared a series of temperature-sensitive alkoxyether-based dendritic polymers, see Afang Zhang, et al. Macromolecules, 2008, 41, 3659-3667, Afang Zhang, et al. It was found that this type of polymer not only has good biocompatibility, but also exhibits excellent temperature-sensitive properties, its phase transition is rapid, and the hysteresis is small, and the phase transition temperature can be regulated by various methods, such as changing the dendron Algebra, terminal structure, OEG chain length, etc. The preparation of gold nanospheres based on such polymers and the development of thermosensitive polymer gold nanospheres with new topological structures have important academic significance and application value in the fields of controlled drug release, nanocontainers, and smart optoelectronic materials.

Contents of the invention

One of the objectives of the present invention is to provide a dendritic alkoxy ether polymer.

The second object of the present invention is to provide the polymer-modified gold nanospheres.

The second object of the present invention is to provide a method for preparing the modified gold nanospheres.

In order to realize the purpose of the above invention, the present invention separately synthesizes gold nanoparticles and alkoxyether dendritic polymers with trithioesters at the end groups, and further reacts the two in aqueous solution to obtain dendritic polymer gold nanospheres. The gold nanoparticles were synthesized by the method reported in the literature, see FrensG, et al. Nature: Physical Science, 1973, 241 (105), 20-22, and the average size was 40nm as determined by light scattering. In order to obtain alkoxyether dendritic polymers with a high retention rate of terminal groups (trithioesters) to efficiently combine with gold nanoparticles, an alkoxyether monomer MG1 with a core point of methyl acrylate was first prepared, and further photocatalytic The corresponding polymer PG1 was prepared by initiating RAFT polymerization. The specific synthesis steps of monomers and polymers are as follows:

According to above-mentioned reaction scheme, the present invention adopts following technical scheme:

A branched alkoxy ether polymer is characterized in that the polymer structural formula is:

Where n=100-400.

A dendritic alkoxyether polymer modified gold nano-microsphere, using the above-mentioned dendritic alkoxyether polymer to modify the gold nano-particles, is characterized in that the gold nano-microspheres are made of trithioester-terminated The branched alkoxyether polymer and the surface of the gold nanoparticles are grafted with the branched alkoxyether polymer on the surface of the gold nanoparticle through the gold-sulfur bond to form a temperature-sensitive branched alkoxyether polymer modified gold nanospheres , the mass ratio of polymer to gold nanoparticles is 1:1;

A method for preparing the above-mentioned dendritic alkoxy ether polymer modified gold nanospheres is characterized in that the specific steps of the method are:

a. The dry dichloromethane solution that is dissolved with acryloyl chloride is added dropwise to the dry dichloromethane solution that dissolves the compound branched alkoxy ether benzyl alcohol G1-OH, triethylamine TEA and 4-dimethylaminopyridine, During the dropwise addition process, keep the temperature of the ice _- water bath for 0.5h _- 1h, continue to stir at room temperature for 4-6h, and then dropwise add methanol to terminate the reaction; phase, filtered, and then purified to obtain the branched alkoxyether monomer MG1; the mol ratio of the acryloyl chloride, branched alkoxyether benzyl alcohol, triethylamine TEA and 4-dimethylaminopyridine is: 1.5: 1:5:0.5;

b. Dissolve the dendritic alkoxyether monomer and RAFT reagent obtained in step a in dimethyl sulfoxide at a molar ratio of 400:1 to 300:1, and polymerize under the protection of inert gas _N2 under photoinitiation Polymerize under photoinitiation for 24h to 48h; after the reaction is completed, dichloromethane is added to fully dissolve the reaction solution, and after purification, a temperature-sensitive dendritic alkoxy ether polymer is obtained;

c. Blend the temperature-sensitive dendritic alkoxyether polymer obtained in step b with gold nanoparticles at a mass ratio of 1:1, stir for 20 hours, and then use a high-speed centrifuge to perform centrifugal purification at 20,000r/min and 5°C 30min, repeated washing with water three times to remove ungrafted polymers, and then dried and weighed the obtained product to obtain gold nanospheres with branched alkoxyether polymers grafted on the surface.

This kind of temperature-sensitive dendritic gold nano-microsphere has the application of specific size and excellent characteristics and performance. The temperature-sensitive dendritic gold nanospheres have a specific nanometer scale (30-60nm), and the observation of the entire microsphere morphology can be realized through an atomic force microscope; it has excellent temperature-sensitive characteristics, and within a certain temperature range ( 30～50℃), it can achieve rapid dehydration and collapse with the increase of temperature, and the size becomes smaller, and it can rehydrate and swell with the decrease of temperature, and the size returns to its original shape. In addition, the temperature-sensitive dendritic gold nanosphere has high loading capacity and good biocompatibility, so it can be applied to fields such as biomedical materials and sensors.

The present invention has the following prominent features and significant advantages:

1. The temperature-sensitive dendritic gold nanospheres of the present invention have good biocompatibility, and exhibit excellent reversible temperature-sensitive shrinkage and swelling behaviors near human body temperature.

2. The temperature-sensitive dendritic gold nanospheres of the present invention have good dispersibility, and the morphology and size of the microspheres can be clearly observed with an atomic force microscope.

3. The preparation method of the temperature-sensitive dendritic gold nanospheres provided by the present invention has mild reaction conditions and is easy to implement.

Description of drawings

Fig. 1 is the ¹ H NMR spectrogram of thermosensitive dendritic alkoxy ether polymer;

Fig. 2 is the turbidity curve of thermosensitive dendritic alkoxy ether polymer;

Fig. 3 is a transmission electron microscope and an atomic force microscope image of gold nanoparticles. a) is a transmission electron microscope of gold nanoparticles; b) is an atomic force microscope image of gold nanoparticles;

Fig. 4 is the transmission electron microscope and the atomic force microscope picture of temperature-sensitive dendritic gold nanosphere; a) the transmission electron microscope of temperature-sensitive dendritic gold nanosphere; b) the atomic force microscope picture of temperature-sensitive dendritic gold nanosphere;

Fig. 5 is a curve of the size variation of temperature-sensitive dendritic gold nanospheres with temperature.

Detailed ways

The present invention will be further described below in conjunction with specific examples, but these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Preferred embodiments of the present invention are described in detail as follows:

Embodiment one:

The invention relates to the preparation of temperature-sensitive dendritic gold nanometer microspheres.

1. Synthesis of dendritic alkoxy ether monomers

A solution of acryloyl chloride (2.50 g) in dry DCM (10 mL) was added dropwise to a solution of compound G1-OH (10.20 g), TEA (8.10 g) and DMAP (0.39 g) in dry DCM (100 mL) , keep the temperature of the ice bath at 0°C during the dropwise addition, remove the ice bath after half an hour, continue stirring at room temperature for 4h, and then drop methanol to terminate the reaction. The reaction solution was washed successively with saturated NaHCO ₃ solution and saturated NaCl solution, and after separation, the organic phase was dried with anhydrous MgSO ₄ and filtered. Purify by silica gel column chromatography to obtain dendritic alkoxy ether monomer MG1 (6.80 g), with a yield of 81%.

2. Synthesis of temperature-sensitive dendritic alkoxyether polymers

Add dendritic alkoxyether monomer (900mg), RAFT reagent (1.58mg) and DMSO (0.9mL) into a 10mL reaction tube respectively, vacuumize for half an hour, replace N ₂ , place the closed reaction tube under LED blue light to trigger In the device, the polymerization reaction is carried out for 12 to 20 hours, until the viscosity of the reaction liquid becomes large, and the magnetic stirring is difficult. An appropriate amount of DCM was added to fully dissolve, and purified by silica gel chromatography to obtain a temperature-sensitive dendritic alkoxy ether polymer (650 mg), with a yield of 72%. See Figure 1 for the NMR spectrum of the temperature-sensitive dendritic alkoxyether polymer.

3. Preparation of temperature-sensitive dendritic gold nanospheres

Blend the obtained temperature-sensitive dendritic alkoxyether polymer and gold nanoparticles with each other at a mass ratio of 1:1, stir for 20 hours, and then use a high-speed centrifuge to perform centrifugal purification at 20,000r/min and 5°C for 30 minutes, and repeat with water After washing three times to remove the ungrafted polymer, the obtained product was dried and weighed to obtain the temperature-sensitive dendritic gold nanospheres grafted with the polymer on the surface.

Embodiment 2: In this embodiment, the prepared aqueous solution of 0.005wt% gold nanoparticles was tested by transmission electron microscope and atomic force microscope. See Figure 3. It shows that the prepared gold nanoparticles have good dispersion.

Embodiment 3: In this embodiment, the prepared aqueous solution of 0.005wt% temperature-sensitive dendritic gold nanospheres was tested by transmission electron microscope and atomic force microscope. See Figure 4. It shows that the temperature-sensitive dendritic gold nanospheres have been successfully prepared.

Embodiment 4: In this embodiment, the prepared aqueous solution of 0.005wt% temperature-sensitive dendritic gold nanospheres was subjected to dynamic light scattering to test its size variation with temperature. See Figure 5. It shows that the temperature-sensitive dendritic gold nanospheres have good temperature-sensitive behavior.

The embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned embodiments, and various changes can also be made according to the invention and creation objectives of the present invention, and all changes made according to the spirit and principles of the technical solutions of the present invention , modification, replacement, combination, and simplification, all should be equivalent replacement methods, as long as they meet the purpose of the present invention, as long as they do not deviate from the technical principle and inventive concept of the preparation method and application of the temperature-sensitive dendritic gold nanospheres of the present invention , all belong to the protection scope of the present invention.

Claims (1)

1. a kind of method of poplar bundles alkyloxy-ethers polymer modification gold nano microballoon, using poplar bundles alcoxyl ether polymer to Jenner Rice grain is modified, which is characterized in that the gold nano microballoon is the poplar bundles alcoxyl ether polymer that three thioesters are had by end Pass through golden sulfide linkage with gold nanoparticle surface, the poplar bundles alcoxyl ether polymer on gold nanoparticle surface grafting and formed temperature sensitive Property poplar bundles alkyloxy-ethers polymer modification gold nano microballoon, the mass ratio of polymer and gold nanoparticle is 1:1, the Thermo-sensitive The polymer formulae of poplar bundles alkyloxy-ethers polymer modification gold nano microballoon are as follows:

Wherein n=100~400；

Temperature sensitive poplar bundles gold nano microballoon has 30~60nm of nano-scale dimension, in 30~50 DEG C of certain temperature section, energy Realize that increasing rapid dehydration with temperature collapses, size becomes smaller, and as temperature reduction can be hydrated swelling again, size restoration is former Shape；

Prepare the specific steps of the method for poplar bundles alkyloxy-ethers polymer modification gold nano microballoon are as follows:

A. dissolved with the dry methylene chloride solution of acryloyl chloride, will be added dropwise to dissolved with compound poplar bundles alkyloxy-ethers benzylalcohol G1-OH, In triethylamine TEA and the dry methylene chloride solution of 4-dimethylaminopyridine, be added dropwise during keep ice water bath temperature 0.5h~ After 1h, continue 4~6h of stirring at room temperature, the rear methanol that is added dropwise terminates reaction；Reaction solution is successively with saturation NaHCO₃Solution and full It is washed with NaCl solution, anhydrous MgSO₄Dry organic phase, filtering using purification, obtain poplar bundles alcoxyl ether monomer MG1；Institute The molar ratio of the acryloyl chloride, poplar bundles alkyloxy-ethers benzylalcohol, triethylamine TEA and 4-dimethylaminopyridine stated are as follows: 1.5:1:5: 0.5；

B. poplar bundles alcoxyl ether monomer, RAFT reagent obtained by step a are dissolved in dimethyl Asia by the molar ratio of 400:1~300:1 In sulfone, in inert gas N₂Under protection, light-initiated lower polymerization reaction for 24 hours~48h；It is abundant that methylene chloride is added after reaction Reaction solution is dissolved, and purified, obtains temperature sensitive poplar bundles alcoxyl ether polymer；

C. temperature sensitive poplar bundles alcoxyl ether polymer and gold nanoparticle 1:1 in mass ratio obtained by step b are mutually blended, are stirred It carries out centrifugation purification 30min after 20h under conditions of 20000r/min, 5 DEG C with supercentrifuge again, repeats to wash three times with water To remove non-grafted polymers, obtained product is dried later, weighing has poplar bundles alcoxyl to get to surface grafting The gold nano microballoon of ether polymer.