CN110818821A - Preparation method of organic-inorganic hybrid material of polystyrene palladium nanocube - Google Patents

Abstract

An organic-inorganic hybrid material PS-SH@Pd of polystyrene palladium nanocubes linked by sulfur-hydrogen bonds and a preparation method belong to the field of polymer self-assembly. The technical problem to be solved by the present invention is to provide a simple, high-efficiency and regular structure of the preparation method of the polymer carrier, so as to obtain small particle size, uniform size, consistent structure, nano-scale and easy to carry catalysts, drugs, fluorescent quantum dots Wait. The material is a thiol-terminated polystyrene synthesized by using high-molecular polystyrene as the main body, modified by end groups and using tetrahydrofuran as a solvent. Then use surfactant as protection, use sodium citrate, hydrazine hydrate, sodium borohydride to reduce to small seed crystals; then use ascorbic acid, palladium seed crystals to mediate growth, by adding halogen chloride, bromine, iodide ions. The growth of some crystal planes can be induced and inhibited, resulting in a stable {110} plane-dominated face-centered cubic structure. Finally, PS-SH@Pd was prepared by 2 times of ligand exchange and 5 times of centrifugal precipitation and washing. The nanoparticle of the present invention can exist stably in any dimension of 25nm±4nm-110nm±4nm. Related substances have been used in controlled drug release, nanoprobes, instrumental sensing, and as important catalysts for carbon-carbon bond-forming coupling reactions and hydrogenation reactions.

Description

A kind of preparation method of organic-inorganic hybrid material of polystyrene palladium nano-cube

technical field

The invention belongs to the technical field of polymer materials, in particular to an organic-inorganic hybrid material of polystyrene palladium nanocubes linked by sulfur-hydrogen bonds and a preparation method thereof.

Background technique

By studying the theory and method of synthesis, we found that block copolymers loaded with metal nanoparticles have practical application value in many fields such as medicine, catalysis, and sensing. In recent years, there have been a lot of literature reports especially on the self-assembly of gold nanoparticles and polymers. The drug carrier based on gold nano-NPs uses coupling, coordination, coating and other means to connect various functional drugs, cells and hormones and other ligands. This kind of gold-connected block copolymer nanocarriers interact with functional groups. The treatment of diseases has been widely studied. Various metal particles and rare earth nanocrystals have gradually become the extensive research objects after gold nanoparticles, such as Au, Ag, pt, pd, Fe magnetic nanoparticles and other metal nanoparticles It forms an organic-inorganic compound with a high polymer, which greatly improves the hydrophobicity and poor solubility of the molecular chain, and prolongs the release time of drugs or catalysts.

In recent years, the assembly system of metal nanocrystals and block copolymers has been extensively and deeply studied. At present, the three-dimensional structures of nanocrystals prepared by in-situ reduction methods are diverse and complex, and the aggregated structure is greatly affected by the preparation conditions. Metal crystals with coexisting three-dimensional structures also affect the linking and release with drugs or catalysts, while the research on cubic nanocrystals is still in the developmental stage. This makes the nanosystems with the same equivalent six crystal faces of cubic nanocrystals and block copolymers in self-assembly research, especially for controlled release, precise delivery of catalysts, sustained release of drugs, and in sensing and In the design of probes, the study of crystal regular assembly structure has broad development space and important research significance.

SUMMARY OF THE INVENTION

The invention provides an organic-inorganic hybrid material of polystyrene palladium nano-cubes linked by sulfur-hydrogen bonds and a preparation method for the deficiency of the size control of the polymer organic-inorganic nano-composite material.

The material is a thiol-terminated polystyrene synthesized by using high-molecular polystyrene as the main body, modified by end groups and using tetrahydrofuran as a solvent. Then use the surfactant cetyltrimethylammonium bromide (CTAB/CTAC) as protection, use sodium citrate, hydrazine hydrate, sodium borohydride to reduce to small seeds; then use ascorbic acid, CTAB and chloropalladium acid and palladium seeds for mediated growth by adding halogen chloride, bromine, iodide ions. The growth of some crystal planes can be induced and inhibited, resulting in a stable {110} plane-dominated face-centered cubic structure. Finally, after 2 times of ligand exchange method and 5 times of centrifugal precipitation washing, p2vp-sh@pd was prepared. The nanoparticle of the present invention can exist stably in any dimension ranging from 25nm±4nm to 110nm±4nm. Using the thiol link between the thiol-terminated polystyrene and the pd nanoparticle, the traditional unstable connection using intermolecular hydrogen bonds is replaced, so that the pd nanoparticle is more stably fixed at one end of the polymer chain, so that it can be A new type of load system is formed. And in this double ligand exchange method, nitrogen-nitrogen-dimethyldiethylamide was used as solvent at the beginning, so that most of the pd cubic nanocrystals were connected to the sulfur-hydrogen bonds, and then chloroform was used after centrifugation. The second connection of the pd nanocubes for the solvent makes the connection rate of the cubic crystals greatly increased. And under the extraction of chloroform, the original surfactant CTAB was also extracted and removed by centrifugation. The separation is convenient, the product is pure, and the collection is convenient. Finally, it is stored in chloroform to become a carrier that can be used or grafted at any time, with stable performance, relatively uniform and high purity. It can be used in sensing, medical, pharmaceutical, catalysis and other fields.

Description of drawings:

Figure 1: Flow chart of composite material preparation;

Figure 2: Infrared test chart of pd nanoparticles;

Figure 3: UV test chart of pd nanoparticles;

Figure 4: Transmission electron microscope transmission and electron diffraction test images of pd nanoparticles.

Specific implementation plan:

An organic-inorganic hybrid material of polystyrene palladium nanocubes linked by sulfur-hydrogen bonds, the preparation process of which is shown in Figure 1, comprising the following steps:

Step 1: Preparation of 10 mM H ₂ PdCl ₄ solution: Dissolve 0.1773 g of PdCl ₂ in 10 ml of 0.2 mol/L hydrochloric acid solution, add 90 ml of double distilled water, and heat for 10 min.

Step 2: Add 0.5 ml of the 10 mM H2PdCl4 solution in Step 1 to 20 ml of 10 mM CTAC solution in an oil bath at 90°C. Stirring was carried out at 800 rpm. Stir for 10 minutes.

Step 3: Add 1ml of 10mM ascorbic acid in water. 0.01 ml of 10 mM sodium borohydride in water. 0.01 ml of 10 mM sodium citrate in water. Continue to stir the reaction for 30 minutes, and store it at a constant temperature of 30 °C as a seed crystal. This seed crystal is then taken to control the crystal size.

Step 4: Add 0.5 ml of 10 mM H2PdCl4 solution to 10 ml of 50 mM CTAC solution, heat in a water bath, magnetically stir at 2000 rmp, and then add different amounts of cubic nanocrystals. We give a gradient contrast here. The 50 ul seed crystal added in step 3 is marked as sample 1; the 250 ul seed crystal added is marked as sample two; the seed crystal added with 500 ul is marked as sample three; the seed crystal added with 1000 ul is marked as sample four; the seed crystal added with 2000 ul is marked as sample four It is sample five; adding 3000 ul of seed crystals is marked as sample six.

Step 5: Add 0.5ml of 10mM KI and 1ml of 10mM ascorbic acid in water. Magnetic stirring was carried out at 2000 rmp, and the water bath was heated at 80 °C to carry out the seed growth reaction.

Step 6: The size of the nanocubes is adjusted by the amount of seeds added. The amount of seeds added and the side lengths of the corresponding nanocubes obtained are as follows: 50 ul of the labeled sample 1 seed crystal is 114 nm; 250 ul of the labeled sample 2 seed crystal is 81 nm , 500 ul of labeled sample 3 seed crystal is 60 nm, 1000 ul of labeled sample 4 seed crystal is 46 nm, 2000 ul of labeled sample 5 seed crystal is 39 nm, and 3000 ul of labeled sample 6 seed crystal is 28 nm. Step 7: After the reaction, centrifuge the reaction solution at 12,000 rpm for 15 minutes. Collect the lower crystals.

Step 8: Under ultrasonic conditions, add the concentrated gold nanocrystals (0.4ml-0.8ml) to the chloroform solution of ps-sh (10mg0.2mg/ml), continue to supergenerate at 30°C for 30 minutes, and let stand for 24 minutes at room temperature. Hour.

Step 9: Centrifuge at 12000rmp for 30min to remove the supernatant.

Step 10: Disperse the centrifuged liquid in the ninth step in tetrahydrofuran, and perform three precipitation and centrifugation at 12000 rmp for 30 min. Then 4 mg of ps-sh (0.2 mg/ml) was added to repeat the same process of supersonication, maturation and purification.

Claims (9)

1. A preparation method of polystyrene palladium nanocube organic-inorganic hybrid material comprises the following steps: preparation of 10mM H2PdCl4 solution (1), dispersion of H2PdCl4 solution in CTAC (2), preparation of Pd seed crystals (3), induction of Pd crystal growth of different sizes by using different Pd seed crystal concentrations (4), regulation of Pd crystal shape (5), selective covering of several sizes (6), separation, purification and concentration (7), and connection of polymer by two-time ligand exchange method (8).

2. The preparation method of the polystyrene palladium nanocube organic-inorganic hybrid material as claimed in claim 1, wherein the preparation of 10mM H2PdCl4 solution (1) is dissolved in 10ml of 0.2 mol/L hydrochloric acid solution, then 90ml of redistilled water is added, and the mixture is heated for 10 min.

3. The method for preparing organic-inorganic hybrid material of palladium nanocube of polystyrene as claimed in claim 1, wherein the dispersion of H2PdCl4 solution in CTAC (2), stirring at 800rmp for 10min in 20 ml 10mM CTAC solution in 90 ℃ oil bath.

4. The method for preparing an organic-inorganic hybrid material of polystyrene palladium nanocube according to claim 1, wherein the preparation of Pd seed crystal (3) comprises adding 1ml of 10mM ascorbic acid aqueous solution, 0.01ml of 10mM sodium borohydride aqueous solution, and 0.01ml of 10mM sodium citrate aqueous solution, continuing stirring reaction for 30 minutes, and storing at constant temperature of 30 ℃ as seed crystal.

5. The method for preparing organic-inorganic hybrid material of polystyrene palladium nanocube as claimed in claim 1, wherein different Pd seed crystal concentrations are used to induce the growth of Pd crystals with different sizes (4), 0.5ml 10mM KI and 1ml 10mM ascorbic acid aqueous solution are added, magnetic stirring is carried out at 2000rmp, water bath heating is carried out at 80 ℃, and seed growth reaction is carried out.

6. The method for preparing organic-inorganic hybrid material of palladium nanocubes polystyrene as claimed in claim 1, wherein the regulation of pd crystal shape (5), regulation of 10mM KI, standing growth and aging are continued for 30 minutes at 30 ℃, and standing is continued for 24 hours at room temperature.

7. A method for preparing organic-inorganic hybrid material of polystyrene palladium nanocubes, according to claim 1, characterized in that the selective coverage (6) of several sizes is adjusted by the amount of seeds added, the amount of seeds added is corresponding to the obtained nanocubes, the 50 ul seed crystal of labeled sample 1 is 114 nm; 250 ul of seed crystal of the marked sample 2 is 81nm, 500 ul of seed crystal of the marked sample 3 is 60nm, 1000 ul of seed crystal of the marked sample 4 is 46nm, 2000 ul of seed crystal of the marked sample 5 is 39nm, and 3000 ul of seed crystal of the marked sample 6 is 28 nm.

8. The method for preparing organic-inorganic hybrid material of polystyrene palladium nanocubes as claimed in claim 1, wherein the separation, purification and concentration (7) are performed, centrifugation is performed at 12000rmp for 30min, and supernatant is removed.

9. A method for preparing polystyrene palladium nanocube organic-inorganic hybrid material according to claim 1, characterized in that two times of ligand exchange method for connecting polymer (8), liquid after centrifugation is dispersed in tetrahydrofuran, and after three times of precipitation and centrifugation 12000rmp for 30min, 4mg of ps-sh (0.2 mg/ml) is added to repeat the same process of generating, curing and purifying.

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