CN110818821A

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

Info

Publication number: CN110818821A
Application number: CN201911116800.9A
Authority: CN
Inventors: 王哲; 水天恩; 朱阳阳; 刘尧; 李晨阳; 陈文波; 申洪城; 孙强
Original assignee: Changchun University of Technology
Current assignee: Changchun University of Technology
Priority date: 2019-11-15
Filing date: 2019-11-15
Publication date: 2020-02-21

Abstract

An organic-inorganic hybrid material PS-SH @ Pd of polystyrene palladium nanocubes linked by a sulfur-hydrogen bond and a preparation method thereof belong to the field of high-molecular self-assembly. The technical problem to be solved by the invention is to provide a simple, efficient and structurally regular preparation method of a polymer carrier, so that the polymer carrier is small in particle size, uniform in size, consistent in structure, nanoscale and easy to carry catalysts, medicines, fluorescent quantum dots and the like. The material is sulfhydryl-terminated polystyrene synthesized by taking macromolecular polystyrene as a main body, modifying end groups and taking tetrahydrofuran as a solvent. Then using surfactant as protection, adopting sodium citrate, hydrazine hydrate and sodium borohydride to reduce them into small crystal seeds, then using ascorbic acid and palladium crystal seeds to make mediated growth, and adding halogen chloride, bromine and iodine ions. Growth of some crystal planes can be induced and suppressed, resulting in a stable 110 face-centered cubic structure. And finally, preparing PS-SH @ Pd by 2 ligand exchange methods and 5 centrifugal precipitation washing. The nano-particles of the invention can stably exist in any size of 25nm +/-4 nm-110nm +/-4 nm. Related substances have been applied to drug controlled release, nanoprobes, instrumental sensing and as important catalysts for carbon-carbon bond formation coupling reactions and hydrogenation reactions.

Description

Preparation method of organic-inorganic hybrid material of polystyrene palladium nanocube

Technical Field

The invention belongs to the technical field of high polymer materials, and particularly relates to a sulfur-hydrogen bond linked polystyrene palladium nanocube organic-inorganic hybrid material and a preparation method thereof.

Background

Through research on the theory and method of synthesis, the block copolymer and metal nanoparticle load has practical application value in many fields such as medicine, catalysis, sensing and the like. In recent years, there are many reports on the self-assembly of gold nanoparticles and high polymers. The metal particles and rare earth nanocrystals also become a wide research object after gradually becoming the gold nanoparticles, and the metal nanoparticles such as Au, Ag, pt, pd, Fe magnetic nanoparticles and the like and the high polymer form organic-inorganic composite, so that the solubility of the hydrophobicity of a molecular chain is greatly improved, and the release time of the drug or the catalyst is prolonged.

In recent years, the assembly system of metal nanocrystals and block copolymers has been extensively and deeply studied, and at the present stage, the nanocrystals prepared by the in-situ reduction method have various and complex three-dimensional structures, the aggregation structure is greatly influenced by the preparation conditions, the metal crystals with various coexisting three-dimensional structures also influence the linkage and release with drugs or catalysts, and the research on cubic nanocrystals is still in the development stage. Therefore, the nano system of the cubic nano crystal and the block copolymer with the same and equivalent six crystal faces has wide development space and important research significance in the self-assembly research of the nano system, particularly the controlled release, the accurate carrying of the catalyst, the slow release of the medicine and the research of the crystal regular assembly structure in the design of the sensing and the probe.

Disclosure of Invention

The invention provides an organic-inorganic hybrid material of polystyrene palladium nanocubes linked by a sulfur-hydrogen bond and a preparation method thereof, which are used for overcoming the defects of size control of a high-molecular organic-inorganic nano composite material.

The material is sulfhydryl-terminated polystyrene synthesized by taking macromolecular polystyrene as a main body, modifying end groups and taking tetrahydrofuran as a solvent. Then using cetyl trimethyl ammonium bromide (CTAB/CTAC) as surfactant protection, adopting sodium citrate, hydrazine hydrate and sodium borohydride to reduce them into small crystal seeds, then using ascorbic acid, CTAB and chloropalladic acid and palladium crystal seeds to make mediated growth, and adding halogen chloride, bromine and iodine ions into them. Growth of some crystal planes can be induced and suppressed, resulting in a stable 110 face-centered cubic structure. Finally, p2vp-sh @ pd was prepared by 2 ligand exchange cycles and 5 centrifugation pellet washes. The nano-particles of the invention can stably exist in any size of 25nm +/-4 nm-110nm +/-4 nm. The sulfhydryl between the sulfhydryl terminated polystyrene and the pd nano-particle is linked, so that the traditional unstable connection by utilizing intermolecular hydrogen bond is replaced, and the pd nano-particle is more stably fixed at one end of the polymer chain, thereby forming a novel loading system. In the two-time ligand exchange method, nitrogen-dimethyl diethylamide is used as a solvent at the beginning, so that most of the pd cubic nanocrystals are connected to a sulfur-hydrogen bond, and chloroform is used as a solvent for connecting the pd cubic nanocrystals for the second time after centrifugation, so that the connection rate of the cubic nanocrystals is greatly increased. Under the extraction of chloroform, the original surfactant CTAB is also extracted and centrifuged to remove. The separation is convenient, the product is pure, and the collection is convenient. Finally, the product is stored in chloroform to become a carrier which can be used or grafted at any time, and has stable performance, relative uniformity and high purity. Can be applied to the fields of sensing, medical treatment, medicine, catalysis and the like.

Description of the drawings:

FIG. 1: a composite material preparation flow chart;

FIG. 2: infrared test pattern of pd nanoparticles;

FIG. 3: a uv test pattern of pd nanoparticles;

FIG. 4: transmission electron microscopy transmission and electron diffraction test patterns of pd nanoparticles.

The specific implementation scheme is as follows:

the preparation process of the organic-inorganic hybrid material of polystyrene palladium nanocubes linked by sulfur-hydrogen bonds is shown in figure 1, and comprises the following steps:

the method comprises the following steps: 10mM H₂PdCl₄Solution preparation: 0.1773g of PdCl₂Dissolving in 10ml of 0.2 mol/L hydrochloric acid solution, adding 90ml of redistilled water, and heating for 10 min.

Step two: 0.5ml of the 10mM H2PdCl4 solution from step one was added to 20 ml of a 10mM CTAC solution in a 90 ℃ oil bath. Stirring was carried out at 800 rmp. Stirred for 10 minutes.

Step three: 1ml of a 10mM aqueous ascorbic acid solution was added. 0.01ml of a 10mM aqueous solution of sodium borohydride. 0.01ml of a 10mM aqueous solution of sodium citrate. The reaction was stirred for 30 minutes and stored at a constant temperature of 30 ℃ as seed crystals. Then taking different crystal seeds to control the crystal size.

Step four: 0.5ml of a 10mM solution of H2PdCl4 was added to 10ml of a 50mM CTAC solution, heated in a water bath, magnetically stirred at 2000rmp, and then different amounts of cubic nanocrystals were added. We here give a contrast amount of the gradient. Adding 50 ul of seed crystals in the third step and marking as a sample 1; adding a seed crystal 250 ul and marking as a sample II; adding seed crystal 500 ul and marking as sample three; adding seed crystal 1000 ul and marking as sample four; seed crystals 2000 ul were added and labeled sample five; seed crystals were added at 3000 ul and labeled as sample six.

Step five: 0.5ml of 10mM KI and 1ml of 10mM aqueous ascorbic acid solution were added. Stirring by magnetic force at 2000rmp, heating in water bath at 80 deg.C, and performing seed growth reaction.

Step six: the size of the nanocubes was adjusted by the amount of seeds added, which together with the side length of the corresponding nanocubes obtained were as follows: marking 50 ul of seed crystal of the sample 1 as 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. Step seven: after completion of the reaction, the reaction mixture was centrifuged at 12000 rpm for 15 minutes. The lower crystals were collected.

Step eight: under the ultrasonic condition, adding the concentrated gold nanocrystals (0.4 ml-0.8 ml) into a chloroform solution of ps-sh (10 mg0.2mg/ml), continuously performing ultrasonic treatment at 30 ℃ for 30 minutes, and standing at room temperature for 24 hours.

Step nine: centrifuge at 12000rmp for 30min to remove the supernatant.

Step ten: the liquid centrifuged in the ninth step was dispersed in tetrahydrofuran, precipitated and centrifuged for 12000rmp three times for 30 min. The same process of sonication, maturation and purification was then repeated with the addition of 4mg of ps-sh (0.2 mg/ml).

Claims

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.