CN101805026A - Method for preparing spherical super-paramagnetic ferroferric oxide nano-clusters - Google Patents

Abstract

A kind of preparation method of spherical superparamagnetic ferriferric oxide nanocluster, it is to get ferric chloride hexahydrate, be dissolved in ethylene glycol, the consumption of ethylene glycol is that every millimole of ferric chloride hexahydrate uses 1-40 Milliliter of ethylene glycol, stir to obtain a uniform reddish-brown solution, take anhydrous sodium acetate, dissolve in the solution of step 1, ultrasonically, stir to obtain a uniform yellow-brown viscous solution, the ratio of the amount of anhydrous sodium acetate to ferric chloride The ratio is 1:1 to 8:1; polyacrylic acid is dissolved in the solution, ultrasonically and stirred to obtain a uniform red viscous solution, and the amount of PAA is to add PPA to every 40-400 ml of the above-mentioned ethylene glycol or diethylene glycol solution 1ml. Transfer the above solution to a hydrothermal kettle liner with a total volume of 50ml (made of polytetrafluoroethylene), seal it at 180-220°C, react for 6-16 hours, cool down to room temperature naturally, take out the sample and wash it with water and alcohol The spherical superparamagnetic iron tetraoxide nanoclusters were obtained. The synthesis method only needs one-step reaction, and the reagents used are cheap and non-toxic.

Description

Preparation of Spherical Superparamagnetic Iron Tetroxide Nanoclusters

technical field

The invention relates to a preparation method of spherical superparamagnetic iron tetraoxide nano-clusters.

Background technique

As a special property of magnetic nanomaterials in small size, superparamagnetism has great advantages in many fields. Superparamagnetic Fe3O4 nanomaterials have a wide range of applications in fields such as magnetic separation and detection, magnetic fluids, targeted drug loading, and hyperthermia. In view of the above reasons, superparamagnetic ferroferric oxide nanomaterials have been widely studied [see: (a) S.Sun, C.B.Murray, D.Weller, L.Folks and A.Moser, Science, 2000, 287, 1989-1992; (b) C.Xu, K.Xu, H.Gu, R.Zheng, H.Liu, X.Zhang, Z.Guo and B.Xu, J.Am.Chem.Soc., 2004, 126, 9938-9939; (c) M.-J.Hu, Y.Lu, S.Zhang, S.-R.Guo, B.Lin, M.Zhang and S.-H.Yu, J.Am. Chem. Soc., 2008, 130, 11606-11607; (d) M. Arruebo, R. Fernandez-Pacheco, M. R. Ibarra and J. Santamaria, Nano Today, 2007, 2, 22-32.]. At present, the preparation methods of superparamagnetic iron tetroxide mainly include coprecipitation method, microemulsion method, thermal decomposition method, solvothermal method and so on. Among them, from the perspective of synthesis operation, co-precipitation is the simplest, and thermal decomposition is the most difficult. From the perspective of synthesis temperature, coprecipitation is the lowest, while thermal decomposition and solvothermal method are higher. However, from the perspective of shape control and particle size distribution, solvent Thermal and pyrolysis methods are preferred. [See: (e) Park, J.; An, K.; Hwang, Y.; Park, J.-G.; Noh, H.-J.; Kim, J.-Y.; Park, J.- H.; Hwang, N.-M.; Hyeon, T. Nat. Mater. 2004, 3, 891. (f) Fried, T.; Shemer, G.; Markovich, G. Adv. Mater. 1158. (g) Arruebo, M.; Fernandez-Pacheco, R.; Ibarra, M.R.; Santamaria, J. Nano Today 2007, 2, 22. (h) Sun, S.; Zeng, H.; Robinson, D.B.; Raoux, S.; Rice, P.M.; Wang, S.X.; Li, G.J. Am. Chem. Soc. 2004, 126, 273.]. The critical size of superparamagnetic ferroferric oxide nanomaterials is generally 15nm, and the small size leads to a small saturation magnetization, but ferric ferric oxide nanoparticles exceeding this size often have remanence when the magnetic field is removed, resulting in agglomeration , affecting applications in fields such as medicine. Moreover, the dispersibility of superparamagnetic iron tetroxide nanomaterials in water is also an important factor in its biological applications. Currently, there is no report on the one-step preparation of superparamagnetic iron tetraoxide nanoclusters with good dispersion in water and high magnetization by solvothermal method. [See: (i) X. Jia, D. Chen, X. Jiao and S. Zhai, Chem. Commun., 2009, 968-970; (j) J. Ge, Y. Hu, M. Biasini, C. Dong, J.Guo, W.P.Beyermann and Y.Yin, Chem.Eur.J.2007, 13, 7153-7161; (k) A.H.Lu, E.L.Salabas and F.Schuth, Angew.Chem.Int.Ed., 2007 , 46, 1222-1244.]

Contents of the invention

The purpose of the present invention is to provide a spherical superparamagnetic ferric oxide nanometer material with uniform size and good dispersibility in water. The clustered spheres are composed of particles of about 10nm, the size of the material is uniform, and the particle size of the clustered spheres is 100-500nm.

Technical scheme of the present invention is as follows:

A kind of preparation method of spherical superparamagnetic iron tetraoxide nanocluster, it comprises the following steps:

Step 1. gets ferric chloride hexahydrate, is dissolved in ethylene glycol or diethylene glycol, and the consumption of ethylene glycol or diethylene glycol is that every millimol ferric chloride hexahydrate uses 1-40 milliliters of ethylene glycol or Diethylene glycol, stirred to obtain a uniform reddish-brown solution;

Step 2. Take anhydrous sodium acetate, dissolve it in the solution of step one, ultrasonically and stir to obtain a uniform yellow-brown viscous solution, and the ratio of the amount of anhydrous sodium acetate to ferric chloride is 1:1～8:1; Then get PAA (polyacrylic acid) and add in this solution, ultrasonic, stir to obtain uniform red viscous solution, the consumption of PAA is to add PPA 1ml in the ethylene glycol of every 40-400 milliliter step 1 or diethylene glycol;

Step 3. The above solution is transferred to a hydrothermal kettle liner (made of polytetrafluoroethylene) with a total volume of 50ml. After airtight, react at 180-220°C for 6-16 hours, cool to room temperature naturally, take out the sample and wash it with alcohol. After washing, spherical superparamagnetic iron tetraoxide nanoclusters are obtained.

In the above preparation method, the number average molecular weight of the polyacrylic acid described in step 2 is 1,000-100,000.

In the above-mentioned preparation method, the spherical superparamagnetic iron tetraoxide nano-clusters prepared in step 3 are stored in alcohol for several months without deterioration after magnetic separation.

In the above-mentioned preparation method, the drying temperature of the spherical superparamagnetic ferric iron tetroxide nanoclusters prepared in step 3 should not be higher than 50° C., and the drying time should not exceed 10 hours.

The spherical superparamagnetic ferric oxide nanomaterial of the present invention is characterized by X-ray powder diffraction (XRD), and the result shows that the prepared sample is ferric oxide (see Figure 1). Scanning electron microscopy (SEM) characterization, the results show that the prepared iron ferric oxide nanomaterials have a cluster structure, along with the adjustment of ferric chloride hexahydrate addition, can obtain diameter 100-500nm adjustable cluster particle stacking ball ( See Figure 2). Transmission electron microscopy, selected area electron diffraction and high-resolution electron microscopy showed that the obtained sample was composed of small particles of about 10 nanometers and had good crystallinity (see Figure 3). Moreover, the surface of the sample is rich in carboxyl modification (see Figure 4), which is very conducive to a good functional treatment. The magnetic test sample showed strong magnetism, with the highest magnetic strength reaching 76.7 emug-1 at room temperature, showing superparamagnetism. The inset photo shows that the material has good dispersion in water (see Figure 5).

The invention provides a method for synthesizing a superparamagnetic ferriferric oxide nanometer material. The synthesis method only needs one-step reaction, and the reagents used are cheap and nontoxic. This method has the advantages of convenience, quickness and good reproducibility. The prepared material has superparamagnetism and strong magnetization, and has good dispersibility in water.

Description of drawings

Fig. 1 is the X-ray powder diffraction (XRD) characterization result of the spherical superparamagnetic iron tetraoxide nanocluster of the present invention (corresponding to the sample obtained in Example 1).

Fig. 2 is the scanning electron microscope (SEM) characterization result of spherical superparamagnetic iron tetraoxide nanoclusters of the present invention (A figure corresponds to the characterization result of the sample obtained in Example 4, and B figure corresponds to the characterization result of the sample obtained in Example 1).

Fig. 3 is a transmission electron microscope (TEM) selection electron diffraction and high-resolution electron microscope characterization results of the spherical superparamagnetic iron tetraoxide nanoclusters in the present invention (corresponding to the sample obtained in Example 1).

Fig. 4 is the infrared characterization result of the spherical superparamagnetic iron tetraoxide nanoclusters in the present invention (corresponding to the sample obtained in Example 1).

Fig. 5 is the magnetic test and characterization results of the spherical superparamagnetic iron tetraoxide nanoclusters in the present invention (the A curve corresponds to the magnetic characterization of the sample obtained in Example 1, and the B curve corresponds to the magnetic characterization of the sample obtained in Example 4).

Detailed ways

Embodiment 1. Preparation of spherical superparamagnetic ferric oxide nanoclusters

Take 5 mmol of ferric chloride hexahydrate, dissolve it in 40 ml of ethylene glycol, and stir to obtain a uniform reddish-brown solution. Take 20mmol of anhydrous sodium acetate and 1ml of PAA (number-average molecular weight: 100,000) and dissolve in the above solution in batches, sonicate and stir to obtain a uniform red viscous solution. The above solution was transferred to a hydrothermal tank with a total volume of 50ml (made of polytetrafluoroethylene), and then reacted at 220°C for 6 hours after airtight, then cooled to room temperature naturally, and the sample was taken out and washed with water and alcohol for several times to obtain the product. The diameter is about 500nm, the XRD characterization is shown in Figure 1, the scanning electron microscope characterization is shown in Figure 2B, the transmission electron microscope characterization is shown in Figure 3, the infrared characterization is shown in Figure 4, and the magnetic characterization is shown in Figure 5A.

Example 2. Preparation of Spherical Superparamagnetic Iron Tetroxide Nanoclusters

The "ethylene glycol" in Example 1 was changed to "diethylene glycol", and the other preparation conditions were the same as in Example 1 to obtain a product similar in appearance and properties to Example 1. Result is with embodiment 1.

Example 3. Preparation of Spherical Superparamagnetic Iron Tetroxide Nanoclusters

The "5mmol ferric chloride hexahydrate" in Example 1 was changed to "40mmol ferric chloride hexahydrate", and the other preparation conditions were the same as in Example 1 to obtain a product similar in appearance and properties to Example 1. Result is with embodiment 1.

Example 4. Preparation of Spherical Superparamagnetic Iron Tetroxide Nanoclusters

The "5mmol ferric chloride hexahydrate" in Example 1 was changed to "1mmol ferric chloride hexahydrate", and the other preparation conditions were the same as in Example 1 to obtain a product similar in appearance and properties to Example 1. The results were the same as in Example 1, and the particle size of the obtained product was about 50 nm. The scanning electron microscope characterization was shown in FIG. 2B , and the magnetic characterization was shown in FIG. 5B .

Example 5. Preparation of Spherical Superparamagnetic Iron Tetroxide Nanoclusters

The "20mmol anhydrous sodium acetate" in Example 1 was changed to "5mmol anhydrous sodium acetate", and the other preparation conditions were the same as in Example 1 to obtain a product similar in appearance and properties to Example 1. Result is with embodiment 1.

Example 6. Preparation of Spherical Superparamagnetic Iron Tetroxide Nanoclusters

The "20mmol anhydrous sodium acetate" in Example 1 was changed to "40mmol anhydrous sodium acetate", and the other preparation conditions were the same as in Example 1 to obtain a product similar in appearance and properties to Example 1. Result is with embodiment 1.

Example 7. Preparation of Spherical Superparamagnetic Iron Tetroxide Nanoclusters

Change "1ml PAA" in Example 1 to "0.1ml PAA", and other preparation conditions are the same as in Example 1 to obtain a product similar to Example 1 in appearance and properties. Result is with embodiment 1.

Example 8. Preparation of Spherical Superparamagnetic Iron Tetroxide Nanoclusters

Change "220°C" in Example 1 to "180°C", and the other preparation conditions are the same as in Example 1 to obtain a product similar in appearance and properties to Example 1. Result is with embodiment 1.

Example 9. Preparation of Spherical Superparamagnetic Iron Tetroxide Nanoclusters

Change "six hours" in Example 1 to "sixteen hours", and the other preparation conditions are the same as in Example 1 to obtain a product similar to Example 1 in appearance and properties. Result is with embodiment 1.

Example 10. Preparation of Spherical Superparamagnetic Iron Tetroxide Nanoclusters

The PPA with a number average molecular weight of 100,000 in Example 1 was changed to PPA with a number average molecular weight of 1000, and the other preparation conditions were the same as in Example 1 to obtain a product similar in appearance and properties to Example 1. Result is with embodiment 1.

Claims (4)

1. the method for making of a spherical super-paramagnetic ferroferric oxide nano-clusters is characterized in that it comprises the following steps:

Step 1. is got Iron trichloride hexahydrate, is dissolved in ethylene glycol or the Diethylene Glycol, and the consumption of ethylene glycol or Diethylene Glycol is every mmole Iron trichloride hexahydrate with 1-40 milliliter ethylene glycol or Diethylene Glycol, stir the homogeneous red tan solution;

Step 2. is got sodium acetate, anhydrous, is dissolved in the step 1 solution, ultrasonic, stir homogeneous yellowish brown viscous solution, sodium acetate, anhydrous is 1: 1～8: 1 with the ratio of the amount of substance of iron(ic) chloride; Get polyacrylic acid then and add in this solution, ultrasonic, stir the red viscous solution of homogeneous, the consumption of PAA is to add PPA 1ml in the ethylene glycol of every 40-400 milliliter step 1 or the Diethylene Glycol;

The above-mentioned solution of step 3. is transferred in the water heating kettle inner bag that cubic capacity is 50ml (tetrafluoroethylene system), airtight back is at 180-220 ℃, reacted 6-16 hour, and naturally cooled to room temperature, the washing of taking-up sample, alcohol obtain spherical super-paramagnetic ferroferric oxide nano-clusters after washing.

2. method for making according to claim 1 is characterized in that: the described polyacrylic number-average molecular weight of step 2 is 1000-100000.

3. method for making according to claim 1 is characterized in that: the prepared spherical super-paramagnetic ferroferric oxide nano-clusters of step 3 is stored in the alcohol after magnetic resolution.

4. method for making according to claim 1 is characterized in that: the prepared spherical super-paramagnetic ferroferric oxide nano-clusters of step 3, drying temperature should not be higher than 50 ℃, and time of drying should not be above 10 hours.

Images