Preparation method of antibacterial deodorizing modified fiber for water purification

Abstract

A preparation method of an antibacterial deodorizing modified fiber for water purification is provided. Maleic anhydride is used to perform an addition reaction with sodium polysulfide to generate a disulfide antibacterial agent I, the disulfide antibacterial agent I continues to react with 2-amino-5-nitropyridine in an acetic acid solution under the catalysis of sodium acetate to obtain a compound II, then, the nitro in the compound II is reduced into amino by ferrous sulfate, meanwhile, anhydride is hydrolyzed into carboxylic acid in a faintly acid aqueous solution to obtain a compound III, and finally, under alkaline conditions, the amino in the compound III reacts with the cyan in a polyacrylonitrile fiber to obtain a modified polyacrylonitrile fiber. The prepared modified polyacrylonitrile fiber can remove various heavy metals in sewage and has good antibacterial and anti-mildew effects, thereby achieving the effects of water purification and deodorization.

Claims

1. A method of preparing an antimicrobial deodorizing modified fiber for water purification, comprising: 1) preparing a Na.sub.2S.sub.x solution comprising: taking 1 mol of sodium sulfide and 1.5 mol of elemental sulfur, adding into 200 mL of water and heating to 50-60° C., stirring to completely dissolve the sodium sulfide and the elemental sulfur, and cooling to room temperature of 20-30° C. to obtain the Na.sub.2S.sub.x solution, wherein the x in the Na.sub.2S.sub.x is from 2-6; 2) preparing a disulfide antibacterial agent I comprising adding 2 mol of sodium bicarbonate into a reaction bottle, adding 2 L of water, stirring to completely dissolve the sodium bicarbonate; adding 2 mol of maleic anhydride; moving the reaction bottle into an ice salt bath, dripping the Na.sub.2S.sub.x solution from step 1) into the reaction bottle while stirring; removing the reaction bottle from the ice salt bath, and stirring for 4-5 h at room temperature of 20-30° C.; performing liquid separation to remove the aqueous solution and yield a crude product solution; adding 1 L of 1 mol/L sodium sulfite solution into the crude product solution, heating to 50° C., stirring for 2-3 h; performing liquid separation to remove the aqueous solution, and yield a crude disulfide antibacterial agent I which is washed with water; distilling the crude disulfide antibacterial agent I to obtain pure disulfide antibacterial agent I of formula I, via the following reaction formula: ##STR00011## 3) introducing a pyridine chelating group comprising adding the disulfide antibacterial agent I from step 2, 1 mol of 2-amino-5-nitropyridine, 1 g of catalyst and 15 ml of acetic acid which forms a reaction mixture; heating to 115-120° C., and stirring for 4-5 h; distilling the reaction mixture under reduced pressure to remove acetic acid, and washing, filtering, and drying the reaction mixture to obtain compound II via the following reaction formula: ##STR00012## 4) reducing compound II comprising adding compound II from step 3 and 100 ml of ethanol aqueous solution with mass fraction of 50%, to form a solution, adjusting the pH of the solution to acidic, and maintaining the temperature at 30-35° C., adding 0.6 mol of reductant at a rate of 0.2 mol of reductant every 20 min to the solution to form a reaction mixture; stirring the reaction mixture for 5-6 h; recrystallizing with absolute ethanol; filtering and drying to obtain compound III, via the following reaction formula: ##STR00013## 5) modifying polyacrylonitrile fiber comprising dissolving compound III from step 4) in 500 ml of tert-amyl alcohol solution, adding 1 g of polyacrylonitrile fiber and adjusting the pH to alkaline; heating to 120-130° C. for 4 h to form a crude fiber product; removing the crude fiber product and washing with water to neutral pH, soaking the crude fiber product in 0.1 mol/L aqueous hydrochloric acid to form a crude secondary-treated fiber; washing the crude secondary-treated fiber with distilled water to neutral pH, and drying via vacuum at 50-55° C. for 15-24 h to yield the modified polyacrylonitrile fiber of formula IV via the following reaction formula: ##STR00014##

2. The method of preparing the antibacterial deodorizing modified fiber for water purification according to claim 1, wherein, in step 2, the temperature of the ice salt bath is maintained at 0-6° C.

3. The method of preparing the antibacterial deodorizing modified fiber for water purification according to claim 1, wherein, in step 3, the catalyst is sodium acetate.

4. The method of preparing the antibacterial deodorizing modified fiber for water purification according to claim 1, wherein, in step 4, the adjusting of the pH of the solution is to a pH of 5.5-6.2, and the adjusting step is accomplished by adding a saturated sodium dihydrogen phosphate aqueous solution.

5. The method of preparing the antibacterial deodorizing modified fiber for water purification according to claim 1, wherein, in step 4, the reductant is ferrous sulfate.

6. The method of preparing the antibacterial deodorizing modified fiber for water purification according to claim 1, wherein, in step 5, the adjusting of the pH of the solution is to a pH of 8.0-8.5, and the adjusting step is accomplished by adding a 1 mol/L sodium hydroxide aqueous solution.

7. The method of preparing the antibacterial deodorizing modified fiber for water purification according to claim 6, wherein in step 4, the adjusting of the pH of the solution is to a pH of 5.5-6.2, and the adjusting step is accomplished by adding a saturated sodium dihydrogen phosphate aqueous solution adjusting.

8. The method of preparing the antibacterial deodorizing modified fiber for water purification according to claim 7, wherein in step 3, the catalyst is sodium acetate.

9. The method of preparing the antibacterial deodorizing modified fiber for water purification according to claim 8, wherein in step 2, the temperature of the ice salt bath is maintained at 0-6° C.

Description

DETAILED DESCRIPTION

(1) A clear and complete description of technical solutions in the embodiments of the present invention will be given below. Apparently, the embodiments described below are merely a part, but not all, of the embodiments of the present invention. All of other embodiments, obtained by those of ordinary skilled in the art based on the embodiments of the present invention without any creative effort, fall into the protection scope of the present invention.

Embodiment 1

(2) The preparation method of an antibacterial deodorizing modified fiber for water purification specifically includes the following steps:

(3) Step 1: preparation of a disulfide antibacterial agent

(4) The reaction formula is as follows:

(5) ##STR00007##

(6) Step 1.1: preparation of a Na.sub.2S.sub.x solution

(7) 1 mol of sodium sulfide and 1.5 mol of elemental sulfur were weighed and placed in a beaker, and 200 ml of water was added, the mixture was then heated to 50-60° C., with continuously stirring to completely dissolve the sodium sulfide and the elemental sulfur. The solution was cooled to room temperature to obtain the Na.sub.2S.sub.x solution for future use, wherein the x in Na.sub.2S.sub.x is a number of 2-6;

(8) Step 1.2: preparation of a disulfide antibacterial agent I

(9) 2 mol of sodium bicarbonate was weighed and added into a reaction bottle, 2 L of water was added, the mixture was stirred to completely dissolve the sodium bicarbonate, and then 2 mol of maleic anhydride was added. The reaction bottle was moved into an ice salt bath, the temperature of the ice salt bath was maintained at 0-6° C., the Na.sub.2S.sub.x solution prepared in step 1.1 was dripped into the reaction bottle while stirring. After the Na.sub.2S.sub.x solution is dripped, the reaction bottle was removed from the ice salt bath and continuously stirred for 5 h at the room temperature of 25° C., then liquid separation was performed to remove the aqueous solution, 1 L of 1 mol/L sodium sulfite solution was added into the crude product solution, the solution was heated to 50° C. and was continuously stirred to react for 2 h, the liquid separation was performed again, and the product was washed with water, distilled to obtain the disulfide antibacterial agent having the structure of formula I (as shown above);

(10) The mass spectrometry result of the obtained target product I is: HRMS m/z (ESI.sup.+) calcd for C.sub.8H.sub.6O.sub.6S.sub.2([M].sup.+), 261.95, found 261.2621.

(11) Step 2: introduction of a pyridine chelating group

(12) The reaction formula is as follows:

(13) ##STR00008##

(14) The disulfide antibacterial agent Iprepared in step 1, 1 mol of 2-amino-5-nitropyridine, 1 g of sodium acetate and 15 ml of acetic acid were added into the reaction bottle in turn, the mixture was heated to 120° C. and stirred to perform the reaction for 4 h, the reduced pressure distillation was then performed to remove acetic acid after the reaction is completed, the sodium acetate was removed by washing with water, and a compound II was obtained by filtering and drying.

(15) The mass spectrometry result of the obtained target product II is: HRMS m/z (ESI.sup.+) calcd for C.sub.13H.sub.9N.sub.3O.sub.7S.sub.2([M].sup.+), 383.36, found 382.9924.

(16) Step 3: reduction of the compound II

(17) The reaction formula is as follows:

(18) ##STR00009##

(19) The compound II prepared in step 2 was added into a three-necked flask provided with a thermometer, a mechanical stirrer and a reflux condensing tube, 100 ml of ethanol aqueous solution with mass fraction of 50% was added, and the pH of the solution was adjusted to 5.8 by using saturated sodium dihydrogen phosphate aqueous solution, the temperature in the three-necked flask was maintained at 30° C., then 0.6 mol of reductant was added in three batches, that is, 0.2 mol of reductant was added every 20 min, after all the reductant is added, the reduction reaction was continued for 5-6 h with stirring, then recrystallization was performed by using absolute ethyl alcohol after the reaction is completed, and filtering and drying ware performed to obtain a compound III, the reductant used was ferrous sulfate.

(20) The mass spectrometry result of the obtained target product III is: HRMS m/z (ESI.sup.+) calcd for C.sub.13H.sub.13N.sub.3O.sub.6S.sub.2([M].sup.+), 371.25, found 371.1279.

(21) The nuclear magnetic characterization of the compound III:

(22) .sup.1H NMR (400 MHz, CDCl.sub.3): δ11.05 (s, 2H), 8.56 (d, J=7.4 Hz, 1H), 7.65 (s, J=8.6 Hz, 1H), 7.11 (d, J=7.0, 1H), 5.84 (s, 2H), 3.71 (t, 2H), 3.12 (d, 2H), 2.75 (d, 2H) ppm.

(23) Step 4: modification of polyacrylonitrile fiber

(24) The compound III prepared in step 3 was dissolved in 500 ml of tert-amyl alcohol solution, 1 g of polyacrylonitrile fiber was weighed and immersed in the tert-amyl alcohol solution, the pH of the tert-amyl alcohol system was adjusted to 8.5 by using a 1 mol/L sodium hydroxide aqueous solution, the reaction solution was heated up to 130° C. to react for 4 h, the fiber was taken out after the reaction is completed, and washed to neutrality with distilled water, the prepared fiber was soaked in 0.1 mol/L hydrochloric acid aqueous solution for 3 h, the fiber was taken out again and washed to neutrality with distilled water, then vacuum drying was performed at 50° C. for 24 h to obtain the modified polyacrylonitrile fiber with the structure of formula IV (as shown below).

(25) The reaction formula is as follows:

(26) ##STR00010##

(27) The infrared characterization of the modified polyacrylonitrile fiber D is shown as follows: IR(KBr): V=3315-3449 cm.sup.−1 (—NH—,—COOH), 3229 cm.sup.−1 (—C═NH—), 3029 cm.sup.−1 (pyridine), 1732 cm.sup.−1 (—CO—), 1655 cm.sup.−1 (—C═NH—).

(28) The performance test of the modified polyacrylonitrile fiber:

(29) 1. Antibacterial property of the modified polyacrylonitrile fiber

(30) In the measurement of the minimum inhibitory concentration (MIC), the minimum concentration of the compound that has obviously aseptically grown in a test tube is the minimum inhibitory concentration of the compound;

(31) TABLE-US-00001 TABLE 1 MIC value of the modified polyacrylonitrile fiber Staphylococcus Escherichia Schizosaccharomyces aureus (mg/ml) coli(mg/ml) (mg/ml) Polyacrylonitrile no no no fiber antibacterial antibacterial antibacterial activity activity activity Carbon fiber 0.254 0.158 0.173 Modified 0.034 0.067 0.095 polyacrylonitrile fiber

(32) 2. Adsorption of heavy metal ions by the modified polyacrylonitrile fiber

(33) 10 g of modified polyacrylonitrile fiber and 10 g of carbon fiber were taken respectively, the fibers were added into 600 mL of waste water containing metal ion for 24 h, and the metal ion adsorption capacity was tested by an inductively coupled plasma emission spectrometer. In the waste water containing metal ion, the concentration of iron ions is 1500 ppm, the concentration of copper ions is 1000 ppm, the concentration of lead ions is 800 ppm, the concentration of silver ions is 500 ppm, and the concentration of mercury ions is 400 ppm;

(34) TABLE-US-00002 TABLE 2 Adsorption results of the heavy metal ions by the modified polyacrylonitrile fiber Adsorption Adsorption Adsorption Adsorption Adsorption capacity of capacity of capacity of capacity of capacity of iron ions copper ions lead ions silver ions mercury ions (mg/g) (mg/g) (mg/g) (mg/g) (mg/g) Carbon fiber 402.7 228.1 189.2 89.2 110.3 Modified 532.3 318.7 226.9 148.6 159.4 polyacrylonitrile fiber

(35) The modified polyacrylonitrile fiber and the carbon fiber after adsorption were placed respectively in 10 L of mixed acid solution (1 mol/L hydrochloric acid and 1 mol/L sulfuric acid). 5 h later, the fibers were taken out, washed and dried for 10 h, and repeated the adsorption experiment of the heavy metal ions with the same waste water, and the results are shown in Table 3:

(36) TABLE-US-00003 TABLE 3 Adsorption results of the heavy metal ions by regenerated fibers Adsorption Adsorption Adsorption Adsorption Adsorption capacity of capacity of capacity of capacity of capacity of iron ions copper ions lead ions silver ions mercury ions (mg/g) (mg/g) (mg/g) (mg/g) (mg/g) Carbon fiber 287.3 148.6 120.7 52.4 88.8 Modified 522.0 312.6 215.8 142.4 150.7 polyacrylonitrile fiber

(37) It can be seen from Table 2 and Table 3 that the modified polyacrylonitrile fiber of the present invention has good adsorption for various heavy metals in the waste water, and still has good adsorption capacity for the heavy metal ions after being regenerated.

(38) The above content is only an example and description of the concept of the present invention. Those skilled in the art to which the present invention belongs can make various modifications or supplements to the specific embodiments described or makes substitutes in a similar manner, and all these modifications or supplements or substitutes all belong to the protection scope of the present invention as long as not deviating from the concept of the present invention or exceeding the scope defined in the claims.