RU2412959C1 - Polymer chemosensory material - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to chemosensory materials which can be used as convertible optical indicators for continuous prolonged determination of presence and content of hydrogen ions in solutions. The invention discloses a polymer chemosensory material which contains cellulose triacetate in amount of 99.997-99.99 wt % and a tetraammonium salt of 5, 10, 15, 20-tetrakis(4-sulfonaphthophenyl)-21H, 23H-porphyrin in amount of 0.003-0.01 wt %.

EFFECT: material has selective optical response on content of hydrogen ions in solutions, does not contaminate the test solution and can be used several times in media with varying pH.

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Description

The invention relates to the chemical industry, in particular to the production of a polymeric chemosensor material, including a polymer and substituted porphyrin, which can be used for selective, continuous, long-term and non-polluting registration of the content of hydrogen ions in solutions.

State of the art

Currently, the production of new materials that can be used as reversible optical indicators for continuous long-term registration of the presence and content of hydrogen ions in solutions is relevant. Hydrogen ions are an integral part of water molecules and are in a state of constant exchange with them. The content of hydrogen ions in the blood, urine, cell plasma and other biological fluids of animals, plants and microorganisms allows us to judge the state of their health. The content of hydrogen ions in water and soil allows us to judge the suitability of a particular habitat for the life of various organisms. The content of hydrogen ions in agricultural and other food products allows us to judge their quality. For these reasons, continuous analytical control of hydrogen ions in biological fluids, the environment, food, technical and technological fluids is an important and integral part of medical, sanitary, environmental and production regulations.

Known polymer composition for chemosensory material [Shumilova G.I., Valiotti A.B., Makarychev-Mikhailov S.M. "Metalloporphyrins in ionometry." / In the book. Advances in the chemistry of porphyrins. T. 3. St. Petersburg: Research Institute of Chemistry, St. Petersburg State University, 2001

p. 314-325]. It contains, wt.%:

- a plasticizer, which can be dibutyl phthalate, di-hexyl sebacinate or o-nitrophenyl octyl ether - 66;

- polyvinyl chloride - 33;

- substituted porphyrin, which may be manganese-tetraphenylporfin chloride, gallium-tetraphenylporfin chloride, indium tetraphenylporfin chloride or thallium-tetraphenylporfin chloride - 1.

The material from this composition has selective, proportional and reversible electrochemical sensitivity to the content of only chloride, bromide, iodide, perchlorate, cyanide and acetate anions in aqueous solutions.

However, the material has the following disadvantages:

1. It does not have a sensitivity to hydrogen ions, which manifests itself in a selective, proportional and reversible color change in the presence of hydrogen ions, because the porphyrins included in its composition are not able to change color in the presence of hydrogen ions, and polyvinyl chloride does not have selective permeability with respect to hydrogen ions.

2. During the operation of the chemosensor material, the test solution becomes contaminated and the service life of the material is reduced due to the fact that the porphyrins dissolved in the plasticizer distributed in the polymer structure and the plasticizer itself are washed out by solvents entering the test solution.

SUMMARY OF THE INVENTION

An inventive task is to search for a polymer chemo-sensor material, including a polymer and substituted porphyrin, which would be capable of selective, proportional and reversible color change in the presence of hydrogen ions and would not contaminate the test solution.

The problem is solved by a polymeric chemosensor material, including a polymer and substituted porphyrin, which contains 99.997-99.99 wt% cellulose triacetate as a polymer, and tetra-ammonium salt 5,10,15,20-tetrakis as substituted porphyrin (4-sulfonaphthophenyl) -21H, 23H-porphyrin in an amount of 0.003-0.01 wt.%.

EFFECT: invention makes it possible to impart a sensitivity to hydrogen ions to a polymeric chemosensor material, which is manifested in selective, proportional and reversible color change in solutions with different contents of hydrogen ions, and does not contaminate the studied solutions.

Information confirming the reproducibility of the invention

The following substances are used to prepare the composition:

1. Cellulose triacetate can be used with any transparency, for example, CAS 9012-09-3, Fergana Production Association “Nitrogen”.

2. Formic acid CAS 64-18-6 PSA (86.5-99.7%) GOST 5848-73.

3. The tetraammonium salt of 5,10,15,20-tetrakis (4-sulfonatophenyl) -21H, 23H-porphin. It was obtained by the method of [Busby C.A., Dinello R.K., Dolphin D.A convenient preparation of ms-tetra (p-sulphonatophenil) porphyrin. - Can. J. Chem., 1975, Vol. 53, No. 11, P.1554]. Tetraphenylporfin (2 g) and concentrated sulfuric acid (50 ml) were ground in a porcelain mortar to a homogeneous consistency. The resulting mixture was placed in a 100 ml flask equipped with a stirrer and heated in a steam bath with stirring for 6 hours, after which it was left for 3 days. The contents of the flask were poured onto 150 g of ice. The precipitated green precipitate of porphyrin was separated by centrifugation and immediately washed several times with acetone (3 portions of 50 ml). The resulting tetrasulfonic acid tetraphenylporfin was mixed with 50 ml of water and transferred to the ammonium salt by careful neutralization with 10% aqueous ammonia. After distillation of the water under vacuum at 333-343 K, the crude product was isolated. The final purification of the tetraammonium salt of 5,10,15,20-tetrakis (4-sulfonatophenyl) -21H, 23H-porphin was carried out by chromatography on alumina of the II degree of activity. As solvent and eluent, n-butanol saturated with ammonia was used. To prepare the eluent, n-butanol and aqueous 25% ammonia were shaken in a separatory funnel. Then the mixture was left until complete separation. The upper butanol layer was carefully separated from the aqueous layer and used for chromatography. The raspberry zone of the ammonium salt of tetrasulfonic acid tetraphenylporfin was collected in a receiver, after which the target product was extracted with 1-2 ml of distilled water. After evaporation of water, a pure target product was obtained in 80% yield.

The invention is implemented as follows.

Example 1. The manufacture of polymer chemosensory material.

The material is obtained in the form of a polymer film by dry molding. To do this, 2 g (99.997 wt.%) Of cellulose triacetate powder is poured into 24 ml of formic acid and this mixture is left for 24 hours at room temperature for swelling. Then, 0.012 g (0.003 wt.%) Of the tetraammonium salt of 5,10,15,20-tetrakis (4-sulfonatophenyl) -21H, 23H-porphin is added, periodically stirring the mixture with a glass rod. Then the solution is passed through a Shot filter to separate mechanical impurities and obtain a homogeneous solution. Then, with the help of an applicator, a polymer film is formed, after which the formed film is left for 24 hours in air to remove formic acid. The formed film is separated from the glass substrate with water. Excess tetraammonium salt of 5,10,15,20-tetrakis (4-sulfonatophenyl) -21H, 23H-porphin from the surface of the formed film is washed by soaking the film in distilled water at 25 ° C for 30 minutes. At the final stage, the film is placed in a vacuum oven for 24 hours at 25 ° C for final drying. The film thickness is regulated by a movable bar, capable of lowering and rising vertically. The film thickness, measured using an IZV-1 thickness gauge with an accuracy of 0.5 μm, was 20–25 μm.

Example 2. Determination of the sensitivity of the polymer chemosensor material to hydrogen ions.

The polymer film obtained as described in example 1 was placed in an optical cuvette filled with a buffer solution with a pH of 6.86, held for 30 minutes, and the electronic absorption spectrum of the film was recorded at a temperature of 25 ° C using an Agilent 8453 recording spectrophotometer in the range from 350 to 850 nm, fix the wavelength of the absorption maximums of the film, which are 420, 483 and 698 nm. Then, the pH of the solution is changed with buffer solutions to 4.01, 3.56 and 1.68, and the electronic absorption spectrum of the film is also recorded at each pH value. In the pH range from 6.86 to 1.68, a gradual change in the color of the film material from almost colorless faint pink to intense green is observed, and a decrease in the intensity of the absorption band at 420 nm and an increase in the intensity of absorption bands at 483 and 698 nm are recorded in the electronic absorption spectrum. In this case, the color intensity of the film material, quantitatively determined by the absorption, at 483 and 698 nm, is proportional to the number of hydrogen ions in the solution.

The experiment was repeated three times. At the same pH values of the solutions, the position of the bands and the maximum absorption in the electronic absorption spectrum of the test polymer chemosensor material coincided. With increasing pH of the analyzed solution, the color intensity of the polymer film changes.

The parameters of the electronic absorption spectra of a polymer film with a different content of the components of the polymer composition placed in a solution with a different content of hydrogen ions (pH) at a temperature of 25 ° C are shown in the table.

These tables clearly confirm that the claimed chemosensor material is capable of selective, proportional and reversible color change in solutions with different contents of hydrogen ions and does not pollute the test solution. The selectivity of the claimed material is evidenced by the fact that during the transition from the alkaline medium of the analyzed solution to acidic in the electronic spectrum of the film, a decrease in the absorption intensity of the band at 420 nm and an increase in the absorption intensity at 483 and 698 nm are observed. The proportionality of the response of the material to the pH of the solution is evidenced by the absorption maximum of the band at 483 and 698 nm. A change in the content of hydrogen ions in the solution reversibly changes the color intensity of the film. This allows you to reuse the same material for rapid analysis of solutions in environments with changing pH.

Table Parameters of electronic absorption spectra of polymer chemosensor material of various compositions placed in a solution with a different content of hydrogen ions (pH) at a temperature of 25 ° C. Example No. The content of cellulose acetate, wt.% The content of porphyrin, wt.% pH Absorption maximum wavelength, nm / Absorption, units one 99.997 0.003 1.68 420 / 0.30 483 / 0.39 698 / 0.19 2 99.997 0.003 3.56 420 / 0.38 483 / 0.33 698 / 0.17 3 99.997 0.003 4.01 420 / 0.43 483 / 0.28 698 / 0.16 four 99.997 0.003 6.86 420 / 0.53 483 / 0.15 698 / disappears 5 99.994 0.006 1.68 420 / 0.59 483 / 0.77 698 / 0.38 6 99.994 0.006 3.56 420 / 0.75 483 / 0.66 698 / 0.34 7 99.994 0.006 4.01 420 / 0.85 483 / 0.53 698 / 0.32 8 99.997 0.006 6.86 420 / 1.05 483 / 0.3 698 / disappears 9 99.99 0.01 1.68 420 / 0.98 483 / 1.28 698 / 0.63 10 99.99 0.01 3.56 420 / 1.25 483 / 1.10 698 / 0.57 eleven 99.99 0.01 4.01 420 / 1.42 483 / 0.88 698 / 0.53 12 99.99 0.01 6.86 420 / 1.75 483 / 0.50 698 / disappears

Claims (1)

A polymeric chemosensory material comprising a polymer and substituted porphyrin, characterized in that it contains cellulose triacetate in the amount of 99.997-99.99 wt.% As the polymer, and the tetraammonium salt 5, 10, 15, 20-tetrakis as substituted porphyrin ( 4-sulfonaphthophenyl) -21H, 23H-porphyrin in an amount of 0.003-0.01 wt.%.