SU1325330A1 - Method of determining average size of polymeric sorbent pores - Google Patents

Abstract

The invention relates to a method for determining the pore size of polymeric sorbents, can be used to analyze the properties of polymeric materials, and allows to simplify the analysis and improve its accuracy. The effect is achieved by using an aqueous solution of p-chloroaniline as the adsorbent and calculating the average pore size using a formula that takes into account the average value of the affinity coefficient, iO, 71, which relates the characteristic adsorption energies of benzene and p-chloroaniline from aqueous solutions. 2 tab. with

Description

The invention relates to the field of chemistry and technology of sorbents and can be used in the analysis of the properties of porous polymeric materials (polymers) used to treat wastewater in the chemical, oil refining and other industrial sectors.

The average pore size is one of the most important physicochemical characteristics of sorption materials and determines the scope of their application.

The purpose of the invention is to simplify the analysis and increase its accuracy.

Example 1. About, 25 g of a polymeric sorbent Polysorb 40/100. - porous copolymer of styrene and divinylbenzene - treated with an aqueous solution of p-chlorine

aniline with a volume of 0.05 l with an initial concentration of CQ of 8.75 mmol / l. After contacting the polymer sorbent with a solution for 8 h, the residual concentration of p-chloroaniline Cf 4.10 mmol / l is determined. P (Co - Cf) - V

formula

but

m

where v

the volume of p-chloroaniline; m is the weighed amount of the sob ,, g, and the value of the capacity of the polymer sorbent in n-chloroaniline is found to be 0.93 mmol / l. According to a known method, the value of the limit capacity of the polymer sorbent for p-chloroaniline Z.ooo mmol / g is determined.

The affinity coefficient / b was determined based on the following experiments. The isotherms of benzene adsorption from vapors and p-chloroaniline from aqueous solutions on active carbons of four grades were measured.

From the obtained data, the values of the characteristic energy of benzene adsorption from vapors (E) and p-chloroaniline from aqueous solutions (E) on each coal grade were calculated and the value of the affinity coefficient for coal was found using the formula ft Е / Ер.

The results are shown in Table. one.

The average affinity coefficient is 0.71.

Calculate the average pore size by the formula

BUT

VTTa

R - t. Ig CTC

- Iga,

where X is the average pore size of the polymer sorbent, nm; R is a universal gas constant, equal to 8.31. Y vkJ. mol.grad T - temperature. TO; Cj - solubility of p-chloranil-. on in water, equal to 24 mmol /

/ l; From here:

Y 8.55-0.71 Vlg 1.51 - Ig 0.93 8.31 -10-3 .293. Ro: 4, f

X

 1.495 nm. ,

 1.494 nm.

Example 2. A portion of the polymer-sorbent grade 40/100 0.25 g is treated with an aqueous solution of p-chloroaniline with a volume of 0.05 l with an initial concentration of 10.3 mmol / l. The residual equilibrium concentration of p-chloroaniline after contacting the solution with a polymer sorbent is 5.10 mmol / l, a value of 1.04 mmol / g. The average pore size of a polysorb is 40/100;

 8.55 .0.71 Vlg 1.51 - Ig 1.04 8.31-10-3 293

Ig

24

5.1

50

35

40

55

Examples 3-7. The determination of the average pore size is carried out as described in Example 1. The data for analysis and the results of the determinations are given in Table. 2

PRI me R 8 (comparative). On a weight of 40/100 polymeric sorbent, 0.25 g is treated with an aqueous solution of p-nitrophenol with a volume of 0.05 l with an initial concentration of C of 5.35 mmol / l. After contacting the polymeric adsorbent with a solution for 8 hours, the residual concentration of p-nitrophenol is 4, 10 mmol / l. The capacity of polymeric sorbent for p-nitrophenol is 0.25 mmol / g. The value of the limiting capacity. The polymeric sorbent for p-nitrophenol is Eoe 0.95 mmol / g Using the found values of the affinity coefficients of 0.925 and 1.66, the following values of average pore sizes for p-nitrophenol are found:

 i

 8.55-0.925 Vlg 0.95 -lgO 25 8.31 -10-3 293

Ig

 1.74 HM;

1325330

characterized in that, in order to simplify the analysis of 109.5 and increase its accuracy, an aqueous solution of p-chloroaniline is used as an organic compound and the treatment is carried out before the onset of

,one

five

about gr. / - ..- constant equilibrium concentration

. oh 55-1, then vie 0.95 - lgO, 25 ,, oss, -,

as ° y, p-vnnnaHunuHa ppm P-9CH G r PPRLR -

8.31 -10-3 293

Ig

p-chloroaniline at 20-25 ° C after.- 109.5 10 by the following calculation of an average pore size of 4.1 using the formula

3.12 nm.

Comparison of these values with an average pore size of 40/100 polymeric sorbent, determined by the method of small angle X-ray scattering and equal to 1.5 nm, shows that p-nitrophenol cannot be used as a standard adsorb. that

Claims (1)

Invention Formula A method for determining the average pore size of a polymeric sorbent by treatment with an organic compound. Polysorb 30/100 Polysorb 30/130 4,953,010,390,891,66 11,307,800,700,891,65 8,105,020,621,10 1,82 16,1211,300,961,101,82 five X 8.55.0,71 flgaco - Iga Cs RT Ig where X is the average pore size of the sorbent, nm; R is a universal gas constant; T is the temperature. TO;  - the maximum capacity of the sorbent for p-chloraniline; a - sorbent capacity for p-chloraniline at an equilibrium concentration Cf} C 5 - solubility of p-chloroaniline in water, Table 1 Polysorb 30/150 12.20 7.80 0.88 1.24 1.97 14.40 9.50 0.98 1.24 1.98 2.00  The average pore size is determined from small-angle X-ray scattering data. Compiled by V.Mkrtychan Editor A.Vorovich Tekhred L.Serdyukova Proofreader G.Reshetnik Order 3042/37 Circulation 776 Subscription VNNPI State Committee of the USSR for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and political enterprise, Uzhgorod, st. Project, 4 Continued table. 2