CN101393239A - Substance surface property parametric analysis system - Google Patents

Abstract

The invention discloses a system for analyzing material surface property parameters. The system can determine surface electric potential of materials accurately. A determining system comprises a sample processing device and a detection system, wherein the sample processing device comprises a sample accommodation device which is used for accommodating the determined materials and liquid, is also provided with a liquid inlet pipe and a liquid outlet pipe which are communicated with the sample accommodation device, wherein the liquid outlet pipe is connected with a constant flow pump, and the sample accommodation device is also provided with a stirring device; the detection system comprises an ionic activity detecting device, an ionic activity operating module and a surface parameter operating module, and the surface parameter operating module is used for receiving the ionic activity operated by the ionic activity operating module so as to work out the surface potential of the determined materials; and in a further technical proposal, total surface charge quantity, surface charge density, surface electric field intensity and specific surface area of the determined materials can be analyzed sequentially so as to realize the combined analysis of the material surface property parameter.

Description

Substance surface property parametric analysis system

Technical field

The present invention relates to colloidal chemistry, surface chemistry, materials science field, be specifically related to a kind of device that the surface nature parameter of material is measured.

Background technology

Surface naturies such as the surface potential of material, surface charge total amount, surface charge density, surface field intensity and specific surface area not only are widely used in the scientific research in fields such as colloid and interface science, material science, life science, soil science, ecology and environmental science, and also have a wide range of applications in field of chemical engineering such as papermaking, cement, pottery, cmp, coal slurry, coating, cosmetics, food industry, mixed dispersions, therefore, the mensuration to above-mentioned substance surface nature parameter seems particularly important.

In the prior art,, generally adopt indication ion absorption method and potentiometric titration, adopt the ionic adsorption method, must at first be informed in H for the mensuration of material surface total amount of electric charge ⁺Or OH ^-The absorption total amount in, how much have is to participate in Electrostatic Absorption, but because H ⁺And OH ^-Also participate in the absorption of chemical bond, can't predict the adsorbance that participates in Electrostatic Absorption, so this method can not be measured the surface charge total amount of system under any pH value, any electrolyte concentration and arbitrary temp that contains variable charge; And potentiometric titration not only is not suitable for containing the mensuration of the total amount of electric charge of permanent charge system, even variable charge system, its reliability also is a query always, therefore at present also be not applicable to the general assay method of material surface total amount of electric charge in different condition and the different systems, any analytical instrument of this not being measured.

In the prior art electric density is carried out one of method for measuring and be based on following formula

${\mathrm{\σ}}_0=\frac{T_C}{S}$

In the formula, σ ₀Be surface charge density, T _cBe the surface charge total amount, S is a specific surface area.

Owing to need this parameter of surface charge total amount in this method, the problem in the total quantitative determination of surface charge necessarily exists in surface charge density is measured.Moreover, in the surface charge density mensuration based on following formula, we also need the determination data of a specific surface area.Yet, different specific area measuring methods, there is very big difference in its measurement result.So, a surface charge density assay method that depends on this parameter of specific surface area, its result's reliability is difficult to hold.

Two of the surface charge density method for measuring are in the prior art, after obtaining the surface electrical place value of material, utilize the correlation formula of Gouy-Chapman can obtain the surface charge density value indirectly.But because of going back the extensively accurate assay method of suitable surface potential of neither one at present.So the application of this method of surface charge density mensuration at present still has difficulties.

So any analytical instrument of surface charge density not being measured in the prior art.

Surface field intensity is measured based on following formula in the prior art:

$E_0=\frac{4\mathrm{\π}}{\mathrm{\ϵ}}{\mathrm{\σ}}_0$

E in the formula ₀Be surface field intensity, ε is the medium specific inductive capacity, the ε of water=8.9 * 10 ^-10C ²/ Jdm.Owing to, exist in the surface field strength detection with surface charge density and measure identical problem to the dependence of surface charge density.Do not measure any analytical instrument of surface field intensity in the prior art yet.

In the prior art, for the mensuration of material specific surface area, existing multiple assay method is as inert gas absorption method, ion negative absorption method, ethylene glycol ethyl ether absorption method or glycerine absorption method or the like of common employing.But adopt these different assay methods with a kind of material, it is very greatly different that its result often differs.Though developed specific surface area measuring instrument according to the inert gas absorption method, this instrument is not suitable for the specific area measuring of swelling property material.

Material surface current potential among the application is defined as the current potential on diffusion layer initial surface in the electrostatic double layer or the OHP (outer Helmholtz face).The assay method of material surface current potential of the prior art comprises charge density method, negative absorption method, positive absorption method, secondary resonance genetic method, pH indication molecule method, fluorescence genetic method, atomic force microscopy and Zeta potential method etc.All these methods all have the limitation of oneself.Charge density method, negative adsorption method, positive absorption method and secondary resonance genetic method all only are suitable under the neutrallty condition, the surface potential pH-value determination pH of the permanent electric charge sample of single electrolyte system.PH indication molecule method, fluorometry and atomic force microscopy will produce the state of material surface itself and destroy, so the reliability of its measurement result often is difficult to hold.Except that the Zeta potential method, people also do not utilize additive method to develop the surface potential detection instrument.Though zeta potential instrument has been extensive use of, what the Zeta potential method was measured is not surface potential, and it is the current potential on the shear surface in the electrophoresis process (or slipping plane), and shear surface is usually away from defined surface here.Zeta potential can be measured under different pH, electrolyte and temperature conditions, so, just because of extensively be suitable under various conditions at present not, surface potential detection method accurately, people can only be the substitute of Zeta potential as surface potential at present.But big quantity research in recent years shows, measures surface potential with the Zeta potential method, only has meaning qualitatively usually.In addition, the Zeta potential method is very harsh to the conditional request of determination object, and promptly it requires the particle density of suspension colloid can not be too high, and particle grain size can not be too big.Even the maximum particle density of the new Zetaprobe type zeta potential instrument of releasing of U.S. Colloidal Dynamics company also only is 60% (volume density).So can't realize the system that density is higher, or " ortho states " of solid particulate matter measured at all.

In sum, present mensuration for material surface total amount of electric charge, specific surface area and material surface current potential, do not have method and apparatus reliable, that extensively be suitable for, and depend on material surface total amount of electric charge, specific area measuring result's material surface electric field intensity respectively, therefore the mensuration of surface charge density also have same defective.More there is not to carry out above-mentioned 5 parameters the device of simultaneous determination in the prior art.

Summary of the invention

In view of this,, the invention provides a kind of substance surface property parametric analysis system, can measure accurately the surface nature parameter of material under various conditions in order to address the above problem.

The object of the present invention is achieved like this, and substance surface property parametric analysis system comprises sample processing device and detection system, and described sample processing device comprises:

The sample storing apparatus is in order to hold measured object and liquid; And

Feed tube and drain pipe, described drain pipe is communicated with sample storing apparatus bottom, and feed tube is communicated with the sample storing apparatus; Described drain pipe is connected with constant flow pump;

Also be provided with stirring apparatus in the described sample storing apparatus;

Described detection system comprises:

The ion activity pick-up unit is used for each ion activity of test sample storing apparatus solution; And

Data processing equipment, the testing result of reception ion activity pick-up unit is analyzed the measured object surface parameter, specifically comprises:

The ion concentration computing module, the testing result according to receiving the ion activity pick-up unit calculates the counterion concentration value; And

The surface parameter computing module receives the ion concentration value that the ion concentration computing module calculates, and calculates the measured object surface potential according to the ion concentration value.

Further, described surface parameter computing module calculates measured object specific surface area, surface charge density, surface field intensity also according to the measured object surface potential, and calculates total amount of electric charge according to surface charge density and specific surface area;

Further, described ion activity pick-up unit comprises the detecting electrode that is arranged in the sample storing apparatus, also comprise millivoltmeter and ion activity arithmetical unit, the input end of described millivoltmeter is connected with described detecting electrode, output terminal is connected with the ion activity arithmetical unit, the ion activity arithmetical unit receives the potential data that millivoltmeter detects, and is converted to the ion activity data and exports to the ion concentration computing module;

Further, described activity arithmetical unit is by the following method the detected potential value of millivoltmeter to be converted to each ion activity value: after each ion is demarcated with the standard solution of known activity, utilize the Nernst equation to obtain each ion activity value of liquid to be measured in the activity arithmetical unit.

Further, described detecting electrode is " H ⁺-A ²⁺-B ⁺" combination electrode, wherein A ²⁺Be bivalent metal ion, B ⁺Be monovalent metallic ion;

Further, described detecting electrode is " H ⁺-K ⁺-Ca ²⁺" combination electrode, described ion concentration computing module is " H ⁺, K ⁺And Ca ²⁺" the concentration computing module; Described millivolt is counted 3, the input end of 3 millivoltmeters respectively with " H ⁺-K ⁺-Ca ²⁺" H in the combination electrode ⁺Electrode, K ⁺Electrode and Ca ²⁺The output terminal of electrode connects, the output terminal of 3 millivoltmeters respectively with pH arithmetical unit, K ⁺Activity arithmetical unit and Ca ²⁺The input end of activity arithmetical unit connects, pH arithmetical unit, K ⁺Activity arithmetical unit and Ca ²⁺The activity arithmetical unit calculates H respectively ⁺, K ⁺And Ca ²⁺Activity after, output to " H ⁺, Ca ²⁺And K ⁺" the concentration computing module;

Described detection system also comprises temp probe, and described temp probe is arranged in the sample storing apparatus; Also comprise electronic thermometer, the input end of described electronic thermometer is connected with temp probe, output terminal respectively with pH arithmetical unit, K ⁺Activity arithmetical unit, Ca ²⁺Activity arithmetical unit, " H ⁺, Ca ²⁺And K ⁺" the concentration computing module is connected with the input end of surface parameter computing module;

Further, described " H ⁺, Ca ²⁺And K ⁺" the concentration computing module calculates K by the following method ⁺, Ca ²⁺And H ⁺Concentration:

With pH arithmetical unit, K ⁺Activity arithmetical unit and Ca ²⁺The activity value of activity arithmetical unit gained is carried out interative computation as the initial value of each ion concentration by following steps:

1) pass through to obtain the ionic strength of solution with the following formula computing:

$I_i=\frac{1}{2}({2c}_i^H+2c_i^K+6c_i^{\mathrm{Ca}})$

I in the formula _iIonic strength when being the i time iteration, the mol/l of unit, H when being the i time iteration ⁺Concentration,

K when being the i time iteration ⁺Concentration,

Ca when being the i time iteration ²⁺Concentration;

2) according to ionic strength, K when calculating the i time iteration by following formula ⁺, Ca ²⁺And H ⁺Activity coefficient:

$\lg {\mathrm{\γ}}_i^H=\lg {\mathrm{\γ}}_i^K=-\frac{2618.4\×T^{-\frac{3}{2}}\sqrt{I_i}}{1+\sqrt{I_i}}$

$\lg {\mathrm{\γ}}_i^{\mathrm{Ca}}=-\frac{10473.6\×T^{-\frac{3}{2}}\sqrt{I_i}}{1+\sqrt{I_i}}$

In the formula

With

H when being the i time iteration respectively ⁺, K ⁺And Ca ²⁺Activity coefficient, T is a temperature, unit K;

3), obtain the K of the required usefulness of next iteration by following formula according to activity coefficient ⁺, Ca ²⁺And H ⁺Concentration value:

$c_i^H=\frac{a_H}{{\mathrm{\γ}}_i^H};$ $c_i^K=\frac{a_K}{{\mathrm{\γ}}_i^K};$ $c_i^{\mathrm{Ca}}=\frac{a_{\mathrm{Ca}}}{{\mathrm{\γ}}_i^{\mathrm{Ca}}}$

In the formula,

With

Be respectively this time iteration gained H ⁺, K ⁺And Ca ²⁺Concentration; With this concentration value as the next iteration desired concn;

Repeat 1) to 3) step carry out interative computation, up to the i=k+1 time, as (I _K+1-I _k)/I _K+1＜0.001 o'clock, the termination of iterations computing, and with the counterion concentration of each ion concentration value of last iteration gained as last output;

Further, described surface parameter computing module receives " H ⁺, Ca ²⁺And K ⁺" K of concentration computing module output ⁺And Ca ²⁺Counterion concentration substitution following formula carry out computing, obtain the material surface current potential

:

In the formula,

Be the material surface current potential, R is a gas law constant, and T is a temperature, and F is the Faraday constant; c _K ⁰Be K ⁺Initial concentration, c _Ca ⁰Be Ca ²⁺Initial concentration; Be K ⁺The equilibrium concentration value,

Be Ca ²⁺The equilibrium concentration value, β _KBe to contain " K ⁺+ Ca ²⁺" system in K ⁺The K that hydrated radius is relevant ⁺Relative effective charge coefficient; β _CaBe to contain " K ⁺+ Ca ²⁺" system in Ca ²⁺The Ca that hydrated radius is relevant ²⁺Relative effective charge coefficient, utilize the final value I of interative computation intermediate ion intensity, calculate the effective charge coefficient by following formula:

$\left\{\begin{array}{c}{\mathrm{\β}}_K=0.0297\ln I+1\\ {\mathrm{\β}}_{\mathrm{Ca}}=-0.0297\ln I+1\end{array}\right.$

Further, described surface parameter computing module is according to the material surface current potential

Specific surface area S by the following formula substance for calculation:

In the formula, V is the cumulative volume of water, unit 1; S is a specific surface area, the dm of unit ²/ g; κ is a Debye-H ü ckel parameter, the dm of unit ^-1, and calculate by following formula:

$\mathrm{\κ}=\sqrt{\frac{{8\mathrm{\πF}}^2(c_H^{\∞}+c_K^{\∞}+{3c}_{\mathrm{Ca}}^{\∞})}{\mathrm{\ϵRT}}}$

In the formula, ε is the medium specific inductive capacity, the ε of water=8.9 * 10 ^-10C ²/ Jdm.

Further, described surface parameter computing module is according to the surface electrical place value, by the surface charge density of following formula substance for calculation:

σ in the formula ₀Be surface charge density, its polarity sign is identical with the polarity sign of surface potential.

Further, described surface parameter computing module (27) is according to surface charge density, by the surface field intensity of following formula substance for calculation:

$E_0=\frac{4\mathrm{\π}}{\mathrm{\ϵ}}{\mathrm{\σ}}_0$

E in the formula ₀Be material surface electric field intensity.

Further, described surface parameter computing module is according to gained surface charge density and specific surface area, by following formula gauging surface total amount of electric charge:

T _c＝S×σ ₀

T in the formula _cIt is the surface charge total amount of material.

The present invention compared with prior art, substance surface property parametric analysis system of the present invention is by to indicating electrolytical counterion concentration to measure, and then calculates the material surface current potential, gets rid of H ⁺Or non-indicative ion (promptly removes A ²⁺And B ⁺Outside other any ion) uncertainty that causes with material surface generation chemical reaction, since pH arbitrarily, arbitrarily the electrolyte type constitute and any electrolyte concentration and temperature under, for the material surface of any charge type, satisfy following formula between the surface potential of equilibrium system and the used indication cation concn all the time:

This has just guaranteed that native system is a general assay method that is applicable to any condition, arbitrary substance type, correspondingly, based on surface potential detection, obtain material surface electric density, surface field intensity, specific surface area and surface charge total amount and all be applicable to any condition, arbitrary substance type; Simultaneously, need use diverse ways and equipment to measure for different substance surface property parameters in the prior art, and utilize native system to measure these parametric joints simultaneously.

Other advantages of the present invention, target and feature will be set forth to a certain extent in the following description, and to a certain extent, based on being conspicuous to those skilled in the art, perhaps can obtain instruction from the practice of the present invention to investigating hereinafter.Target of the present invention and other advantages can be passed through following instructions, claims, and the specifically noted structure realizes and obtains in the accompanying drawing.

Description of drawings

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention is described in further detail below in conjunction with accompanying drawing, wherein:

Fig. 1 shows the structural representation of sample processing device among the present invention;

Fig. 2 shows the structural representation of detection system among the present invention.

Embodiment

Hereinafter with reference to accompanying drawing, the preferred embodiments of the present invention are described in detail.

The substance surface property parametric analysis system of present embodiment comprises sample processing device and detection system, and referring to Fig. 1, described sample processing device comprises sample storing apparatus 11, in order to hold measured object; Described sample storing apparatus 11 also comprises feed tube 12 and drain pipe 13, and described drain pipe 13 is communicated with sample storing apparatus 11 bottoms, and described feed tube 12 is communicated with sample storing apparatus 11, and described drain pipe 13 is connected with constant flow pump; Also be provided with stirring apparatus 15 in the described sample storing apparatus 11.

Referring to Fig. 2, described detection system comprises:

The ion activity pick-up unit is used for each ion activities of test sample storing apparatus 11 solution, comprises the detecting electrode 16 that is arranged in the sample storing apparatus 11, also comprises millivoltmeter 22 and ion activity arithmetical unit, and described detecting electrode is " H ⁺-K ⁺-Ca ²⁺" combination electrode, the input end of 3 millivoltmeters 22 respectively with " H ⁺-K ⁺-Ca ²⁺" H in the combination electrode ⁺Electrode, K ⁺Electrode and Ca ²⁺The output terminal of electrode connects, the output terminal of 3 millivoltmeters 22 respectively with pH arithmetical unit 23, Na ⁺Activity arithmetical unit 24 and Ca ²⁺The input end of activity arithmetical unit 25 connects, and described millivoltmeter adopts the high impedance millivolt to count good; And

Data processing equipment can adopt programmable processor such as single-chip microcomputer as data processing equipment, and described data processing equipment receives the testing result of ion activity pick-up unit, analyzes the measured object surface parameter, specifically comprises:

" H ⁺, Ca ²⁺And K ⁺" concentration computing module 26, with pH arithmetical unit 23, K ⁺Activity arithmetical unit 24 and Ca ²⁺The output terminal of activity arithmetical unit 25 connects, and receives the testing result of above-mentioned arithmetical unit, calculates the ion concentration value; And

Surface parameter computing module 27 receives " H ⁺, Ca ²⁺And K ⁺" ionic equilibrium concentration value that concentration computing module 26 calculates, calculate measured object surface potential, surface charge total amount, surface charge density, surface field intensity and specific surface area.

Referring to Fig. 1, Fig. 2, described substance surface property parametric analysis system also comprises temp probe 14, and described temp probe 14 is arranged in the sample storing apparatus 11; Also comprise electronic thermometer 21, the input end of described electronic thermometer 21 is connected with temp probe 14, output terminal and pH arithmetical unit 23, K ⁺Activity arithmetical unit 24 and Ca ²⁺Activity arithmetical unit 25, concentration arithmetical unit and the input end of surface nature parameter arithmetical unit are connected.

Described pH arithmetical unit 23, K ⁺Activity arithmetical unit 24 and Ca ²⁺Activity arithmetical unit 25 converts the detected potential value of millivoltmeter to each ion activity value by the following method: after each ion is demarcated with the standard solution (its pH value should be same with liquid phase to be measured) of known activity, utilize the Nernst equation to obtain each ion activity value of liquid to be measured in the activity arithmetical unit.

Described " H ⁺, Ca ²⁺And K ⁺" concentration computing module 26 calculates K by the following method ⁺, Ca ²⁺And H ⁺Concentration:

With pH arithmetical unit 23, K ⁺Activity arithmetical unit 24 and Ca ²⁺The activity value of activity arithmetical unit 25 gained is carried out interative computation as the initial value of each ion concentration by following steps:

A) pass through to obtain the ionic strength of solution with the following formula computing:

$I_i=\frac{1}{2}({2c}_i^H+2c_i^K+6c_i^{\mathrm{Ca}})$

I in the formula _iIonic strength when being the i time iteration, the mol/l of unit,

H when being the i time iteration ⁺Concentration,

K when being the i time iteration ⁺Concentration,

Ca when being the i time iteration ²⁺Concentration;

B) according to ionic strength, K when calculating the i time iteration by following formula ⁺, Ca ²⁺And H ⁺Activity coefficient:

$\lg {\mathrm{\γ}}_i^H=\lg {\mathrm{\γ}}_i^K=-\frac{2618.4\×T^{-\frac{3}{2}}\sqrt{I_i}}{1+\sqrt{I_i}}$

$\lg {\mathrm{\γ}}_i^{\mathrm{Ca}}=-\frac{10473.6\×T^{-\frac{3}{2}}\sqrt{I_i}}{1+\sqrt{I_i}}$

In the formula

With

H when being the i time iteration respectively ⁺, K ⁺And Ca ²⁺Activity coefficient, T is a temperature, unit K.

C), obtain the K of the required usefulness of next iteration by following formula according to activity coefficient ⁺, Ca ²⁺And H ⁺Concentration value:

$c_i^H=\frac{a_H}{{\mathrm{\γ}}_i^H};$ $c_i^K=\frac{a_K}{{\mathrm{\γ}}_i^K};$ $c_i^{\mathrm{Ca}}=\frac{a_{\mathrm{Ca}}}{{\mathrm{\γ}}_i^{\mathrm{Ca}}}$

In the formula,

With

Be respectively this time iteration gained H ⁺, K ⁺And Ca ²⁺Concentration; This concentration value as the next iteration desired concn, is repeated a) to c) step carry out interative computation, up to the i=k+1 time, as (I _K+1-I _k)/I _K+1＜0.001 o'clock, the termination of iterations computing, and with the counterion concentration of last each ion concentration of iteration gained as last output.

Described surface parameter computing module 27 receives " H ⁺, Ca ²⁺And K ⁺" K of concentration computing module 26 output ⁺And Ca ²⁺Counterion concentration (final value of interative computation) substitution following formula carry out computing, obtain the material surface current potential

In the formula,

Be the material surface current potential, R is a gas law constant, and T is a temperature, and F is the Faraday constant.c _K ⁰Be the K of system when beginning to add KCl ⁺Initial concentration, c _Ca ⁰Be to begin to add CaCl ₂The time system Ca ²⁺Initial concentration, these two concentration values are to calculate divided by the water cumulative volume according to each ion total mole number that system adds, and can pass through the input media input detection systems during mensuration.

Be K ⁺The equilibrium concentration value, Be Ca ²⁺The equilibrium concentration value; β _KBe to contain " K ⁺+ Ca ²⁺" system in K ⁺The K that hydrated radius is relevant ⁺Relative effective charge coefficient; β _CaBe to contain " K ⁺+ Ca ²⁺" system in Ca ²⁺The Ca that hydrated radius is relevant ²⁺Relative effective charge coefficient, utilize the final value I of interative computation intermediate ion intensity, calculate the effective charge coefficient by following formula:

$\left\{\begin{array}{c}{\mathrm{\β}}_K=0.0297\ln I+1\\ {\mathrm{\β}}_{\mathrm{Ca}}=-0.0297\ln I+1\end{array}\right.$

Described surface parameter computing module 27 is according to the material surface current potential

Specific surface area by the following formula substance for calculation:

In the formula, V is the cumulative volume of water, unit 1; S is a specific surface area, the dm of unit ²/ g; κ is a Debye-H ü ckel parameter, the dm of unit ^-1, and calculate by following formula:

$\mathrm{\κ}=\sqrt{\frac{{8\mathrm{\πF}}^2(c_H^{\∞}+c_K^{\∞}+{3c}_{\mathrm{Ca}}^{\∞})}{\mathrm{\ϵRT}}}$

In the formula, ε is the medium specific inductive capacity, the ε of water=8.9 * 10 ^-10C ²/ Jdm.

Described surface parameter computing module 27 is according to the surface electrical place value, by the surface charge density of following formula substance for calculation:

σ in the formula ₀Be surface charge density, its symbol is identical with the symbol of surface potential, the C/dm of unit ²

Described surface parameter computing module 27 is according to surface charge density, by the surface field intensity of following formula substance for calculation:

$E_0=\frac{4\mathrm{\π}}{\mathrm{\ϵ}}{\mathrm{\σ}}_0$

E in the formula ₀Be material surface electric field intensity, the V/dm of unit.

Described surface parameter computing module 27 is according to surface charge density and specific surface area, by following formula gauging surface total amount of electric charge:

T _c＝S×σ ₀

T in the formula _cBe the surface charge total amount of material, the C/g of unit.

The substance surface property parametric analysis system of present embodiment, its analytical approach comprises the steps:

1) saturated processing is carried out on the determinand surface, specifically comprised the steps:

11) get the 3-5g testing sample sample storing apparatus of packing into,, at the uniform velocity flow through determinand, make the determinand surface charge entirely by H with the flow velocity of 1ml/min with the HCl solution 150-250ml of 0.1mol/l ⁺And Cl ^-Institute is saturated; Also can adopt HNO ₃Wait other acid solutions that testing sample is carried out saturated processing;

12) at the uniform velocity flow through determinand, the H that flush away is unnecessary with 150-250ml water with the flow velocity of 1ml/min ⁺And Cl ^-

13) take out gap water in the determinand with constant flow pump, till anhydrous outflow.

2) KCl, HCl (or KOH) and the CaCl of adding concentration known in sample cell ₂Mixed solution 50ml fully stirred back placement, balance more than 24 hours; Wherein KCl and CaCl ₂As the indication electrolyte, HCl and KOH are used to regulate the pH value; Above-mentioned each electrolyte concentration can determine according to researcher's requirement, but the system ionic strength control is advisable with interior at 0.2mol/l during with balance.Also can adopt other indication electrolyte in this step, but the indication electrolyte is at least two kinds, comprise at least a divalent metal and a kind of monovalence metal cation, the electrolytical negative ion of described indication should be identical with the negative ion of acid described in the step 11), as adopting HNO in the step 11) ₃Solution carries out saturated processing to the testing sample surface, then can adopt KNO accordingly in this step ₃And Ca (NO ₃) ₂As the indication electrolyte, adopt HNO ₃Be used to regulate the pH value with KOH.

3) treat step 2) (be balance more than 24 hours under the continuous stirring after the gained potpourri ion-exchange equilibrium; Equilibration time requires at least 72 hours under non-stirring condition, and type per sample, equilibration time also can be variant, but affiliated technical field personnel are not difficult to determine this time), each ion activity in the described potpourri of ion activity detection means measure, data processing equipment analyzes measured object surface potential, surface charge total amount, surface charge density, surface field intensity and specific surface area with this.

The above is the preferred embodiments of the present invention only, is not limited to the present invention, and obviously, those skilled in the art can carry out various changes and modification and not break away from the spirit and scope of the present invention the present invention.Like this, if of the present invention these are revised and modification belongs within the scope of claim of the present invention and equivalent technologies thereof, then the present invention also is intended to comprise these changes and modification interior.

Claims (12)

1. substance surface property parametric analysis system, it is characterized in that: comprise sample processing device and detection system, described sample processing device comprises:

Sample storing apparatus (11) is in order to hold measured object and liquid; And

Feed tube (12) and drain pipe (13), described drain pipe (13) is communicated with sample storing apparatus (11) bottom, and feed tube (12) is communicated with sample storing apparatus (11); Described drain pipe (13) is connected with constant flow pump;

Also be provided with stirring apparatus (15) in the described sample storing apparatus (11);

Described detection system comprises:

The ion activity pick-up unit is used for each ion activity of test sample storing apparatus (11) solution; And

Data processing equipment, the testing result of reception ion activity pick-up unit is analyzed the measured object surface parameter, specifically comprises:

Ion concentration computing module (26), the testing result according to receiving the ion activity pick-up unit calculates the counterion concentration value; And

Surface parameter computing module (27) receives the ion concentration value that ion concentration computing module (26) calculates, and calculates the measured object surface potential according to the ion concentration value.

2. substance surface property parametric analysis system as claimed in claim 1, it is characterized in that: described surface parameter computing module (27) is also according to the measured object surface potential, calculate measured object specific surface area, surface charge density, surface field intensity, and calculate total amount of electric charge according to surface charge density and specific surface area.

3. substance surface property parametric analysis system as claimed in claim 1 or 2, it is characterized in that: described ion activity pick-up unit comprises the detecting electrode (16) that is arranged in the sample storing apparatus (11), also comprise millivoltmeter (22) and ion activity arithmetical unit, the input end of described millivoltmeter (22) is connected with described detecting electrode (16), output terminal is connected with the ion activity arithmetical unit, the ion activity arithmetical unit receives the potential data that millivoltmeter (22) detects, and is converted to the ion activity data and exports to ion concentration computing module (26).

4. substance surface property parametric analysis system as claimed in claim 3, it is characterized in that: described activity arithmetical unit is by the following method the detected potential value of millivoltmeter to be converted to each ion activity value: after each ion is demarcated with the standard solution of known activity, utilize the Nernst equation to obtain each ion activity value of liquid to be measured in the activity arithmetical unit.

5. substance surface property parametric analysis system as claimed in claim 4 is characterized in that: described detecting electrode is " H ⁺-A ²⁺-B ⁺" combination electrode, wherein A ²⁺Be bivalent metal ion, B ⁺Be monovalent metallic ion.

6. substance surface property parametric analysis system as claimed in claim 5 is characterized in that: described detecting electrode is " H ⁺-K ⁺-Ca ²⁺" combination electrode, described ion concentration computing module is " H ⁺, K ⁺And Ca ²⁺" concentration computing module (26); Described millivoltmeter (22) is 3, the input end of 3 millivoltmeters (22) respectively with " H ⁺-K ⁺-Ca ²⁺" H+ electrode, K+ electrode and Ca in the combination electrode ²⁺The output terminal of electrode connects, the output terminal of 3 millivoltmeters (22) respectively with pH arithmetical unit (23), K ⁺Activity arithmetical unit (24) and Ca ²⁺The input end of activity arithmetical unit (25) connects, pH arithmetical unit (23), K ⁺Activity arithmetical unit (24) and Ca ²⁺Activity arithmetical unit (25) calculates H respectively ⁺, K ⁺And Ca ²⁺Activity after, output to " H ⁺, Ca ²⁺And K ⁺" concentration computing module (26);

Described detection system also comprises temp probe (14), and described temp probe (14) is arranged in the sample storing apparatus (11); Also comprise electronic thermometer, the input end of described electronic thermometer is connected with temp probe (14), output terminal respectively with pH arithmetical unit (23), K ⁺Activity arithmetical unit (24), Ca ²⁺Activity arithmetical unit (25), " H ⁺, Ca ²⁺And K ⁺" concentration computing module (26) is connected with the input end of surface parameter computing module (27).

7. substance surface property parametric analysis system as claimed in claim 6 is characterized in that: described " H ⁺, Ca ²⁺And K ⁺" concentration computing module (26) calculates K by the following method ⁺, Ca ²⁺And H ⁺Concentration:

With pH arithmetical unit (23), K ⁺Activity arithmetical unit (24) and Ca ²⁺The activity value of activity arithmetical unit (25) gained is carried out interative computation as the initial value of each ion concentration by following steps:

1) pass through to obtain the ionic strength of solution with the following formula computing:

$I_i=\frac{1}{2}(2c_i^H+2c_i^K+6c_i^{\mathrm{Ca}})$

I in the formula _iIonic strength when being the i time iteration, the mol/l of unit,

H when being the i time iteration ⁺Concentration,

K when being the i time iteration ⁺Concentration,

Ca when being the i time iteration ²⁺Concentration;

2) according to ionic strength, K when calculating the i time iteration by following formula ⁺, Ca ²⁺And H ⁺Activity coefficient:

$\lg {\mathrm{\γ}}_i^H=\lg {\mathrm{\γ}}_i^K=-\frac{2618.4\×T^{-\frac{3}{2}}\sqrt{I_i}}{1+\sqrt{I_i}}$

$\lg {\mathrm{\γ}}_i^{\mathrm{Ca}}=-\frac{10473.6\×T^{-\frac{3}{2}}\sqrt{I_i}}{1+\sqrt{I_i}}$

In the formula

With

H when being the i time iteration respectively ⁺, K ⁺And Ca ²⁺Activity coefficient, T is a temperature, unit K;

3), obtain the K of the required usefulness of next iteration by following formula according to activity coefficient ⁺, Ca ²⁺And H ⁺Concentration value:

$c_i^H=\frac{a_H}{{\mathrm{\γ}}_i^H};$ $c_i^K=\frac{a_K}{{\mathrm{\γ}}_i^K};$ $c_i^{\mathrm{Ca}}=\frac{a_{\mathrm{Ca}}}{{\mathrm{\γ}}_i^{\mathrm{Ca}}}$

In the formula,

With

Be respectively this time iteration gained H+, K ⁺And Ca ²⁺Concentration; With this concentration value as the next iteration desired concn;

Repeat 1) to 3) step carry out interative computation, up to the i=k+1 time, as (I _K+1-I _k)/I _K+1＜0.001 o'clock, the termination of iterations computing, and with the counterion concentration of each ion concentration value of last iteration gained as last output.

8. substance surface property parametric analysis system as claimed in claim 7 is characterized in that: described surface parameter computing module (27) receives " H ⁺, Ca ²⁺And K ⁺" K of concentration computing module (26) output ⁺And Ca ²⁺Counterion concentration substitution following formula carry out computing, obtain the material surface current potential

In the formula,

Be the material surface current potential, R is a gas law constant, and T is a temperature, and F is the Faraday constant; c _K ⁰Be K ⁺Initial concentration, c _Ca ⁰Be Ca ²⁺Initial concentration;

Be K ⁺The equilibrium concentration value,

Be Ca ²⁺The equilibrium concentration value, β _KBe to contain " K ⁺+ Ca ²⁺" system in K ⁺The K that hydrated radius is relevant ⁺Relative effective charge coefficient; β _CaBe to contain " K ⁺+ Ca ²⁺" system in Ca ²⁺The Ca that hydrated radius is relevant ²⁺Relative effective charge coefficient, utilize the final value I of interative computation intermediate ion intensity, calculate the effective charge coefficient by following formula:

$\left\{\begin{array}{c}{\mathrm{\β}}_K=0.0297\ln I+1\\ {\mathrm{\β}}_{\mathrm{Ca}}=-0.0297\ln I+1\end{array}\right..$

9. substance surface property parametric analysis system as claimed in claim 8 is characterized in that: described surface parameter computing module (27) is according to the material surface current potential , by the specific surface area S of following formula substance for calculation:

In the formula, V is the cumulative volume of water, unit 1; S is a specific surface area, the dm of unit ²/ g; κ is a Debye-H ü ckel parameter, the dm of unit ^-1, and calculate by following formula:

$\mathrm{\κ}=\sqrt{\frac{8\mathrm{\π}{F}^2(c_H^{\∞}+c_B^{\∞}+3c_A^{\∞})}{\mathrm{\ϵRT}}}$

In the formula, ε is the medium specific inductive capacity, the ε of water=8.9 * 10 ^-10C ²/ Jdm.

10. substance surface property parametric analysis system as claimed in claim 9 is characterized in that: described surface parameter computing module (27) is according to the surface electrical place value, by the surface charge density of following formula substance for calculation:

σ in the formula ₀Be surface charge density, its polarity sign is identical with the polarity sign of surface potential.

11. as claim 9 or 10 described substance surface property parametric analysis systems, it is characterized in that: described surface parameter computing module (27) is according to surface charge density, by the surface field intensity of following formula substance for calculation:

$E_0=\frac{4\mathrm{\π}}{\mathrm{\ϵ}}{\mathrm{\σ}}_0$

E in the formula ₀Be material surface electric field intensity.

12. substance surface property parametric analysis system as claimed in claim 11 is characterized in that: described surface parameter computing module (27) is according to gained surface charge density and specific surface area, by following formula gauging surface total amount of electric charge:

T _c＝S×σ ₀

T in the formula _cIt is the surface charge total amount of material.

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