JPS60162936A - Device for measuring contact angle between powder and granular material and liquid - Google Patents

Abstract

PURPOSE:To speed up measurement and to improve the accuracy thereof by storing the change with time of the measured weight Wt of a pipe immersed with a liquid in the sample powder and granular material therein and calculating and displaying the contact angle from the inclination of the specific equations of the coordinate plane having both axes at 1/Wt, dWt/dt. CONSTITUTION:The liquid L in a vessel 5 is penetrated into the sample powder and granular material S in a pipe 1 from the bottom and the weight Wt of the pipe 1 is measured by a measuring instrument 2 and is stored by a microcomputer 9. An inclination KWinfinity, y-axis intercept K are calculated from the equation I on the coordinate plane with 1/Wt, dWt/dt as x-axis, y-axis and the weight Winfinity after the equil. state is determined. Voids epsilon of the packed layer of the material S in the pipe 1, the sectional area of the packed layer of the material S, etc. are set from an input means 6 and the average capillary radius (r) in the packed layer of the material S is calculated; further the surface tension gammaL of the liquid L is set by the means 6 and a contact angle theta is calculated by using the equation II (r; average capillary radius) and is displayed on a display device 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a pipe for filling a powder sample having a bottom through which liquid can freely flow, a container for storing a liquid to be permeated into the sample powder in the pipe from the bottom, and a sample powder. It is equipped with a measuring device that measures the weight change of the pipe as the liquid permeates into the body, and based on the information from the measuring device, the contact angle between the sample powder and the liquid in the container, as shown in Fig. 6, is installed. The present invention relates to an improvement in an apparatus for setting t to an angle θ determined by the surface tension γL of the liquid fLl, the surface tension γ8 of the solid +81, and the interfacial tension γ and L at the solid-liquid interface.

Conventional devices were configured to automatically record changes in the weight of the pipe due to liquid permeation into the sample powder on a graph showing the correlation between the measured weight and measurement time. In order to find the contact angle between the There are disadvantages such as a decrease in measurement accuracy due to errors in reading, and a large amount of time and effort required for calculation.

An object of the present invention is to automatically calculate and display the contact angle between a powder and a liquid, so that highly accurate measurement can be performed reliably and quickly.

A characteristic configuration of the contact angle measuring device according to the present invention is that a measuring device for measuring a change in weight of a pipe due to liquid permeation into a sample powder filled in the pipe memorizes the temporal change in the measurement type 1ift. means for calculating the slope KW- and the y-axis leg K of the following formula % in coordinates with W as the r-axis and dWt/dt2 as the y-axis from the stored weight change; 1 and the following value ε set by the input means or calculated from the set value of the input means: porosity S of the sample powder packed bed in the pipe: cross-sectional area PL of the sample powder packed bed = Density of the liquid in the container for infiltrating the sample powder in the pipe η: Viscosity of the liquid g: Based on the gravitational acceleration, calculate the average capillary radius r in the sample powder packed layer in the pipe. ε, S and g1 set or calculated by the following formula KW calculated above
Based on the Woa calculated from ~ and 7)- and the surface tension γ□ of the liquid in the container set by the input means or actually measured by the measuring device, the sample powder in the pipe and the surface tension in the container are determined. A means for calculating the contact angle θ between the liquid and the liquid is provided, and a device for displaying the calculated θ is provided, and its effects are as follows.

In other words, the permeation rate U of liquid into the packed bed of powder and granular material inside the pipe
is expressed in principle by the following equation (a).

= KW66 --- K - (a) t However, W, ... is the weight of the permeated liquid at the time when liquid permeation into the sample powder reaches equilibrium, and is 1.

Therefore, the measured NWtO time change is stored, and as shown in FIG.
The value of seven is N
/W (k-r axis and dWZ, -2y axis), as is clear from the above formula (a) and the above formula +1), a straight line as shown in Figure 4 is obtained. It will be done. Then, the slope α of the straight line is KW-, the y thin section B is K, and from α and β, W~ and K can be determined.

Capacity, the above formula (b) 'r transform gives the above formula t21, and if K is multiplied as described above, from formula (2), and
r can be calculated based on the input t + S + P(,, η1g.

Then, if W~ and r can be calculated as described above, then from the above equation (3) and the input εl S 1γL
, g, the contact angle θ can be calculated, the above information processing and arithmetic processing are processed by a microcomputer, and the calculated contact angle θ is numerically displayed on a display device.

As a result, the contact angle θ can be determined extremely accurately and extremely quickly without any analytical errors or calculation errors when determining W~ and K. We are now able to provide measuring devices that have great practical value in a wide range of fields such as paints, chemicals, cosmetics, and foods.

Next, examples will be shown.

As shown in Fig. 1, a pipe +11 having a bottom made of filter paper or the like through which liquid can freely flow is suspended from a measuring device +21 such as an electronic balance, and a lifting actuator (3
Place the container (5) on the stand (4) attached to ), and place the sample powder (container (5) in
The liquid fLl 'k in the container (5) is raised by the actuator (3) and permeated from the bottom of the 7-inch eve ill, and the liquid (pipe i accompanying the permeation of Ll
It is configured to measure the weight change of l+ with a measuring instrument (2+).

Based on the measured values from the measuring instrument (2) and the set values from the input means (6) such as a keyboard, operate a device (7) for displaying all measurement results such as an X-Y plotter, and
Operation unit (8) for starting and stopping the actuator (3)
A microcomputer (9) is provided for giving operation commands based on information from the input means (61) and for receiving measurement start commands from its operation section (8).
A speed regulator (101) is used to artificially set the rate of rise of the saucer (5) by the actuator (3).

The operation steps of the measuring device are shown in flow (1) of FIG. 2. The following various setting values are input from the input means (6).

I) 5: True density Ws of the sample powder (S) filled in the pipe (1): Weight H of the sample powder (S) 2 Filling height T of the sample powder (S): Measurement time PL: Density of the liquid (L, ) in the container (5) η: Viscosity of the liquid (L) γL=Surface tension of the liquid (L) g: Gravitational acceleration (2) Set value P8. W8. Based on H, the cross-sectional area, S, and porosity ε of the sample powder layer are calculated using the following formula (a).

Calculated according to (b).

(3) In response to a measurement start command from the input means (6), the actuator (3)K raises the container (5) and liquid (L)
) comes into contact with the pipe il+, simultaneously stopping the actuator (3) and starting the measurement timer.

(4) The weight W (measured by the measuring device (2) is input, and W
At the same time that t starts to increase, measurement time t is input from the measurement timer.

151 Store the correlation of Wt7t in memory.

(6) When the measurement time T has elapsed, a permeation rate curve as shown in FIG. 8 is plotted on the display device (7) based on the stored correlation between W( and t).

(7) Based on the penetration rate curve, the dW shown in Figure 4 is
A relationship diagram between t//dt and 1/w is drawn on the display device (7).

f8) Based on the slope α of dW/at and Vwt and the y-ring intercept B, the penetrating liquid weight W ~ and the constant &K at the time when liquid (L) permeation into the sample powder (S) reaches equilibrium.
is calculated using the following formulas (c) and (d).

(9) Setting value・9, 1. Based on g and the calculated values ε, S, and K, the average capillary radius r of the sample powder layer can be calculated using the following formula (e).
Calculated by

(10) Set value γ. 9g and the calculated values ε, S, W~, r, the contact angle θ between the sample powder (S) and the liquid (L)
, and the adhesion tension γ-80 are calculated by the following formula (f).

(11) Setting values Is, Ws, H, T, FL
, r), 7L, g and calculated values W~, ε, r,
γLCmθ and θ are recorded and displayed on a display device (7).

(12) The actuator (3) lowers the container (5) to the lower limit setting position to complete the measurement.

Next, another example will be shown.

Input means (
6) may be manually set.

The surface tension γ of the broken liquid (L) may be actually measured using a measuring device using the circular ring method, and the measured value may be automatically set in the input means (6). Instead, a platinum ring is suspended from the measuring device (2), and the surface tension γ1 of the liquid (L) is actually measured in advance by the ring method.
The actual measured value may be stored in the microcomputer (9) and inputted when measuring the contact angle θ. The ring method will be explained below with reference to FIG. 7, taking as an example the case where the measuring device (2) is used. An attachment configured to suspend the platinum ring (11) from the rigging (12) in an almost horizontal position is attached to the measuring instrument (2).
), the platinum ring (11) is brought into contact with the liquid (L) by raising the container (5), and then the container (5) is lowered to measure the maximum load P with the measuring instrument ( 2), and the microcomputer (9) calculates the surface tension γ using the following formula.

P γL″″ Stone 5 However, F is the correction coefficient, π is the circumference, R is the platinum ring (1
1) is the radius.

The display device (7) only needs to display at least the contact angle θ, and therefore the microcomputer (9) only needs to have at least the functions shown in FIG.

The container (5) is configured to be raised and lowered artificially, and the timing for the start of measurement by the microcoscipulator (9) and the start of calculation of the contact angle θ is determined based on the state of change in the weight Wt measured by the measuring device (2). It may be configured as follows.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention. Second
The figure is a flowchart showing the operating state in the embodiment of the present invention. FIG. 8 is a J- diagram, and FIG. 4 is a dWt/dt-1/wt diagram. FIG. 5 is a diagram showing how microcomputers respond to complaints. FIG. 6 is an explanatory diagram of the contact angle θ. FIG. 7 is an explanatory diagram of the circular ring method. +1+...pipe, (2)...measuring instrument, (6)...container, (S)...sample powder, (L)... ·····liquid. Agent Patent Attorney Osamu Kitamura

Claims (1)

[Claims] Pipe (1) for filling sample powder or granular material having a bottom portion through which liquid can freely flow
, a container (5) that stores the sample powder and granule material in the pipe Lll (liquid +Ll that permeates from the bottom into the sample powder material fsl), and a container (5) that stores the sample powder and granule material fsl (liquid that permeates into the sample powder and granule material fsl from the bottom of the pipe 111)
The device is equipped with a measuring device +21 for measuring all changes in weight, including means for storing temporal changes in the amount of N measured by the measuring device 121, and a means for storing temporal changes in the amount of N measured by the measuring device 121, and calculating X/Wt from the stored weight change.
In the coordinates where dWy is the y-axis and t is the y-axis, the nod of the following formula % formula %, 14KW- and ylliI11 means for calculating the intercept K, the calculated 1 of 7 and the input means (set in 61 or The following value ε calculated from the set value of the input means: Porosity S in the sample powder (81 packed bed) in the curved pipe 111: Cross-sectional area PL of the sample powder (Sl) (5) Based on the density η of the liquid (Ll) in the liquid (Ll): the viscosity g of the liquid (Ll): the gravitational acceleration, the average capillary radius r in the sample powder (81 packed bed) in the pipe (l) 1 can be calculated using the following formula: Means for calculating, the calculated r1 said set or calculated ε, S and g1 said music KW- and K
Based on W-1 calculated from (81 and a device (7) that is provided with means for calculating the liquid (Ll) in the container (5) and displays the calculated θ
A contact angle measurement device between powder and liquid is provided.