Method for quantifying amine compound constituting separator active layer prior to preparation of separator active layer, method for quantifying polyamide or unreacted amine compound in separator active layer, and method for setting preparation conditions of separator active layer or establishment standards for preparation conditions of separator active layer
Provided are a method for quantifying an amine compound forming a membrane active layer before preparing the membrane active layer, a method for quantifying a polyamide or an unreacted amine compound in a membrane active layer, and a method for determining criteria for a manufacturing condition of a membrane active layer or a method for setting a manufacturing condition.
1. A method for determining setting criteria for a manufacturing condition of a membrane active layer for a reverse osmosis layer, the method comprising:
a) coating a composition including an amine compound on a surface of a support to form a coated support surface and then quantifying a distribution of the amine compound by depth from an outermost surface on the coated support surface using an energy dispersive spectrometer (EDS) method by irradiating with an electron beam having sufficient energy to generate X-rays and determining a distribution profile of a nitrogen constituent of the amine compound in a depth direction from the outermost surface on the coated support surface to quantify an amount of the amine compound that can form a membrane active layer of a membrane by participating in a reaction on the coated surface of the support,
wherein:
in the EDS method, a combination of an acceleration voltage of 5 kV and a current within a range of 68 μA to 77 μA is used, and
the distribution profile is determined prior to coating a composition including an acyl halide compound on the coated surface including the amine compound to perform an interfacial polymerization to form a polyamide layer, and
the EDS method uses line scans of 10 lines or more, and scans 5 times or more for each line;
b) preparing a membrane active layer by interfacially polymerizing polyamide by coating a composition including an acyl halide compound on the surface of the support on which the composition including an amine compound is coated;
c) deriving a first evaluation result by evaluating performance of the prepared membrane active layer;
d) deriving a second or higher evaluation result by repeating a) and b) and evaluating performance of the prepared membrane active layer one or more times except that at least a part of the condition in the coating of the composition including an amine compound on a support in a) is adjusted to be a different condition from the above-described a); and
e) comparing the first evaluation result and the second or higher evaluation result to determine a distribution of the amine compound by depth from the coated surface on the support in order to set materials or process conditions to be used in the membrane active layer manufacturing process.
2. The method of claim 1 , wherein each line of the plurality of line scans has 400 analysis points or more.
3. The method of claim 1 , wherein the different condition is at least one of a type of the support, a moisture content of the support, a solid content of the composition including an amine compound, a coating amount of the composition including an amine compound, a method for coating the composition including an amine compound, and presence of additives in the support or the composition including an amine compound.
4. The method of claim 1 , further comprising:
f) preparing a membrane active layer by manufacturing the membrane active layer for a reverse osmosis layer of a reverse osmosis membrane according to the set materials or process conditions.