Gas separation membrane and method of producing gas separation membrane
A gas separation membrane includes a resin layer including an organopolysiloxane and a modified layer provided at a surface on one side of the resin layer and including a functional group introduced into the surface on one side. When X-ray photoelectron spectrometry, in which X-rays are irradiated from the front surface side of the modified layer, is performed to generate an XPS spectrum in a range including an Si2p peak and the Si2p peak is subjected to waveform separation, the area ratio of the Si—O peak to the Si2p peak is from 2% to 30%.
1 . A gas separation membrane comprising:
a resin layer including an organopolysiloxane; and
a modified layer provided at a surface on one side of the resin layer and including a polar group introduced into the surface on the one side, wherein
in an X-ray photoelectron spectrometry process, when X-rays are irradiated from a front surface side of the modified layer, an XPS spectrum in a range including an Si2p peak is generated,
the Si2p peak is subjected to a fitting process to separate an Si—O peak from the Si2p peak, and
a ratio of an area of the Si—O peak in the XPS spectrum to an area of the Si2p peak in the XPS spectrum is from 2% to 30%.
2 . The gas separation membrane according to claim 1 , wherein
the XPS spectrum is a spectrum in a range including the Si2p peak, a C1s peak, and a O1s peak, and
an area ratio of the Si2p peak to a whole of the XPS spectrum is 5% or greater when elemental analysis is performed based on the XPS spectrum.
3 . The gas separation membrane according to claim 1 , wherein
the polar group includes an amino group, a carboxylic acid group, or a phenyl group.
4 . A method of producing a gas separation membrane, the method comprising:
an activation treatment step of subjecting a surface on one side of a resin layer to an activation treatment, the resin layer including an organopolysiloxane; and
a polar group-introducing step of bringing a coupling agent into contact with a surface on the one side subjected to the activation treatment to introduce a polar group into the surface on the one side, the polar group-introducing step being provided after the activation treatment step, wherein
in an X-ray photoelectron spectrometry process, when X-rays are irradiated from the surface on the one side with the polar group introduced, an XPS spectrum in a range including an Si2p peak is generated,
the Si2p peak is subjected to a fitting process to separate an Si—O peak from the Si2p peak, and
a ratio of an area of the Si—O peak in the XPS spectrum to an area of the Si2p peak in the XPS spectrum is from 2% to 30%.
5 . The method of producing the gas separation membrane according to claim 4 , wherein
the coupling agent includes one or two hydrolyzable groups per molecule, and
the hydrolyzable group is an alkoxy group or a carboxylic acid group.