US-12616958-B2 - Micro-separator including 3D ordered nanoshell structure of ceramic-polymer composite for gas chromatography, method for fabricating the same and method for separating gas mixture using the same

US12616958B2US 12616958 B2US12616958 B2US 12616958B2US-12616958-B2

Abstract

A micro-separator for gas chromatography includes a base substrate having a trench defining a micro-column, and a three-dimensional (3D) porous ceramic-polymer composite disposed in the micro-column and having pores that three-dimensionally connected to each other with periodicity. The 3D porous ceramic-polymer composite includes a ceramic nano-structure, which forms an array of three-dimensionally arranged nano-shells, and a reaction-activating layer combined on a surface of the ceramic nano-structure and including a polymeric reaction-activating material. A thickness of the 3D porous ceramic-polymer composite is 10 μm to 20 μm, a column length of the 3D porous ceramic-polymer composite is 30 cm to 70 cm, and a shell thickness of the ceramic nano-structure is 20 nm to 60 nm. The micro-separator may have improved separation performance and durability.

Inventors

Seokwoo Jeon
Kisun Kim
Caiyan QIN
Yongseong CHA

Assignees

KOREA ADVANCED INSTITUTE OF SCIENCE AND TECHNOLOGY

Dates

Publication Date: 20260505
Application Date: 20220708
Priority Date: 20210823

Claims (10)

1 . A method for fabricating a micro-separator for gas chromatography, the method comprising: preparing a base substrate having a trench defining a micro-column and being combined with a sacrificial layer covering an area where the trench is not formed; forming a 3D porous template in the trench; providing a ceramic material in the 3D porous template to form a ceramic nano-structure forming an array of three-dimensionally arranged nano-shells; removing the 3D porous template; removing the sacrificial layer after the 3D porous template is removed; combining a cover substrate with the base substrate; providing a polymer solution including a polymeric reaction-activating material and a solvent in the micro-column of the base substrate; and removing the solvent to form a composite of the ceramic nano-structure and the polymeric reaction-activating material.
2 . The method for fabricating a micro-separator for gas chromatography of claim 1 , wherein the ceramic nano-structure includes oxide, nitride or sulfide of at least one selected from the group consisting of Zn, Al, Ni, Mo, Co, Sn, Fe, W, Ti, Mn, Zr and Cu.
3 . The method for fabricating a micro-separator for gas chromatography of claim 2 , wherein the ceramic nano-structure is formed through atomic layer deposition.
4 . The method for fabricating a micro-separator for gas chromatography of claim 1 , wherein the polymeric reaction-activating material includes a siloxane-based polymer.
5 . The method for manufacturing a micro-separator for gas chromatography of claim 4 , wherein the siloxane-based polymer includes at least one selected from the group consisting of polydimethylsiloxane (PDMS), polymethylphenylsiloxane and polymethylphenylcyanopropylsiloxane.
6 . The method for manufacturing a micro-separator for gas chromatography of claim 4 , wherein a content of the siloxane-based polymer in the polymer solution is 0.05 wt % to 1 wt %.
7 . The method for manufacturing a micro-separator for gas chromatography of claim 1 , wherein the sacrificial layer includes a metal.
8 . The method for manufacturing a micro-separator for gas chromatography of claim 1 , wherein preparing the base substrate combined with the sacrificial layer comprises: forming the sacrificial layer on an upper surface of the base substrate; and partially removing the sacrificial layer and the base layer to form the trench.
9 . The method for manufacturing a micro-separator for gas chromatography of claim 1 , wherein forming the 3D porous template in the trench comprises: forming a photoresist film in the trench; disposing a phase mask on a rear surface of the base substrate, which is spaced apart from the trench; irradiating a light onto the photoresist film through the phase mask; and developing the light-exposed photoresist film.
10 . The method for manufacturing a micro-separator for gas chromatography of claim 1 , wherein a thickness of the composite is 10 μm to 20 μm, a column length of the composite is 30 cm to 70 cm, and a shell thickness of the ceramic nano-structure is 20 nm to 60 nm.

Description

TECHNICAL FIELD The invention relates to a micro-separator for gas chromatography. More particularly, the invention relates to a micro-separator including three-dimensionally ordered nano-shell structure of ceramic-polymer composite for gas chromatography, a method for fabricating the same and method for separating gas mixture using the same. BACKGROUND Gas chromatography (GC) is an analysis method in which a sample (analyte) is carried by a carrier gas and passes through a material separator column to separate mixed components into a single component. The performance of the material separator column may be an important factor in determining the overall system performance. A stationary phase is coated in the material separator column. When the carrier gas with the sample passes through the material separator column, chemical equilibrium, adsorption and distribution, which are different depending on components in the sample, appear due to difference in chemical properties between the components and the stationary phase. Thus, a time difference when they pass through the column is caused so that the materials (components) are separated. In general, as a material separator column, a packed column or a capillary column is used. The packed column consists of an inert material, a solid support, and a coated stationary phase. The packed column may have a relatively large diameter (approximately 2-4 mm of an inner diameter) and a relatively short length (approximately 1.5-10 m), since the packed column has a shape of a tube, of which an inside is entirely filled. The capillary column can be divided into a Wall Coated Open Tubular (WCOT) column coated with a liquid stationary phase, and a Porous Layer Open Tubular (PLOT) column in which a solid porous material having a thin film stationary phase is coated on an inner wall. Conventional GC systems have advantages of superior reliability and superior separation efficiency compared to other separation systems. However, they have a large volume of m3 level due to a long column of several meters, an oven to maintain a proper temperature of the column, and a signal processing system. Therefore, they have an intrinsic difficulty in being applied for precise analysis of unknown samples collected at industrial scenes. In order to overcome the above problems, studies on u-Gas Chromatography (u-GC) using Microelectromechanical Systems (MEMS) technology have been recently reported. For example, a semi-packed column with a rectangular columnar array within a sputtered open tubular column has been demonstrated to be able to separate short hydrocarbons and natural gas (Non-patent Literature (3)). As another example, it was successful to separate saturated and unsaturated hydrocarbon chains using silica or graphite sputtered micro-columns with metal filaments for temperature programming (Non-patent Literature (4)). In addition, possibility for practical application of micro-GC was suggested by integrating ZIF-8-PVA cryogel in a laser-etched acrylic micro-separator column to separate a polycyclic aromatic hydrocarbon (Non-patent Literature (5)). Furthermore, technologies, which increase specific surface area by using three-dimensional nano-structure thereby increasing the number of absorbed and separated molecules in a volume unit and fabricates a separator having a micro-column shape, were suggested for a GC system having a much less size than the conventional GC systems (Non-patent Literature (2), Patent Literature (3)) Patent Literature (1) U.S. Pat. No. 7,704,684(2) Korean Granted Patent 10-1699454(3) Korean Granted Patent 10-2183456 Non-Patent Literature (1) Analytical Chemistry, 75, 5525-5531 (2003)(2) PNAS, 101, 12428-12433 (2004)(3) Journal of Chromatography A, 1218, 3262-3266 (2011)(4) Analytical Chemistry, 85, 114-120 (2013)(5) Talanta, 167, 573-582 (2017)(6) Analytical Chemistry, 39, 247-259 (2020) DETAILED DESCRIPTION OF THE INVENTION Technical Problem to be Solved One object of the invention is to provide a micro-separator for gas chromatography with separation performance improved by a 3D nano-shell structure of ceramic-polymer composite having a periodic structure. Another object of the invention is to provide a method for fabricating the micro-separator for gas chromatography. Another object of the invention is to provide a method for separating gas. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Means for Solving Problem According to embodiments to accomplish the objectives of the present invention, a micro-separator for gas chromatography includes a base substrate having a trench defining a micro-column, and a three-dimensional (3D) porous ceramic-polymer composite disposed in the micro-column and having pores that three-dimensionally connected to each other with periodicity. The 3D porous ceramic-polymer composite includes a ceramic nano-structure, which forms an array of