157 results about "Microporous material" patented technology

The invention provides a micropore machining method capable of adjusting a laser incidence angle in real time. The micropore machining method comprises the steps that S1, parameters such as the type of a micropore material, the micropore size and the depth-diameter ratio are determined according to the specific application environment and the use performance requirement; s2, according to the type and the characteristic parameters of the microporous material, a machining path drawing file is written, and a laser beam is controlled to conduct punching layer by layer according to the drawing file path in a spiral line mode; s3, when each layer is machined, laser scans in a spiral line mode according to a drawing and file path, and then trimming is conducted at the edge position in a concentric circle mode; s4, fitting a function relationship between the incident angle and the taper through an experiment, adjusting the incident angle of each layer of laser processing, determining layer-by-layer decreasing compensation of the compensation amount of the incident angle of each layer through the function, and eliminating the positive taper of the through hole; s5, circulation is conducted in this way, and machining of all layers is completed according to the mode; and S6, after machining of the last layer is finished, bottom-to-top and top-to-bottom reciprocating trimming is conducted in a concentric circle mode, and high-quality machining of the micropores is achieved.

A composition of matter is provided comprising hierarchically ordered crystalline microporous material having well-defined long-range mesoporous ordering of lamellar symmetry. The composition possesses mesopores having walls of crystalline microporous material and a mass of mesostructure between mesopores of crystalline microporous material. Long-range ordering is defined by presence of secondary peaks in an X-ray diffraction (XRD) pattern and / or lamellar symmetry observable by microscopy.

The invention discloses a method for using a traditional Chinese medicine preparation to spray the traditional Chinese medicine preparation on the inner wall surfaces with air permeability, humidity regulation, diatom ooze, large white putty walls, inorganic coatings and other adsorption and porous walls, so that the inner wall surface layer has a traditional Chinese medicine health care function. Comprising the following steps: preparing a slow-release traditional Chinese medicine preparation with a health-care function according to health-care and treatment requirements; drying the microporous material which is smeared on the surface of the inner wall and has an adsorption function; the traditional Chinese medicine preparation is uniformly sprayed on a microporous wall, and after being absorbed, the traditional Chinese medicine preparation can be slowly released into a room within an effective time according to treatment and health care requirements, and functional traditional Chinese medicine gas is released into air so as to achieve the effects of improving immunity, delaying senescence, sterilizing, inhibiting diseases and improving air quality. And through mutual compatibility of the medicines, the effects of purifying indoor air and improving living comfort are achieved.

The invention discloses a preparation method of a self-assembled cellulose diaphragm, a membrane prepared by the self-assembled cellulose diaphragm and application of the self-assembled cellulose diaphragm. The preparation method comprises the following steps: mixing a solvent solution containing cellulose and zinc salt with a solvent solution containing a microporous material, ultrasonically crushing, and forming a membrane to obtain the self-assembled cellulose diaphragm, the cellulose is selected from cellulose nanofibers and / or cellulose nanowires; after the cellulose and the microporous material are uniformly dispersed in the solution, a film-forming base solution of the self-assembled diaphragm can be formed without adding any binder in the film-forming process, and the self-assembled diaphragm has a good film-forming effect. The composite diaphragm provides an effective channel, promotes the transmission of zinc ions in the battery, has smaller internal resistance than a traditional diaphragm, has high electrolyte preservation rate, is smaller than the traditional diaphragm in thickness, and can improve the energy density and cycle performance of the battery. The preparation process of the diaphragm is simple, the reaction condition is mild, the preparation period is short, and the diaphragm is suitable for large-scale industrial production and commercial application.

The invention relates to a fiber with improved thermal insulation properties comprising a polymeric fiber base material and a microporous material in particle form, wherein the microporous material comprises an agglomerate of precipitated insoluble amorphous metal silicates, in particular precipitated silicon dioxide. The invention further includes a method for producing a fiber with improved thermal insulation properties.

The invention discloses a lead-acid storage battery electrolyte density measuring device, and belongs to the technical field of battery measurement, the lead-acid storage battery electrolyte density measuring device comprises a detection mechanism, the detection mechanism comprises a connecting column and a tuning fork mechanism, the tuning fork mechanism comprises a tuning fork base and a tuning fork sensor, and the tuning fork mechanism is sleeved with a double-layer isolation mechanism; the double-layer isolation mechanism comprises an inner cover mechanism and a microporous outer cover mechanism, a microporous material of the outer cover mechanism enables the electrolyte to penetrate through the outer cover mechanism and block bubbles, and the inner cover mechanism enables the electrolyte to turn and flow many times to make contact with the tuning fork sensor through an inner cover first channel and an outer cover second channel which are arranged in a staggered mode. The tuning fork mechanism is sleeved with the double-layer isolation mechanism, the outer cover mechanism adopts a microporous material to achieve electrolyte permeation and bubble blocking, the inner cover forces electrolyte to flow circuitously through the staggered channel design, the double structures cooperatively eliminate bubble attachment and inhibit turbulence interference, and it is ensured that frequency signals of the tuning fork sensor are stable; and the measurement precision and sensitivity are obviously improved.

The invention discloses a green MOF-resin nano composite adsorbent as well as a preparation method and application thereof. A preparation method of a green MOF-resin nano composite adsorbent comprises the following steps: (1) soaking resin in absolute ethyl alcohol for pretreatment to obtain pretreated resin; (2) dissolving an aluminum salt in water to form an aluminum salt solution, and soaking the pretreated resin in the aluminum salt solution to serve as a first reactant; (3) dissolving 2, 5-furandicarboxylic acid in an acetic acid-water mixed solution to serve as a second reactant; and (4) uniformly mixing the first reactant and the second reactant, heating and refluxing the mixture, and washing, drying and sieving the obtained product to obtain the MOF-resin nano composite adsorbent. According to the invention, macroporous resin and a microporous MOF material are combined to form a nano composite adsorbent with a hierarchical pore structure; the nano composite adsorbent has a good adsorption effect on CO2, and is simple and convenient to regenerate, good in cycle performance and wide in application prospect.

The invention discloses a water taking and ferromanganese removal device based on a seepage collecting gallery, and belongs to the technical field of ferromanganese removal of seepage collecting galleries, the water taking and ferromanganese removal device comprises a seepage collecting gallery main body, an aeration assembly and a vibration piece, a gabion is installed on the upper surface of the seepage collecting gallery main body, the aeration assembly is installed inside the gabion, and the vibration piece is installed on the upper surface of the seepage collecting gallery main body. According to the manganese ore catalytic oxidation device, external gas enters the aeration ball through the air inlet cover, the connecting pipe and the aeration pipe, and the gas is extruded through a microporous material of a bubble film to form microbubbles, so that the content of dissolved oxygen in a water body is greatly increased, a sufficient oxygen source is provided for a manganese ore catalytic oxidation reaction, and the gas-liquid mass transfer effect is enhanced; meanwhile, the other part of gas enters the spherical shell and blows the vibration ball to drive the vibration rod to swing, the impact ball impacts the vibration piece through the connecting block and the connecting rod and then is transmitted to the aeration ball to enable the aeration ball to swing greatly, a water body generates turbulent flow, and the contact area and frequency of pollutants and manganese ore are increased.

A composition of matter is provided comprising hierarchically ordered crystalline microporous material having well-defined long-range mesoporous ordering of hexagonal symmetry. The composition possesses mesopores having walls of crystalline microporous material and a mass of mesostructure between mesopores of crystalline microporous material. Long-range ordering is defined by presence of secondary peaks in an X-ray diffraction (XRD) pattern and / or hexagonal symmetry observable by microscopy.

The invention discloses a preparation method of a polymer microporous material, and relates to the field of polymer microporous material research. The microporous material prepared by the invention has rich and controllable pore structures, and the permeability and hydrophilicity of the material are remarkably improved, so that the microporous material can quickly absorb moisture and keep a wet state; and meanwhile, effective regulation and control on the microporous structure are realized by adjusting process parameters such as solution concentration, solvent type, coagulating bath temperature and time. In addition, the mechanical strength and stability of the material are enhanced through uniform micropore distribution, and the reliability of the material in practical application is ensured. The polymer microporous material shows excellent hydrophilicity and structural stability, and is suitable for the fields of water treatment, environmental protection and the like.

The utility model discloses an air bearing structure which comprises a bearing seat, a bearing inner ring and a bearing outer ring, the bearing outer ring is assembled on the bearing seat, the bearing inner ring is assembled in the bearing outer ring, the bearing seat is provided with a first air hole used for conveying air, and the bearing outer ring is provided with a second air hole used for being matched with the first air hole. The bearing outer ring is provided with air passing grooves used in cooperation with the second air holes, and the bearing inner ring is made of a microporous material. Through the arrangement of the first air holes, the second air holes and the air passing grooves and the arrangement of the bearing inner ring made of the microporous material, the introduced high-pressure air can be more uniform and stable, so that an air film formed between an external shaft and the bearing inner ring is more uniform and stable, and the stability of the air bearing under high load and high rotating speed can be better realized.

The utility model is suitable for the technical field of electronic atomization equipment, and provides an atomization core and an atomizer, the atomization core comprises a base body and a heating element, the base body is made of a microporous material, the base body is provided with a first surface and a second surface which are opposite to each other, and a ventilation opening is formed in the first surface of the base body; the heating body is arranged on the second surface of the base body, the surface of the heating body is provided with a heating area, and the heating area surrounds the ventilation opening. According to the atomization core, in the atomization work process, air in the external environment can enter the base body through the ventilation opening and make full contact with the liquid substrate located in the heating area, combustion is more sufficient, dry burning is avoided, and therefore the service life of the atomization core can be relatively prolonged, and the atomization efficiency is improved. The taste of the aerosol before and after can be kept consistent, and the use experience of consumers is improved.

The invention belongs to the technical field of ion exchange membranes, and relates to a composite membrane with a high ion selective catalytic function and a preparation method thereof. The composite membrane has a three-layer structure, namely a high-ion-selectivity base membrane doped with a microporous material and catalytic functional composite layers doped with a positive electrode catalyst and a negative electrode catalyst on two sides of the base membrane. The preparation method comprises the following steps: firstly, dissolving perfluorinated sulfonic acid resin in an organic solvent, then dividing the obtained solution into three parts, and respectively adding a microporous material, a positive electrode catalyst and a negative electrode catalyst into the three parts for dispersion; after concentration treatment, a step-by-step tape casting mode is adopted to sequentially prepare a high-ion-selectivity base membrane, a positive electrode catalytic function composite layer and a negative electrode catalytic function composite layer, and finally, the three layers are compounded to form the high-ion-selectivity catalytic function composite membrane. The prepared composite membrane endows the flow battery diaphragm with a catalytic function; through fusion of the catalyst and the diaphragm resin, the problem of catalyst shedding is solved, and the conductivity and the ion barrier ability of the diaphragm are improved at the same time.

The invention relates to the field of noise reduction, in particular to a blower silencer, a blower silencing device and a noise reduction blower. The blower silencer comprises a hard cavity, a microporous medium filled in the hard cavity, and an airflow channel penetrating through a hard end face of the hard cavity and the interior of the microporous medium. An air outlet and an air inlet are respectively formed in two ends of the airflow channel; the Young modulus of the hard cavity is greater than 1MPa; the microporous medium is a microporous material or a component processed with micropores; the hard cavity, the microporous medium and the airflow channel form an assembly with a series of resonant frequencies, and within the spectral range of the resonant frequencies, acoustic wave impedance in the airflow channel is lower than air impedance, so that acoustic wave propagation is hindered. The hair dryer solves the problem that hearing may be damaged due to the fact that an existing hair dryer is too high in noise.

The invention relates to the technical field of filter materials, in particular to a mineral composite filter element and a preparation method and application thereof. The mineral composite filter element comprises the following raw materials in parts by weight: 1-50 parts of a hydrogen production material, 1-15 parts of a mineralization material, 5-10 parts of a microporous material, 1-10 parts of an antibacterial material, 5-50 parts of activated carbon and 5-60 parts of a thermoplastic polymer, the hydrogen production material is one or two of magnesium-based and silicon-based mineral hydrogen production material particles. Through the integrated structural design, multiple functions of filtration, mineralization, hydrogen production, antibiosis and the like are efficiently, stably and enduringly integrated, and the defects that in the prior art, a filter element is single in function, short in service life, unstable in efficiency, complex in system and the like are overcome.

The application provides a method for high-selectivity adsorption of extremely low concentration NH3 by using alcohol amine ionic liquid microporous materials, and belongs to the technical field of gas separation and purification. In the method, the ionic liquid microporous material uses a mesoporous material as a carrier, and is modified by a multi-site alcohol amine ionic liquid to form a novel ionic adsorption material with selective adsorption NH3 sites and microporous structure. Since the proton hydrogen on the cation of the alcohol amine ionic liquid can form a hydrogen bond with NH3, and the material has a micropore effect, the material can efficiently capture NH3, especially has high selectivity at extremely low NH3 concentration, and the adsorbed NH3 can be completely desorbed by heating or reducing pressure, and the adsorbent has good circulation after regeneration, and still has a high adsorption capacity after ten cycles, thereby providing a new way for efficient purification and separation of NH3.

This invention discloses a polyetheretherketone (PEEK) / aramid fiber composite microporous material and its molding method, belonging to the field of engineering plastics processing. The invention first modifies aramid fibers by amylation and prepares carboxylated PEEK. Covalent bonding between the amino and carboxyl groups is achieved through a chemical reaction, resulting in aramid fibers coated with PEEK. These fibers are then mixed with PEEK resin, a melt flow modifier, and additives to obtain a composite material. The composite material is then subjected to biaxial thermo-stretching orientation to improve its transverse / longitudinal orientation and crystallinity. Finally, the composite microporous material is obtained through supercritical CO2 microporous foaming. Because the foaming temperature is lower than the thermo-stretching orientation temperature, the biaxial orientation structure of the composite material is well preserved, and the well-dispersed aramid fibers effectively improve the cell wall strength, inhibit cell growth and merging, significantly increase cell density, and drastically reduce cell size, thereby constructing a high-strength, heat-insulating PEEK composite microporous material.

Methods for synthesis of hierarchically ordered zeolites and zeolite-type materials are provided. Synthesized hierarchically ordered zeolites and zeolite-type materials formed according to the methods herein possess a high-degree of well-defined long-range mesoporous ordering. The methods include base-mediated reassembly, by dissolution of the parent material to the level of oligomeric structural building units of the parent material, and minimizing or avoiding amorphization / structural collapse. The dissolution and self-assembly is comprehensively controlled to produce hierarchically ordered zeolites and zeolite-type materials according to the methods herein.

The invention relates to the technical field of ammonium dinitramide preparation methods, in particular to an ammonium dinitramide coating material and a preparation method and application thereof.The preparation method comprises the following steps that under the protective atmosphere, an acetic acid solution, trialdehyde phloroglucinol, ammonium dinitramide and an amino compound are mixed and subjected to a Schiff base reaction, and an intermediate material is obtained; and depositing a fluorocarbon on the surface of the intermediate material to prepare the ammonium dinitramide coated material. According to the invention, trialdehyde phloroglucinol reacts with an amino compound to generate an interlinked interlayer microporous material (COFs framework material), and the interlinked interlayer microporous material has good compatibility with strong-polarity ammonium dinitramide and a non-polar fluorocarbon compound, so that transition of ammonium dinitramide (strong-polarity)-microporous material (moderate-polarity)-fluorocarbon (non-polarity) is formed; the abrupt change of interfacial tension when the surface of ammonium dinitramide is directly coated with the fluorocarbon is relieved.

The invention provides a PVDF (Polyvinylidene Fluoride) microporous material as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out heat preservation treatment on PVDF powder for a period of time at the temperature of more than or equal to 100 DEG C to obtain a microporous material with a stable shape, namely PVDFamp; the invention relates to an inorganic hybrid microporous material. The preparation method of the material is simple, the thickness can be effectively increased, then the PVDF microporous material meeting large-capacity adsorption is obtained, the PVDF microporous material has the advantages of being improved in temperature resistance, solvent resistance and the like, and when the material serves as a filtering material or a loading material, the temperature resistance, the solvent resistance and the filtering efficiency are excellent.

The invention relates to a [Cu6I6] cluster lanthanide series-containing microporous catalytic material and a preparation method and application thereof in catalysis of CO2 carboxylic acid cyclization, the molecular formula of the catalytic material is [Eu2Cu6I6 (pyrc) 4 (DMF) 6], and the ligand pyrc is 4-pyrazole carboxylic acid; the crystal structure of the catalytic material belongs to a triclinic system, the space group is Pi, and the cell parameters are as follows: # imgabs0 # imgabs1 # alpha = 84.072 (4) degrees, beta = 88.384 (3) degrees, gamma = 87.343 (4) degrees and # imgabs2 #. The preparation method comprises the following steps: S1, adding 4-pyrazole carboxylic acid and Eu (NO3) 3.9 H2O into DMF (Dimethyl Formamide), and performing ultrasonic treatment to form a solution A; s2, adding CuI into DMF, and performing ultrasonic treatment to form a turbid liquid B; and S3, mixing A and B, carrying out ultrasonic treatment, transferring into a pressure-resistant bottle, heating to 125 DEG C at a speed of 10 DEG C / min, carrying out heat preservation for 24 hours, carrying out solvothermal reaction, and cooling to room temperature at a speed of 5 DEG C / min to obtain the crystal. The [Cu6I6] cluster lanthanide series microporous material catalyzes CO2 and propargyl alcohol to perform carboxylic acid cyclization at normal temperature and normal pressure to obtain a target product alkylene cyclic carbonate product. The [Cu6I6] cluster lanthanide series microporous catalytic material is used for catalyzing CO2 and propargyl alcohol to carry out carboxylic acid cyclization reaction at normal temperature and normal pressure.

A method for synthesizing hierarchical ordered zeolites and zeolite-type materials is provided. The synthesized hierarchical ordered zeolites and zeolite-type materials formed by the methods herein possess a high degree of defined long-range mesoporous order. The method includes base-mediated reassembly by decomposition of the parent material to the level of the oligomeric structural building units of the parent material and minimization or avoidance of amorphization / structural collapse. The decomposition and self-assembly are comprehensively controlled to produce hierarchical ordered zeolites and zeolite-type materials by the methods herein.

The invention discloses an inorganic fluorine-containing anion functionalized microporous material, a preparation method thereof and application of the inorganic fluorine-containing anion functionalized microporous material in carbon dioxide adsorption and selective adsorption separation of olefin / alkane. The microporous material is a polymer formed by coordination of a metal ion M, an inorganic fluorine-containing anion A and an azole organic ligand L through a solvothermal reaction, and the solvothermal reaction adopts a rotary oven or a microwave reaction. The metal ion M is selected from at least one of Zn < 2 + >, Ni < 2 + > and Cu < 2 + >. The inorganic fluorine-containing anion A is selected from at least one of SiF6 < 2->, GeF6 < 2->, TiF6 < 2->, NbOF5 < 2->, SnF6 < 2-> and ZrF6 < 2->. The microporous material has a proper aperture size # imgabs0 # and rich fluorine-containing anions and nitrogen azole adsorption sites, and by taking the microporous material as an adsorbent, the selective adsorption separation of ethylene / ethane can be realized, alkane is preferentially adsorbed under a low-pressure condition, and a certain trapping capability on carbon dioxide is realized.

The present invention belongs to the field of metal organic framework materials, and specifically relates to a microporous material SDMOF-1, a preparation method thereof, and an application thereof. According to the difference in the sizes of C2H2 and C2H4 molecules, a microporous MOFs with a suitable size is designed to capture C2H2 molecules, thereby achieving the purpose of separating a mixture of C2H2 and C2H4 and purifying C2H4. The present invention selects H2bodc and bpy ligands and copper nitrate to construct a microporous material SDMOF-1 with a pore size of #imgabs0#. The Cu2(COO)4 paddle wheel secondary building unit is connected to four H2bodc ligands to form a twisted lattice-shaped two-dimensional layer. The bpy ligand coordinates with copper along the c-axis direction and supports each layer to form a complete three-dimensional structure. The pore size of the framework is very compatible with the size of the C2H2 molecule, but cannot accommodate the C2H4 molecule, thereby achieving a molecular sieving effect.

Methods of making hierarchically ordered crystalline microporous materials are provided. The method may include forming an aqueous suspension comprising a parent crystalline microporous material, an alkaline reagent, a supramolecular template, and a silica source material, an alumina source material, or both. The method may further include hydrothermally treating the aqueous suspension to form the hierarchically ordered crystalline microporous material. The hierarchically ordered crystalline material may have a greater degree of mesoporosity than the parent crystalline microporous material and may have a silica-to-alumina ratio (SAR) that is at least 0.5 different than the parent crystalline microporous material.

The utility model relates to the field of breathable tiles, in particular to a two-way clamped breathable tile. According to the technical scheme, an upper-end rack is arranged on an upper-end connecting strip, a lower-end connecting strip is arranged on the other side of a plate-shaped breathable tile body, a lower-end rack is arranged on the lower-end connecting strip, open holes are formed in the upper-end connecting strip and the lower-end connecting strip, the upper-end rack is connected with a strip-shaped lower-end breathable tile body in a wedge-shaped mode, and the lower-end rack is connected with a strip-shaped upper-end breathable tile body in a wedge-shaped mode. The plate-shaped breathable tile body is arranged to provide a covering main body, the reinforcing supporting strips are arranged in the hollow protruding blocks to enhance the reinforcing and supporting effects, the anti-collision protection layer performs anti-collision buffering protection work, and the waterproof protection layer performs waterproof protection. The upper end rack is fixed by the upper end connecting strip, the lower end rack is fixed by the lower end connecting strip, wedge-shaped connection can be carried out, bidirectional clamping connection can be realized, the strip-shaped upper end breathable tile body and the strip-shaped lower end breathable tile body can be independently connected, and the whole structure is prepared by adopting a microporous material based on a foaming process.

The invention relates to the technical field of sewage treatment, in particular to an aluminum-silicon nano microporous material and a sewage treatment device. An aluminum-silicon nano microporous material is composed of a non-conductive amorphous silicon dioxide aluminum-silicon shell and superconductive aluminum-silicon nano micropores, and a preparation method of the aluminum-silicon nano microporous material comprises the following steps: S1, preparing an aluminum-silicon nano material; s2, titanium tetraacetylacetonate and ferric acetylacetonate are mixed, and hydrogen serves as a gas carrier and reacts with the aluminum-silicon nano material; annealing treatment; s3, forming an amorphous silicon dioxide shell; and S2, dispersing the aluminum-silicon nano material treated in S2 in sol containing a silicon dioxide precursor, forming a silicon dioxide layer on the surface of the material through hydrolysis and condensation reaction, and after the reaction is completed, centrifuging, washing, drying and calcining to obtain the aluminum-silicon nano microporous material. The obtained material has relatively strong adsorption capacity and specific surface area, adsorbs pollutants, and forms unbalanced potential and external field potential on the surface, so that the pollutants in sewage are quickly physically flocculated and precipitated.

Compositions of matter are provided that include a hierarchically ordered crystalline microporous material having a well-defined long-range mesoporous orderliness of cubic symmetry. The composition has mesopores having walls of the crystalline microporous material and a large number of mesostructures between the mesopores of the crystalline microporous material. The long-range order is defined by the presence of secondary peaks in X-ray diffraction (XRD) maps and / or cubic symmetry observable by microscopy.

The present application relates to a kind of water-soluble polyolefin dissolving agent, polyolefin microporous material and its preparation method, wherein, by mass fraction, the water-soluble polyolefin dissolving agent includes 20%~60% main porogen, 5%~30% auxiliary porogen, 20% or less compatibility regulator and the balance of water, the main porogen is selected from at least one of water-soluble polyether amine, water-soluble polyether ester, the auxiliary porogen is selected from onium salt type ionic liquid, the compatibility regulator is selected from amphiphilic substance.The water-soluble polyolefin dissolving agent of the present application can completely replace white oil / space oil as porogen, replace dichloromethane with water to extract, eliminate the safety, environmental protection and residual problems caused by organic solvent, simultaneously, by regulating the composition of water-soluble polyolefin dissolving agent and extraction condition can realize the controllable adjustment of microporous structure, and the water-soluble solution containing dissolving agent obtained by extraction can be concentrated, distilled and recycled and closed loop utilization.

The application discloses a kind of hexafluorosilicic acid anion functionalized microporous material and its preparation method and application in adsorption separation olefin / alkane.The microporous material is by metal ion Zn 2+ , inorganic anion SiF6 2‑ And azole organic ligand L are formed by the coordination of static solvothermal reaction polymer, the microporous material with the separation property can only be synthesized using static solvothermal reaction method.The microporous material has high density of anion and azole site, and the structure properties of the material can be controlled by adjusting the solvent type of the reaction, the feeding ratio of anion and azole organic ligand and the type of azole organic ligand.The microporous material obtained by the application can realize the separation of olefin / alkane based on size and electronic effect.