CN112933982A - Thiophene selective graphene biomimetic mineralization film and preparation method thereof - Google Patents

Thiophene selective graphene biomimetic mineralization film and preparation method thereof Download PDF

Info

Publication number
CN112933982A
CN112933982A CN202110129990.9A CN202110129990A CN112933982A CN 112933982 A CN112933982 A CN 112933982A CN 202110129990 A CN202110129990 A CN 202110129990A CN 112933982 A CN112933982 A CN 112933982A
Authority
CN
China
Prior art keywords
thiophene
membrane
biomimetic
preparation
biomimetic mineralization
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202110129990.9A
Other languages
Chinese (zh)
Other versions
CN112933982B (en
Inventor
彭平
兰永强
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sanming University
Original Assignee
Sanming University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sanming University filed Critical Sanming University
Priority to CN202110129990.9A priority Critical patent/CN112933982B/en
Publication of CN112933982A publication Critical patent/CN112933982A/en
Application granted granted Critical
Publication of CN112933982B publication Critical patent/CN112933982B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/36—Pervaporation; Membrane distillation; Liquid permeation
    • B01D61/362—Pervaporation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0079—Manufacture of membranes comprising organic and inorganic components
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/12—Composite membranes; Ultra-thin membranes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/30—Polyalkenyl halides
    • B01D71/32—Polyalkenyl halides containing fluorine atoms
    • B01D71/34—Polyvinylidene fluoride
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/70—Polymers having silicon in the main chain, with or without sulfur, nitrogen, oxygen or carbon only

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Water Supply & Treatment (AREA)
  • Inorganic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)

Abstract

The invention provides a thiophene selective graphene biomimetic mineralization membrane and a preparation method thereof, wherein the preparation method of the biomimetic mineralization membrane comprises the polymerization of polydimethylsiloxane oligomers in an oil phase, and the hydrolysis and condensation reaction of methyl orthosilicate and inducer molecules at a water/oil interface by taking methyl orthosilicate as a precursor of silicon dioxide and cysteamine as an inducer and a catalyst, so that silicon dioxide particles are generated in situ on the surface of graphene oxide and are uniformly embedded into a PDMS (polydimethylsiloxane) matrix to obtain the biomimetic mineralization membrane. The biomimetic mineralization membrane has good compatibility, can keep higher enrichment factors and has high permeation flux.

Description

Thiophene selective graphene biomimetic mineralization film and preparation method thereof
Technical Field
The invention relates to the technical field of pervaporation membranes, and particularly relates to a thiophene selective graphene biomimetic mineralization membrane and a preparation method thereof.
Background
Gasoline is refined and processed from petroleum and consists of alkanes, a mixture of C5-C14 alkenes and cycloalkanes, and aromatic compounds. Its composition depends on the crude oil used and generally consists of different blending components from reforming, isomerization and Fluid Catalytic Cracking (FCC) processes. FCC gasoline accounts for 30-40% of the total gasoline yield, making it the main source of sulfur components in gasoline. Sulfur in gasoline is in many forms, such as sulfides, mercaptans, and thioethers, among others. These organic sulfur impurities can generate sulfur dioxide after high temperature combustion, which in turn can lead to acid rain. For this reason, gasoline desulfurization technology is vigorously promoted and developed in various countries of the world.
Currently, the commonly used desulfurization techniques are selective oxidation, catalytic extraction, alkylation extraction, selective hydrotreating, membrane separation, and the like. Compared with other separation processes, membrane separation has many advantages, such as high separation efficiency, low energy consumption, low operation cost, simple operation, easy process amplification and the like. Pervaporation (PV) is a new membrane separation technology, is used for gasoline desulfurization, has the characteristics of no loss of octane number, low energy consumption, environmental friendliness, simplicity in operation, easiness in industrial amplification and the like, and has attracted attention worldwide. The existing pervaporation membrane is mainly characterized in that inorganic materials and high polymer materials are simply blended, so that the problem of poor compatibility exists, and the poor separation performance of the composite membrane is directly caused.
Disclosure of Invention
The invention aims to provide a preparation method of a thiophene selective graphene biomimetic mineralization film, which is simple, easy to operate and suitable for industrial production.
The invention also aims to provide the thiophene selective graphene biomimetic mineralization film, silica particles are formed on the surface of graphene oxide in situ and are uniformly embedded into a polymer matrix to obtain the biomimetic mineralization film, and the biomimetic mineralization film has good compatibility, can keep higher enrichment factors and has high permeation flux.
The technical problem to be solved by the invention is realized by adopting the following technical scheme.
The invention provides a preparation method of a thiophene selective graphene biomimetic mineralization film, which comprises the following steps:
s1, dissolving a surfactant, a polydimethylsiloxane oligomer, Graphene Oxide (GO) and methyl orthosilicate in n-heptane, and stirring at room temperature to obtain a first mixed solution;
s2, dissolving cysteamine in a Tris-hydrochloric acid buffer solution to obtain an inducer;
s3, dropwise adding the inducer into the first mixed solution, stirring for 20-40 min, and dropwise adding a catalyst to obtain a second mixed solution;
and S4, casting the second mixed solution on the polyvinylidene fluoride micro-filtration membrane at room temperature by taking the polyvinylidene fluoride micro-filtration membrane as a supporting layer, and drying and annealing in the air to obtain the biomimetic mineralized membrane.
The invention provides a thiophene selective graphene biomimetic mineralization film, which is prepared according to the preparation method.
The thiophene selective graphene biomimetic mineralization film and the preparation method thereof have the beneficial effects that:
the biomimetic mineralization film is prepared in situ through the synergistic effect of polymerization of Polydimethylsiloxane (PDMS) oligomer in an oil phase and silicon dioxide precipitation on the surface of graphene oxide in reverse microemulsion. The preparation of the silicon dioxide precipitate Takes Methyl Orthosilicate (TMOS) as a precursor of silicon dioxide, takes cysteamine as an inducer and a catalyst, and when TMOS and inducer molecules meet at a water/oil interface, hydrolysis and condensation reactions occur, so that silicon dioxide particles are generated in situ on the surface of graphene oxide, and are uniformly embedded into a PDMS matrix, and the biomimetic mineralization membrane is obtained. The biomimetic mineralization membrane has good compatibility, can keep higher enrichment factors and has high permeation flux.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
FIG. 1 is a flow chart of the preparation of a biomimetic mineralization membrane according to an embodiment of the present invention;
FIG. 2 is an SEM image of a cross section of a biomimetic mineralization membrane in example 3 of the present invention;
FIG. 3 is an infrared spectrum of a biomimetic mineralized membrane according to example 3 of the present invention;
FIG. 4 is an XRD pattern of a biomimetic mineralized film according to example 3 of the present invention;
FIG. 5 is a TGA, DTG and DSC plots of a biomimetic mineralized membrane according to example 3 of the present invention and a PDMS membrane of comparative example 1;
FIG. 6 is a graph of the effect of GO addition on pervaporation desulfurization performance of a biomimetic mineralized membrane;
FIG. 7 is a graph showing the influence of thiophene content in a feed liquid on the separation performance of a biomimetic mineralization film;
FIG. 8 is a graph of the effect of operating temperature on the separation performance of a biomimetic mineralized membrane;
FIG. 9 is a graph of the effect of operating temperature on n-octane flux and thiophene flux;
FIG. 10 is a graph of the operational stability of biomimetic mineralized membranes according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
The thiophene-selective graphene biomimetic mineralization film and the preparation method thereof according to the embodiment of the invention are specifically described below.
Referring to fig. 1, the preparation method of the thiophene-selective graphene biomimetic mineralization film provided by the embodiment of the present invention includes the following steps:
s1, dissolving the surfactant, the polydimethylsiloxane oligomer, the graphene oxide and the methyl orthosilicate in n-heptane, and stirring at room temperature to obtain a first mixed solution.
Further, in a preferred embodiment of the invention, the surfactant is a mixed surfactant of tween and span in a mass ratio of 1: 1-1.5.
Further, in a preferred embodiment of the present invention, the mass ratio of the polydimethylsiloxane oligomer, the surfactant and the methyl orthosilicate is 1: 0.05-0.15: 0.1-0.2.
S2, dissolving cysteamine in Tris-hydrochloric acid buffer solution to obtain the inducer.
Further, in a preferred embodiment of the present invention, the molar concentration of the Tris-hydrochloric acid buffer solution is 0.02-0.03 mol/L.
Further, in a preferred embodiment of the present invention, the molar concentration of the inducing agent is 0.45-0.55 mol/L, and the pH of the inducing agent is 6.5-7.5. Preferably, the inducer has a pH of 7. The mechanism of the TMOS hydrolysis catalyzed by cysteamine is nucleophilic substitution-attack of the silicon atom by negative anions. The size and shape of the silica particles produced at the water/oil interface is primarily affected by the pH of the aqueous solution. Si (OR)4The hydrolysis rate of (a) is lowest at pH 7.0 and increases exponentially with increasing pH. In contrast, the condensation rate is the smallest at pH 2.0 and the largest at pH 7.0, where the dissolution rate of the silica produced is the largest and the size is smaller. The pH value of the cysteamine aqueous solution of the present invention is 7.0, which is not only beneficial to Si (OR)4Does not favor Si (OH)4Condensation of (2). Therefore, under the action of cysteamine, the generated silicon dioxide can be uniformly deposited on the surface of graphene oxide.
And S3, dropwise adding the inducer into the first mixed solution, stirring for 20-40 min, and dropwise adding the catalyst to obtain a second mixed solution. And mixing the first mixed solution with an inducer under mechanical stirring to form reverse micelles, wherein the inducer is embedded in the center of the microemulsion and can be stably dispersed in the non-polar solvent n-heptane under the action of the surfactant. TMOS is used as a silicon dioxide precursor, cysteamine is used as an inducer and a catalyst, when the silicon dioxide precursor and inducer molecules meet at a water/oil interface, hydrolysis and condensation reactions occur, and therefore silicon dioxide is deposited on the GO surface in situ. According to the invention, the biomimetic mineralization film is prepared in situ through the synergistic effect of polymerization of PDMS oligomer in the oil phase and generation of silicon dioxide on the surface of graphene oxide in the reverse microemulsion.
In the process of preparing the biomimetic mineralized membrane, TMOS is not only used as a silica precursor for generating silica, but also can be used as a crosslinking agent of PDMS to promote polymerization of PDMS oligomers. The existence of PDMS can obviously improve the viscosity of the system and reduce the possibility of collision between droplets, thereby greatly improving the stability of the microemulsion. In addition, the good compatibility of the PDMS matrix and the graphene-silicon dioxide core-shell structure can also promote the uniform dispersion of the mineralized graphene-silicon dioxide core-shell structure in the PDMS matrix.
Further, in a preferred embodiment of the present invention, the catalyst is dibutyltin dilaurate.
And S4, casting the second mixed solution on the polyvinylidene fluoride micro-filtration membrane at room temperature by taking the polyvinylidene fluoride micro-filtration membrane as a supporting layer, and drying and annealing in the air to obtain the biomimetic mineralized membrane. The second mixture is cast on a polyvinylidene fluoride micro-filtration membrane, dried in air and annealed, so that PDMS can be completely crosslinked and residual solvent can be evaporated.
Further, in a preferred embodiment of the present invention, in the biomimetic mineralization film, the mass percentage of the graphene oxide is 0.01-0.5 wt.%.
Further, in the preferred embodiment of the present invention, the drying time is 23-25 h, and the annealing temperature is 75-85 ℃.
The invention also provides a thiophene selective graphene biomimetic mineralization film which is prepared according to the preparation method. According to the invention, silicon dioxide particles are generated on the surface of graphene oxide in situ and are uniformly embedded into a PDMS matrix, so that the biomimetic mineralization film is obtained. The biomimetic mineralization membrane has good compatibility, can keep higher enrichment factors and has high permeation flux.
The features and properties of the present invention are described in further detail below with reference to examples.
Example 1
The thiophene-selective graphene biomimetic mineralization film provided by the embodiment is prepared according to the following method:
(1) pretreatment of the support layer: before use, the polyvinylidene fluoride micro-filtration membrane is soaked in deionized water for 3 hours.
Preparing a biomimetic mineralized membrane: 0.05g of tween and 0.05g of span are mixed to form a mixed surfactant, 1g of PDMS oligomer, a certain amount of GO and 0.15g of TMOS are dissolved in 10g of n-heptane, and the mixture is stirred for a period of time at room temperature to obtain a uniform mixed solution. Cysteamine was dissolved in 0.025mol/L neutral Tris-hydrochloric acid buffer to make 0.5mol/L inducer (pH 7.0). Then, 0.2mL of inducer was added dropwise to the above mixture under strong mechanical stirring. After stirring was continued for 30 minutes, 0.02g of the catalyst dibutyltin dilaurate was added dropwise. And after the viscosity of the solution is increased to a certain degree, casting the solution on the soaked polyvinylidene fluoride micro-filtration membrane at room temperature. Finally, the biomimetic mineralized film obtained was dried in air for 24 hours and then annealed at 80 ℃ to complete the cross-linking and evaporate the residual solvent. Wherein the addition amount of GO in the biomimetic mineralized membrane is 0.1 wt.%.
The bionic mineralized membrane prepared in the embodiment is used for measuring the pervaporation desulfurization performance in thiophene n-octane feed liquid with the thiophene content of 1312ppm at the temperature of 30 ℃, and the permeation flux of the bionic mineralized membrane is 4203g m-2·h-1The enrichment factor was 5.01.
Example 2
The difference between the thiophene-selective graphene biomimetic mineralization film provided in this embodiment and embodiment 1 is that the addition amount of GO in the biomimetic mineralization film is 0.2 wt.%.
The bionic mineralized membrane prepared by the embodiment is used for measuring the pervaporation desulfurization performance in thiophene n-octane feed liquid with the thiophene content of 1312ppm at the temperature of 30 ℃, and the permeation flux of the bionic mineralized membrane is 5755g m-2·h-1The enrichment factor was 5.99.
Example 3
The difference between the thiophene-selective graphene biomimetic mineralization film provided in this embodiment and embodiment 1 is that the addition amount of GO in the biomimetic mineralization film is 0.3 wt.%.
The bionic mineralized membrane prepared by the embodiment is used for measuring the pervaporation desulfurization performance in thiophene n-octane feed liquid with the thiophene content of 1312ppm at the temperature of 30 ℃, and the permeation of the bionic mineralized membraneThe flux was 6973 g.m-2·h-1The enrichment factor was 6.30.
Example 4
The difference between the thiophene-selective graphene biomimetic mineralization film provided in this embodiment and embodiment 1 is that the addition amount of GO in the biomimetic mineralization film is 0.4 wt.%.
The bionic mineralized membrane prepared by the embodiment is used for measuring the pervaporation desulfurization performance in thiophene n-octane feed liquid with the thiophene content of 1312ppm at the temperature of 30 ℃, and the permeation flux of the bionic mineralized membrane is 7948g m-2·h-1The enrichment factor was 5.39.
Example 5
The difference between the thiophene-selective graphene biomimetic mineralization film provided in this embodiment and embodiment 1 is that the addition amount of GO in the biomimetic mineralization film is 0.5 wt.%.
The bionic mineralized membrane prepared by the embodiment measures the pervaporation desulfurization performance in the thiophene n-octane feed liquid with the thiophene content of 1312ppm at the temperature of 30 ℃, and the permeation flux of the bionic mineralized membrane is 8747 g.m-2·h-1The enrichment factor was 5.17.
Comparative example 1
This comparative example provides a PDMS film, which was prepared in a manner different from that of example 1 in that GO was added in an amount of 0 in the PDMS film.
The bionic mineralized membrane prepared by the comparative example is used for measuring the pervaporation desulfurization performance in thiophene n-octane feed liquid with the thiophene content of 1312ppm at the temperature of 30 ℃, and the permeation flux of the bionic mineralized membrane is 2737 g.m-2·h-1The enrichment factor was 3.43.
As shown in fig. 2, SEM image of cross section of biomimetic mineralized membrane. As can be seen from fig. 2, the graphene oxide is uniformly dispersed in the PDMS matrix. Due to the high flexibility of the PDMS molecular chain, a dense structure can be formed during the curing process, so no significant pores are observed in the SEM image of the cross section of the biomimetic mineralized membrane.
FIG. 3 shows the infrared spectrum of the biomimetic mineralized membrane. Wherein, 3450cm-1The broad absorption peak appearing nearby is silicon dioxide (SiO)2·xH2O) O-H antisymmetric stretching vibration of water in the structure;the mineralized film has a high PDMS content of 2962cm-1And 2856cm-1The absorption peaks appeared at are respectively belonging to-CH3Antisymmetric and symmetric telescopic vibrations. As can be seen from FIG. 3, silica synthesized by induced mineralization was present inside the mineralized film at 2927cm-1Characteristic peaks of the synthetic silica residue appear there. 1262cm-1The absorption peak at (A) is attributed to Si-CH3Of a group-CH3Is vibrated by the symmetrical deformation of the vibrating member. Due to the structural similarity of PDMS and silicon dioxide, the thickness of the layer can be 1096cm-1And 1024cm-1The wide and strong bimodal absorption band belonging to the Si-O-Si stretching vibration absorption peak was observed and also illustrates that a large amount of long linear PDMS was contained in the mineralized film. 802cm-1The characteristic absorption peaks of (A) are attributed to the stretching vibration of Si-C and the symmetric stretching vibration of Si-O.
FIG. 4 shows an XRD pattern of the biomimetic mineralized film, wherein the diffraction peak at 22.3 ° is SiO2Typical characteristic peaks of (a). As can be seen from fig. 4, a characteristic diffraction peak of graphene appears at 26.5 °, indicating that a small amount of uncoated graphene exists in the biomimetic mineralized film, and the diffraction peak at 12.5 ° is a characteristic peak of PDMS. According to the method, the biomimetic mineralization film is successfully prepared.
Thermal stability of PDMS films and biomimetic mineralized films was characterized using TGA, DTG, and DSC plots as shown in figure 5. Wherein, fig. 5a is a TGA graph, fig. 5b is a DTG graph, and fig. 5c is a DSC graph. As can be seen from fig. 5a, the presence of graphene nanoplatelets decreases the thermal stability of PDMS, such that the thermal decomposition temperature (260 ℃) of the biomimetic mineralized film is lower than the thermal decomposition temperature (280 ℃) of the PDMS film. Temperature (t) corresponding to the peak on the curve in FIG. 5bd) Is the temperature at which the maximum degradation rate occurs and can be used to evaluate the thermal stability of the material. Typically, the thermal decomposition temperature of graphene is about 450 ℃. However, since graphene is dispersed in the PDMS matrix in the form of nanosheets, resulting in a decrease in thermal stability, there is a relatively small absorption peak near 350 ℃.
As shown in FIG. 6, the pervaporation desulfurization performance of GO on a biomimetic mineralized membrane is studied in thiophene n-octane feed liquid with thiophene content of 1312ppm at 30 DEG CThe influence of (c). In fig. 6, 1 is a variation trend line of permeation flux, and 2 is a variation trend line of enrichment factor. As can be seen from fig. 6, the permeation flux of the biomimetic mineralized membrane gradually increased with increasing GO content. The accumulation of PDMS chain segments is effectively broken through by the high GO addition amount in the biomimetic mineralization film, and more diffusion paths are provided for permeating molecules. Thus, the permeation flux of biomimetic mineralized membranes was increased compared to PDMS membranes. On the other hand, as GO addition was increased from 0 to 0.3 wt.%, the enrichment factor of biomimetic mineralized membranes increased. Compared with PDMS, the rigidity of the molecular chain of PDMS is gradually enhanced along with the increase of the addition amount of GO, so that the selectivity of the biomimetic mineralization film to thiophene is directly improved. In addition, as the amount of GO added increases, the hydrophilicity of the membrane surface increases, while thiophene is more hydrophilic than n-octane, which favors preferential dissolution of thiophene. However, when the addition amount of GO is higher than 0.3 wt.%, the random distribution of excess GO in the polymer matrix causes a large number of aggregates inside the biomimetic mineralized membrane, which in turn causes non-selective interface defects, resulting in a decrease in enrichment factor. But the reduction is not large because of the coated SiO2The dispersity of GO is enhanced, the area of a polymer/particle interface inside the mineralized membrane is increased, and the formation of interface defects is reduced. When the addition amount of GO is 0.3 wt.%, the maximum enrichment factor of the biomimetic mineralization membrane desulfurization is 6.30, and the corresponding permeation flux is 6973 g.m-2·h-1。
As shown in fig. 7, the biomimetic mineralization film with 0.3 wt.% of GO added is used as a separation film to study the separation performance of the biomimetic mineralization film with thiophene content in the feed liquid in the range of 1312-2512 ppm. Wherein 1 is a variation trend line of permeation flux, and 2 is a variation trend line of enrichment factor. As can be seen from FIG. 7, as the thiophene content of the feed liquid increases from 1312ppm to 2512ppm, the permeation flux increases and the enrichment factor decreases. The increased thiophene content in the feed results in an increase in thiophene activity, which helps to increase the solubility of thiophene in the membrane. Therefore, an increase in the concentration of thiophene on the upstream side causes a continuous increase in the permeation flux. Solubility parameter of PDMS (21.0 (J. cm) due to good affinity between thiophene and biomimetic mineralized membrane as thiophene content in the feed increased-3)1/2) Near thiophene (20.0(J · cm)-3)1/2) Higher than n-octane (15.5(J · cm)-3)1/2) Leading to significant swelling of the biomimetic mineralized membrane and, therefore, the selectivity to thiophene decreases as the thiophene content in the feed increases.
As shown in fig. 8, the operating temperature plays a key role in pervaporation desulfurization performance of the biomimetic mineralized membrane. Therefore, it is important to investigate the influence of the sulfur removal performance by pervaporation. The influence of temperature on the pervaporation desulfurization performance of the biomimetic mineralization film is researched in thiophene n-octane feed liquid with the thiophene content of 1312 ppm. In fig. 8, 1 is a graph showing the change trend of permeation flux, and 2 is a line showing the change trend of enrichment factor. As can be seen from FIG. 8, the enrichment factor for thiophene decreased from 6.32 to 5.36 and the permeate flux was from 6948g m as the operating temperature increased from 303K to 343K-2·h-1Increased to 16339 g.m-2·h-1. The temperature rise can improve the flexibility of the PDMS chains, so that the free volume pore diameter of the molecule permeation is more uniform, and the permeation flux of the permeation molecules in the membrane is improved. At the same time, the saturated vapor pressure of the permeate component on the upstream side increases, while the permeate pressure on the permeate side hardly changes, which also directly leads to an increase in permeate flux.
As shown in fig. 9, the effect of temperature on octane flux and thiophene flux was investigated in a thiophene n-octane feed solution having a thiophene content of 1312 ppm. In fig. 9, 1 is a graph showing a change trend of the n-octane flux, and 2 is a graph showing a change trend of the thiophene flux. Compared with n-octane, the biomimetic mineralized membrane has lower thiophene activation energy. As the feed temperature increases, the thiophene flux increases by a lesser extent than the n-octane flux, resulting in a decrease in the enrichment factor. This is because thiophene has a smaller molecular size than n-octane, and the increase in free volume is more favorable for the increase in n-octane flux. Thus, the temperature sensitivity of n-octane permeation is higher than that of thiophene permeation.
As shown in fig. 10, biomimetic mineralized films with a GO content of 0.3 wt.% were tested for operational stability at 30 ℃. In fig. 10, 1 is a graph showing the change in permeation flux, and 2 is a graph showing the change in enrichment factor. As can be seen from FIG. 10, both the permeation flux and the enrichment factor can be kept stable within 168h, thereby indicating that the biomimetic mineralization membrane has good separation performance under long-term operation conditions.
The embodiments described above are some, but not all embodiments of the invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Claims (10)

1. The preparation method of the thiophene selective graphene biomimetic mineralization film is characterized by comprising the following steps:
s1, dissolving the surfactant, the polydimethylsiloxane oligomer, the graphene oxide and the methyl orthosilicate in n-heptane, and stirring at room temperature to obtain a first mixed solution;
s2, dissolving cysteamine in a Tris-hydrochloric acid buffer solution to obtain an inducer;
s3, dropwise adding the inducer into the first mixed solution, stirring for 20-40 min, and dropwise adding a catalyst to obtain a second mixed solution;
and S4, casting the second mixed solution on the polyvinylidene fluoride micro-filtration membrane at room temperature by taking the polyvinylidene fluoride micro-filtration membrane as a supporting layer, and drying and annealing in the air to obtain the biomimetic mineralized membrane.
2. The preparation method according to claim 1, wherein the surfactant is a mixed surfactant of tween and span in a mass ratio of 1: 1-1.5.
3. The method according to claim 1, wherein the mass ratio of the polydimethylsiloxane oligomer to the surfactant to the methyl orthosilicate is 1:0.05 to 0.15:0.1 to 0.2.
4. The preparation method of claim 1, wherein the biomimetic mineralization film comprises graphene oxide in an amount of 0.01-0.5 wt.%.
5. The method according to claim 1, wherein the Tris-hcl buffer solution has a molarity of 0.02 to 0.03 mol/L.
6. The method according to claim 1, wherein the molar concentration of the inducer is 0.45 to 0.55mol/L, and the pH of the inducer is 6.5 to 7.5.
7. The method of claim 1, wherein the catalyst is dibutyltin dilaurate.
8. The method according to claim 1, wherein in step S4, the drying time is 23-25 h, and the annealing temperature is 75-85 ℃.
9. The preparation method of claim 1, wherein the polyvinylidene fluoride micro-filtration membrane is soaked in deionized water for 2.5-3.5 hours in advance.
10. A thiophene-selective graphene biomimetic mineralization film, characterized by being prepared according to the preparation method of any one of claims 1-9.
CN202110129990.9A 2021-01-29 2021-01-29 Thiophene selective graphene biomimetic mineralization film and preparation method thereof Active CN112933982B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110129990.9A CN112933982B (en) 2021-01-29 2021-01-29 Thiophene selective graphene biomimetic mineralization film and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110129990.9A CN112933982B (en) 2021-01-29 2021-01-29 Thiophene selective graphene biomimetic mineralization film and preparation method thereof

Publications (2)

Publication Number Publication Date
CN112933982A true CN112933982A (en) 2021-06-11
CN112933982B CN112933982B (en) 2022-07-26

Family

ID=76240156

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110129990.9A Active CN112933982B (en) 2021-01-29 2021-01-29 Thiophene selective graphene biomimetic mineralization film and preparation method thereof

Country Status (1)

Country Link
CN (1) CN112933982B (en)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140255636A1 (en) * 2013-03-06 2014-09-11 Saudi Basic Industries Corporation Polymeric Membranes
CN105148741A (en) * 2015-08-14 2015-12-16 浙江大学 Preparation method of inorganic nano-hybrided and positively-charged polyelectrolyte complex pervaporation membrane
US20170157570A1 (en) * 2014-07-17 2017-06-08 The Research Foundation For The State University Of New York Porous graphene based composite membranes for nanofiltration, desalination, and pervaporation
CN107117608A (en) * 2017-05-19 2017-09-01 天津大学 A kind of preparation method of graphene-based hybrid aerogel
CN109126469A (en) * 2018-09-01 2019-01-04 常州大学 A kind of preparation method and application of polyimide/inorganic impregnation vaporization hybridized film
CN110743396A (en) * 2019-10-18 2020-02-04 上海电气集团股份有限公司 Porous graphene composite pervaporation membrane material with preferential alcohol permeability and preparation method thereof
CN111001315A (en) * 2019-12-09 2020-04-14 天津大学 Double-crosslinked graphene oxide composite membrane, preparation and application
US20200197878A1 (en) * 2018-12-21 2020-06-25 King Fahd University Of Petroleum And Minerals Hybrid membrane and method for separating oil and water

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140255636A1 (en) * 2013-03-06 2014-09-11 Saudi Basic Industries Corporation Polymeric Membranes
US20170157570A1 (en) * 2014-07-17 2017-06-08 The Research Foundation For The State University Of New York Porous graphene based composite membranes for nanofiltration, desalination, and pervaporation
CN105148741A (en) * 2015-08-14 2015-12-16 浙江大学 Preparation method of inorganic nano-hybrided and positively-charged polyelectrolyte complex pervaporation membrane
CN107117608A (en) * 2017-05-19 2017-09-01 天津大学 A kind of preparation method of graphene-based hybrid aerogel
CN109126469A (en) * 2018-09-01 2019-01-04 常州大学 A kind of preparation method and application of polyimide/inorganic impregnation vaporization hybridized film
US20200197878A1 (en) * 2018-12-21 2020-06-25 King Fahd University Of Petroleum And Minerals Hybrid membrane and method for separating oil and water
CN110743396A (en) * 2019-10-18 2020-02-04 上海电气集团股份有限公司 Porous graphene composite pervaporation membrane material with preferential alcohol permeability and preparation method thereof
CN111001315A (en) * 2019-12-09 2020-04-14 天津大学 Double-crosslinked graphene oxide composite membrane, preparation and application

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
JAESUNG PARK ET AL.,: "《Gas sorption and diffusion in poly(dimethylsiloxane) (PDMS)/graphene》", 《POLYMER》 *
杨森: "《石墨烯基渗透蒸发杂化膜的制备及其汽油脱硫性能研究》", 《中国优秀硕士学位论文全文数据库(工程科技I辑)》 *

Also Published As

Publication number Publication date
CN112933982B (en) 2022-07-26

Similar Documents

Publication Publication Date Title
CN106914152B (en) Polyamide film composite membrane and preparation method and application thereof
Kaleekkal et al. Performance evaluation of novel nanostructured modified mesoporous silica/polyetherimide composite membranes for the treatment of oil/water emulsion
CN110585930A (en) Preparation method of ceramic membrane for oil-water separation
Rosli et al. Enhancing membrane hydrophobicity using silica end-capped with organosilicon for CO2 absorption in membrane contactor
Xu et al. Pervaporative desulfurization of model gasoline using PDMS/BTESE-derived organosilica hybrid membranes
KR20200097796A (en) Graphene oxide film protective coating
CN104014255B (en) The preparation method of the preferential alcohol hybridized film thoroughly of a kind of self-assembled modified silicon rubber/inorganic particulate
CN112933981B (en) Ethanol selective pervaporation composite membrane, preparation method thereof and method for separating and purifying ethanol
CN112933982B (en) Thiophene selective graphene biomimetic mineralization film and preparation method thereof
Yue et al. Increasing the hydrophobicity of filter medium particles for oily water treatment using coupling agents
Zhao et al. MOF@ Polydopamine-incorporated membrane with high permeability and mechanical property for efficient fouling-resistant and oil/water separation
Bonyadi et al. Bio-inspired hybrid coating of microporous polyethersulfone membranes by one-step deposition of polydopamine embedded with amino-functionalized SiO2 for high-efficiency oily wastewater treatment
Liu et al. Polysulfone Ultrafiltration Membrane Promoted by Brownmillerite SrCu x Co1–x O3− λ-Deposited MCM-41 for Industrial Wastewater Decontamination: Catalytic Oxidation and Antifouling Properties
CN113509845B (en) Graphene oxide-cage type oligomeric silsesquioxane hybrid membrane for preferential alcohol permeation, preparation and application
Sun et al. Design of poly (arylene ether nitrile)@ SiO2 nanoparticles super-wetting membrane for the fast separation of oil-in-water emulsions fabricated through physical confinement effect and dopamine-assisted bio-inspired deposition
CN110799260B (en) Crosslinked polymer film and method for producing same
Bet-Moushoul et al. Investigation of the performance and solvent-resistant properties of NH2-modified MWCNTs/PES-based mixed matrix membranes for biodiesel separation
CN103170258A (en) Polydimethylsiloxane/polydopamine hybrid membrane and preparation method thereof
CN112933983B (en) Graphene silicon dioxide core-shell structure filled PDMS hybrid membrane and preparation method thereof
Abdali et al. Elimination of dibenzothiophene from n-hexane by nano-composite membrane containing Cu-MOF in a pervaporation process
Leng et al. Fabrication of a high-performance polyurethane pervaporation membrane via surface grafting of silane coupling agent
CN112933984B (en) GYSNs (gysan) -filled polyurethane hybrid film and preparation method thereof
CN103923493B (en) A kind of method of silicon hydride oil treatment porous material
Jafarinasab et al. Structure and performance characterization of PDMS/PES-based pervaporation membranes for ethanol/water separation
Gui et al. Surface engineering of a pervaporation desulfurization membrane with crack structures by the self‐condensation of silane coupling agent

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant