CN107740196A - A kind of preparation method based on micro-fluidic doughnut - Google Patents

A kind of preparation method based on micro-fluidic doughnut Download PDF

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Publication number
CN107740196A
CN107740196A CN201710944329.7A CN201710944329A CN107740196A CN 107740196 A CN107740196 A CN 107740196A CN 201710944329 A CN201710944329 A CN 201710944329A CN 107740196 A CN107740196 A CN 107740196A
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CN
China
Prior art keywords
solvent
polymer
nucleocapsid
microchannel
micro
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CN201710944329.7A
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Chinese (zh)
Inventor
陈学梅
刘蔡华
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Nanjing Polytechnic Institute
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Nanjing Polytechnic Institute
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Priority to CN201710944329.7A priority Critical patent/CN107740196A/en
Publication of CN107740196A publication Critical patent/CN107740196A/en
Pending legal-status Critical Current

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    • DTEXTILES; PAPER
    • D01NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01DMECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D1/00Treatment of filament-forming or like material
    • D01D1/10Filtering or de-aerating the spinning solution or melt
    • DTEXTILES; PAPER
    • D01NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01DMECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D5/00Formation of filaments, threads, or the like
    • D01D5/06Wet spinning methods
    • DTEXTILES; PAPER
    • D01NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01DMECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D5/00Formation of filaments, threads, or the like
    • D01D5/28Formation of filaments, threads, or the like while mixing different spinning solutions or melts during the spinning operation; Spinnerette packs therefor
    • D01D5/30Conjugate filaments; Spinnerette packs therefor
    • D01D5/34Core-skin structure; Spinnerette packs therefor

Abstract

Present invention relates particularly to a kind of preparation method based on micro-fluidic doughnut, comprise the following steps:Select material:Material includes:First solvent, first polymer, the second solvent, second polymer;Wherein:First polymer, which can be dissolved in the first solvent, generates mixed liquor A, and second polymer can be dissolved in the second solvent generation mixed liquid B, and the first solvent can be dissolved in the second solvent, and first polymer is immiscible in the second solvent;Mixed liquor A and mixed liquid B are immiscible;Mixed liquor A and mixed liquid B is promoted to be injected by nucleocapsid microchannel in water by syringe pump, the solution entered through nucleocapsid microchannel in water is in the form of a column, the columnar fiber caused by roller collector is wound collection;The columnar fiber gathered removal internal layer material can obtain to the doughnut of first polymer.Present invention process is simple and convenient, and the stability for the doughnut prepared is good, and diameter can adjust, and has good physical property.

Description

A kind of preparation method based on micro-fluidic doughnut
Technical field
The present invention relates to composite technology and micro-fluidic field, specifically relates to a kind of based on micro-fluidic hollow fibre The preparation method of dimension.
Background technology
It is micro-fluidic to refer to using microchannel(Size arrives hundreds of microns to be tens of)Processing manipulates minute fluid(Volume is Nanoliter arrive A Sheng)System involved by Science and Technology, be one and be related to chemistry, fluid physics, microelectronics, new material, life The emerging cross discipline of thing and biomedical engineering.Because with the feature such as miniaturization, integrated.
Doughnut is the significant components of hollow-fibre membrane, and hollow-fibre membrane is compared to conventional tubular or the film group of flat sheet configuration Part has advantages below:Height loads density, and unit bodies integrated membrane effective separation area is big, and cost is low, unit bodies integrated membrane trumpet raw material Lack, low mass transfer resistance, it is more high that flux is separated on per membrane area.And corresponding Hollow Fiber Membrane Separation Technology has energy consumption low And the advantages that efficiency high, create huge interests for the mankind.
Since the 1960s till now, the technology of preparing of doughnut oneself through developing fairly perfect, according to point The difference for reason of disembarking, phase separation can be divided into, evaporation causes to be separated and Thermal inactive.Dry-wet spinning is a kind of Solution phase inversion, what is utilized is the principle of phase separation.For current situation, prepare hollow fibre method and only stop Walk in dry-wet spinning, and be not directed to emerging field, this patent mainly carries out preparing doughnut using micro-fluidic means, can It is big effectively to solve fibre diameter prepared by prior art, fiber surface uneven the features such as drawing.
The content of the invention
1st, technical problem to be solved:
The present invention provides a kind of preparation method based on micro-fluidic doughnut, using microflow control technique, can effectively contract It is small to prepare the diameter of fiber, and make fiber surface regular.
2nd, technical scheme:
A kind of preparation method based on micro-fluidic doughnut, comprises the following steps:
Step 1: selection material:Material includes:First solvent, first polymer, the second solvent, second polymer;Wherein:The One polymer, which can be dissolved in the first solvent, generates mixed liquor A, and second polymer can be dissolved in the generation mixing of the second solvent Liquid B, the first solvent can be dissolved in the second solvent, and first polymer is immiscible in the second solvent;Mixed liquor A and mixed liquor B is immiscible.
Step 2: it is equipped with solution:The mixing of second polymer and the second solvent is generated into mixed liquid B;By first polymer Mixing with the first solvent generates mixed liquor A;Above-mentioned two kinds of mixed liquors of A, the B configured are utilized respectively ultrasound and remove bubble removing.
Step 3: build experimental provision;The experimental provision include [S1] binary channels syringe pump, two syringes, two Flexible pipe, nucleocapsid microchannel, roller collector and the container for being placed with water.
The nucleocapsid microchannel includes two entrances, one outlet the tubular passage different from two sliver transvers sections product;Two Entrance is connected with two tubular passages respectively;The V-type that is shaped as from two tubular passages to downward liter, and in the bottom two of V-type Individual tubular passage intersects, and the big tubular passage of intersecting rear cross-sectional area entangles the small tubular passage of cross-sectional area, makes in two cylinders Fluid partitioning in shape passage is opened, and fluid is flowed out simultaneously from outlet;In nucleocapsid microchannel:The small tubular of cross-sectional area Passage is the inner passage of nucleocapsid microchannel;The big tubular passage of cross-sectional area be nucleocapsid microchannel external channel, two cylinders Shape passage intersects rear center's overlapping of axles.
The syringe pump promotes two syringe piston movements;The outlet of each syringe passes through a flexible pipe and core The entrance of shell microchannel is connected;The nucleocapsid microchannel is suspended in water, and the outlet of the nucleocapsid microchannel is in water;Roller is received Storage collects the material from the outlet of nucleocapsid microchannel.
Step 4: the preparatory stage:Configured in each aspiration step one of two syringes in the mixed liquor A and mixed liquid B come One kind;Two syringes are placed on syringe pump;Absorb syringe and the nucleocapsid micro passage reaction inner passage of mixed liquid B It is connected;The syringe for absorbing mixed liquor A is connected with nucleocapsid micro passage reaction external channel.
Step 5: course of reaction:Start syringe pump, inside of the mixed liquid B along nucleocapsid microchannel under the promotion of syringe pump Passage flows, external channel flowing of the mixed liquor A along nucleocapsid microchannel;Mixed liquor A and effect of the mixed liquid B in nucleocapsid microchannel Under the product that is collectively forming flowed out to from the outlet of nucleocapsid microchannel columnar fiber be formed by curing in water;[S2] is collected using roller Device is wound columnar fiber caused by collection;The columnar fiber gathered is soaked to 12h removals in second of solvent or water Internal layer material is the doughnut that can obtain first polymer.
Further, first solvent is DMF, and first polymer is polyurethane, and the second solvent is water, second polymer For Sodium Polyacrylate.
Further, first solvent is DMF, and the first polymer is polymethyl methacrylate, described second Solvent is calcium chloride water, and the second polymer is sodium alginate.
Further, first solvent is DMAc liquid, and the first polymer is Kynoar, and described second is molten Agent is ethanol, and the second polymer is polyvinylpyrrolidone;
Further, the thickness of the nucleocapsid form micro passage reaction can adjust as needed.
Further, in above-mentioned steps five, when starting syringe pump, the driving velocity of syringe pump is first slow, treats that fluid is steady Variation flow rate again after constant current is dynamic.
3rd, beneficial effect:
(1)The present invention is the raw material that uses for the DMF solution of polyurethane, the aqueous solution etc. of Sodium Polyacrylate, and its raw material is all For common material, particular/special requirement is had no.
(2)The present invention is not high to environmental requirement, and preparation method is simple and convenient, and the product stability prepared is good, tool There is lightweight, high-strength.
(3)The present invention can be realized using method and the diameter of doughnut is effectively controlled, by as needed The inner and outer diameter of microchannel is adjusted so as to change the diameter of doughnut, its controllability is very good, and error is small.
Brief description of the drawings
Fig. 1 is to realize that the present invention produces the experiment schematic diagram of doughnut process(Material is polyurethane, DMF solution, poly- third Olefin(e) acid sodium, water);
Fig. 2 is the nucleocapsid MCA schematic diagram used in the present invention;
Fig. 3 is doughnut complexion figure caused by the present invention;
Fig. 4 is other common doughnut complexion figures.
Embodiment
It is next below in conjunction with the accompanying drawings that the present invention will be described:
Accompanying drawing 1 is realizes that the present invention produces the experiment schematic diagram of doughnut process, as shown in figure 1 with the DMF of polyurethane Solution, the aqueous solution of Sodium Polyacrylate are raw material, and water promotes polyurethane and Sodium Polyacrylate molten as coagulator by syringe pump Liquid is by nucleocapsid microchannel injection water, the DMF solution of the polyurethane entered through nucleocapsid microchannel in water is in the form of a column, and outer layer is direct Directly solidification, internal layer are contacted with water to contact and solidify with aqueous sodium polyacrylate, and collection is wound using the roller of rotation, It is that can obtain polyurethane hollow fiber to soak 12h afterwards to remove internal layer Sodium Polyacrylate.
The nucleocapsid MCA schematic diagram used in the present invention of accompanying drawing 2, it can be seen that the stream for passing through the passage What body finally came out is the product with inside and outside Rotating fields.
The structure for doughnut caused by this method and other common doughnuts is carried out pair as shown in Figures 2 and 3 Than, it can be seen that it is that doughnut surface is more regular that this method, which produces, and the diameter of doughnut can adjust.
Specific embodiment:
Embodiment 1:Raw material is aqueous sodium polyacrylate, the DMF solution water of polymethyl methacrylate as coagulator;It is wrapped Include following specific method and step:
A. be equipped with mass fraction be 2.5% aqueous sodium polyacrylate, mass fraction be 5% polymethyl methacrylate DMF solution, then ultrasound removes bubble removing;
B. experimental provision is built;
C. sodium polyacrylate solution and polymethyl methacrylate solution are drawn respectively with syringe, be placed on syringe pump, note Emitter is connected with microchannel with flexible pipe, and in microchannel, aqueous sodium polyacrylate walks inner passage, polymethyl methacrylate DMF solution walk external channel, microchannel is suspended in water;
D. syringe pump is started, solution forms the fiber of nucleocapsid form behind nucleocapsid form microchannel, outside polymethyl methacrylate Layer solidifies with water Contact, and internal layer solidifies with sodium polyacrylate solution Contact, and receipts are wound using the roller of rotation Collection, after 12h soaked in water remove internal layer Sodium Polyacrylate and can obtain polymethyl methacrylate doughnut.
Embodiment 2:Raw material is polyvinylpyrrolidone ethanol solution, Kynoar DMAc solution, and ethanol is as solidification Agent;It includes following specific method and step:
A. be equipped with mass fraction be 2.5% polyvinylpyrrolidone ethanol solution, mass fraction be 5% Kynoar DMAc solution, then ultrasound remove bubble removing;
B. experimental provision is built;
C. Kynoar solution and polyvinylpyrrolidonesolution solution are drawn respectively with syringe, be placed on syringe pump, inject Device is connected with microchannel with flexible pipe, and in microchannel, polyvinylpyrrolidone ethanol solution walks inner passage, Kynoar DMAc solution walks external channel, and microchannel is suspended in water;
D. syringe pump is started, solution forms the fiber of nucleocapsid form behind microchannel, and Kynoar outer layer contacts wink with ethanol Between solidify, internal layer and polyvinylpyrrolidone ethanol solution Contact solidify, and collection is wound using the roller of rotation, after It is that can obtain polyvinylidene fluoride hollow fiber to soak 12h in water to remove inner layer polyethylene pyrrolidones.
During above-mentioned outfit it can be seen that two kinds of mixed liquors proportioning size mainly according to solvent in the solution For solubility come what is be adjusted, this is ordinary skill in the art means with regard to no longer carrying out special explanation.
Although the present invention disclosed as above with preferred embodiment, they be not for limit the present invention, it is any ripe This those skilled in the art is practised, without departing from the spirit and scope of the invention, can make various changes or retouch from working as, therefore the guarantor of the present invention What shield scope should be defined by claims hereof protection domain is defined.

Claims (6)

1. a kind of preparation method based on micro-fluidic doughnut, it is characterised in that comprise the following steps:
Step 1: selection material:Material includes:First solvent, first polymer, the second solvent, second polymer;Wherein:The One polymer, which can be dissolved in the first solvent, generates mixed liquor A, and second polymer can be dissolved in the generation mixing of the second solvent Liquid B, the first solvent can be dissolved in the second solvent, and first polymer is immiscible in the second solvent;Mixed liquor A and mixed liquor B is immiscible;
Step 2: it is equipped with solution:The mixing of second polymer and the second solvent is generated into mixed liquid B;By first polymer and the The mixing generation mixed liquor A of one solvent;Above-mentioned two kinds of mixed liquors of A, the B configured are utilized respectively ultrasound and remove bubble removing;
Step 3: build experimental provision;The experimental provision includes speed-adjustable syringe pump, two syringes, two flexible pipes, cores Shell microchannel, roller collector and the container for being placed with water;
The nucleocapsid microchannel includes two entrances, one outlet the tubular passage different from two sliver transvers sections product;Two entrances It is connected respectively with two tubular passages;The V-type that is shaped as from two tubular passages to downward liter, and in the cylinder of the bottom of V-type two Shape passage intersects, and the big tubular passage of intersecting rear cross-sectional area entangles the small tubular passage of cross-sectional area, makes to lead in two tubulars Fluid partitioning in road is opened, and fluid is flowed out simultaneously from outlet;In nucleocapsid microchannel:The small tubular passage of cross-sectional area For the inner passage of nucleocapsid microchannel;The big tubular passage of cross-sectional area is the external channel of nucleocapsid microchannel, and two tubulars lead to Intersect rear center's overlapping of axles in road;
The syringe pump promotes two syringe piston movements;The outlet of each syringe is micro- by a flexible pipe and nucleocapsid The entrance of passage is connected;The nucleocapsid microchannel is suspended in water, and the outlet of the nucleocapsid microchannel is in water;Roller collector Collect the material from the outlet of nucleocapsid microchannel;
Step 4: the preparatory stage:One in the mixed liquor A and mixed liquid B come is configured in each aspiration step one of two syringes Kind;Two syringes are placed on syringe pump;Absorb the syringe and nucleocapsid micro passage reaction inner passage phase of mixed liquid B Even;The syringe for absorbing mixed liquor A is connected with nucleocapsid micro passage reaction external channel;
Step 5: course of reaction:Start syringe pump, inner passage of the mixed liquid B along nucleocapsid microchannel under the promotion of syringe pump Flowing, external channel flowing of the mixed liquor A along nucleocapsid microchannel;Mixed liquor A and mixed liquid B are common in the presence of nucleocapsid microchannel Flowed out to the product formed from the outlet of nucleocapsid microchannel and columnar fiber is formed by curing in water;Solution-stabilized flowing is treated, is removed former After first irregular fiber columnar fiber caused by collection is wound using roller collector;By the columnar fiber gathered It is the doughnut that can obtain first polymer to soak 12h in two kinds of solvents or water to remove internal layer material.
2. the preparation method based on micro-fluidic doughnut according to claims 1, it is characterised in that
First solvent is DMF, and first polymer is polyurethane, and the second solvent is water, and second polymer is Sodium Polyacrylate.
3. the preparation method based on micro-fluidic doughnut according to claims 1, it is characterised in that
First solvent is DMF, and the first polymer is polymethyl methacrylate, and second solvent is calcium chloride water Solution, the second polymer are sodium alginate.
4. the preparation method based on micro-fluidic doughnut according to claims 1, it is characterised in that
First solvent is DMAc liquid, and the first polymer is Kynoar, and second solvent is ethanol, described Second polymer is polyvinylpyrrolidone.
5. the preparation method based on micro-fluidic doughnut according to claims 1, it is characterised in that the nucleocapsid The thickness of form micro passage reaction can adjust as needed.
6. the preparation method based on micro-fluidic doughnut according to claims 1, it is characterised in that in step 5 In, when starting syringe pump, the driving velocity of syringe pump is first slow, the variation flow rate again after fluid stable flowing.
CN201710944329.7A 2017-10-12 2017-10-12 A kind of preparation method based on micro-fluidic doughnut Pending CN107740196A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111391303A (en) * 2020-04-17 2020-07-10 南京鼓楼医院 Preparation method of three-dimensional super-smooth fabric based on microfluidic 3D printing technology
CN111549396A (en) * 2020-05-29 2020-08-18 南京鼓楼医院 Fiber wrapping liquid metal and preparation method thereof
CN114395821A (en) * 2022-01-20 2022-04-26 苏州大学 Preparation method of conductive drug-loaded composite fiber

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH026829A (en) * 1988-06-24 1990-01-11 Daicel Chem Ind Ltd Production of hollow fiber membrane
EP0497185A1 (en) * 1991-01-28 1992-08-05 W.R. Grace & Co.-Conn. Process for preparing protein non-adsorptive microporous polysulfone membranes
CN101935892A (en) * 2009-07-03 2011-01-05 清华大学 Method and special device for preparing hollow fiber material
CN102089070A (en) * 2008-06-10 2011-06-08 水技术国际公司 Preparation of high performance ultra filtration hollow fiber membrane
CN102453967A (en) * 2011-08-29 2012-05-16 上海贵达科技有限公司 Preparation method of hollow polyester fiber with controllable hollowness
US20160008528A1 (en) * 2014-07-11 2016-01-14 Indian Institute Of Technology, Kharagpur Low cost spinning and fabrication of high efficiency (he) haemodialysis fibers and method thereof
CN105821504A (en) * 2016-05-12 2016-08-03 南京工业大学 Preparation method of polyacrylamide fibers

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH026829A (en) * 1988-06-24 1990-01-11 Daicel Chem Ind Ltd Production of hollow fiber membrane
EP0497185A1 (en) * 1991-01-28 1992-08-05 W.R. Grace & Co.-Conn. Process for preparing protein non-adsorptive microporous polysulfone membranes
CN102089070A (en) * 2008-06-10 2011-06-08 水技术国际公司 Preparation of high performance ultra filtration hollow fiber membrane
CN101935892A (en) * 2009-07-03 2011-01-05 清华大学 Method and special device for preparing hollow fiber material
CN102453967A (en) * 2011-08-29 2012-05-16 上海贵达科技有限公司 Preparation method of hollow polyester fiber with controllable hollowness
US20160008528A1 (en) * 2014-07-11 2016-01-14 Indian Institute Of Technology, Kharagpur Low cost spinning and fabrication of high efficiency (he) haemodialysis fibers and method thereof
CN105821504A (en) * 2016-05-12 2016-08-03 南京工业大学 Preparation method of polyacrylamide fibers

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111391303A (en) * 2020-04-17 2020-07-10 南京鼓楼医院 Preparation method of three-dimensional super-smooth fabric based on microfluidic 3D printing technology
CN111391303B (en) * 2020-04-17 2020-10-30 南京鼓楼医院 Preparation method of three-dimensional super-smooth fabric based on microfluidic 3D printing technology
CN111549396A (en) * 2020-05-29 2020-08-18 南京鼓楼医院 Fiber wrapping liquid metal and preparation method thereof
CN114395821A (en) * 2022-01-20 2022-04-26 苏州大学 Preparation method of conductive drug-loaded composite fiber
CN114395821B (en) * 2022-01-20 2023-10-27 苏州大学 Preparation method of conductive medicine-carrying composite fiber

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Application publication date: 20180227