CN108982299A - A kind of micro-structure surface wetting state judgment method based on total reflection principle - Google Patents
A kind of micro-structure surface wetting state judgment method based on total reflection principle Download PDFInfo
- Publication number
- CN108982299A CN108982299A CN201810512071.8A CN201810512071A CN108982299A CN 108982299 A CN108982299 A CN 108982299A CN 201810512071 A CN201810512071 A CN 201810512071A CN 108982299 A CN108982299 A CN 108982299A
- Authority
- CN
- China
- Prior art keywords
- drop
- total reflection
- light
- structure surface
- wetting state
- 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.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N13/00—Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The micro-structure surface wetting state judgment method based on total reflection principle that the invention discloses a kind of, when drop is in Cassie state, when with light from liquid incident air, if incidence angle is greater than critical angle of incidence, light will be totally reflected in gas-liquid surface, if reflection light can be observed, then drop is in Cassie state, conversely, drop is in Wenzel state, therefore this method passes through the drop wetting state for judging the surface of solids, can reflect the hydrophobic characteristic of the surface of solids.Compared to AFM equipment, this method only needs laser and corresponding observation device, and price is lower, and is able to satisfy precision needs.
Description
Technical field
The invention belongs to moistened surface property field of measuring technique, and in particular to a kind of micro-structure based on total reflection principle
Moistened surface state judging method.
Background technique
According to the infiltration degree on drop in the micron-scale micro-structure rough surface, the wetting state of drop can be divided into two
Kind: Cassie and Wenzel state, as shown in Fig. 1 (a) and Fig. 1 (b), under normal circumstances, the liquid in Cassie state is more
It is easy to flow away from the surface of solids.To which drop directly reflects the flowing of surface of solids liquid in the wetting state of the surface of solids
Easy degree, this is because when fluid is in Cassie state, since the active area flowed between solid reduces, therefore solid convective
The power effect of body also reduces, and resistance reduces when thus fluid being caused to flow through.Since different surfaces structure is to the resistance of flow process
Reduced effect is different, therefore the surface of solids can be by judging drop in the wetting state of the surface of solids to the hydrophobic characteristic of liquid
It determines.It is therefore proposed that judging that liquid is of great significance in the experimental method of the wetting state of different solid surface.
The method that surface local feature mainly is obtained using AFM for the conversion of Cassie and Wenzel at present, this method
Although liquid exactly accurate can must be obtained in the distribution situation on surface, it needs the support of AFM system, therefore very high
It is expensive.
Summary of the invention
In view of this, the object of the present invention is to provide a kind of, the micro-structure surface wetting state based on total reflection principle judges
Method can judge wetting state of the drop locating for body structure surface, and this method measurement result is accurate, and operating method,
It is cheap, it is easy to promote and apply.
A kind of micro-structure surface wetting state judgment method of total reflection principle of the invention, includes the following steps:
Step 1 drips drop in micro-structure surface；
Step 2 uses light to be greater than the angular illumination drop of critical angle of incidence；Wherein, the critical angle of incidence is light
The critical angle of incidence that line is totally reflected when entering air from drop；
Step 3, observation reflection light, in case of total reflection phenomenon, then micro-structure surface is in Cassie wetting shape
State.
Preferably, the drop uses Cu (OH)2Suspension.
Preferably, the light is laser beam.
Preferably, light enters drop with the angle incidence greater than 5 ° -10 ° of critical angle of incidence in the step 2.
Preferably, constantly changing incidence point of the light on the drop, set when the number of light transmitting total reflection reaches
When determining number, then it is judged to that total reflection phenomenon occurs, that is, is now in Cassie wetting state.
Preferably, using the propagation condition of micro- sem observation light.
Preferably, using the propagation condition of CCD record light.
The invention has the following beneficial effects:
The detection micro-structure surface wetting state that the invention proposes a kind of based on total reflection principle (Cassie and
Wenzel wetting state) method, when drop is in Cassie state, when with light from liquid incident air, if incident
Angle is greater than critical angle of incidence, and light will be totally reflected in gas-liquid surface, if it is possible to observe reflection light, then drop is in
Cassie state, conversely, drop is in Wenzel state, therefore this method passes through the drop wetting state for judging the surface of solids,
It can reflect the hydrophobic characteristic of the surface of solids.Compared to AFM equipment, this method only needs laser and corresponding observation device, valence
Lattice are lower, and are able to satisfy precision needs.
Detailed description of the invention
Fig. 1 (a) is Cassie status diagram, and Fig. 1 (b) is Wenzel status diagram；
Fig. 2 is rectangular array body structure surface parameter schematic diagram；
Fig. 3 is total reflection principle schematic diagram；
The experimental provision schematic diagram that Fig. 4 is judged based on the wetting state of total reflection principle；
Fig. 5 Droplet in Experiment measurement position schematic diagram.
Wherein, 1- objective table, 2- laser, 3- clamping device, 4- body structure surface.
Specific embodimentThe present invention will now be described in detail with reference to the accompanying drawings and examples.
As shown in Fig. 1 (b), there are Cassie wetting states in the solid with surface micro-structure for drop, when drop is in
When Cassie state, there are gas blanket between drop and the surface of solids, which is located between the gap of surface texture, i.e. drop
Middle liquid does not enter between the gap of micro-structure；In contrast, as shown in Fig. 1 (a), when being in Wenzel wetting state, liquid
Liquid enters in the gap of micro-structure in drop.For the ease of explaining the specific steps of this method, below with the rectangular array of rule
For body structure surface, the specific steps of judgment method of the invention are described in detail.Fig. 2 is that rectangular array body structure surface shows
It is intended to, p distance between adjacent two structure centre, h is microstructure height, and b is structure length.When liquid in drop on a surface
When, if drop is in Cassie state, liquid gas interface can specifically be enlarged into Fig. 3.
As shown in figure 3, when light has certain incidence angle θ along with plane x1When incident, θ2For refraction angle, in water due to light
Refractive index be n1, aerial refractive index is n2, from the law of refraction:
n1sinθ1=n2sinθ2
Due to n1>n2, therefore θ2>θ1, consider θ2It is necessarily less than 90 °, therefore, θ1Maximum can only be:
θ* 1=asin (n2/n1)
θ* 1For critical angle of incidence, when incidence angle is greater than θ* 1, light will be totally reflected in liquid gas interface.Since drop is in
Cassie state, then after light being entered drop with the angle incidence greater than critical angle of incidence, due to existing in micro-structure gap
Air layer, then total reflection phenomenon will occur for light；Therefore, by observing whether incident ray occurs total reflection phenomenon, so that it may
Judge the wetting state of drop.However, pure water can not see optical path, therefore the present invention considers that PS fluorescence grain is added in water
Son forms suspension and scatters since it encounters fluorescent particles, when light passes through the suspension so as to see light
Propagation condition.In the present embodiment, using Cu (OH)2Suspension, concentration are desalinated as far as possible, using 10-8nmolar)。
Fig. 4 is experiment device schematic diagram.Objective table 1 is used to place the transparent configuration surface 4 of carrying drop, transparent configuration table
Face 4 is suspended on objective table 1, so that light be allowed to penetrate, can be moved in the z-direction with the direction x, the direction z kinematic accuracy
5 μm of the direction 1mm, x kinematic accuracy；Wherein, along the vertical direction, x-y plane is horizontal plane in the direction z；Laser 2 passes through clamping dress
It sets 3 to fix, the optical axis included angle with laser 2 is 90 °, which can rotate along x-z-plane and move in the y-direction
Dynamic, rotation angular accuracy is 1 °, and the direction y mobile accuracy is 5 μm, and laser beam incidence angle is φ, is changed according to rotation angle ψ
Become.CCD and microscope are placed in the side of drop, for observing and recording the case where light passes through drop.
Its specific measuring process is as follows:
1, drop 1ml-2ml PS solution is on transparent configuration surface 4；
2, the transparent configuration plane 4 for carrying water droplet is placed on objective table 1, and adjusts the z-axis position of objective table 1, make its with
Microscope sustained height is located in the range of microscopic.The direction the x position for adjusting objective table 1 simultaneously, is located at sight
Survey visual field bosom；
3, rotation angle ψ is adjusted, so that 90- ψ is approximately more than 5-10 ° of critical angle of incidence or so, and open laser 2, at this point, will folder
It holds device 3 to move in the y-direction, incident laser is made just to be better than x direction position incident on the right side of drop, and adjusting objective table 1 at this time
It sets, so that laser is located at drop front, (reconnaissance is random in figure, but to be uniformly distributed in as shown in Fig. 5 for final laser light incident position
Subject to plane is chosen)；
4, at this point, can be by path of the CCD recording laser in drop, and number Fig. 1；Since micro-structure is period profile
Gap structure, incident laser may be irradiated in the protrusion of micro-structure, and total reflection phenomenon will not occur for light at this time, therefore need
The incidence point that repeatedly move laser, makes it possible to be incident in the groove of micro-structure, i.e., in air layer, just it is observed that being all-trans
Penetrate phenomenon.Therefore, laser position position b into Fig. 5 is moved later, again recording laser path, number Fig. 2；Successively record figure
The laser path of 16 positions in 5, Fig. 1,2,3 ... 15,16.
5, when being more than the display total reflection of a certain number of pictures, then the drop is in Cassie state on a surface.
In conclusion the above is merely preferred embodiments of the present invention, being not intended to limit the scope of the present invention.
All within the spirits and principles of the present invention, any modification, equivalent replacement, improvement and so on should be included in of the invention
Within protection scope.
Claims (7)
1. a kind of micro-structure surface wetting state judgment method of total reflection principle, which comprises the steps of:
Step 1 drips drop in micro-structure surface；
Step 2 uses light to be greater than the angular illumination drop of critical angle of incidence；Wherein, the critical angle of incidence be light from
Drop enters the critical angle of incidence being totally reflected when air；
Step 3, observation reflection light, in case of total reflection phenomenon, then micro-structure surface is in Cassie wetting state.
2. a kind of body structure surface wetting state judgment method of total reflection principle as described in claim 1, which is characterized in that institute
Drop is stated using Cu (OH)2Suspension.
3. a kind of body structure surface wetting state judgment method of total reflection principle as claimed in claim 2, which is characterized in that institute
Stating light is laser beam.
4. a kind of body structure surface wetting state judgment method of total reflection principle as described in claim 1, which is characterized in that institute
It states in step 2, light enters drop with the angle incidence greater than 5 ° -10 ° of critical angle of incidence.
5. a kind of body structure surface wetting state judgment method of total reflection principle as described in claim 1, which is characterized in that no
The disconnected incidence point for changing light on the drop is then determined as when the number of light transmitting total reflection reaches setting number
Total reflection phenomenon occurs, that is, is now in Cassie wetting state.
6. a kind of body structure surface wetting state judgment method of total reflection principle as claimed in claim 3, which is characterized in that adopt
With the propagation condition of micro- sem observation light.
7. a kind of body structure surface wetting state judgment method of total reflection principle as claimed in claim 6, which is characterized in that adopt
With the propagation condition of CCD record light.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810512071.8A CN108982299A (en) | 2018-05-25 | 2018-05-25 | A kind of micro-structure surface wetting state judgment method based on total reflection principle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810512071.8A CN108982299A (en) | 2018-05-25 | 2018-05-25 | A kind of micro-structure surface wetting state judgment method based on total reflection principle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108982299A true CN108982299A (en) | 2018-12-11 |
Family
ID=64542050
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810512071.8A Pending CN108982299A (en) | 2018-05-25 | 2018-05-25 | A kind of micro-structure surface wetting state judgment method based on total reflection principle |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108982299A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5831184A (en) * | 1995-09-22 | 1998-11-03 | U.S. Philips Corporation | Sample holder for a sample to be subjected to radiation analysis |
| CN101216406A (en) * | 2008-01-17 | 2008-07-09 | 江苏大学 | Energy analysis based stable ultra-hydrophobic surface controllable design method |
| CN101256132A (en) * | 2008-01-17 | 2008-09-03 | 江苏大学 | Steady ultra-hydrophobic surface controllable design method based on geometric analysis |
| CN101819126B (en) * | 2010-03-24 | 2012-01-18 | 江苏大学 | Super-hydrophobic surface fluid slip length self-comparison measurement method based on state transition |
| CN203849133U (en) * | 2014-04-10 | 2014-09-24 | 西北工业大学 | Equipment for testing stability of super-hydrophobic state under water pressure effect |
| CN105571993A (en) * | 2015-12-28 | 2016-05-11 | 清华大学 | Method for measuring contact angle of liquid droplet |
| JP2016200414A (en) * | 2015-04-07 | 2016-12-01 | 住友ゴム工業株式会社 | Method for evaluating wet grip performance of polymer test piece |
-
2018
- 2018-05-25 CN CN201810512071.8A patent/CN108982299A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5831184A (en) * | 1995-09-22 | 1998-11-03 | U.S. Philips Corporation | Sample holder for a sample to be subjected to radiation analysis |
| CN101216406A (en) * | 2008-01-17 | 2008-07-09 | 江苏大学 | Energy analysis based stable ultra-hydrophobic surface controllable design method |
| CN101256132A (en) * | 2008-01-17 | 2008-09-03 | 江苏大学 | Steady ultra-hydrophobic surface controllable design method based on geometric analysis |
| CN101819126B (en) * | 2010-03-24 | 2012-01-18 | 江苏大学 | Super-hydrophobic surface fluid slip length self-comparison measurement method based on state transition |
| CN203849133U (en) * | 2014-04-10 | 2014-09-24 | 西北工业大学 | Equipment for testing stability of super-hydrophobic state under water pressure effect |
| JP2016200414A (en) * | 2015-04-07 | 2016-12-01 | 住友ゴム工業株式会社 | Method for evaluating wet grip performance of polymer test piece |
| CN105571993A (en) * | 2015-12-28 | 2016-05-11 | 清华大学 | Method for measuring contact angle of liquid droplet |
Non-Patent Citations (3)
| Title |
|---|
| 侯绍行: "荷叶在水下的超疏水状态的寿命测试与分析", 《科学通报》 * |
| 王四芳: "超疏水表面混合蒸汽滴状冷凝液滴行为与传热", 《中国博士学位论文全文数据库 工程科技Ⅱ辑》 * |
| 黄建业等: "超疏水状态的润湿转变与稳定性测试", 《物理化学学报》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Cierpka et al. | On the calibration of astigmatism particle tracking velocimetry for microflows | |
| US20050018882A1 (en) | Controlled surface wave image velocimetry | |
| Pereira et al. | Microscale 3D flow mapping with μDDPIV | |
| CN106019608B (en) | One type Gauss flat top beam laser system | |
| CN109061229B (en) | Calibration method of light field Micro-PIV system | |
| TWI569016B (en) | Light-trapping cancer cell stage testing method | |
| CN105203503B (en) | A kind of Laser Films element ultra-smooth optical substrate surface inspecting method | |
| CN105136743B (en) | A kind of single-particle scatter measurement method based on micro-fluidic chip particle-capture formula | |
| CN104390895A (en) | Microimaging-based method for measuring particle size by utilizing image gray scale | |
| CN100410718C (en) | Sample observation method, microscope, and solid immersion lens, optical contact liquid used in the method | |
| CN106092828A (en) | The contact angle measuring method focused on based on microscope | |
| CN108982299A (en) | A kind of micro-structure surface wetting state judgment method based on total reflection principle | |
| CN110057294A (en) | Optical optical tweezers system particle axial direction nano-grade displacement measurement method | |
| CN104345015A (en) | Image sensor based on micro-nanofibers and micro-fluidic chip and preparation method of image sensor | |
| Yoon et al. | Correlation of fluid refractive index with calibration coefficient for micro-defocusing digital particle image velocimetry | |
| CN113916139B (en) | Device and method for measuring foam size distribution | |
| CN208384222U (en) | The microscopic slide for facilitating positioning and magnifying | |
| Min et al. | Hybrid micro-/nano-particle image velocimetry for 3D3C multi-scale velocity field measurement in microfluidics | |
| CN202522502U (en) | Oblique incidence laser particle analyzer | |
| CN208736353U (en) | A kind of detection focal length measures greatly the optical system of off axis paraboloidal mirror off axis | |
| CN101900675B (en) | Enhanced optical signal detection system | |
| CN108801864B (en) | Transparent ellipsoid particle steering discrimination method based on interference focusing image | |
| Luo et al. | Tracking sub-micron fluorescent particles in three dimensions with a microscope objective under non-design optical conditions | |
| CN104677788A (en) | Liquid particle counting detection device and method | |
| US12000769B2 (en) | Particle standards for reflected light scatter measurements from degenerate particle foci |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20181211 |