A kind of oxygen permeable silicone hydrogel material and preparation method thereof

Abstract

The present application relates to the technical field of silicon hydrogel preparation, and specifically to a kind of oxygen-permeable silicon hydrogel material and its preparation method, which method comprises: obtaining polyvinyl alcohol solution; taking PDMS prepolymer and curing agent and mixing them, adding them to the polyvinyl alcohol solution and stirring, heating to obtain PDMS microsphere suspension, washing them by centrifugation with deionized water for many times, and obtaining PDMS microsphere dispersion; mixing polyvinyl alcohol powder, PDMS microsphere dispersion, deionized water and water-soluble silicone oil, putting them into a reactor and stirring them at a temperature, calculating the stirring coefficient and stirring compensation coefficient of silicon hydrogel raw materials at each moment during the stirring process, constructing a temperature adaptation index, and adjusting the temperature of the reactor; taking them out from the reactor after stirring at a temperature, and freezing and thawing them for many times to obtain oxygen-permeable silicon hydrogel material. Thereby improving the uniformity and quality of silicon hydrogel raw materials during the stirring process, and ensuring the preparation quality of silicon hydrogel.

Description

Technical Field

[0001] The present application relates to the technical field of silicone hydrogel preparation, and in particular to an oxygen-permeable silicone hydrogel material and a preparation method thereof. Background Art

[0002] Hydrogel is a type of water-containing polymer material with a three-dimensional network structure. In order to meet the needs of practical applications, researchers have developed hydrogels with different chemical structures and mechanical properties in recent years, and the main material of hydrogel is polyvinyl alcohol. Polyvinyl alcohol hydrogel has attracted widespread attention in the field of biomedical materials due to its low friction, low protein adhesion and good biocompatibility. However, the mechanical properties of polyvinyl alcohol hydrogel have largely limited its practical application. Silicone rubber has excellent mechanical strength, oxygen permeability and biocompatibility, and is widely used as a medical device material, but silicone rubber surface modification is difficult. In actual use, its strong adhesion characteristics will produce obvious protein adhesion, thus affecting its application in the field of bioengineering. Therefore, in practical applications, the characteristics of the above two materials are usually combined to prepare high oxygen permeability silicone hydrogel composites.

[0003] In the preparation process of high oxygen permeability silicone hydrogel materials, in order to prepare high oxygen permeability silicone hydrogel materials with better quality, various raw materials need to be insulated and stirred. The insulation temperature and processing time of the insulation and stirring are usually pre-set in the preparation process, and it is difficult to ensure that they meet the current mixing state of the raw materials. If the insulation and stirring temperature is too high, the mixing uniformity of the silicone hydrogel raw materials may decrease, affecting the gel performance. If the insulation and stirring temperature is too low, the polymerization reaction of the silicone hydrogel raw materials may be weak, resulting in a decrease in the quality of the finished gel product. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide an oxygen-permeable silicone hydrogel material and a preparation method thereof. The technical solutions adopted are as follows:

[0005] In a first aspect, an embodiment of the present application provides a method for preparing an oxygen-permeable silicone hydrogel material, the method comprising the following steps:

[0006] (1) Preparation of polyvinyl alcohol solution: mixing polyvinyl alcohol powder with deionized water and heating the mixture to obtain a polyvinyl alcohol solution;

[0007] (2) Preparation of PDMS microsphere suspension: After mixing the PDMS precursor and the curing agent, add them to the cooled polyvinyl alcohol solution and stir mechanically, then add 60 parts of deionized water to dilute it, and heat and stir to obtain a PDMS microsphere suspension, wherein all the components are calculated by weight.

[0008] (3) Centrifugal washing: The PDMS microsphere suspension is centrifuged and washed with deionized water for multiple times, each time for 10 min, and the washed PDMS microsphere suspension is dispersed in a small amount of deionized water to obtain a PDMS microsphere dispersion;

[0009] (4) Insulation and stirring: polyvinyl alcohol powder, PDMS microsphere dispersion, deionized water and water-soluble silicone oil are mixed, and the mixture is placed in an insulation and stirring reactor, and continuously stirred to obtain a silicone hydrogel raw material mixture;

[0010] During the heat preservation and stirring process, a high-spectrum graph in the reactor at each moment is collected, and various silicone hydrogel raw materials are obtained according to the distribution of the absorbance of the data points in each band in the high-spectrum graph at each moment;

[0011] According to the average level of absorption rate of various silicone hydrogel raw materials at each moment and the difference degree of absorption rate of adjacent peak points of each data point, the raw material concentration coefficient of each silicone hydrogel raw material at each moment is constructed, and the silicone hydrogel raw material stirring coefficient at each moment is calculated by combining the raw material concentration coefficients of all types of silicone hydrogel raw materials at each moment;

[0012] Analyze the difference in wavelength corresponding to the peak point of the data point in the hyperspectral graph at each moment and the previous moments, and the difference in the absorbance of the data point, and combine the difference in the absorbance of each silicone hydrogel raw material between each moment and the previous moments to obtain the stirring compensation coefficient at each moment;

[0013] The temperature of the reactor is adaptively adjusted according to the stirring coefficient and the stirring compensation coefficient of the silicone hydrogel raw material at each moment;

[0014] (5) Cooling: taking the prepared silica hydrogel raw material mixed solution out of the reactor and placing it in a container for cooling;

[0015] (6) Gel preparation: After the silicone hydrogel raw material mixture is cooled, it is poured into a mold and subjected to multiple cycles of freezing and thawing. The thawed hydrogel is then placed in deionized water, and the deionized water is replaced multiple times to remove residual chemical components to obtain an oxygen-permeable silicone hydrogel material.

[0016] Preferably, during the preparation of the polyvinyl alcohol solution, the weight ratio of polyvinyl alcohol powder to deionized water is 1:9.

[0017] Preferably, the amount of the curing agent is 0.5 parts.

[0018] Preferably, the centrifugal speed of the mechanical stirring is 2000-3000 rpm, and the stirring time is 1 hour.

[0019] Preferably, the mixed liquid in the heat-insulating stirring reactor contains 3.7 parts of polyvinyl alcohol powder, 5.8 parts of PDMS microsphere dispersion, 20.47 parts of deionized water, and 3.7 parts of water-soluble silicone oil.

[0020] Preferably, the step of obtaining the silicone hydrogel raw material at each moment includes:

[0021] For the data points in the hyperspectral graph at each moment, the absorbance of each data point in each band is arranged in ascending order of the band to form an absorbance sequence for each data point. Each absorbance sequence is fitted to obtain a fitting curve for each data point. The wavelength corresponding to the maximum peak point of the fitting curve of each data point is counted, and the wavelengths corresponding to all peak points are clustered and divided through a clustering algorithm. The data points corresponding to all wavelengths in the same category are regarded as the same type of silicone hydrogel raw materials.

[0022] Preferably, the process of obtaining the stirring coefficient of the silicone hydrogel raw material at each moment includes:

[0023] For various silicone hydrogel raw materials, the mean of the absorbance corresponding to the peak point of all data points in the y-th silicone hydrogel raw material is analyzed and recorded as the peak mean; the absolute value of the difference in absorbance between adjacent peak points of each data point in the y-th silicone hydrogel raw material is analyzed and recorded as the peak absolute value;

[0024] The raw material concentration coefficient of the yth silicone hydrogel raw material at each moment is positively correlated with the wave peak mean value, and negatively correlated with the wave peak absolute value;

[0025] The stirring coefficient of the silicone hydrogel raw material at each time is negatively correlated with the raw material concentration coefficient of all types of silicone hydrogel raw materials at each time.

[0026] Preferably, the process of obtaining the stirring compensation coefficient at each moment includes:

[0027] Calculate the difference between the peak point of each data point at each moment and the corresponding wavelength of the peak points at the previous moments, take the absolute value and accumulate it, and record it as the wavelength difference of each data point at each moment;

[0028] The distance between the absorption rate sequence of each data point at each moment and the absorption rate sequence of the previous multiple moments is accumulated, and recorded as the absorption rate difference of each data point at each moment;

[0029] The ratio of the wavelength difference to the absorbance difference is used as the stirring spectrum shift index of each data point at each time;

[0030] Analyze the average of the absorbance of the data points included in each silicone hydrogel raw material at each moment, record it as the average absorbance at each moment, obtain the result of accumulating the difference between the average absorbance of each silicone hydrogel raw material at each moment and the average absorbance of multiple moments before it, and use the reciprocal of the result as the stirring uniformity index of each silicone hydrogel raw material at each moment;

[0031] The stirring compensation coefficient at each moment is positively correlated with the stirring spectrum shift index of all data points at each moment and the stirring uniformity index of all types of silicone hydrogel raw materials at each moment.

[0032] Preferably, the adaptively adjusting the temperature of the reactor comprises:

[0033] The product of the stirring coefficient of the silicone hydrogel raw material at each moment and the stirring compensation coefficient is used as the temperature adaptation index of the silicone hydrogel raw material stirring at each moment. The temperature adaptation indexes collected at all moments are arranged in the order of collection time to form a temperature adaptation index sequence, which is input into the neural network to obtain the optimal temperature for the silicone hydrogel raw material stirring and adjust the temperature of the reactor.

[0034] In a second aspect, an embodiment of the present application further provides an oxygen-permeable silicone hydrogel material, wherein the oxygen-permeable silicone hydrogel material is made by any of the methods described above.

[0035] This application has at least the following beneficial effects:

[0036] The present application constructs a silicon hydrogel stirring effect coefficient to characterize the stirring effect of the current silicon hydrogel raw material through analyzing the changes in the hyperspectral graph when the silicon hydrogel raw material is stirred, and constructs a silicon hydrogel raw material stirring compensation coefficient to characterize the degree of stirring of the current silicon hydrogel raw material, and analyzes the subsequent stirring temperature in combination with the stirring degree of the raw material, thereby improving the accuracy of adaptive adjustment of the raw material stirring temperature; finally, a temperature adaptation index for stirring the silicon hydrogel raw material is constructed to characterize the appropriateness of the stirring temperature of the current silicon hydrogel raw material, so as to adaptively adjust the temperature, and then adaptively adjust the stirring temperature of the silicon hydrogel stirring reactor, thereby solving the problem that the stirring temperature cannot be adjusted according to the actual situation of the silicon hydrogel raw material when the silicon hydrogel raw material is stirred, improving the uniformity and quality of the silicon hydrogel raw material during the stirring process, and then improving the subsequent preparation quality of the silicon hydrogel. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 A schematic diagram of a process for preparing an oxygen-permeable silicone hydrogel material provided in one embodiment of the present application;

[0039] Figure 2 It is a schematic diagram of the polynomial fitting curve of the hyperspectral points;

[0040] Figure 3 This is a schematic diagram of the hyperspectral image of the uneven state at the initial stage of stirring;

[0041] Figure 4 Schematic diagram of the hyperspectral image of the uniform state at the later stage of stirring. DETAILED DESCRIPTION

[0042] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of an oxygen-permeable silicone hydrogel material and its preparation method proposed in the present application, its specific implementation method, structure, characteristics and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0043] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0044] The specific scheme of an oxygen-permeable silicone hydrogel material and a preparation method thereof provided by the present application is described in detail below with reference to the accompanying drawings.

[0045] See also Figure 1 , which shows a schematic flow chart of a method for preparing an oxygen-permeable silicone hydrogel material provided by an embodiment of the present application, the method comprising the following process:

[0046] Embodiment 1:

[0047] (1) Preparation of polyvinyl alcohol solution: 5 parts of polyvinyl alcohol powder was mixed with 45 parts of deionized water and heated to 90° C. to obtain a polyvinyl alcohol solution, which was allowed to stand and cool. It should be noted that in this embodiment, the amounts of all components are calculated by weight.

[0048] (2) Preparation of PDMS microsphere suspension: PDMS (polydimethylsiloxane) precursor was mixed with 0.5 parts of curing agent (the curing agent model in this embodiment is SYLGARD 184), and then added to the cooled polyvinyl alcohol solution. The mixture was mechanically stirred at a centrifugal speed of 2000-3000 rpm. In this embodiment, the centrifugal speed of mechanical stirring was 2200 rpm and the stirring time was 1 h. Subsequently, 60 parts of deionized water were added for dilution. Finally, the mixture was heated to 85°C and stirred for 2 h to obtain a PDMS microsphere suspension.

[0049] (3) Centrifugal washing: In this embodiment, the PDMS microsphere suspension is centrifuged and washed 10 times with deionized water. The centrifugal speed in this embodiment is 12000 rpm, and the centrifugal time for each time is 10 minutes. Finally, the washed PDMS microsphere suspension is dispersed in a small amount of deionized water to obtain a PDMS microsphere dispersion.

[0050] (4) Insulated stirring: Mix 3.7 parts of polyvinyl alcohol powder, 5.8 parts of PDMS microsphere dispersion, 20.47 parts of deionized water and 3.7 parts of water-soluble silicone oil, and place the mixture in an insulated stirring reactor. Stir at room temperature for 30 minutes. After stirring, heat to 80°C~90°C and continue stirring for 6 hours to obtain a uniform and transparent silicone hydrogel raw material mixture.

[0051] The polymerization reaction is carried out by continuous stirring in the heat-insulating stirring reactor, and the temperature range of the polymerization reaction is 60℃~110℃, that is, the temperature range of heat-insulating stirring is 60℃~110℃. Further, considering that the temperature has a great influence on the preparation quality of the material during the heat-insulating stirring reaction process, if the temperature of heat-insulating stirring is too high, it may cause the mixing uniformity of the silicone hydrogel raw materials to decrease, affecting the gel performance, while if the temperature of heat-insulating stirring is too low, it may cause the polymerization reaction of the silicone hydrogel raw materials to be weak, resulting in a decrease in the quality of the gel finished product.

[0052] Therefore, when heat preservation and stirring are performed in the reactor, the temperature adaptive adjustment process of heat preservation and stirring specifically includes the following steps:

[0053] Step S001, during the heat preservation and stirring process, collect the hyperspectral graph in the reactor at each moment, and obtain various silicone hydrogel raw materials according to the distribution of the absorbance of the data points in the hyperspectral graph at each moment in each band.

[0054] A hyperspectrometer is set in the reactor for heat preservation and stirring. The implementer can also arrange the positions of various devices in the data collection process according to actual conditions. This embodiment does not impose any special restrictions on this.

[0055] It should be noted that, considering that the temperature is high during the stirring and mixing process in the reactor, but the general operating temperature of the spectrometer is about 40°, therefore, when collecting spectral data during the insulation stirring process, the spectrometer needs to be connected to a high-temperature probe infrared thermal imager to transmit and collect spectral signals. The high-temperature probe infrared thermal imager can generally operate in the range of -20°C to 250°C. The specific deployment and data transmission process are not particularly limited in this embodiment.

[0056] In this embodiment, when collecting spectral data, the wavelength of the hyperspectral imager is 900nm, the spectral resolution is 4nm, and the hyperspectral image is collected every time interval T. In this embodiment, T=0.5s. The parameter setting of the hyperspectrometer during the spectral data collection process can be set by the implementer, and this embodiment does not impose any special restrictions. The hyperspectrometer will record the absorbance of each data point of the mixed liquid in the reactor in each band, sort the absorbance of each data point in each band in descending order according to the wavelength, construct the absorbance sequence of each data point, and record it as ,in The meaning is the absorbance of the first data point in the hyperspectral image collected at the first moment at the nth wavelength.

[0057] Since the position of the hyperspectrometer is fixed and the mixed liquid during stirring is changing in real time, the data at the same data point collected by the hyperspectrometer each time will also change in real time. For each data point, in the hyperspectral graph collected at the same time, the more similar the data point is to its hyperspectral graph, the more likely it is that the substances at the locations of the two data points are the same silicone hydrogel raw material. During stirring, the silicone hydrogel raw materials are put into the reactor one by one. In other words, the initial state of each raw material may be more concentrated in the reactor, and the concentration of the same silicone hydrogel raw material at a local position may be larger. When the concentration of the same silicone hydrogel raw material is higher, the absorption intensity of its hyperspectral graph is relatively higher, but the overall absorption peak position will not change significantly.

[0058] Based on the above characteristics, taking the hyperspectral image collected at the jth moment as an example, the absorbance sequence of each data point is taken as input, and the polynomial curve fitting algorithm is used to output the polynomial fitting curve of the absorbance sequence of each data point, and the polynomial fitting curve of the absorbance sequence of the hyperspectral image of the ith data point is recorded as a curve , and obtain the peak point, which is the absorption peak of the corresponding data point in the hyperspectral graph. The schematic diagram of the polynomial fitting curve of the hyperspectral graph point is as follows Figure 2 The polynomial fitting algorithm is a well-known technology, and the process will not be described in detail in this embodiment.

[0059] For the data points in the hyperspectral graph at the jth moment, the maximum peak point corresponding to the curve of each data point is counted, and the wavelength of the maximum peak point corresponding to all data points is clustered and divided using a clustering algorithm. The data points corresponding to all peak points in the same category after clustering are taken as the same type of silicone hydrogel raw materials, and various silicone hydrogel raw materials can be obtained. The clustering algorithm described in this embodiment is a K-means clustering algorithm, where the K value is 5 in this embodiment.

[0060] Step S002, constructing a raw material concentration coefficient of each silicone hydrogel raw material at each moment according to the average level of the absorption rate of various silicone hydrogel raw materials at each moment and the degree of difference in the absorption rate of adjacent peak points of each data point, and calculating the silicone hydrogel raw material stirring coefficient at each moment in combination with the raw material concentration coefficients of all types of silicone hydrogel raw materials at each moment.

[0061] For a certain type of silicone hydrogel raw material, if the stirring effect is poor, the raw material may have a locally high concentration in the reactor. The higher the concentration, the greater the absorption intensity of the corresponding band, that is, the peak value of the corresponding absorption peak will also become larger. Construct the stirring coefficient of the silicone hydrogel raw material at each moment, and the construction process is:

[0062] For various silicone hydrogel raw materials, the mean of the absorbance corresponding to the peak point of all data points in the y-th silicone hydrogel raw material is analyzed and recorded as the peak mean; the absolute value of the difference in absorbance between adjacent peak points of each data point in the y-th silicone hydrogel raw material is analyzed and recorded as the peak absolute value;

[0063] The raw material concentration coefficient of the yth silicone hydrogel raw material at each moment is positively correlated with the wave peak mean value, and negatively correlated with the wave peak absolute value;

[0064] The stirring coefficient of the silicone hydrogel raw material at each time is negatively correlated with the raw material concentration coefficient of all types of silicone hydrogel raw materials at each time.

[0065] It should be noted that the positive correlation and negative correlation in this application are used to express the mutual change relationship between the independent variable and the dependent variable. The positive correlation is that the dependent variable increases with the increase of the independent variable, and decreases with the decrease of the independent variable. It can be a multiplication relationship, an addition relationship, etc.; the negative correlation is that the dependent variable decreases with the increase of the independent variable, and increases with the decrease of the independent variable. It can be a division relationship, a reciprocal relationship, and the opposite, etc. The specific relationship is determined according to the actual application scenario.

[0066] Optionally, in this embodiment, the raw material concentration coefficient of the y-th silicone hydrogel raw material at each moment may be the ratio of the peak mean value to the peak absolute value, wherein, in order to avoid the situation where the denominator is zero during the calculation of the ratio, a minimum value may be added to the denominator, which is set to 0.001 in this embodiment;

[0067] The silicon hydrogel raw material stirring coefficient may be obtained by taking the inverse of the average of the raw material concentration coefficients of all types of silicon hydrogel raw materials at each moment as the silicon hydrogel raw material stirring coefficient at each moment.

[0068] It should be understood that when the mean of the peak points of the high-spectrum graph of the y-th silicon hydrogel raw material in the high-spectrum graph collected at the j-th moment is larger, and the difference of each peak point is smaller, that is, the raw material concentration coefficient of the y-th silicon hydrogel raw material at the j-th moment is larger, indicating that the mixing degree of this silicon hydrogel raw material in the reactor is lower and the concentration is higher. When the mixing degree of various raw materials of the silicon hydrogel in the reactor at the j-th moment is better, the stirring coefficient of the silicon hydrogel raw material is smaller, and the stirring coefficient of the silicon hydrogel raw material is larger, it means that the stirring effect in the current reactor is better, and the temperature of the reactor does not need to be adjusted temporarily.

[0069] At this point, the stirring coefficient of the silicone hydrogel raw material at each moment can be calculated by the above method.

[0070] Step S003, analyzing the difference in wavelength corresponding to the peak point of the data point in the hyperspectral graph at each moment and the difference in absorbance of the data point between the previous moments, and combining the difference in absorbance of each silicone hydrogel raw material between the previous moments and the previous moments, to obtain the stirring compensation coefficient at each moment.

[0071] However, due to the long duration of the heat preservation and stirring process, the stirring is not uniform in the initial stage. The schematic diagram of the hyperspectral diagram of the uneven state in the initial stage of stirring is shown in the figure. Figure 3 As shown in the figure, the local concentration of the raw materials in the reactor is still relatively large, which leads to a low stirring effect coefficient of the gel raw materials at each moment in the hyperspectral graph collected in the initial stage, resulting in a poor stirring effect at this time. Therefore, further analysis is needed to determine the stirring effect.

[0072] As the stirring progresses, the substances in the reactor will undergo polymerization reactions and produce cross-linked polymers. The cross-linking density of the solution in the reactor will gradually increase, which will lead to changes in the absorption peak intensity or absorption peak position of the spectral data of the substances in the reactor. As new substances are generated, the content of old substances is gradually decreasing. The data points contained in each silicone hydrogel raw material are also changing to a certain extent, and the concentration of each silicone hydrogel raw material will decrease, which will affect the size of the hyperspectral graph of each silicone hydrogel raw material. The schematic diagram of the hyperspectral graph of the uniform state in the late stage of stirring is as follows: Figure 4 Based on the above characteristics, the stirring compensation coefficient at each moment is constructed, specifically:

[0073] Calculate the difference between the peak point of each data point at each moment and the corresponding wavelength of the peak points at the previous moments, take the absolute value and accumulate it, and record it as the wavelength difference of each data point at each moment;

[0074] The distance between the absorption rate sequence of each data point at each moment and the absorption rate sequence of the previous multiple moments is accumulated, and recorded as the absorption rate difference of each data point at each moment;

[0075] The ratio of the wavelength difference to the absorbance difference is used as the stirring spectrum shift index of each data point at each time;

[0076] Analyze the average of the absorbance of the data points included in each silicone hydrogel raw material at each moment, record it as the average absorbance at each moment, obtain the result of accumulating the difference between the average absorbance of each silicone hydrogel raw material at each moment and the average absorbance of multiple moments before it, and use the reciprocal of the result as the stirring uniformity index of each silicone hydrogel raw material at each moment;

[0077] The stirring compensation coefficient at each moment is positively correlated with the stirring spectrum shift index of all data points at each moment and the stirring uniformity index of all types of silicone hydrogel raw materials at each moment.

[0078] Among them, as an embodiment of the present application, the distance between the absorption rate sequence of each data point at each moment and the absorption rate sequence of multiple moments before it can be the DTW distance. As other implementation methods, the implementer can use other distance measurement methods between sequences in the prior art to calculate the distance between two sequences, and the present application does not impose any special restrictions on this.

[0079] Preferably, as an embodiment of the present application, the stirring compensation coefficient at each moment can be: analyzing the sum of the stirring spectrum shift index of all data points at each moment, recorded as the shift sum value; analyzing the sum of the stirring uniformity index of all types of silicone hydrogel raw materials at each moment, recorded as the uniform sum value; adding the shift sum value and the uniform sum value to obtain the stirring compensation coefficient at each moment.

[0080] Specifically, as another embodiment of the present application, the stirring compensation coefficient at each moment can be obtained by multiplying the offset sum value by the uniform sum value.

[0081] It should be understood that when the difference between the corresponding band length of the peak point in the hyperspectral graph of the qth data point at the jth moment and the corresponding band length of the peak point of the qth data point at all moments before the jth moment is larger, and the dtw distance between the absorptivity sequence of the hyperspectral graph of the qth data point and the absorptivity sequence of the hyperspectral graph of the qth data point at all moments before the jth moment is smaller, that is, the greater the stirring spectrum shift index of the qth data point at the jth moment, it means that the degree of shift of the hyperspectral graph of the data point at the qth moment caused by stirring is greater than that of the previous moments;

[0082] When the data points of the p-th silicone hydrogel raw material at the j-th moment change more obviously from the data points of the p-th silicone hydrogel raw material at all moments before the j-th moment, and the mean value of the hyperspectral graph of all data points contained in the p-th silicone hydrogel raw material is less than the mean value of the hyperspectral graph of the data points contained in the p-th silicone hydrogel raw material at all moments before the j-th moment, and the difference is larger, that is, the stirring uniformity index of the p-th silicone hydrogel raw material at the j-th moment is larger, indicating that the uniformity of the p-th silicone hydrogel raw material is increasing with the progress of stirring. When all the raw materials in the reactor are stirred more evenly at the j-th moment, and the degree of spectral shift of each data point caused by stirring is larger, that is, the stirring compensation coefficient at the j-th moment is larger, indicating that the stirring effect at the current moment is better than that at the previous moment, the stirring degree is higher, and there is no need to adjust the temperature of the stirring equipment temporarily.

[0083] At this point, the stirring compensation coefficient at each moment can be obtained.

[0084] Step S004, adaptively adjusting the temperature of the reactor according to the stirring coefficient and the stirring compensation coefficient of the silicone hydrogel raw material at each moment.

[0085] Further, in this embodiment, the temperature adaptation index of the silicone hydrogel material stirring at each moment is constructed according to the silicone hydrogel material stirring coefficient and the stirring compensation coefficient at each moment, and the corresponding expression is: ; In the formula, is the temperature adaptation index of the silicone hydrogel raw material stirring at the jth moment, is the stirring coefficient of the silicone hydrogel raw material at the jth moment, is the stirring compensation coefficient at the jth moment.

[0086] It should be noted that the temperature adaptation index is positively correlated with the stirring coefficient and the stirring compensation coefficient, and the temperature adaptation index is positively correlated with the optimal temperature of heat preservation and stirring. It can be understood that the positive correlation described in this application is that the dependent variable increases with the increase of the independent variable and decreases with the decrease of the independent variable.

[0087] At this point, the temperature adaptation index of the silicone hydrogel raw material stirring at each moment is obtained.

[0088] The temperature adaptation index of the silicon hydrogel raw material stirring is used to construct a temperature adaptation index sequence of the silicon hydrogel raw material stirring in time sequence, and the temperature adaptation index sequence is used as the input of the BP neural network. The optimization algorithm of the BP neural network is the SGD algorithm, and the output of the BP neural network is the optimal temperature of the silicon hydrogel raw material stirring. The BP neural network is a well-known technology, and its process is not repeated in this embodiment.

[0089] The stirring temperature in the reactor is adjusted according to the optimal temperature for stirring the silicon hydrogel raw material, so as to improve the uniform mixing efficiency of the silicon hydrogel raw material during the stirring process, and finally obtain a uniform silicon hydrogel raw material mixed liquid. Preferably, after obtaining the optimal temperature, the implementer can use a PID controller to control the temperature in the heat-insulating stirring reactor, or prompt the optimal temperature to relevant technicians through the corresponding system, and the technicians control the temperature of the heat-insulating stirring reactor through corresponding operations to ensure that the temperature of the heat-insulating stirring is at the optimal temperature. The process of temperature control based on PID can be achieved by existing technology, and this embodiment does not impose any special restrictions on this.

[0090] (5) Cooling: The prepared silica hydrogel raw material mixed solution is taken out from the reactor and placed in a container for cooling.

[0091] (6) Gel preparation: After the mixed solution is cooled to 40°C, it is poured into a mold and subjected to three cycles of freezing and thawing. Finally, the thawed hydrogel is placed in deionized water. The deionized water is replaced every 8 hours. This embodiment is repeated 5 times to remove residual chemical components, thereby obtaining an oxygen-permeable silicone hydrogel material.

[0092] Based on the same inventive concept as the above method, an embodiment of the present application further provides an oxygen-permeable silicone hydrogel material, wherein the oxygen-permeable silicone hydrogel material is produced by any one of the above methods for preparing an oxygen-permeable silicone hydrogel material.

[0093] It should be noted that the above sequence of the embodiments of the present application is for description only and does not represent the advantages and disadvantages of the embodiments. The above is a description of a specific embodiment of this specification. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0094] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0095] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing an oxygen-permeable silicone hydrogel material, characterized in that: The method comprises the following steps: (1) Preparation of polyvinyl alcohol solution: mixing polyvinyl alcohol powder with deionized water and heating the mixture to obtain a polyvinyl alcohol solution; (2) Preparation of PDMS microsphere suspension: After mixing the PDMS precursor and the curing agent, add them to the cooled polyvinyl alcohol solution and stir mechanically, then add 60 parts of deionized water to dilute it, and heat and stir to obtain a PDMS microsphere suspension, wherein all the components are calculated by weight. (3) Centrifugal washing: The PDMS microsphere suspension is centrifuged and washed with deionized water for multiple times, each time for 10 min, and the washed PDMS microsphere suspension is dispersed in a small amount of deionized water to obtain a PDMS microsphere dispersion; (4) Insulation and stirring: polyvinyl alcohol powder, PDMS microsphere dispersion, deionized water and water-soluble silicone oil are mixed, and the mixture is placed in an insulation and stirring reactor, and continuously stirred to obtain a silicone hydrogel raw material mixture; During the heat preservation and stirring process, a high-spectrum graph in the reactor at each moment is collected, and various silicone hydrogel raw materials are obtained according to the distribution of the absorbance of the data points in each band in the high-spectrum graph at each moment; According to the average level of absorption rate of various silicone hydrogel raw materials at each moment and the difference degree of absorption rate of adjacent peak points of each data point, the raw material concentration coefficient of each silicone hydrogel raw material at each moment is constructed, and the silicone hydrogel raw material stirring coefficient at each moment is calculated by combining the raw material concentration coefficients of all types of silicone hydrogel raw materials at each moment; Analyze the difference in wavelength corresponding to the peak point of the data point in the hyperspectral graph at each moment and the previous moments, and the difference in the absorbance of the data point, and combine the difference in the absorbance of each silicone hydrogel raw material between each moment and the previous moments to obtain the stirring compensation coefficient at each moment; The temperature of the reactor is adaptively adjusted according to the stirring coefficient and the stirring compensation coefficient of the silicone hydrogel raw material at each moment; (5) Cooling: taking the prepared silica hydrogel raw material mixed solution out of the reactor and placing it in a container for cooling; (6) Gel preparation: After the silicone hydrogel raw material mixture is cooled, it is poured into a mold and subjected to multiple cycles of freezing and thawing. The thawed hydrogel is then placed in deionized water, and the deionized water is replaced multiple times to remove residual chemical components, thereby obtaining an oxygen-permeable silicone hydrogel material; The silicone hydrogel raw materials obtained at each time include: For the data points in the hyperspectral graph at each moment, the absorbance of each data point in each band is arranged in ascending order of the band to form an absorbance sequence of each data point, and each absorbance sequence is fitted to obtain a fitting curve of each data point. The wavelength corresponding to the maximum peak point of the fitting curve of each data point is counted, and the wavelengths corresponding to all peak points are clustered and divided by a clustering algorithm, and the data points corresponding to all wavelengths in the same category are regarded as the same type of silicone hydrogel raw materials; The process of obtaining the stirring coefficient of the silicone hydrogel raw material at each time includes: For various silicone hydrogel raw materials, the mean of the absorbance corresponding to the peak point of all data points in the y-th silicone hydrogel raw material is analyzed and recorded as the peak mean; the absolute value of the difference in absorbance between adjacent peak points of each data point in the y-th silicone hydrogel raw material is analyzed and recorded as the peak absolute value; The raw material concentration coefficient of the yth silicone hydrogel raw material at each moment is positively correlated with the wave peak mean value, and negatively correlated with the wave peak absolute value; The stirring coefficient of the silicone hydrogel raw material at each time is negatively correlated with the raw material concentration coefficient of all types of silicone hydrogel raw materials at each time; The process of obtaining the stirring compensation coefficient at each moment includes: Calculate the difference between the peak point of each data point at each moment and the corresponding wavelength of the peak points at the previous moments, take the absolute value and accumulate it, and record it as the wavelength difference of each data point at each moment; The distance between the absorption rate sequence of each data point at each moment and the absorption rate sequence of the previous multiple moments is accumulated, and recorded as the absorption rate difference of each data point at each moment; The ratio of the wavelength difference to the absorbance difference is used as the stirring spectrum shift index of each data point at each time; Analyze the average of the absorbance of the data points included in each silicone hydrogel raw material at each moment, record it as the average absorbance at each moment, obtain the result of accumulating the difference between the average absorbance of each silicone hydrogel raw material at each moment and the average absorbance of multiple moments before it, and use the reciprocal of the result as the stirring uniformity index of each silicone hydrogel raw material at each moment; The stirring compensation coefficient at each moment is positively correlated with the stirring spectrum shift index of all data points at each moment and the stirring uniformity index of all types of silicone hydrogel raw materials at each moment; Adaptive regulation of reactor temperature includes: The product of the stirring coefficient of the silicone hydrogel raw material at each moment and the stirring compensation coefficient is used as the temperature adaptation index of the silicone hydrogel raw material stirring at each moment. The temperature adaptation indexes collected at all moments are arranged in the order of collection time to form a temperature adaptation index sequence, which is input into the neural network to obtain the optimal temperature for the silicone hydrogel raw material stirring and adjust the temperature of the reactor.

2. The method for preparing an oxygen-permeable silicone hydrogel material according to claim 1, characterized in that: During the preparation of the polyvinyl alcohol solution, the weight ratio of polyvinyl alcohol powder to deionized water is 1:

9.

3. The method for preparing an oxygen-permeable silicone hydrogel material according to claim 1, characterized in that: The amount of the curing agent is 0.5 parts.

4. The method for preparing an oxygen-permeable silicone hydrogel material according to claim 1, characterized in that: The centrifugal speed of the mechanical stirring is 2000-3000 rpm, and the stirring time is 1 hour.

5. The method for preparing an oxygen-permeable silicone hydrogel material according to claim 1, characterized in that: The mixed liquid in the heat-insulating stirring reactor comprises 3.7 parts of polyvinyl alcohol powder, 5.8 parts of PDMS microsphere dispersion, 20.47 parts of deionized water, and 3.7 parts of water-soluble silicone oil.

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