CN114874341B - Fluorescent nanoparticle with AIE characteristic, bionic nano composite hydrogel actuator, preparation method and application - Google Patents

Abstract

Translated fromChinese

本发明公开了一种具有AIE特性的荧光纳米粒子、仿生纳米复合水凝胶致动器、制备方法及应用。本发明提供了一种具有聚集诱导发光(AIE)特性的荧光纳米粒子，其是由TPE‑pyo荧光分子和纤维素纳米晶在催化剂的作用下制备而成。基于该荧光纳米粒子的共轭施主‑受主(D‑A)结构，可以灵敏地感应微环境的变化，从而实现追踪荧光纳米粒子在水凝胶成型过程中的动态运动；可视化荧光纳米粒子在水凝胶中的静态分布；监测纳米复合水凝胶在热刺激下发生弯曲运动的过程及相转变行为。本发明的AIE特性的荧光纳米粒子及其相关应用方法有望推动荧光技术在人工肌肉、智能致动及仿生纳米复合材料领域的应用。

The invention discloses a fluorescent nanoparticle with AIE characteristics, a biomimetic nanocomposite hydrogel actuator, a preparation method and an application. The invention provides a fluorescent nanoparticle with aggregation-induced emission (AIE) characteristics, which is prepared from TPE-pyo fluorescent molecules and cellulose nanocrystals under the action of a catalyst. Based on the conjugated donor-acceptor (D-A) structure of the fluorescent nanoparticles, it can sensitively sense the changes in the microenvironment, so as to track the dynamic movement of the fluorescent nanoparticles during the hydrogel forming process; visualize the fluorescent nanoparticles in the Static distribution in hydrogels; monitoring the process of bending motion and phase transition behavior of nanocomposite hydrogels under thermal stimulation. The fluorescent nanoparticles with AIE characteristics and related application methods of the present invention are expected to promote the application of fluorescent technology in the fields of artificial muscles, intelligent actuation and bionic nanocomposite materials.

Description

Translated fromChinese

一种具有AIE特性的荧光纳米粒子、仿生纳米复合水凝胶致动器、制备方法及应用A fluorescent nanoparticle, biomimetic nanocomposite hydrogel actuated with AIE propertiesdevice, preparation method and application

技术领域technical field

本发明涉及一种具有AIE特性的荧光纳米粒子、仿生纳米复合水凝胶致动器、制备方法及应用，属于荧光纳米复合材料技术领域。The invention relates to a fluorescent nanoparticle with AIE characteristics, a bionic nanocomposite hydrogel actuator, a preparation method and an application, and belongs to the technical field of fluorescent nanocomposite materials.

背景技术Background technique

水凝胶驱动器是一种能够对外界刺激(光、热、化学、电等)产生可逆形变或者体积改变的新型智能材料。作为一类与生物组织相似的“软、湿”态材料，水凝胶驱动器在软体机器人、人工肌肉、组织工程等领域存在巨大的潜在应用价值。向水凝胶体系中添加纳米粒子来诱导产生非对称性网络结构是一种有效的方法。Hydrogel actuator is a new type of smart material that can produce reversible deformation or volume change in response to external stimuli (light, heat, chemistry, electricity, etc.). As a class of "soft and wet" materials similar to biological tissues, hydrogel actuators have great potential application value in soft robots, artificial muscles, tissue engineering and other fields. Adding nanoparticles to hydrogel systems to induce an asymmetric network structure is an effective method.

为了实现非对称性水凝胶网络的构筑，精确调控纳米粒子在高分子基体中的分布情况是至关重要的。然而，传统的测试手段如扫描电子显微镜(SEM)、透射电子显微镜(TEM)以及原子力显微镜(AFM)等，都需要经过复杂的制样过程，如破碎、切割、真空干燥等，这难免会造成材料的内部结构破坏从而导致信息失真，尤其是当材料是水凝胶这种“又湿又软”的材料时，观察纳米粒子的分布变得更加困难。而且，传统测试的测试窗口很小，难以代表宏观材料的结构信息。因此，亟需一种操作简单、无损、湿态可用的测试方式来研究纳米粒子在水凝胶体系中的分布信息，推动水凝胶驱动器的快速发展。In order to realize the construction of asymmetric hydrogel network, it is crucial to precisely control the distribution of nanoparticles in the polymer matrix. However, traditional testing methods such as scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM) all require complex sample preparation processes, such as crushing, cutting, vacuum drying, etc., which will inevitably cause The internal structure of the material is destroyed, which leads to information distortion, especially when the material is a "wet and soft" material such as hydrogel, which makes it more difficult to observe the distribution of nanoparticles. Moreover, the test window of traditional tests is very small, which makes it difficult to represent the structural information of macroscopic materials. Therefore, there is an urgent need for a simple, non-destructive, and wet-state test method to study the distribution information of nanoparticles in hydrogel systems and promote the rapid development of hydrogel actuators.

荧光技术具有高分辨、无损、生物相容性好等众多优势，在化学和生物传感、生物成像、催化及新能源材料等领域受到许多关注。然而传统的荧光染料如罗丹明B和荧光素等，在溶液状态下具有较高的量子产率，而在固态和聚集状态下，由于分子间紧密堆积，从而使发光性能大大减弱甚至不发光，即出现聚集诱导淬灭(Aggregation CausedQuenching，ACQ)，这极大的限制了荧光技术在材料科学领域的应用。直到2001年，唐本忠院士发现了聚集诱导发光(Aggregation-Induced Emission，AIE)现象。具有高度扭曲的螺旋桨状构象AIE分子能够有效的抑制在聚集状态下的分子间π-π堆叠，阻止了激发态能量通过非辐射衰变通道的耗散，而聚集状态下发光强烈。此外，根据分子内运动的限制(RIM)机制，AIE分子对微环境极为敏感，已被成功地用于各种微环境的研究。因此，如果将AIE分子修饰到纳米粒子上，并将其引入水凝胶体系中，有望实现纳米粒子在水凝胶体系中的可视化研究，从而进一步探究水凝胶内部结构与宏观性能间的关系，推动水凝胶驱动器在众多领域的发展。Fluorescence technology has many advantages such as high resolution, non-destructive, and good biocompatibility, and has attracted a lot of attention in the fields of chemical and biological sensing, biological imaging, catalysis, and new energy materials. However, traditional fluorescent dyes such as rhodamine B and fluorescein have high quantum yields in the solution state, but in the solid state and aggregated state, due to the tight packing between molecules, the luminescence performance is greatly weakened or even does not emit light. That is, aggregation-induced quenching (Aggregation Caused Quenching, ACQ) appears, which greatly limits the application of fluorescence technology in the field of material science. Until 2001, Academician Tang Benzhong discovered the phenomenon of aggregation-induced emission (Aggregation-Induced Emission, AIE). The highly twisted propeller-like conformation of AIE molecules can effectively inhibit the intermolecular π-π stacking in the aggregated state, preventing the dissipation of excited state energy through non-radiative decay channels, while the aggregated state emits strongly. In addition, AIE molecules are extremely sensitive to microenvironments according to the restriction of intramolecular motion (RIM) mechanism, and have been successfully used in the study of various microenvironments. Therefore, if AIE molecules are modified onto nanoparticles and introduced into the hydrogel system, it is expected to realize the visualization of nanoparticles in the hydrogel system, so as to further explore the relationship between the internal structure of the hydrogel and the macroscopic properties. , to promote the development of hydrogel actuators in many fields.

发明内容Contents of the invention

本发明解决的技术问题是：水凝胶的软湿性、低导电性以及纳米粒子和聚合物基质的低对比度等原因导致其表征困难，难以实现动态实时检测等技术问题。The technical problems solved by the present invention are: soft wetness, low conductivity and low contrast of nanoparticles and polymer matrix of hydrogel lead to difficult characterization, difficult to realize dynamic real-time detection and other technical problems.

为了解决上述技术问题，本发明提供了一种具有AIE特性的荧光纳米粒子，其化学结构式如式I所示：In order to solve the above-mentioned technical problems, the present invention provides a kind of fluorescent nanoparticle with AIE characteristic, and its chemical structural formula is as shown in formula I:

所述的荧光纳米粒子发黄光，固态发射波长在518nm，液态分散体系发射波长在520-532nm。The fluorescent nanoparticles emit yellow light, the emission wavelength of the solid state is 518nm, and the emission wavelength of the liquid dispersion system is 520-532nm.

本发明还提供了上述的具有AIE特性的荧光纳米粒子的制备方法，包括如下步骤：The present invention also provides the preparation method of the above-mentioned fluorescent nanoparticles with AIE characteristics, comprising the following steps:

步骤1：将纤维素纳米晶充分干燥，分散到二氯甲烷中，得到CNC分散液；Step 1: Fully dry the cellulose nanocrystals and disperse them in dichloromethane to obtain a CNC dispersion;

步骤2：将如式II所示的TPE-pyo荧光分子和催化剂4-二甲氨基吡啶分别溶解到二氯甲烷中，得到相应的TPE-pyo溶液和催化剂溶液；Step 2: Dissolving the TPE-pyo fluorescent molecule shown in formula II and the catalyst 4-dimethylaminopyridine respectively in dichloromethane to obtain the corresponding TPE-pyo solution and catalyst solution;

步骤3：将上述所得的TPE-pyo溶液加入到CNC分散液中，同时加入催化剂溶液，混合均匀，磁力搅拌使其反应；Step 3: Add the TPE-pyo solution obtained above into the CNC dispersion liquid, and add the catalyst solution at the same time, mix well, and stir magnetically to make it react;

步骤4：反应结束后，将所得产物依次经过过滤、洗涤和干燥，得到具有AIE特性的荧光纳米粒子TPE-CNC，其化学结构如式I所示；Step 4: After the reaction is completed, the obtained product is filtered, washed and dried in sequence to obtain a fluorescent nanoparticle TPE-CNC with AIE characteristics, and its chemical structure is shown in formula I;

优选地，所述步骤1中的纤维素纳米晶的直径为20-30nm，长度200-300nm，长径比约等于10；所述CNC分散液的浓度为1～5wt％；所述步骤2中的TPE-pyo溶液和催化剂溶液的浓度分别为：0.5～2mg/mL、0.001-0.008M。Preferably, the diameter of the cellulose nanocrystal in the step 1 is 20-30nm, the length is 200-300nm, and the aspect ratio is approximately equal to 10; the concentration of the CNC dispersion is 1-5wt%; in the step 2 The concentrations of the TPE-pyo solution and the catalyst solution are: 0.5-2mg/mL, 0.001-0.008M, respectively.

优选地，所示步骤中TPE-pyo溶液中的TPE-pyo和CNC溶液中的纤维素纳米晶的质量比为0.075-0.1：1。Preferably, the mass ratio of the TPE-pyo in the TPE-pyo solution to the cellulose nanocrystals in the CNC solution in the steps shown is 0.075-0.1:1.

本发明还提供了上述的具有AIE特性的荧光纳米粒子的应用。The present invention also provides the application of the above-mentioned fluorescent nanoparticles with AIE characteristics.

优选地，包括在制备仿生纳米复合水凝胶致动器中的应用，和/或在可视化监测仿生纳米复合水凝胶致动器的成型过程中的应用，和/或在可视化检测仿生纳米复合水凝胶致动器的内部结构中的应用，和/或在可视化监测仿生纳米复合水凝胶致动器的热刺激响应中的应用。Preferably, it includes the application in the preparation of biomimetic nanocomposite hydrogel actuators, and/or the application in visual monitoring of the forming process of biomimetic nanocomposite hydrogel actuators, and/or the application in visual detection of biomimetic nanocomposite hydrogel actuators. applications in the internal structure of hydrogel actuators, and/or in visual monitoring of thermal stimulus responses of biomimetic nanocomposite hydrogel actuators.

优选地，包括在制备仿生纳米复合水凝胶致动器的过程中同时可视化监测其成型过程。Preferably, it includes simultaneously visually monitoring the forming process of the biomimetic nanocomposite hydrogel actuator during the preparation process.

优选地，还包括可视化检测所述制备得到的仿生纳米复合水凝胶致动器的内部结构及热刺激响应行为。Preferably, it also includes visual inspection of the internal structure and thermal stimulus response behavior of the prepared biomimetic nanocomposite hydrogel actuator.

本发明还提供了一种仿生纳米复合水凝胶致动器，是由式I所示的荧光纳米粒子、N-异丙基丙烯酰胺、N,N’-亚甲基双丙烯酰胺和聚乙二醇单甲醚甲基丙烯酸酯通过光引发自由基聚合形成的复合水凝胶纤维，其发射波长在482nm。The present invention also provides a bionic nanocomposite hydrogel actuator, which is composed of fluorescent nanoparticles represented by formula I, N-isopropylacrylamide, N,N'-methylenebisacrylamide and polyethylene The composite hydrogel fiber formed by photoinitiated free radical polymerization of glycol monomethyl ether methacrylate has an emission wavelength of 482nm.

优选地，所述复合水凝胶纤维的成型过程或热刺激响应行为通过荧光检测仪器或工具进行可视化监测；所述复合水凝胶纤维的内部结构通过荧光检测仪器或工具进行可视化表征。具体地，通过荧光光谱和荧光显微镜追踪纳米粒子在复合水凝胶成型过程中的动态运动；通过荧光显微镜、激光共聚焦显微镜监控水凝胶动态成型过程及可视化荧光纳米粒子在水凝胶中的静态分布；通过荧光拍摄及荧光光谱监测纳米复合水凝胶致动器在热刺激下发生螺旋运动及水凝胶相转变的过程。Preferably, the molding process or thermal stimulus response behavior of the composite hydrogel fiber is visually monitored by a fluorescence detection instrument or tool; the internal structure of the composite hydrogel fiber is visually characterized by a fluorescence detection instrument or tool. Specifically, the dynamic movement of nanoparticles in the composite hydrogel formation process was tracked by fluorescence spectroscopy and fluorescence microscopy; the dynamic formation process of hydrogels and the visualization of fluorescent nanoparticles in hydrogels were monitored by fluorescence microscopy and laser confocal microscopy. Static distribution; the process of helical motion and hydrogel phase transition of the nanocomposite hydrogel actuator under thermal stimulation was monitored by fluorescence photography and fluorescence spectroscopy.

本发明与现有技术相比，具有如下有益效果：Compared with the prior art, the present invention has the following beneficial effects:

(1)本发明提供了一种具有聚集诱导发光(AIE)特性的荧光纳米粒子，基于该荧光纳米粒子的共轭施主-受主(D-A)结构，可以灵敏地感应微环境的变化，从而实现追踪荧光纳米粒子在水凝胶成型过程中的动态运动；可视化荧光纳米粒子在水凝胶中的静态分布；监测纳米复合水凝胶在热刺激下发生弯曲运动的过程及相转变行为；(1) The present invention provides a fluorescent nanoparticle with aggregation-induced emission (AIE) characteristics. Based on the conjugated donor-acceptor (D-A) structure of the fluorescent nanoparticle, it can sensitively sense changes in the microenvironment, thereby realizing Track the dynamic movement of fluorescent nanoparticles during hydrogel formation; visualize the static distribution of fluorescent nanoparticles in hydrogel; monitor the bending process and phase transition behavior of nanocomposite hydrogels under thermal stimulation;

(2)本发明所提供的聚集诱导发光分子标记纤维素纳米晶的方法，反应条件为常温磁力搅拌，无须除水除氧，过程简单易行，荧光标记效果显著，所得荧光纳米粒子的量子产率由固态的4.7％到水分散液的7.3％到水凝胶中的16.0％，表现出典型的AIE特性，可以用于多种体系的研究；(2) The method for labeling cellulose nanocrystals with aggregation-induced luminescent molecules provided by the present invention, the reaction conditions are magnetic stirring at room temperature, no need to remove water and oxygen, the process is simple and easy, the fluorescent labeling effect is remarkable, and the quantum yield of the obtained fluorescent nanoparticles is The rate ranges from 4.7% in solid state to 7.3% in water dispersion to 16.0% in hydrogel, showing typical AIE characteristics and can be used in the research of various systems;

(3)本发明所得荧光纳米粒子的TICT效应显著，发射波长由水分散液中的532nm到水凝胶中的482nm，颜色变化显著，可以用于检测微环境变化；且聚集诱导发光分子无生物毒性，纤维素纳米晶是一种常用的生物材料，将极大的推动荧光检测技术在纳米复合水凝胶领域的应用；(3) The TICT effect of the fluorescent nanoparticles obtained in the present invention is remarkable, and the emission wavelength is from 532nm in the water dispersion to 482nm in the hydrogel, and the color changes significantly, which can be used to detect changes in the microenvironment; and the aggregation-induced luminescent molecules have no biological Toxicity, cellulose nanocrystals are a commonly used biological material, which will greatly promote the application of fluorescence detection technology in the field of nanocomposite hydrogels;

(4)本发明所提供的具有AIE特性的荧光纳米粒子用于可视化监测CNC纳米复合水凝胶致动器成型过程内部结构时，避免了传统测试方法的复杂样品处理，保护了水凝胶的网络结构不被破坏，检测结果准确，分辨率<100μm，可以实现实时可视化监测，数据反馈时间低于500ms；(4) When the fluorescent nanoparticles with AIE characteristics provided by the present invention are used to visually monitor the internal structure of the CNC nanocomposite hydrogel actuator molding process, it avoids the complicated sample processing of the traditional test method and protects the hydrogel. The network structure is not damaged, the detection result is accurate, the resolution is <100μm, real-time visual monitoring can be realized, and the data feedback time is less than 500ms;

(5)本发明所提供的具有AIE特性的荧光纳米粒子可用于可视化监测CNC纳米复合水凝胶致动器的热刺激响应过程，可以实时的反馈水凝胶致动过程中的内部网络结构，并直接通过肉眼观察；同时，荧光强度测试可以检测水凝胶变形过程中的低临界转变温度(LCST)及变形温度(T_df)，样品无损，可重复检测50次以上；(5) The fluorescent nanoparticles with AIE characteristics provided by the present invention can be used to visually monitor the thermal stimulus response process of CNC nanocomposite hydrogel actuators, and can provide real-time feedback on the internal network structure in the hydrogel actuation process, And directly observed by naked eyes; at the same time, the fluorescence intensity test can detect the low critical transition temperature (LCST) and deformation temperature (T_df ) of the hydrogel during deformation, the sample is non-destructive, and the detection can be repeated more than 50 times;

(6)本发明所提供的具有AIE特性的荧光纳米粒子可用于表征CNC纳米复合水凝胶的内部结构，无需复杂的样品制备，灵敏度高，分辨率高，无损，且能够实现实时观测，有望推动荧光技术在人工肌肉、智能致动及仿生纳米复合材料领域的应用。(6) The fluorescent nanoparticles with AIE characteristics provided by the present invention can be used to characterize the internal structure of CNC nanocomposite hydrogels, without complex sample preparation, high sensitivity, high resolution, non-destructive, and real-time observation can be achieved, which is expected Promote the application of fluorescence technology in the fields of artificial muscles, intelligent actuation and biomimetic nanocomposites.

附图说明Description of drawings

图1为荧光纳米粒子TPE-CNC的合成过程及所得荧光纳米粒子的光物理性质；其中，a为TPE-pyo荧光分子通过点击反应接枝到CNC纳米粒子上，b为荧光光谱表征所获得的荧光纳米粒子在固态及水分散体系中均发射强烈的黄色荧光，c为薄层色谱分离(TLC)证明TPE-pyo荧光分子与CNC纳米粒子之间为共价连接，d为TPE-CNC荧光纳米粒子水分散液的荧光强度与浓度呈线性关系；Figure 1 shows the synthesis process of fluorescent nanoparticles TPE-CNC and the photophysical properties of the resulting fluorescent nanoparticles; where, a is the TPE-pyo fluorescent molecule grafted onto CNC nanoparticles through a click reaction, and b is obtained by fluorescence spectrum characterization Fluorescent nanoparticles emit strong yellow fluorescence in both solid-state and water dispersion systems, c is thin layer chromatography (TLC) to prove that TPE-pyo fluorescent molecules and CNC nanoparticles are covalently connected, d is TPE-CNC fluorescent nanoparticle The fluorescence intensity of the particle aqueous dispersion has a linear relationship with the concentration;

图2为CNC纳米粒子接枝前后的粒径变化；其中，a为接枝前的原子力显微镜图片，b为接枝后的原子力显微镜图片，c为CNC纳米粒子和TPE-CNC荧光纳米粒子的粒径分布，d为分子理论计算的CNC纳米粒子和TPE-CNC荧光纳米粒子的直径；Figure 2 is the particle size change of CNC nanoparticles before and after grafting; among them, a is the atomic force microscope picture before grafting, b is the atomic force microscope picture after grafting, and c is the particle size of CNC nanoparticles and TPE-CNC fluorescent nanoparticles diameter distribution, d is the diameter of CNC nanoparticles and TPE-CNC fluorescent nanoparticles calculated by molecular theory;

图3为仿生纳米复合水凝胶致动器的制备过程中TPE-CNC处于不同微环境中荧光颜色和发光强度的变化，随着体系由水到粘度更高的水凝胶前驱体，再到聚合完成形成水凝胶，TPE-CNC的荧光颜色由黄色逐渐变为蓝色，发光强度不断增大；其中，a为制备过程及发光变化示意图，b为荧光光谱表征结果；Figure 3 shows the changes in fluorescence color and luminous intensity of TPE-CNC in different microenvironments during the preparation of biomimetic nanocomposite hydrogel actuators, as the system changes from water to higher viscosity hydrogel precursors, and then to After the polymerization is completed to form a hydrogel, the fluorescent color of TPE-CNC gradually changes from yellow to blue, and the luminous intensity continues to increase; where a is a schematic diagram of the preparation process and luminescent changes, and b is the characterization result of the fluorescence spectrum;

图4为利用荧光光谱监测水凝胶成型过程中纳米粒子的沉降过程，随着时间的延长，观察到荧光强度先增大后减小，最后在320min达到平衡态；Figure 4 is the use of fluorescence spectroscopy to monitor the sedimentation process of nanoparticles during the hydrogel forming process. With the prolongation of time, it was observed that the fluorescence intensity first increased and then decreased, and finally reached an equilibrium state at 320 minutes;

图5为利用荧光光谱检测水凝胶中的梯度结构，位置I-X为自上而下高度间隔为1mm，可观察到沿重力方向上荧光强度逐渐增加，激发波长为370nm；其中，a为荧光光谱图，b为荧光强度梯度变化曲线；Figure 5 is the detection of the gradient structure in the hydrogel by fluorescence spectroscopy. The position I-X is from top to bottom with a height interval of 1mm. It can be observed that the fluorescence intensity gradually increases along the gravity direction, and the excitation wavelength is 370nm; where a is the fluorescence spectrum Figure, b is the fluorescence intensity gradient curve;

图6为利用荧光显微镜追踪凝胶成型过程和激光共聚焦显微镜观察凝胶中纳米粒子的分布，扫描电镜(SEM)图印证了纳米粒子的分布与水凝胶网络的关系，即纳米粒子分布多的区域凝胶网络密度大；其中，a为通过荧光显微镜实时拍摄的纳米复合水凝胶驱动器成型过程中的照片；b为通过激光共聚焦显微镜可视化观察水凝胶中荧光纳米粒子的分布，c为利用SEM观察水凝胶网络结构，d为c的放大图；Figure 6 shows the use of fluorescence microscopy to track the gel forming process and laser confocal microscopy to observe the distribution of nanoparticles in the gel. The scanning electron microscope (SEM) image confirms the relationship between the distribution of nanoparticles and the hydrogel network, that is, the distribution of nanoparticles The gel network density in the region is high; among them, a is the photo of the nanocomposite hydrogel actuator forming process taken in real time by fluorescence microscope; b is the distribution of fluorescent nanoparticles in the hydrogel visualized by laser confocal microscope, c In order to use SEM to observe the hydrogel network structure, d is the enlarged view of c;

图7为利用荧光成像可视化监测水凝胶致动器致动过程，在60℃热引发下，水凝胶纤维发生不对称弯曲变形，在紫外灯(365nm)的照射下，卷曲纤维内侧的荧光强度高于外侧，说明内部具有更多的荧光纳米粒子TPE-CNC，诱导了水凝胶纤维的弯曲；其中，a为自然光下水凝胶纤维发生不对称弯曲变形的照片及内部网络结构示意图，b为紫外灯下监测水凝胶纤维发生不对称弯曲变形的荧光照片；Figure 7 is a visual monitoring of the actuation process of the hydrogel actuator using fluorescence imaging. Under the thermal trigger of 60°C, the hydrogel fiber undergoes asymmetric bending deformation. The intensity is higher than the outside, indicating that there are more fluorescent nanoparticles TPE-CNC inside, which induces the bending of the hydrogel fiber; among them, a is a photo of the asymmetric bending deformation of the hydrogel fiber under natural light and a schematic diagram of the internal network structure, b Fluorescent photographs of asymmetric bending deformation of hydrogel fibers monitored under ultraviolet light;

图8为利用变温荧光光谱测试的水凝胶热刺激响应过程中内部微观网络结构的变化，32℃和49℃分别为水凝胶的LCST和T_df。Fig. 8 shows the change of the internal micro-network structure of the hydrogel in response to thermal stimulation by temperature-variable fluorescence spectroscopy. 32°C and 49°C are the LCST and T_df of the hydrogel, respectively.

具体实施方式Detailed ways

为使本发明更明显易懂，兹以优选实施例，并配合附图作详细说明如下。In order to make the present invention more comprehensible, preferred embodiments are described in detail below with accompanying drawings.

本发明的一个实施例中，设计并合成了一种荧光纳米粒子，其中，荧光分子为带有活化炔基的四苯基乙烯(TPE)衍生物TPE-pyo，纳米粒子为生物质纤维素纳米晶(CNC)，TPE-pyo:CNC的质量比为0.075-0.1，DMAP的摩尔浓度为0.002-0.008M。TPE与CNC之间通过点击反应共价连接，具有AIE特性，在粉末态、水分散体系及水凝胶复合体系中均有强荧光发射。In one embodiment of the present invention, a fluorescent nanoparticle is designed and synthesized, wherein the fluorescent molecule is tetraphenylethylene (TPE) derivative TPE-pyo with an activated alkynyl group, and the nanoparticle is biomass cellulose nanoparticle crystal (CNC), the mass ratio of TPE-pyo:CNC is 0.075-0.1, and the molar concentration of DMAP is 0.002-0.008M. TPE and CNC are covalently connected by click reaction, which has AIE characteristics, and has strong fluorescence emission in powder state, water dispersion system and hydrogel composite system.

本发明所述荧光纳米粒子具有D-A结构，对微环境有灵敏响应：由于扭曲的分子内电荷转移(TICT)作用，随微环境极性增加，所述荧光纳米粒子的发光颜色由黄色(532nm)变为蓝色(482nm)；由于分子间运动受限(RIM)作用，随微环境硬度的增加，所述荧光纳米粒子的发光强度不断增大。The fluorescent nanoparticles of the present invention have a D-A structure and are sensitive to the microenvironment: due to twisted intramolecular charge transfer (TICT), as the polarity of the microenvironment increases, the luminescent color of the fluorescent nanoparticles changes from yellow (532nm) Change to blue (482nm); due to the restriction of intermolecular motion (RIM), the luminous intensity of the fluorescent nanoparticles increases continuously with the increase of the hardness of the microenvironment.

本发明的一个实施例中，提出的纳米复合水凝胶致动器是由CNC纳米粒子添加到水凝胶前驱体中，由引发剂引发聚合形成的可产生刺激响应运动的水凝胶。其中，水凝胶体系是一种具有典型的温敏性水凝胶，PNIAM与Bis、PEGMEMA形成交联网络，CNC纳米粒子在交联网络中调节网络密度。In one embodiment of the present invention, the proposed nanocomposite hydrogel actuator is a hydrogel that can generate stimuli-responsive motion by adding CNC nanoparticles to the hydrogel precursor and triggering polymerization by an initiator. Among them, the hydrogel system is a typical temperature-sensitive hydrogel. PNIAM forms a cross-linked network with Bis and PEGMEMA, and CNC nanoparticles adjust the network density in the cross-linked network.

本发明通过荧光标记纳米粒子，可以追踪荧光纳米粒子的动态运动及在水凝胶复合体系中的静态分布。The invention can track the dynamic movement of the fluorescent nano-particles and the static distribution in the hydrogel composite system by fluorescently marking the nano-particles.

本发明在一个实施例中通过荧光光谱，监测在凝胶成型过程中纳米粒子在重力作用下不断沉降，最终在水凝胶沿重力方向上形成了浓度梯度。In one embodiment of the present invention, fluorescence spectroscopy is used to monitor the continuous sedimentation of nanoparticles under the action of gravity during the gel forming process, and finally a concentration gradient is formed in the hydrogel along the direction of gravity.

本发明在一个实施例中，通过荧光显微镜，观察纳米粒子在凝胶成型过程中由于马兰戈尼效应发生不对称流动；激光共聚焦显微镜观察到荧光纳米粒子在水凝胶纤维截面形成了偏心圆状浓度梯度；扫描电镜观察到纳米粒子的偏心圆状浓度梯度导致了水凝胶的环月形网络结构。In one embodiment of the present invention, the asymmetric flow of nanoparticles due to the Marangoni effect during the gel forming process is observed through a fluorescence microscope; the laser confocal microscope observes that the fluorescent nanoparticles form an eccentric circle in the cross section of the hydrogel fiber Concentration gradient; the scanning electron microscope observed that the eccentric concentration gradient of nanoparticles led to the ring-shaped network structure of the hydrogel.

本发明中，纳米复合水凝胶纤维致动器的内部结构通过纳米粒子的荧光强度表现，在网络密度大的区域，荧光强度大，在网络密度小的区域，荧光强度小。In the present invention, the internal structure of the nanocomposite hydrogel fiber actuator is represented by the fluorescence intensity of the nanoparticles. In the area with high network density, the fluorescence intensity is high, and in the area with low network density, the fluorescence intensity is small.

本发明所制备的纳米复合水凝胶致动器能够对热刺激做出快速响应，发生不对称弯曲，在一个实施例中，通过荧光成像，可以可视化响应过程中纤维内部的不对称结构。The nanocomposite hydrogel actuator prepared in the present invention can quickly respond to thermal stimulation and undergo asymmetric bending. In one embodiment, the asymmetric structure inside the fiber during the response process can be visualized through fluorescence imaging.

本发明通过荧光追踪纳米粒子，进一步分析得到了纳米粒子分布与凝胶的微观网络结构及宏观致动性能之间的关系。In the present invention, the relationship between the distribution of the nanoparticles and the microscopic network structure and macroscopic actuation performance of the gel is further analyzed by tracking the nanoparticles through the fluorescence.

以下实施例中，纤维素纳米晶(直径为20-30nm，长度为200-300nm)购自闪思科技(Science K)，N-异丙基丙烯酰胺(98％)购自TCI梯希爱(上海)化成工业发展有限公司，N,N'-亚甲基双丙烯酰胺(99％)、聚乙二醇单甲醚甲基丙烯酸酯(M_n＝500g mol^-1)以及光引发剂α，α-二乙氧基苯乙酮购自阿拉丁试剂(上海)有限公司，TPE-pyo荧光分子购自上海美迪西生物医药有限公司。In the following examples, cellulose nanocrystals (20-30nm in diameter and 200-300nm in length) were purchased from Sansi Technology (Science K), and N-isopropylacrylamide (98%) was purchased from TCI ( Shanghai) Chemical Industry Development Co., Ltd., N,N'-methylenebisacrylamide (99%), polyethylene glycol monomethyl ether methacrylate (M_n =500g mol^-1 ) and photoinitiator α, α-diethoxyacetophenone was purchased from Aladdin Reagents (Shanghai) Co., Ltd., and TPE-pyo fluorescent molecules were purchased from Shanghai Medicilon Biopharmaceutical Co., Ltd.

实施例1设计并合成荧光纳米粒子TPE-CNCEmbodiment 1 designs and synthesizes fluorescent nanoparticle TPE-CNC

通过点击反应将TPE-pyo荧光分子接枝到CNC上，合成荧光纳米TPE-CNC，如图1a所示，具体包括如下步骤：The fluorescent nano-TPE-CNC was synthesized by grafting TPE-pyo fluorescent molecules onto the CNC through a click reaction, as shown in Figure 1a, which specifically included the following steps:

(1)溶液的配制：将10-30mg TPE-pyo荧光分子(alkyne-TPE)溶解于10-30mLCH₂Cl₂溶剂中，将0.1-0.4g纤维素纳米晶(Cellulose Nanocrystal，CNC)分散在10-90mLCH₂Cl₂中，超声10-40min，将DMAP(4-二甲氨基吡啶)溶于CH₂Cl₂中得到20mg/mL的溶液；其中，TPE-pyo荧光分子和CNC化学结构式如下所示：(1) Solution preparation: Dissolve 10-30mg TPE-pyo fluorescent molecule (alkyne-TPE) in 10-30mL CH₂ Cl₂ solvent, disperse 0.1-0.4g cellulose nanocrystal (Cellulose Nanocrystal, CNC) in 10 -90mL CH₂ Cl₂ , sonicate for 10-40min, dissolve DMAP (4-dimethylaminopyridine) in CH₂ Cl₂ to obtain a 20mg/mL solution; among them, TPE-pyo fluorescent molecule and CNC chemical structure formula are as follows :

(2)取上述配制的0.5-4mL DMAP溶液与TPE-pyo溶液混合，边搅拌边逐滴滴入CNC悬浮液，室温下搅拌12h充分反应；(2) Take 0.5-4mL DMAP solution prepared above and mix it with TPE-pyo solution, add dropwise to the CNC suspension while stirring, and stir at room temperature for 12h to fully react;

(3)反应结束后将所得TPE-CNC产物进行过滤，并用大量CH₂Cl₂不断清洗，直至滤液无荧光，真空常温干燥48h，即得TPE-CNC荧光纳米粒子，其在固态及水分散体系中均发射强烈的黄色荧光，如图1b所示，薄层色谱分离(TLC)证明AIE分子与CNC纳米粒子之间为共价连接，如图1c所示，荧光纳米粒子水分散液的荧光强度与浓度呈线性关系，如图1d所示。(3) After the reaction, filter the obtained TPE-CNC product, and wash it continuously with a large amount of CH₂ Cl₂ until the filtrate has no fluorescence, and dry it under vacuum at room temperature for 48 hours to obtain TPE-CNC fluorescent nanoparticles. Both emit strong yellow fluorescence, as shown in Figure 1b. Thin layer chromatography (TLC) proves that AIE molecules and CNC nanoparticles are covalently linked, as shown in Figure 1c, the fluorescence intensity of the aqueous dispersion of fluorescent nanoparticles There is a linear relationship with the concentration, as shown in Fig. 1d.

图2显示了CNC纳米粒子接枝前后的粒径变化，TPE-CNC的直径较CNC增大3nm，与分子理论计算结果一致。Figure 2 shows the particle size change of CNC nanoparticles before and after grafting. The diameter of TPE-CNC is 3nm larger than that of CNC, which is consistent with the molecular theoretical calculation results.

实施例2制备仿生纳米复合水凝胶致动器Example 2 Preparation of biomimetic nanocomposite hydrogel actuator

将TPE-CNC荧光纳米粒子引入到复合水凝胶体系中，制备仿生纳米复合水凝胶致动器(TPE-CNC纳米复合水凝胶纤维)，包括：Introduce TPE-CNC fluorescent nanoparticles into the composite hydrogel system to prepare biomimetic nanocomposite hydrogel actuators (TPE-CNC nanocomposite hydrogel fibers), including:

取0.02-0.06g TPE-CNC分散到2mL H₂O中，超声3min，加入0.1-0.3g N-异丙基丙烯酰胺(NIPAM)，0.001-0.004g N，N′-亚甲基双丙烯酰胺(Bis)，10-40μL聚乙二醇单乙醚甲基丙烯酸酯(PEGMEMA)，2-6μL光引发剂DEAP，室温避光搅拌10-60min。将上述溶液灌入纤维模具中，紫外引发10-60min聚合，得到TPE-CNC纳米复合水凝胶纤维。其中，图3展示了在制备过程中，TPE-CNC处于不同微环境中荧光颜色和发光强度的变化，随着体系由水到粘度更高的水凝胶前驱体，再到聚合完成形成水凝胶，TPE-CNC的荧光颜色由黄色逐渐变为蓝色，发光强度不断增大。Disperse 0.02-0.06g TPE-CNC into 2mL H₂ O, sonicate for 3min, add 0.1-0.3g N-isopropylacrylamide (NIPAM), 0.001-0.004g N,N′-methylenebisacrylamide (Bis), 10-40 μL polyethylene glycol monoethyl ether methacrylate (PEGMEMA), 2-6 μL photoinitiator DEAP, stirred at room temperature for 10-60 min in the dark. The above solution is poured into a fiber mold, and ultraviolet light is used to initiate polymerization for 10-60 minutes to obtain a TPE-CNC nanocomposite hydrogel fiber. Among them, Figure 3 shows the change of fluorescent color and luminous intensity of TPE-CNC in different microenvironments during the preparation process. glue, the fluorescent color of TPE-CNC gradually changed from yellow to blue, and the luminous intensity continued to increase.

实施例3追踪荧光纳米粒子在水凝胶制备过程中的动态运动及静态分布过程：Example 3 Tracking the dynamic movement and static distribution process of fluorescent nanoparticles in the hydrogel preparation process:

通过荧光光谱检测仪对TPE-CNC水凝胶前驱体分散液进行连续扫描(图4)，激发波长设置为350-400nm，扫描范围为400-800nm，狭缝设为1nm。所用比色皿为750μL微量比色皿，光程为2mm，为了保证均匀，在测试前将样品充分混合，测试在室温下进行，且保证荧光光谱仪及样品不受干扰。测试时间≥400min，随时间的推移，样品的荧光强度先增强后减弱，是由于荧光纳米粒子TPE-CNC在水凝胶分散体系中先发生粒子间的聚集，后在重力作用下不断发生沉降，同时，由于布朗运动与重力的共同作用，会使粒子的沉降达到一个平衡态，荧光强度不再增加。最终，在重力方向上荧光强度逐渐增强，纳米粒子呈现梯度分布，即沿重力方向纳米粒子的浓度逐渐增加(图5)。The TPE-CNC hydrogel precursor dispersion is continuously scanned by a fluorescence spectrometer (Figure 4), the excitation wavelength is set to 350-400nm, the scanning range is 400-800nm, and the slit is set to 1nm. The cuvette used is a 750 μL micro cuvette with an optical path of 2 mm. In order to ensure uniformity, the sample was fully mixed before the test. The test was carried out at room temperature, and the fluorescence spectrometer and the sample were not disturbed. The test time is ≥400min. As time goes by, the fluorescence intensity of the sample increases first and then decreases. This is because the fluorescent nanoparticles TPE-CNC first aggregate among the particles in the hydrogel dispersion system, and then continue to settle under the action of gravity. At the same time, due to the joint action of Brownian motion and gravity, the sedimentation of particles will reach an equilibrium state, and the fluorescence intensity will no longer increase. Finally, the fluorescence intensity gradually increases in the gravitational direction, and the nanoparticles present a gradient distribution, that is, the concentration of the nanoparticles increases gradually along the gravitational direction (Fig. 5).

实施例4监控水凝胶的成型过程及观察水凝胶内部微观结构：Example 4 Monitoring the forming process of the hydrogel and observing the internal microstructure of the hydrogel:

通过荧光显微镜实时监控纳米复合水凝胶驱动器的成型过程(图6a)，荧光显微镜型号为Nikon Eclipse Ni-U，激发光源选用汞灯，360nm波长，透射模式。在载物台侧方安装365nm紫外光源，以用来激发水凝胶前驱体发生自由基聚合。利用CCD拍摄实时观察水凝胶聚合过程，拍摄时长≥30min，每次拍摄时关闭365nm紫外光源，打开360nm汞灯光源。随着聚合过程的进行，水凝胶与空气界面不断发生移动，形成不对称界面形状。通过激光共聚焦显微镜可视化水凝胶中荧光纳米粒子的分布(图6b)，激光共聚焦显微镜型号为Lecia TCSSP5II，405nm激发，单通道。测试前将水凝胶进行切片，沿纤维径向垂直切为直径≤100μm的薄片，浸泡于去离子水中，保持水凝胶溶胀状态，保证结构不发生破坏。测试时将样品平铺于激光共聚焦培养皿中，密封，观察到纤维截面上荧光纳米粒子呈现偏心轴梯度分布。将同一样品进行冷冻干燥处理，利用SEM观察水凝胶网络结构(图6c，d)，与纳米粒子分布相对应，纳米粒子的不对称分布形成了环月形网络结构。The forming process of the nanocomposite hydrogel driver was monitored in real time through a fluorescence microscope (Figure 6a). The model of the fluorescence microscope was Nikon Eclipse Ni-U, and the excitation light source was a mercury lamp with a wavelength of 360nm and transmission mode. A 365nm ultraviolet light source is installed on the side of the stage to stimulate the free radical polymerization of the hydrogel precursor. Use CCD to shoot and observe the polymerization process of hydrogel in real time, the shooting time is ≥30min, turn off the 365nm ultraviolet light source and turn on the 360nm mercury light source for each shooting. As the polymerization process progressed, the interface between the hydrogel and the air continued to move, forming an asymmetric interface shape. The distribution of fluorescent nanoparticles in the hydrogel was visualized by confocal laser microscopy (Fig. 6b), Lecia TCSSP5II, excitation at 405 nm, single channel. Before the test, the hydrogel was sliced, cut vertically along the radial direction of the fiber into thin slices with a diameter of ≤100 μm, soaked in deionized water, and kept the hydrogel in a swollen state to ensure that the structure was not damaged. During the test, the sample was flatly spread in the laser confocal culture dish and sealed, and it was observed that the fluorescent nanoparticles on the fiber section presented a gradient distribution of the eccentric axis. The same sample was freeze-dried, and the hydrogel network structure was observed by SEM (Fig. 6c, d). Corresponding to the distribution of nanoparticles, the asymmetric distribution of nanoparticles formed a ring-shaped network structure.

实施例5可视化水凝胶致动器热刺激响应致动过程：Example 5 Visualize the actuation process of hydrogel actuators in response to thermal stimuli:

通过自制荧光拍摄装置可视化监测水凝胶致动器热刺激响应致动过程(图7)，所述装置由IKA加热板HP 10连接接触式电子温度计ETS-D5，精确控制温度在60℃，加热板上方10cm处固定紫外灯，加热板上方20cm处垂直固定佳能EOS 80D拍摄系统。测试前将水凝胶致动器置于去离子水中充分溶胀48h，荧光拍摄在暗室中进行。开启紫外灯，开启相机，将样品迅速放入60℃恒温水中，观察并记录样品形状及荧光性质变化，水凝胶纤维向荧光强度强的一侧弯曲(图7b)。通过荧光光谱进一步监测水凝胶热刺激响应过程中内部微观网络结构的变化(图8)，荧光光谱配备温控系统，温度从20升温至50℃，每升高0.5℃扫描一次。观察到随着温度升高，在32℃(LCST)之前荧光强度降低，说明此时水凝胶内部分子链由亲水变得疏水，开始卷曲蜷缩，散射效应增强；43℃时荧光强度开始升高，在49℃时变化速率最快，说明此时凝胶发生了内部网络的坍塌，产生形变，即49℃为水凝胶的形变温度。Visually monitor the actuation process of the hydrogel actuator in response to thermal stimuli through a self-made fluorescent imaging device (Fig. 7). The ultraviolet lamp is fixed 10cm above the board, and the Canon EOS 80D shooting system is vertically fixed 20cm above the heating plate. The hydrogel actuator was fully swelled in deionized water for 48 h before the test, and the fluorescence photography was carried out in a dark room. Turn on the UV lamp, turn on the camera, quickly put the sample into 60°C constant temperature water, observe and record the change of sample shape and fluorescence properties, and the hydrogel fiber bends to the side with strong fluorescence intensity (Figure 7b). Fluorescence spectroscopy was used to further monitor the changes in the internal micro-network structure of the hydrogel in response to thermal stimulation (Figure 8). The fluorescence spectroscopy was equipped with a temperature control system, and the temperature was raised from 20 to 50°C, and the scan was performed every 0.5°C increase. It was observed that as the temperature increased, the fluorescence intensity decreased before 32°C (LCST), indicating that the internal molecular chains of the hydrogel changed from hydrophilic to hydrophobic, and began to curl up, and the scattering effect increased; at 43°C, the fluorescence intensity began to increase. High, the rate of change is the fastest at 49°C, indicating that the gel has collapsed in the internal network at this time, resulting in deformation, that is, 49°C is the deformation temperature of the hydrogel.

综上所述，本发明有望推动荧光技术在人工肌肉、智能致动及仿生纳米复合材料领域的应用。In summary, the present invention is expected to promote the application of fluorescence technology in the fields of artificial muscles, intelligent actuation and bionic nanocomposites.

Claims (9)

Translated fromChinese

1.一种具有AIE特性的荧光纳米粒子，其特征在于，其化学结构式如式I所示：1. A fluorescent nanoparticle with AIE characteristics, characterized in that its chemical structural formula is as shown in formula I:

所述的荧光纳米粒子发黄光，固态发射波长在518nm，液态分散体系发射波长在520-532nm。The fluorescent nanoparticles emit yellow light, the emission wavelength of the solid state is 518nm, and the emission wavelength of the liquid dispersion system is 520-532nm.2.权利要求1所述的具有AIE特性的荧光纳米粒子的制备方法，其特征在于，包括如下步骤：2. the preparation method of the fluorescent nanoparticle with AIE characteristic described in claim 1, is characterized in that, comprises the steps:步骤1：将纤维素纳米晶充分干燥，分散到二氯甲烷中，得到CNC分散；Step 1: Fully dry the cellulose nanocrystals and disperse them in dichloromethane to obtain CNC dispersion;步骤2：将如式II所示的TPE-pyo荧光分子和催化剂4-二甲氨基吡啶分别溶解到二氯甲烷中，得到相应的TPE-pyo溶液和催化剂溶液；Step 2: Dissolving the TPE-pyo fluorescent molecule shown in formula II and the catalyst 4-dimethylaminopyridine respectively in dichloromethane to obtain the corresponding TPE-pyo solution and catalyst solution;步骤3：将上述所得的TPE-pyo溶液加入到CNC分散液中，同时加入催化剂溶液，混合均匀，磁力搅拌使其反应；Step 3: Add the TPE-pyo solution obtained above into the CNC dispersion liquid, and add the catalyst solution at the same time, mix well, and stir magnetically to make it react;步骤4：反应结束后，将所得产物依次经过过滤、洗涤和干燥，得到具有AIE特性的荧光纳米粒子TPE-CNC，其化学结构如式I所示；Step 4: After the reaction is completed, the obtained product is filtered, washed and dried in sequence to obtain a fluorescent nanoparticle TPE-CNC with AIE characteristics, and its chemical structure is shown in formula I;

3.如权利要求2所述的具有AIE特性的荧光纳米粒子的制备方法，其特征在于，所述步骤1中的纤维素纳米晶的直径为20-30nm，长度200-300nm；所述CNC分散液的浓度为1～5wt％；所述步骤2中的TPE-pyo溶液和催化剂溶液的浓度分别为：0.5～2mg/mL、0.001-0.008M。3. the preparation method of the fluorescent nanoparticle with AIE characteristic as claimed in claim 2, is characterized in that, the diameter of the cellulose nanocrystal in described step 1 is 20-30nm, length 200-300nm; Described CNC disperses The concentration of the solution is 1-5wt%; the concentrations of the TPE-pyo solution and the catalyst solution in the step 2 are respectively: 0.5-2mg/mL and 0.001-0.008M.4.如权利要求2所述的具有AIE特性的荧光纳米粒子的制备方法，其特征在于，所示步骤中TPE-pyo溶液中的TPE-pyo和CNC溶液中的纤维素纳米晶的质量比为0.075-0.1：1。4. the preparation method of the fluorescent nanoparticle with AIE characteristic as claimed in claim 2 is characterized in that, the mass ratio of the cellulose nanocrystal in the TPE-pyo in the TPE-pyo solution and the CNC solution in the shown step is 0.075-0.1:1.5.权利要求1所述的具有AIE特性的荧光纳米粒子的应用，其特征在于，包括在制备仿生纳米复合水凝胶致动器中的应用，和/或在可视化监测仿生纳米复合水凝胶致动器的成型过程中的应用，和/或在可视化检测仿生纳米复合水凝胶致动器的内部结构中的应用，和/或在可视化监测仿生纳米复合水凝胶致动器的热刺激响应中的应用。5. the application of the fluorescent nanoparticle with AIE characteristic described in claim 1, is characterized in that, comprises the application in the preparation biomimetic nanocomposite hydrogel actuator, and/or in visual monitoring biomimetic nanocomposite hydrogel Application in the shaping process of the actuator, and/or in the visual inspection of the internal structure of the bioinspired nanocomposite hydrogel actuator, and/or in the visual monitoring of the thermal stimulation of the biomimetic nanocomposite hydrogel actuator App in response.6.如权利要求5所述的应用，其特征在于，包括在制备仿生纳米复合水凝胶致动器的过程中同时可视化监测其成型过程。6. The application according to claim 5, comprising visually monitoring the forming process of the biomimetic nanocomposite hydrogel actuator simultaneously during the process of preparing it.7.如权利要求6所述的应用，其特征在于，还包括可视化检测所述制备得到的仿生纳米复合水凝胶致动器的内部结构及热刺激响应行为。7. The application according to claim 6, further comprising visual inspection of the internal structure and thermal stimulus response behavior of the prepared biomimetic nanocomposite hydrogel actuator.8.一种仿生纳米复合水凝胶致动器，其特征在于，是由式I所示的荧光纳米粒子、N-异丙基丙烯酰胺、N,N’-亚甲基双丙烯酰胺和聚乙二醇单甲醚甲基丙烯酸酯通过光引发自由基聚合形成的复合水凝胶纤维，其发射波长在482nm；8. A biomimetic nanocomposite hydrogel actuator, characterized in that, is made of fluorescent nanoparticles shown in formula I, N-isopropylacrylamide, N, N'-methylene bisacrylamide and poly Ethylene glycol monomethyl ether methacrylate is a composite hydrogel fiber formed by photoinitiated free radical polymerization, and its emission wavelength is at 482nm;

9.如权利要求8所述的仿生纳米复合水凝胶致动器，其特征在于，所述复合水凝胶纤维的成型过程或热刺激响应行为通过荧光检测仪器或工具进行可视化监测；所述复合水凝胶纤维的内部结构通过荧光检测仪器或工具进行可视化表征。9. The biomimetic nanocomposite hydrogel actuator according to claim 8, wherein the forming process or thermal stimulus response behavior of the composite hydrogel fiber is visually monitored by a fluorescence detection instrument or tool; The internal structure of composite hydrogel fibers is visualized and characterized by fluorescence detection instruments or tools.

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