【作者】 林倩；

【导师】 沈慧芳；

【作者基本信息】 华南理工大学 ， 化学工程与技术， 2022， 硕士

【摘要】 光子晶体水凝胶是将光子晶体与水凝胶相结合,通过外界刺激使水凝胶溶胀或收缩,引起光子带隙的改变,并导致结构色的变化,从而将物理或化学信号转变为光学信号,在传感、检测等领域具有广阔的应用前景。目前光子晶体水凝胶主要采用模板法制备。其中大面积光子晶体模板通常由垂直沉积法制得,过程耗时长且制备的光子晶体膜易产生裂纹。另外,基于聚（N-异丙基丙烯酰胺）（PNIPAm）的光子晶体水凝胶由于自身传输速率慢且易发生塌陷形成致密的表皮层,导致其响应速率慢,限制了它在实时检测领域的应用。基于以上问题,本文对制备无裂纹、高色彩对比度的光子晶体膜以及具有快速响应速率的光子晶体水凝胶等方面进行探索研究。（1）采用无皂乳液聚合法合成了粒径可控、单分散性良好的交联聚苯乙烯（PS）纳米微球,随后通过添加氧化石墨烯（GO）,将其与PS微球通过热辅助共组装制备成PS@GO光子晶体膜。对其微观形貌、反射光谱和光学照片进行了表征,结果表明当GO用量为PS用量的0.3 wt%,自组装温度为60°C时,所制备的光子晶体膜无裂纹且具有较高的色彩对比度。（2）以N-异丙基丙烯酰胺（NIPAm）为单体,N,N-亚甲基双丙烯酰胺（BIS）为交联剂,醋酸/水（HAc/H₂O）为混合溶剂制备水凝胶预聚液,将其填充到PS@GO光子晶体膜的缝隙中,随后紫外光引发聚合得到PS@GO-PNIPAm光子晶体水凝胶。通过微观形貌、反射光谱、退溶胀动力学以及光学照片等表征,得出当BIS用量占单体用量的1 wt%,HAc/H₂O比例为1:1时,光子晶体水凝胶具有较宽的响应范围和较快的响应速率。当温度由25°C上升至40°C,光子晶体水凝胶的结构色在120 s内由橙红色变为绿色,反之则由绿色变为橙红色。光子晶体水凝胶对C1-C4醇同样表现出快速的响应性,当醇溶液浓度由40 wt%增加至100 wt%时,在120 s内就能发生显著的颜色变化。（3）利用光子晶体水凝胶在低温下（15°C）溶胀将莫西沙星（Mox）负载到凝胶网络中制备载药光子晶体水凝胶,并对其微观形貌和红外光谱等进行了表征,随后通过升高温度使凝胶收缩从而进行药物释放。通过紫外吸光度和反射光谱表征其载药和释药过程,结果表明当Mox浓度为30 mg/m L时载药量可达到62%,且载药量与最大反射光波长成正比;当温度分别为30°C,37°C和40°C时,最大释药量分别为70%,95%和89%,且均与其对应的最大反射光波长成反比。最后对释药过程进行动力学拟合,发现其释药过程均可以用Korsmeyer-Peppas模型和Gompertz模型进行描述。更多还原

【Abstract】 Photonic crystal hydrogel is the combination of photonic crystal and hydrogel,the hydrogel is swelled or contracted by external stimuli,resulting in the change of photonic bandgap and structure color,thus transforming physical or chemical signals into optical signals,making it have broad application prospects in sensing,detection and other fields.At present,photonic crystal hydrogels are mainly fabricated by template method.Therein,large-area photonic crystal templates are usually prepared by vertical deposition,which is time-consuming and the prepared photonic crystal films are prone to crack.Moreover,the photonic crystal hydrogels based on poly N-isopropylacrylamide（PNIPAm）have slow transmission rates and are prone to collapse and form dense layers,resulting in a slow response rate,which limits their application in the field of real-time detection.Based on the above issues,this work explores the fabrication of crack-free,high color contrast photonic crystal films and photonic crystal hydrogels with fast response rate.（1）A soap-free emulsion polymerization method was used to synthesize cross-linked polystyrene（PS）nanoparticles with controllable sizes and good monodispersity,then the graphene oxide（GO）was introduced to construct PS@GO photonic crystal films by a thermal-assisted co-assembly method.The characterizations of microstructures,reflection spectra and optical images demonstrate that when the amount of GO is 0.3 wt%of the amount of PS and the self-assembly temperature is 60°C,the prepared photonic crystal films are crack-free and have enchanced color contrast.（2）Using N-isopropylacrylamide（NIPAm）as monomer,N,N-methylene bisacrylamide（BIS）as crosslinking agent,and acetic acid/water（HAc/H₂O）as mixed solvent,the PS@GO-PNIPAm photonic crystal hydrogels were fabricated by filling pregel into the gaps of PS@GO photonic crystal films and then initiating polymerization by ultraviolet（UV）light.The characterization of microstructures,reflection spectra,deswelling kinetics and optical images,indiate that when the amount of BIS is 1%of the amount of monomer and the ratio of HAc/H₂O is 1:1,the photonic crystal hydrogels have wide response ranges and fast response rates.When the temperature increases from 25°C to 40°C,the structure colors of the photonic crystal hydrogels change from orange to green within 120 s,and otherwise,change from green to orange.Photonic crystal hydrogels also show rapid response to C1-C4 alcohol solutions,when the concentration of alcohol solutions increase from 40 wt%to 100 wt%,significant color changes occur within 120 s.（3）The drug-loaded photonic crystal hydrogels were fabricated relying on the swelling of hydrogels at low temperature（15°C）to load Moxifloxacin（Mox）into the network,and their microscopic morphology and infrared spectrum were characterized.Subsequently,the Mox was released by shrinking the hydrogel via increasing the temperature.The drug loading and release process were characterized by UV absorbance and reflection spectra.The results exhibit that the drug loading ratio reach 62%when the concentration of Mox is 30 mg/m L,and the drug loading ratio is proportional to the reflaction peak value.When the temperature is 30°C,37°C and 40°C,the maximum drug release ratio is 70%,95%and 89%,respectively,and all of them are inversely proportional to the corresponding reflaction peak value.Finally,the kinetic model fitting of drug release process are carried out,and it is found that the drug release process could be described by both Korsmeyer-Peppas model and Gompertz model.更多还原