| 摘要: | 功能材料的進步取決於引入新的合成單元和方法，以賦予其多樣化的特性。多種基於硫的化學因其易於實施、高產率和轉化率、反應速率快等特性，在彈性體合成、金屬離子去除和表面修飾中得到廣泛應用。在這項研究中，我們設計了一種含有芳香族雙硫鍵的丙烯酸酯交聯劑，命名為Bis[4-(acrylyl-2-methyl-isocyanato-isophorone)phenyl] disulfide (AIS）。芳香族雙硫鍵交聯劑AIS被用於與丙烯酸丁酯 (Butyl acrylate, BA)單體和丙烯酸羥乙酯 (Hydroxyethyl acrylate, HEA)單體進行自由基光聚合，形成芳香族雙硫鍵交聯的AIS-BA彈性體和AIS-HEA水凝膠，而使用商業用交聯劑聚乙二醇二甲基丙烯酸酯 (Polyethylene glycol dimethacrylate, PEGDMA)所合成的彈性體則作為對照樣品 (即PEGDMA-BA和PEGDMA-HEA)。芳香族雙硫鍵的低解離能使雙硫鍵更容易發生斷裂以生成硫醇，從而進行各種基於硫的化學反應，如硫醇-烯聚合反應、硫醇-邁克爾加成反應和硫-金屬鍵的形成等。透過施加外部力，如壓縮或切割等方式，能誘導結構中相對較弱的芳香族雙硫鍵斷裂，從而生成硫醇基團。第一個功能是基於自由基介導的硫醇-烯聚合反應。可以在彈性體表面塗覆由2-三甲基氨基乙基甲基丙烯酸鹽(2-Trimethylammonioethyl methacrylate chloride, TMAEMA)和磺基甜菜鹼丙烯醯胺 (Sulfobetaine acrylamide, SBAA)組成的單層聚合物。第二個功能基於硫醇-邁克爾加成反應。藉由鹼性催化劑促使SBAA單體對彈性體表面進行改質。此外，也根據機械化學中透過施加外在機械力使水凝膠中的雙硫鍵發生裂解以生成硫醇自由基或遊離硫醇並與螢光分子螢光素-5-馬來酰亞胺進行加成反應。通過X射線光電子能譜 (X-ray Photoelectron Spectroscopy, XPS）和衰減全反射傅立葉變換紅外光譜 (Attenuated Total Reflectance-Fourier-Transform Infrared Sepectroscopy, ATR-FTIR)對表面元素組成進行了表徵分析，通過水接觸角測量評估了修飾表面的濕潤性，通過細菌和蛋白黏附測試評估了修飾彈性體表面的抗沾黏和抗菌性能，使用光學顯微鏡拍攝螢光照片並量化螢光強度。對於第三和第四個功能，我們利用硫基團與金屬之間的相互作用，與金和銀形成Au-S和Ag-S化學吸附。AIS-BA及AIS-HEA分別被用作金基板的黏著劑和抗菌水凝膠。通過剪切測試評估了黏合強度和可重複使用性，並利用XPS和飛行時間二次離子質譜 (Time-of-Flight Secondary Ion Mass Spectrometer, ToF-SIMS)確認了金屬-硫鍵的存在。通過掃描電子顯微鏡（Scanning Electron Microscope, SEM）和能量色散X射線光譜（Energy-dispersive X-ray spectroscopy, EDX）分析了彈性體與基板之間的黏附形貌和化學組成。藉由抑菌圈和液體培養基抑菌測試評估了水凝膠的抗菌效果。雙硫鍵和硫醇在結構中展現了獨特的性質和反應性，使得含硫化學成為一個重要的研究領域，在各種應用中展現出巨大的潛力。;Advancement of functional materials relies on new synthetic building blocks and methods that endow various functionalities. Versatile sulfur-based chemistries have garnered widespread application in elastomer synthesis, metal-ion removal, and surface modification due to their ease of implementation, high yield and conversion, rapid reaction rates. In this study, we designed an acrylic cross-linker containing an aromatic disulfide bond, Bis[4-(acryloyl-2-methyl-isocyanato-isophorone)phenyl] disulfide (AIS). The aromatic disulfide cross-linker, AIS, was employed for radical photopolymerization with butyl acrylate (BA) and hydroxyethyl acrylate (HEA) monomer to form the aromatic disulfide-crosslinked AIS-BA elastomer and AIS-HEA hydrogel, and polyethylene glycol dimethacrylate (PEGDMA) commercial cross-linker as a control sample (i.e. PEGDMA-BA and PEGDMA-HEA). The low dissociation energy of aromatic disulfide bond facilitates thiol generation upon cleavage, enabling various sulfur-based reactions such as thiol-ene polymerization, thiol-Michael addition, and sulfur-metal bond formation. External forces such as compression or cutting were applied to induce the cleavage of relatively weak aromatic disulfide bonds, leading to thiol group generation. The first function base on radical-mediated thiol-ene polymerization. A monolayer of polymer of 2-Trimethylammonioethyl methacrylate chloride (TMAEMA) and sulfobetaine acrylamide (SBAA) can be coated on the surface of the elastomer. The second function base on thiol-ene Michael addition. The surface of the elastomer can be modified with a monolayer of sulfobetaine acrylamide (SBAA) monomer based on a alkaline catalyst and mechanical force mediates the cleavage of disulfide bonds in the hydrogel via mechanochemistry, facilitating addition reactions with thiol radicals or free thiols in the presence of the fluorescent molecule Fluorescein-5-Maleimide. The surface elemental composition was characterized by X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), the wetting properties of the modified surface were evaluated through water contact angle measurements, the antifouling and antibacterial properties of the modified elastomers surface were evaluated through bacterial and protein adhesion tests, the fluorescence images were acquired using an optical microscope and the fluorescence intensity was quantified. For the third and fourth functions, we have exploit the interaction between sulfur groups and metals to chemically adsorb onto gold and silver through the formation of Au-S and Ag-S. AIS-BA and AIS-HEA was employed as an adhesive for gold substrates and an antibacterial hydrogel, respectively. The adhesive strength and reusability were evaluated through lap shear test, while the presence of metal-sulfur bond was confirmed using XPS and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). The adhesion morphology and chemical composition between the elastomer and substrate were analyzed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The antibacterial effect of hydrogels was evaluated through zone of inhibition and liquid culture tests. Disulfide bonds and thiols exhibit unique properties and reactivity within structures, establishing sulfur chemistry as a critical field of research, with substantial potential across various applications. |
