分會

第三十五分會：膠體與界面化學(xué)

摘要

采用實驗和分子動力學(xué)(MD)模擬相結(jié)合的方法研究了脫氧膽酸鈉(NaDC)和反式-鄰甲氧基肉桂酸鈉(trans-NaOMCA)復(fù)配系統(tǒng)在水中的多刺激響應(yīng)行為?？疾炝硕喾N外部刺激對NaDC/trans-NaOMCA復(fù)配系統(tǒng)的相行為、流變性質(zhì)和微觀結(jié)構(gòu)的影響，測定了施加各種刺激前后復(fù)配系統(tǒng)的FT-IR和1H-NMR譜圖，并從分子水平上對其多刺激響應(yīng)機(jī)理進(jìn)行了探討。實驗結(jié)果表明，該復(fù)配系統(tǒng)表現(xiàn)出良好的pH和CO2/N2循環(huán)響應(yīng)性，293.15 K時在7.43-7.05的較窄pH范圍內(nèi)實現(xiàn)了溶液狀態(tài)和凝膠狀態(tài)的可逆轉(zhuǎn)換，剪切粘度變化了5個數(shù)量級。此外，將293.15 K下pH = 7.05的凝膠樣品升溫到305.65 K或紫外光照40 min，剪切粘度可下降3個數(shù)量級，實現(xiàn)了凝膠向溶膠的轉(zhuǎn)變。MD模擬結(jié)果表明，橋聯(lián)氫鍵、疏水作用和靜電相互作用在各種刺激誘導(dǎo)的自組裝過程中起著關(guān)鍵作用。由于多刺激響應(yīng)型膠束系統(tǒng)可以通過多元化的參數(shù)實現(xiàn)更豐富的調(diào)控，因此對復(fù)雜的外部環(huán)境具有更好的適應(yīng)性，有助于拓展其應(yīng)用范圍。 The multi-stimuli responsive behaviors of sodium deoxycholate (NaDC) and sodium trans-ortho-methoxycinnamate (trans-NaOMCA) mixed systems in water have been investigated by combining experiments and molecular dynamics (MD) simulations. The effects of various external stimuli on the phase behaviors, rheological properties and microstructures of the NaDC/ trans-NaOMCA mixed systems have been explored. The FT-IR and 1H-NMR spectra of the mixed systems before and after applying various stimulus were measured, and the multi-stimuli responsive mechanism was discussed at the molecular level. The experimental results illustrate that the mixed systems show excellent recycled pH and CO2/N2 response, and the reversible switching between solution state and gel state with 5 orders of magnitude variation in shear viscosity has been achieved within a narrow pH range of 7.43-7.05 at 293.15K. Furthermore, when the gel sample with pH = 7.05 and T = 293.15 K was heated to 305.65 K or UV-irradiated for 40 min, the gel-to-sol transition with 3 orders of magnitude reduction in shear viscosity could be achieved. MD simulation results reveal that the bridging hydrogen bonds, hydrophobic interaction and electrostatic interactions play important roles in the various stimuli-induced self-assembly morphology transitions. Since multi-stimuli responsive micellar systems can be regulated through multiple parameters, resulting in their better adaptability to complex external environments, which is helpful to expand the scope of their application.

關(guān)鍵詞

多刺激響應(yīng);脫氧膽酸鈉;反式-鄰甲氧基肉桂酸鈉;自組裝;分子動力學(xué)模擬

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