本文選題：超分子自組裝 + 螺旋結(jié)構(gòu)�。� 參考：《中國(guó)科學(xué)技術(shù)大學(xué)》2017年博士論文

【摘要】：自組裝聚電解質(zhì)是由小分子組裝單元通過(guò)弱相互作用力(非共價(jià)鍵作用力)形成的超分子聚合物,并且在溶液中可以電離為表面帶電的聚離子和帶相反電荷的反離子。自組裝螺旋聚電解質(zhì),即具有螺旋結(jié)構(gòu)的自組裝聚電解質(zhì)。它既保留了自組裝體系的超分子特性又帶來(lái)了表面電荷非均勻分布以及繞軸向旋轉(zhuǎn)等螺旋結(jié)構(gòu)的特點(diǎn),提供了研究水溶液中聚電解質(zhì)相互作用以及聚集行為的獨(dú)特的模型體系。同時(shí)由于其與生物大分子比如普遍研究的DNA具有相類(lèi)似的結(jié)構(gòu)特性等因素受到科學(xué)工作者的廣泛關(guān)注。眾多關(guān)于螺旋聚電解質(zhì)的研究工作僅僅關(guān)注小分子單元形成單個(gè)超分子結(jié)構(gòu)的行為,即自組裝的初級(jí)結(jié)構(gòu)。然而如何讓自組裝初級(jí)螺旋聚電解質(zhì)形成更高級(jí)的周期結(jié)構(gòu)的機(jī)制以及影響因素等相關(guān)方面的研究仍處于起步階段�；谝陨媳尘�,本論文工作以自主合成的C3對(duì)稱(chēng)三羧酰胺分子在水溶液中形成的自組裝螺旋帶電納米管作為研究對(duì)象系統(tǒng)的研究了其在稀溶液中的介觀相行為;更高級(jí)四方周期結(jié)構(gòu)的形成機(jī)制以及結(jié)晶過(guò)程;同時(shí)研究了自組裝帶電螺旋納米管形成的四方結(jié)構(gòu)對(duì)反離子的種類(lèi)、大小等性質(zhì)的響應(yīng)。主要研究?jī)?nèi)容及結(jié)果如下:1.研究了稀溶液中超分子自組裝螺旋納米管的介觀相行為,以及相行為對(duì)陳化時(shí)間和外加離子的響應(yīng)。超分子螺旋納米管在水溶液中首先形成短程位置有序、角向無(wú)序的中間態(tài)六角液體相。通過(guò)增加陳化時(shí)間或者引入NaCl鹽,中間態(tài)的六角結(jié)構(gòu)會(huì)轉(zhuǎn)化為穩(wěn)定的位置高度位置有序的四方相。中間態(tài)對(duì)初態(tài)溶液的狀態(tài)比如溶液的濃度、反離子的種類(lèi)非常敏感。從六角結(jié)構(gòu)到四方相的轉(zhuǎn)變是由于角向關(guān)聯(lián)以及帶電螺旋納米管沿著軸向的相對(duì)旋轉(zhuǎn)造成的。角向關(guān)聯(lián)來(lái)源于帶電螺旋結(jié)構(gòu)間靜電相互作用的角向作用部分。穩(wěn)定態(tài)的四方結(jié)構(gòu)并不會(huì)隨著離子濃度,反離子的種類(lèi)等發(fā)生顯著變化。與生物大分子以及膠體結(jié)晶相比,在我們體系中觀察到的緩慢的結(jié)晶過(guò)程以及穩(wěn)定的終態(tài)為溶液中制備結(jié)晶材料提供了新的思路。不僅有助于深入理解聚電解的相行為而且對(duì)溶液中軟物質(zhì)的組裝過(guò)程有廣泛的指導(dǎo)意義。2.系統(tǒng)地研究螺旋帶電超分子納米管形成長(zhǎng)程有序結(jié)構(gòu)的機(jī)制以及結(jié)晶過(guò)程。棒狀的超分子帶電納米管如何由均勻的納米管溶液組裝形成穩(wěn)定的四方聚集體。研究了溶液的濃度對(duì)超分子帶電螺旋納米管的結(jié)晶過(guò)程的影響。反離子在帶電螺旋納米管結(jié)晶過(guò)程中所發(fā)揮的作用,以及超分子帶電螺旋納米管如何通過(guò)調(diào)控角向的旋轉(zhuǎn)來(lái)實(shí)現(xiàn)調(diào)控角向關(guān)聯(lián)。溶液中的超分子納米管經(jīng)歷短程位置有序、二維長(zhǎng)程位置有序及角向有序調(diào)整的結(jié)晶過(guò)程最終獲得三維長(zhǎng)程位置有序多級(jí)結(jié)構(gòu),在溶液中形成獨(dú)特穩(wěn)定的四方相。結(jié)果對(duì)理解溶液中的結(jié)晶過(guò)程以及液晶相行為的調(diào)控具有重要的借鑒意義。3.對(duì)比研究?jī)煞N不同的反離子對(duì)穩(wěn)定的四方晶格的影響。出乎意料的,在共離子相同的條件下體積較小的、親水的、與帶電螺旋納米管表面的羧酸基團(tuán)有較強(qiáng)親和力的堿金屬陽(yáng)離子會(huì)導(dǎo)致帶電螺旋納米管形成的四方晶格發(fā)生各向異性的膨脹,并且膨脹的程度與反離子與羧酸基團(tuán)的親和程度呈正相關(guān)。在此情形下,共離子會(huì)不同程度的影響四方晶格內(nèi)部的有序程度。然而當(dāng)用體積較大的、疏水的、與帶電螺旋納米管表面的羧酸基團(tuán)親和力較差的季銨陽(yáng)離子替換單價(jià)的堿金屬陽(yáng)離子時(shí)四方晶格發(fā)生各向同性的收縮并且無(wú)共離子效應(yīng)。以上結(jié)果說(shuō)明在高度帶電的,緊密排列的聚電解質(zhì)體系中存在非常明顯的離子關(guān)聯(lián),獨(dú)特的離子效應(yīng)不僅對(duì)于強(qiáng)靜電作用下的離子特異性有借鑒意義而且可以用來(lái)指導(dǎo)通過(guò)離子調(diào)控聚電解結(jié)構(gòu)的相關(guān)生命科學(xué)過(guò)程。
[Abstract]:Self assembled polyelectrolyte is a supramolecular polymer formed by a small molecule assembly unit through a weak interaction force (non covalent bond force) and can be ionized into a surface charged polyion and reverse charge in the solution. Self assembled spiral polyelectrolytes, that is, a self assembled polyelectrolyte with a spiral structure, are retained. The supramolecular characteristics of the self-assembly system also bring about the characteristics of the nonuniform distribution of surface charge and the spiral structure around the axis, which provide a unique model system to study the interaction and aggregation of polyelectrolyte in aqueous solution. At the same time, it has a similar structure to the biological macromolecule, which is similar to the commonly studied DNA. A large number of research work on helix polyelectrolytes is concerned only with the behavior of small molecular units to form a single supramolecular structure, that is, the primary structure of self-assembly. However, how to make self assembled primary helix polyelectrolytes form a more advanced periodic structure and influence factors, etc. The research is still in the initial stage. Based on the above background, the self assembled spiral charged nanotube formed by the self synthesized C3 symmetric three carboxamide molecule in the aqueous solution is used as the research object to study the mesoscopic phase behavior in the dilute solution, the formation mechanism of the higher tetragonal periodic structure and the crystallization. The main research contents and results are as follows: 1. the mesoscopic phase behavior of supermolecule self assembled spiral nanotube in dilute solution, and the response of phase behavior to the aging time and the added ion are investigated. The nanotube is first formed in a water solution with a short range position and a disordered six angle liquid phase in the middle state. By increasing the aging time or introducing NaCl salt, the six angle structure of the intermediate state will be transformed into a stable and highly ordered Quartet phase. The state of the intermediate state to the state of the initial state solution, such as the concentration of the solution, is not the type of the counter ion. The change from the six angle structure to the Quartet phase is caused by the angular correlation and the relative rotation of the charged spiral nanotube along the axial direction. The angular correlation comes from the angular action part of the electrostatic interaction between the charged helical structures. The Quartet structure of the stable state does not occur with the concentration of the separated ions and the types of the reverse ions. Compared with the biological macromolecules and colloidal crystals, the slow crystallization process observed in our system and the stable end state provide a new idea for the preparation of crystalline materials in the solution. It not only helps to understand the phase behavior of the electrolysis but also has a broad guiding significance for the.2. system in the process of the assembly of soft substances in the solution. The mechanism of the long-range ordered structure of the spiral charged supermolecular nanotube and the crystallization process are studied. How can the rod like supermolecule nanotube be assembled by the uniform nanotube solution to form a stable Quartet aggregate. The effect of the concentration of the solution on the crystallization of the supermolecule charged spiral nanotubes is studied. The role of the spiral nanotube in the crystallization process and how the supermolecule charged spiral nanotube can regulate angular correlation by regulating the rotation of the angular direction. The supermolecular nanotube in the solution has a short range position order, the two-dimensional long range position order and the angular ordering process finally obtain the three-dimensional long range position order. The formation of a unique stable tetragonal phase in the solution is an important reference for understanding the crystallization process in the solution and the regulation of the behavior of liquid crystal phase..3. contrasts and studies the effects of two different anti ions on the stable tetragonal lattice. The alkali metal cation with strong affinity on the surface of the charged spiral nanotube leads to anisotropic expansion of the tetragonal lattice formed by the charged spiral nanotube, and the degree of expansion is positively correlated with the affinity between the anti ion and the carboxylic acid group. In this case, the Co ions will affect the tetragonal lattice in varying degrees. An isotropic contraction and no Co ion effect occurs when a larger, hydrophobic, quaternary ammonium cation is replaced by a quaternary ammonium cation with poor affinity to the carboxylic acid group on the surface of a charged spiral nanotube. The above results show that the highly charged, closely arranged polyelectrolysis is shown. There is a very obvious ion correlation in the mass system. The unique ion effect is not only useful for the ion specificity under the strong electrostatic action, but also can be used to guide the related life science process of the electrolysis structure through ion regulation.

【學(xué)位授予單位】：中國(guó)科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：O631

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 Min-fang An;You Lv;Hao-jun Xu;Qun-Gu;王宗寶;;Structure and Properties of Gel-spun Ultra-high Molecular Weight Polyethylene Fibers with High Gel Solution Concentration[J];Chinese Journal of Polymer Science;2017年04期

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本文編號(hào)：1846180