發(fā)布時(shí)間：2018-05-11 22:02

  本文選題：水溶液 + 玻璃化轉(zhuǎn)變�。� 參考：《北京科技大學(xué)》2017年博士論文

【摘要】：水是地球上最常見(jiàn)之物,也被視為生命之源。盡管水分子結(jié)構(gòu)簡(jiǎn)單,但這并不意味著水簡(jiǎn)單或容易理解。相反,由于液態(tài)水中存在皮秒量級(jí)內(nèi)打開(kāi)和形成的氫鍵,幾乎水所有的性質(zhì)都異于尋常液體,因此水也被譽(yù)為最復(fù)雜的液體。水參與各種物理、化學(xué)和生命過(guò)程,對(duì)水的研究是理解自然種種奧秘的關(guān)鍵。然而,到目前為止我們對(duì)水所知甚少。直接對(duì)純水展開(kāi)研究十分困難,但水溶液的研究則相對(duì)簡(jiǎn)單。盡管溶質(zhì)的引入會(huì)使得水變得更加復(fù)雜,但水溶液的多種性質(zhì)都與溶質(zhì)類(lèi)型和濃度密切相關(guān),低溫水溶液的熱力學(xué)和動(dòng)力學(xué)性質(zhì)往往蘊(yùn)含豐富的物理圖像。水溶液的晶化和玻璃化是水科學(xué)領(lǐng)域的研究熱點(diǎn)及難點(diǎn)之一。本文通過(guò)差示掃描量熱儀、寬頻介電譜以及拉曼光譜等實(shí)驗(yàn)手段研究多種常見(jiàn)電解質(zhì)、有機(jī)物二元水溶液、電解質(zhì)和有機(jī)物的三元混合水溶液以及受限水溶液的液-固轉(zhuǎn)變和玻璃化轉(zhuǎn)變行為,本論文的主要研究?jī)?nèi)容如下:(1)通過(guò)系統(tǒng)的對(duì)多種水溶液玻璃化轉(zhuǎn)變行為的測(cè)量,發(fā)現(xiàn)水溶液的玻璃化轉(zhuǎn)變溫度(T_g)對(duì)水的質(zhì)量分?jǐn)?shù)濃度(X_(aqu))有普適的依賴(lài)關(guān)系,并依據(jù)此關(guān)系把水溶液分為三個(gè)濃度區(qū)域。當(dāng)X_(aqu) X_(aqu)~(cr)時(shí)(1區(qū)),水溶液的T_g是一個(gè)與濃度無(wú)關(guān)的常數(shù)T_g~',發(fā)生玻璃化轉(zhuǎn)變的成分為冰析出后濃度為X_(aqu)~'的濃縮相水溶液;當(dāng)X_(aqu)X_(aqu)~(cr)時(shí),水溶液完全玻璃化,其T_g隨X_(aqu)增加單調(diào)遞減(Ⅱ區(qū):X_(aqu)~(cr)X_(aqu)X_(aqu)~', Ⅲ區(qū):X_(aqu)X_(aqu)~')。根據(jù)三個(gè)濃度區(qū)域內(nèi)水溶液的液-固轉(zhuǎn)變和玻璃化轉(zhuǎn)變行為,我們將濃度為X_(aqu)~'和X_(aqu)~(cr)的水溶液中水與溶質(zhì)的摩爾比nh和化ncr分別定義為溶質(zhì)的結(jié)合水?dāng)?shù)和最大(臨界)結(jié)合水?dāng)?shù)。確定了溶質(zhì)的結(jié)合水?dāng)?shù),同時(shí)也就確定了水溶液中自由水的含量。我們發(fā)現(xiàn)自由水的質(zhì)量分?jǐn)?shù)(x_f)可以普適的描述電解質(zhì)和小分子有機(jī)物水溶液的均質(zhì)形核溫度(T_H)、冰的熔化溫度(T_m)以及相應(yīng)水溶液的活度(a_w)。此外,X_f與T_H、T_m和a_w的關(guān)系對(duì)壓力條件下的純水和水溶液依然有效。(2)水的液-液相變是水科學(xué)領(lǐng)域內(nèi)的一個(gè)充滿(mǎn)爭(zhēng)議的熱門(mén)話(huà)題。最近,有課題組基于一些特定濃度的水溶液經(jīng)過(guò)退火處理后T_g的變化斷言水溶液中確實(shí)存在水的液-液相變。我們發(fā)現(xiàn)他們提出的特定濃度的水溶液均處于區(qū)濃度范圍內(nèi)。經(jīng)過(guò)對(duì)Ⅱ區(qū)濃度范圍內(nèi)水溶液的細(xì)致研究發(fā)現(xiàn),樣品退火前后T_g的變化是由于水溶液經(jīng)過(guò)再結(jié)晶后濃度變化引起的,而不是由于水溶液中的高密度水變?yōu)榈兔芏人匆?液相變?cè)斐傻摹?3)含有可晶化結(jié)合水的水溶液的玻璃化轉(zhuǎn)變和再結(jié)晶現(xiàn)象通常糾纏在一起,這不僅給實(shí)際應(yīng)用帶來(lái)困難還經(jīng)常造成相關(guān)實(shí)驗(yàn)解釋上的誤解。我們根據(jù)水溶液玻璃化轉(zhuǎn)變溫度與濃度的關(guān)系提出了一個(gè)確定可晶化結(jié)合水含量的方法,并對(duì)可能發(fā)生再結(jié)晶現(xiàn)象的水溶液的濃度給出了一個(gè)明確的界定。我們還發(fā)現(xiàn)可晶化結(jié)合水的性質(zhì)與其含量相關(guān),根據(jù)可晶化結(jié)合水的含量需要設(shè)計(jì)不同實(shí)驗(yàn)方案才能使其完全析出晶化。(4)通過(guò)對(duì)多種二元水溶液和三元混合水溶液體系的結(jié)合水?dāng)?shù)(n_h)和臨界結(jié)合水?dāng)?shù)(n_(cr))的測(cè)量,我們發(fā)現(xiàn)電解質(zhì)水溶液中的n_(cr)/n_h～1.7,有機(jī)物水溶液中的n_(cr)/n_h依賴(lài)于溶質(zhì)類(lèi)型且明顯大于電解質(zhì)水溶液,除氯化鋅以外的氯化物和甘油三元混合水溶液的n_(cr)~(mix)/n_h~(mix)均處于電解質(zhì)水溶液與甘油水溶液之間。通過(guò)測(cè)量溶質(zhì)結(jié)合水?dāng)?shù)隨水溶液濃度的變化,揭示了甘油、氯化鋅和水三者間的多體相互作用,發(fā)現(xiàn)甘油與氯化鋅之間的相互作用同時(shí)依賴(lài)于甘油和水的含量。并依此提出一種探討混合溶質(zhì)水溶液中多體相互作用的方法。(5)體相氯化鈉水溶液玻璃形成能力弱,只有在高壓環(huán)境下才能玻璃化。通過(guò)測(cè)量受限于不同孔徑納米孔內(nèi)氯化鈉水溶液的玻璃化轉(zhuǎn)變行為,討論受限尺寸和受限載體內(nèi)表面的浸潤(rùn)性對(duì)氯化鈉水溶液玻璃形成能力的影響,發(fā)現(xiàn)受限尺寸效應(yīng)是導(dǎo)致氯化鈉水溶液玻璃化的主要原因,并提出了一個(gè)模型來(lái)解釋受限氯化鈉水溶液的玻璃化轉(zhuǎn)變行為對(duì)臨界濃度的依賴(lài)性。
[Abstract]:Water is the most common thing on earth and is also considered as the source of life. Although the structure of water is simple, it does not mean that water is simple or easy to understand. On the contrary, almost all the properties of water are different from ordinary liquids because of the hydrogen bonds that are opened and formed in the picosecond order of magnitude in liquid water, so water is also known as the most complex liquid. Water is involved in each water. The study of water is the key to understanding the mysteries of nature. However, we know little about water so far. It is difficult to study pure water directly, but the study of water solution is relatively simple. Although the introduction of the solute will make the water more complex, the various properties of the aqueous solution are all with the solute. Types and concentrations are closely related. The thermodynamic and kinetic properties of low temperature aqueous solutions often contain rich physical images. Crystallization and vitrification of aqueous solutions are one of the hotspots and difficulties in the field of water science. In this paper, a variety of common electrolytes are studied by means of differential scanning calorimeter, broadband dielectric spectroscopy and Raman spectroscopy. In this paper, the main contents of this paper are as follows: (1) the glass transition temperature (T_g) of aqueous solution (T_g) has been found by measuring the glass transition behavior of a variety of aqueous solutions by measuring the glass transition behavior of various aqueous solutions. The concentration (X_ (aqu)) has a universal dependence, and the water solution is divided into three concentration regions according to this relationship. When X_ (aqu) X_ (aqu) ~ (CR) is (1), the T_g of the aqueous solution is a constant T_g~'unrelated to the concentration, and the composition of the glass transition is a concentrated phase aqueous solution of X_ (aqu) ~' after the ice precipitates. The solution is fully vitrified, and its T_g increases monotonically with X_ (aqu) (X_ (aqu) ~ (CR) X_ (aqu) X_ (aqu) X_ (aqu) ', III region: X_ (aqu)). The number of combined water and the maximum (critical) water number are defined as the solute. The number of water in the solute is determined and the free water content in the aqueous solution is determined. We found that the mass fraction of the free water (x_f) can be used to describe the homogeneous nucleation temperature (T_H) of the electrolyte and the water solution of the small molecule organic matter (T_m), and the melting temperature of the ice (T_m) and The activity of corresponding aqueous solutions (a_w). In addition, the relationship between X_f and T_H, T_m and a_w is still effective for pure water and aqueous solutions under pressure conditions. (2) liquid liquid phase transition in water is a controversial hot topic in water science. Recently, the group based on the changes of some specific concentration of aqueous solution after annealing treatment of T_g asserted water solubility. There is a liquid liquid phase transition in the liquid. We find that the specific concentration of water solution they put forward is in the range of concentration. After careful study of the water solution in the concentration range of the second region, the change of T_g before and after the annealing is due to the concentration change after the water solution is recrystallized, not the high of the water solution. The change of density water into low density water is caused by liquid liquid phase transformation. (3) the glass transition and recrystallization of aqueous solutions containing crystallizable water are usually entangled together, which not only brings difficulties to practical applications but also often causes misunderstandings in relevant experimental explanations. We suggest that the relationship between temperature and concentration of glass transition in aqueous solution is based on the relationship between the glass transition temperature and the concentration of aqueous solution. A method for determining the content of the crystallizable binding water is determined and a definite definition is given to the concentration of the aqueous solution that may be recrystallized. We also found that the properties of the crystallizable binding water are related to its content. According to the content of the crystallizable binding water, different testing schemes can be designed to crystallize them completely. (4) through the crystallization of the crystallizable binding water For the measurement of the combined water number (n_h) and the critical combined water number (n_ (CR)) of a variety of two yuan aqueous solutions and three mixed solution systems, we found that the n_ (CR) /n_h ~ 1.7 in the electrolyte solution, n_ (CR) /n_h in the aqueous solution of the organic matter depended on the type of solute and was obviously larger than the electrolyte solution, except for the chloride and glycerol three other than zinc chloride. The n_ (CR) ~ (mix) /n_h~ (mix) of the mixed aqueous solution is between the electrolyte solution and the glycerol solution. By measuring the change of the number of solute combined water with the concentration of water solution, the multibody interaction between glycerol, zinc chloride and water are revealed, and the interaction between glycerol and zinc chloride is found to be dependent on the content of glycerol and water at the same time. In addition, a method is proposed to discuss the interaction of multibody in mixed solute aqueous solution. (5) the glass formation ability of the glass of bulk sodium chloride solution is weak and can be vitrified only in the high pressure environment. By measuring the glass transition behavior of sodium chloride solution confined in different pore sizes, the limited size and the confined body surface are discussed. The influence of wettability on the glass formation ability of sodium chloride aqueous solution is found. It is found that the limited size effect is the main reason for the vitrification of sodium chloride solution, and a model is proposed to explain the dependence of the glass transition behavior on the critical concentration of the restricted sodium chloride solution.

【學(xué)位授予單位】：北京科技大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：O645.16

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本文編號(hào)：1875786