本文關(guān)鍵詞： 介穩(wěn)態(tài)膠體晶 磁誘導(dǎo)組裝 組裝與解組裝 微弱刺激響應(yīng)　出處：《華東師范大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：膠體晶是以膠體顆粒作為結(jié)構(gòu)基元并遵循一定的空間對(duì)稱性堆積出的一維,二維或三維有序結(jié)構(gòu)。在過(guò)去的研究中,人們更多關(guān)注處在穩(wěn)定狀態(tài)的膠體晶結(jié)構(gòu),然而對(duì)"介穩(wěn)態(tài)膠體晶"的結(jié)構(gòu)、特性和應(yīng)用卻鮮有報(bào)道。缺乏有效可控的介穩(wěn)態(tài)膠體晶制備方法,缺少高度重現(xiàn)的研究對(duì)象,是相關(guān)研究進(jìn)展緩慢的主要原因,然而不可否認(rèn)的是,深入理解介穩(wěn)態(tài)膠體晶對(duì)膠體組裝具有重要的科學(xué)意義。也因此,介穩(wěn)態(tài)膠體晶的相關(guān)研究目前正面臨重大的機(jī)遇和挑戰(zhàn)。本論文采用磁誘導(dǎo)的方式將Fe304磁流體中的聚苯乙烯非磁顆粒在磁場(chǎng)下進(jìn)行組裝,以獲得具有介穩(wěn)態(tài)特性的膠體晶。通過(guò)TEM,XRD,TGA,SEM,VSM,PH值,表面電勢(shì)測(cè)定,電泳等測(cè)試技術(shù)來(lái)表征聚苯乙烯膠粒和Fe304納米顆粒的磁響應(yīng)性,表面電荷,膠粒穩(wěn)定性等組裝相關(guān)性質(zhì)。通過(guò)實(shí)驗(yàn)和優(yōu)化,我們得到單分散的,粒徑均勻,有良好穩(wěn)定性的膠體顆粒,完全滿足磁場(chǎng)條件下組裝的需求。在由體積分?jǐn)?shù)為25%的聚苯乙烯膠粒和體積分?jǐn)?shù)為3%的磁流體Fe304的組裝體系中,非磁顆粒在外磁場(chǎng)作用下會(huì)產(chǎn)生與其所置換的磁流體相反的磁矩。因此,當(dāng)施加磁場(chǎng)時(shí),體系的聚苯乙烯傾向于向遠(yuǎn)離磁場(chǎng)的方向富集,從而會(huì)導(dǎo)致液體上方的非磁顆粒過(guò)飽和而形成介穩(wěn)態(tài)膠體晶。這種利用磁組裝形成介穩(wěn)態(tài)膠體晶的方法相較于蒸發(fā)濃縮的方法具有耗時(shí)短,過(guò)程可逆,制備方便等優(yōu)勢(shì),同時(shí)還能夠?qū)ν饨绲母蓴_和變化產(chǎn)生響應(yīng)。為了進(jìn)一步探究磁誘導(dǎo)的介穩(wěn)態(tài)組裝與典型磁組裝的區(qū)別,本論文設(shè)計(jì)了磁流體中高體積分?jǐn)?shù)和低體積分?jǐn)?shù)聚苯乙烯膠體晶這兩種組裝體系。通過(guò)顯微鏡觀察,反射光譜等分析手段,探究組裝與解組裝的行為。實(shí)驗(yàn)結(jié)果證明,高體積分?jǐn)?shù)的聚苯乙烯膠體晶是由磁場(chǎng)誘導(dǎo)形成的介穩(wěn)態(tài)膠體晶,具有組裝時(shí)間較長(zhǎng),容易解組裝的特性;而低體積分?jǐn)?shù)的聚苯乙烯膠體晶是傳統(tǒng)磁組裝的膠體晶,具有瞬時(shí)組裝和解組裝后瞬時(shí)恢復(fù)的特性,但不易受外界干擾的特性。
[Abstract]:Colloidal crystal is a kind of one-dimensional, two-dimensional or three-dimensional ordered structure, which is formed by colloidal particles as the structural unit and follows a certain spatial symmetry. In the past studies, more attention has been paid to the colloidal crystal structure in a stable state. However, there are few reports on the structure, properties and applications of the "metastable colloidal crystal". There is no effective and controllable preparation method for the meso-stable colloidal crystal and a highly reproducible object of study. Is the main reason for the slow development of the related research, however, it is undeniable that it is of great scientific significance to further understand the meso-stable colloid crystal for colloid assembly. At present, the study of mesostable colloidal crystals is facing great opportunities and challenges. In this paper, the polystyrene nonmagnetic particles in Fe304 magnetofluids are assembled in magnetic field by magnetic induction. In order to obtain the colloidal crystal with steady dielectric property, the PH value of SEMS-VSMV was determined by TEMX XRDX TGASMA VSMH, and the surface potential was determined. Electrophoretic techniques were used to characterize the magnetic response, surface charge and stability of polystyrene and Fe304 nanoparticles. Through experiments and optimization, we obtained monodisperse. The colloidal particles with uniform particle size and good stability. In the assembly system composed of polystyrene particles with volume fraction of 25% and magnetohydrodynamic Fe304 with volume fraction of 3%. When the magnetic field is applied, the polystyrene of the system tends to enrich away from the magnetic field. This method can lead to the supersaturation of the nonmagnetic particles over the liquid and form the metastable colloidal crystal. The method of using magnetic assembly to form the metastable colloidal crystal is less time-consuming and reversible than the method of evaporation and concentration. At the same time, it can respond to external interference and change. In order to further explore the difference between magnetically induced mesostatic assembly and typical magnetic assembly. In this paper, two kinds of assembly systems, high volume fraction and low volume fraction polystyrene colloid crystal in magnetofluid, were designed and analyzed by microscope and reflectance spectroscopy. The experimental results show that polystyrene colloidal crystal with high volume fraction is a kind of metastable colloidal crystal induced by magnetic field, which has the characteristics of long assembling time and easy to unassemble. The low volume fraction polystyrene colloid crystal is the traditional magnetic assembly colloid crystal, which has the characteristics of instantaneous assembly and recovery, but not easily disturbed by the outside world.
【學(xué)位授予單位】：華東師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O734
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本文編號(hào)：1469589