以溶膠-凝膠法製備含矽奈米材料及性質之研究：(1)以離子熔液為溶劑兼模板製備孔洞材料(2)PEG/聚矽氧烷固態高分子電解質(3)含磷矽難燃PMMA奈米複合材料

The Preparation and Properties of Silica-Containing Nano Materials by Sol-Gel Method：(1)Porous Materials Using Ionic Liquids as Solvent (2) Solid Polymer Electrolyte Based on PEG/Polysilsesquioxanes (3) Flame Retardant Phosphazene/Silica-Containing PMMA

袁敬堯(ching-yao yuan)

指導教授 ： 陳玉惠

中原大學/理學院/化學研究所/博士(2003年)

https://doi.org/10.6840/cycu200300094

摘要

本研究乃探討以溶膠-凝膠法製備三種新開發的材料，其內容主要分為三部份：
第一部份 以離子熔液為溶劑兼模板製備孔洞材料
1. 本部份以Si(OCH3)4、(C2H5O)3SiCH2CH2Si(OC2H5)3和(C2H5O)3SiC6H4Si(OC2H5)3)為前驅物，利用親水性及疏水性二類型及不同含量之離子熔液為溶劑，取代超臨界二氧化碳的過程，成功製備二氧化矽氣凝膠及聚矽氧烷氣凝膠。結果發現由於二氧化矽結構為親水性，以親水性的離子熔液製備氣凝膠，較易穩定二氧化矽結構；另由等溫吸附曲線得知所有樣品為中孔洞物質的第4類型且以添加50~100%之離子熔液有較高孔洞體積(最高為2.2 cm3/g)及高表面積(500~1200 m2/g)。
另外，亦成功的以離子熔液為溶劑和模版，採用NH2(CH2)3Si(OMe)3、NH2CH2CH2NH(CH2)3Si(OMe)3等極性官能基，和CH3Si(OMe)3、C6H5Si(OMe)3等非極性官能基，製備奈米級孔洞二氧化矽氣凝膠及其表面之修飾。結果顯示，所製備之氣凝膠均為中孔洞物質的第4類型，其孔洞體積及孔洞半徑隨著修飾物增加而降低。此外，以極性官能基修飾之氣凝膠，可應用於銅及鋅離子之吸附, 最高吸附率達99%；而以非極性官能基修飾，則降低氣凝膠表面吸濕性之功能。
2. 成功的以離子熔液為溶劑，製備TiO2及TiO2-SiO2氣凝膠。由各樣品之XRD及BET等測試結果顯示，該方法所製備的TiO2及TiO2-SiO2氣凝膠均為銳鈦礦(anatase)晶體結構，且具奈米粒徑(20~50nm)，及高表面積(500~800 m2/g)等性質。
3. 以甲烷基咪呻為主體，合成新的表面活性劑，用以製備中孔分子篩。其結果顯示，以此表面活性劑製備之MCM-41為排列規則的直通孔道之六角邊形中孔洞材料，並有相當高之表面積(大於1200 m2/g)。

第二部份 PEG/聚矽氧烷之固態高分子複合材料電解質之製備及應用
本研究是以不同之Poly(ethylene glycol)(PEG，MW=200，400，1000)/聚矽氧烷比例，製備有機/無機固態高分子複合電解質材料。製備時係以溶膠-凝膠法將BTSE(Bis(trimethoxysilyl)ethane)經水解後，加入適當鋰金屬鹽類（LiClO4），在HCl的催化下，與PEG作用，經縮合反應產生共價鍵，所得之複合材料為尺寸安定性之透明物。由結果得知，以溶膠-凝膠法所製備之固態電解質中，聚矽氧烷之矽上含有Si-OH，易與Li+形成配位。在 PEG 200/聚矽氧烷，重量比為1.5及F=0.05 (O/Li=20)之比例下所製備之複合材料有最佳的導電度（1.05*10-4 s/cm），為純PEO導電度之100倍。另外，此複合電解質材料具有良好電化學穩定性。

第三部份 含磷/矽之奈米PMMA材料之製備與性質之研究
本研究探討一系列含phosphazene與Silica之PMMA，用以改進PMMA的熱穩定性與難燃性。首先，合成含OH末端基之phosphazene化合物[N3P3(OC6H4OH)6] (HPP)，並以溶膠-凝膠技術嵌入適量的Silica以形成有機-無機互穿式高分子網狀(Interpenetrating network, IPN)材料。從TGA測試結果顯示，藉由溶膠-凝膠反應添加HPP/TEOS於PMMA中，可提高PMMA之裂解溫度約800C左右，且隨HPP量之增加，其熱穩定性與殘渣量亦增加。在燃燒測試上，則發現隨TEOS、HPP增加時，有機-無機IPN薄膜之LOI亦隨之提高，最高達到39。由殘渣量(Yc)、熱裂解溫度變化(T5%)及LOI值之提昇，可以判定矽(Si)與磷(P)之加入有協成效應，是提高PMMA的耐熱與難燃性質之主因。

關鍵字

難燃材料 ； 二氧化鈦 ； 固態高分子複合材料電解質 ； 二氧化矽 ； 孔洞材料 ； 奈米材料 ； 離子熔液 ； 溶膠-凝膠

並列摘要

This research is to investigate three kinds of new novel silicon-containing nano-materials prepared via sol-gel method. It is divided into three parts.
Part 1. Preparation of mesoporous materials using ionic liquids as solvents and templates
This part included three sections:
Section 1: In this section, a new methodology, without the supercritical drying step, has been developed by using ionic liquids as solvents to prepare silica aerogels and organosilica aerogels via sol-gel reactions of tetramethylorthosilicate, bis(triethoxysilyl)ethane and bis(triethoxysilyl)benzene, respectively. In addition, the modification agents, NH2(CH2)3Si(OMe)3, NH2CH2CH2NH(CH2)3Si(OMe)3, CH3Si(OMe)3 and C6H5Si(OMe)3, have been successfully incorporated into the silica and the organosilica aerogel matrixes on a molecular level. The synthetic conditions have been systematically studied and optimized. For all the aerogels prepared above, their pore structures have been studied in detail by Transmission Electron Microscopy (TEM), X-ray diffraction and Brunauer-Emmett-Teller (BET) measurement. The relationship between the ionic liquid concentration and the pore parameters has been established.
The results indicated that all the aerogels prepared in the study exhibit type IV isotherms and mesoporosity with a pore surface area larger than 600m2/g and pore volume over 2cm3/g. The surface areas and the pore volumes of all the modified aerogels decrease with increasing the content of the modification agent. It was found that the amino group modified aerogels were good absorbents for Cu2+ and Zn2+ ions. The efficiency of the absorption was as high as 99%. The alkyl group modified aerogels have lower water wettability than the unmodified aerogels. With meso-sized pore structure the aerogels are also anticipated to be used as catalyst support, host for enzymes and other proteins, and material for controlled drug delivery.
Section 2: The nano-structured mesoporous photocatalysts, titania and silica-titania binary have also been successfully synthesized by using ionic liquids as template (or pore-forming agent) via sol-gel reactions of tetrabutyl titanate alone and with tetraethylorthosilicate, respectively, followed by removing the ionic liquids by extraction with acetonitrile.
The powder X-ray diffraction patterns reveal that both the as-prepared mesoporous TiO2 and the mesoporous SiO2-TiO2 binary systems have anatase structures. The BET results showed that both have high surface area (500~800 m2/g) and large diameter of skeletal particles (20~50nm).
Section 3: A new cationic surfactant, 1-methyl-hexadecane-imidazole bromide synthesized from 1-methylimidazole and 1-bromohexadecane, was used as template to prepare the mesoporous silica MCM-41. Periodic arrangement of mesoscopically ordered pores with 2-d hexagonal symmetry was observed by TEM micrograph and X-ray diffraction.
The BET measurement of the MCM-41 showed that the surface area was as high as 1200m2/g, the total pore volume was 1.048cm3/g and the pore diameter was 27.8 Å, though no micropore volume was found.

Part 2 Physical and Electrochemical Properties of Low Molecular Weight Poly (ethylene glycol)s-Bridged Polysilsesquioxane Organic-Inorganic Composite Electrolytes via Sol-Gel Process
A new class of ionic conducting organic/inorganic hybrid composite electrolyte with high conductivity, better electrochemical stability and mechanical behavior was prepared through the sol-gel reaction between ethylene-bridged polysilsesquioxane and poly (ethylene glycol). The composite electrolyte with 0.05 LiClO4 per poly(ethylene glycol) repeat unit has the best conductivity of up to 10-4 Scm-1 at room temperature with the transference number up to 0.48 and the electrochemical stability window as high as 5.5V vs. Li/Li+. Moreover, the effect of the PEG chain length on the properties of composite electrolyte has been analyzed.
The interactions between ions and polymer in the composite electrolyte in the presence of LiClO4 have been investigated by means of FT-IR, DSC and TGA measurements. The results demonstrated that the interactions of Li+ ions with the ether oxygen of the PEG, and the formation of transient cross-links with LiClO4 resulted in an increase in Tg. The VTF-type behavior of ionic conductivity with temperature implied that the diffusion of charge carrier was assisted by the segmental motions of the polymer chains.

Part 3 Preparation and Properties of Novel Flame Retardant Materials based on Phosphorus, Nitrogen and Silicon for PMMA by Sol-Gel Technique
A free-OH-contained cyclotriphosphazene, N3P3(OC6H4OH)6, HPP, has been synthesized and incorporated with various amount of silica and PMMA to form hybrids by sol-gel technique. The characterization and properties of the hybrids were investigated by FTIR, solid-state 29Si NMR, TGA, DSC, LOI and SEM/EDX measurements. The results indicated that the hybrids were well-hybridized, transparent materials caused by the formation of the covalent bonding between HPP and silica and the hydrogen bonding between the unreacted hydroxyl group on HPP/SiO2 and the carbonyl groups of PMMA polymer. The thermal degradation temperature up to above 300oC and LOI value up to 39 were obtained, indicating that compared to PMMA, the thermal stability and the flame retardancy of the hybrids with proper ratio of HPP and SiO2 were greatly improved.

並列關鍵字

Organic-Inorganic Composite Electrolytes ； titania ； ionic liquids ； nano-materials ； flame fretardant ； porous materials ； silica ； sol-gel

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