本文選題：靜電紡絲 + 離心甩絲�。� 參考：《山東大學(xué)》2017年博士論文

【摘要】：一維納米材料相對(duì)于其他納米材料有明顯的優(yōu)勢(shì),如大長(zhǎng)徑比、各向異性、比表面積大、電子定向傳輸?shù)?在催化劑、電極、超級(jí)電容器、超強(qiáng)超硬復(fù)合材料、傳感器等領(lǐng)域都有很廣的應(yīng)用。因此對(duì)一維納米材料的制備、形貌、結(jié)構(gòu)、成分以及性質(zhì)進(jìn)行深入的研究是一項(xiàng)非常重要的研究工作。金屬氧化物纖維,也就是由金屬元素和氧元素結(jié)合構(gòu)成的化合物纖維。金屬種類繁多,除了幾種不活潑的貴金屬外,其他金屬均可以形成相應(yīng)的氧化物,如氧化鎳(NiO)、二氧化鈦(Ti02)、二氧化鋯(Zr02)、四氧化三鈷(Co304)等。金屬氧化物因具有良好的電、光、熱、力、磁、聲學(xué)等性質(zhì),受到了廣泛研究。每一種氧化物結(jié)構(gòu)不盡相同,導(dǎo)致各自具有獨(dú)特的性質(zhì),應(yīng)用往往也有很大差別。制備一維纖維材料的方法通常有水熱法、模板法、溶劑熱法、靜電紡絲法、離心甩絲法等。其中靜電紡絲法是近些年來(lái)新興的制備纖維材料的方法,該方法通過(guò)調(diào)整不同的溶膠性質(zhì)、工藝參數(shù)和環(huán)境條件,可以得到多種形貌和直徑的納米纖維。離心甩絲法工藝簡(jiǎn)單,產(chǎn)率高,極易實(shí)現(xiàn)批量化制備纖維。材料的性質(zhì)不僅與其結(jié)構(gòu)有關(guān),還與組成物質(zhì)的成分、結(jié)晶狀態(tài)等因素有關(guān)。Ti02是一種常用的光催化材料,其光催化活性受到本身禁帶寬度大和光生載流子復(fù)合率高的限制而往往偏低;Zr02作為一種極重要的超高溫隔熱材料,要求具備高的強(qiáng)度和低的熱導(dǎo)率,這與本身的晶型、結(jié)晶度、晶粒大小等有很大關(guān)聯(lián);NiO和Co304纖維的研究偏少,更鮮有批量制備兩種纖維的報(bào)道。基于此,本論文首先通過(guò)用靜電紡絲或離心甩絲法制備幾種氧化物纖維,再分別對(duì)各個(gè)纖維存在的問(wèn)題進(jìn)行了進(jìn)一步優(yōu)化。這對(duì)于氧化物纖維的研制具有重要的理論意義和應(yīng)用價(jià)值。本論文主要研究?jī)?nèi)容如下:1.Ti02復(fù)合纖維的制備及其光催化性能研究通過(guò)靜電紡絲獲得直徑均勻的T丨02納米纖維,纖維直徑大約在500 nm左右,用Turkevich方法得到直徑為16 nm的金納米球,再采取配體交換的方式將納米金負(fù)載在T丨02纖維上。SEM和TEM檢測(cè)結(jié)果表明,所得Au/Ti02復(fù)合纖維中金納米粒子在纖維表面均勻分布,含量可控,應(yīng)用此方法還可以制備多種尺寸納米金(6 nm和30 nm)負(fù)載的復(fù)合纖維。在紫外或可見(jiàn)光條件下進(jìn)行光降解甲基橙實(shí)驗(yàn),發(fā)現(xiàn)Au1/Ti02復(fù)合纖維的光催化活性要明顯高于P25和純Ti02纖維,在40 min時(shí)降解率可達(dá)90%。對(duì)不同金含量Au/Ti02復(fù)合纖維的光催化活性進(jìn)行了對(duì)比,表明隨著納米金含量的增加,光催化活性逐漸變高,直到含量超過(guò)1%后,光催化活性減弱。在紫外光和可見(jiàn)光條件下,納米金含量為1%時(shí)復(fù)合纖維光催化效果均最好。通過(guò)對(duì)不同金含量Au/Ti02復(fù)合纖維的紫外可見(jiàn)漫反射光譜,熒光光譜和光電流譜圖測(cè)試,研究了光催化機(jī)理。結(jié)果表明,在紫外光條件下,光生電子從Ti02的導(dǎo)帶轉(zhuǎn)移到納米金的能帶上,從而被有效分離。在可見(jiàn)光照射下,基于表面等離子共振效應(yīng),納米金可以吸收可見(jiàn)光,激發(fā)所得的熱電子轉(zhuǎn)移到Ti02導(dǎo)帶參與光催化反應(yīng),從而有效利用了可見(jiàn)光。納米金含量較大時(shí),可能會(huì)作為復(fù)合中心,也會(huì)覆蓋Ti02的部分表面,復(fù)合纖維的光催化效率反而變低。此外,還制備了類石墨相氮化碳(g-C3N4)納米片,通過(guò)SEM,TEM,FT-IR和XRD等測(cè)試證明了其片層結(jié)構(gòu)和成分。采用沉積方法得到了 g-C3N4/Ti02復(fù)合纖維,并且對(duì)復(fù)合纖維做了光降解甲基橙測(cè)試,表明了復(fù)合纖維在可見(jiàn)光下有較好的光催化效果。同時(shí)也對(duì)光催化機(jī)理作了討論,g-C3N4在可見(jiàn)光下被激發(fā)產(chǎn)生的光生電子可以轉(zhuǎn)移到TiO2的導(dǎo)帶,光生電子被有效分離,更高效地參與光催化反應(yīng)。2.Zr02纖維的制備、高壓水蒸汽處理及高溫結(jié)構(gòu)研究采用溶膠凝膠結(jié)合靜電紡絲方法得到了 Zr02前驅(qū)體纖維,然后將纖維進(jìn)行了高壓水蒸汽處理。纖維經(jīng)高壓水蒸汽處理后,內(nèi)部的有機(jī)物幾乎可以全部去除,且可以在較低溫度下結(jié)晶,形成小晶粒組成的多晶纖維。直接將前驅(qū)體纖維高壓水蒸汽處理效果不佳,原因前驅(qū)體中溶劑含量過(guò)多,而將前驅(qū)體纖維先在300 ℃預(yù)處理2 h后再高壓水蒸汽處理效果最佳。對(duì)高壓水蒸汽處理不同條件進(jìn)行了對(duì)比實(shí)驗(yàn),研究了溫度、水量和保溫時(shí)間對(duì)纖維處理的影響。溫度較低時(shí),效果不明顯,當(dāng)溫度為300 ℃或400 ℃時(shí)有機(jī)物去除更充分。保溫時(shí)間的不同(2 h、5 h和10 h)對(duì)高壓水蒸汽處理效果影響不顯著,結(jié)果無(wú)太大差異。水對(duì)高壓水蒸汽處理起重要作用,能夠在封閉系統(tǒng)內(nèi)提供蒸氣壓,有利于促進(jìn)前驅(qū)體結(jié)晶。最終優(yōu)選條件是400 ℃,保溫2 h,水量為30%。此外,還研究了纖維在高溫?zé)崽幚砗蟮奶匦�。高壓水蒸汽處理過(guò)的纖維在1000 ℃熱處理后比未處理的樣品晶粒明顯減小。晶粒隨著處理溫度升高而長(zhǎng)大,1400 ℃以上時(shí)晶粒出現(xiàn)異常長(zhǎng)大現(xiàn)象。3.NiO和Co304纖維的制備及性能研究采用溶膠凝膠法結(jié)合離心甩絲制備了 NiO和Co304微米纖維,纖維直徑均在10 μm左右。用檸檬酸作為配體制備相應(yīng)的前驅(qū)體溶膠,研究發(fā)現(xiàn)鎳鹽或鈷鹽與檸檬酸的比例對(duì)前驅(qū)體溶膠的可紡性有重要的影響,在比例為1.5時(shí)所得前驅(qū)體溶膠可紡性最好。利用TG-DSC、FT-IR、XRD分析了前驅(qū)體纖維在不同熱處理溫度下的演變過(guò)程,發(fā)現(xiàn)前驅(qū)體纖維先后經(jīng)歷了吸附水的脫除,有機(jī)物分解和氧化物結(jié)晶幾個(gè)階段。TEM和拉曼分析證實(shí)了纖維的成分。根據(jù)SEM結(jié)果進(jìn)一步確認(rèn)了纖維的微觀形貌,結(jié)果顯示NiO纖維為實(shí)心結(jié)構(gòu),而Co304纖維是空心結(jié)構(gòu)。測(cè)定了兩種纖維的磁滯回線,證明了 NiO和Co304纖維具有弱的鐵磁性,和塊體材料的反鐵磁性不同。隨著熱處理溫度增大,磁飽和強(qiáng)度和矯頑力都變小。NiO纖維還表現(xiàn)出對(duì)于剛果紅良好的光催化活性。此外,還用類似的方法制備出了多孔NiO/Co304復(fù)合纖維,證明其也具有了一定的鐵磁性。綜上所述,本論文中采用靜電紡絲法制備T丨02和ZrO2纖維,用離心甩絲法制備NiO和Co304纖維,在此基礎(chǔ)上,分別對(duì)纖維的性能做了進(jìn)一步的優(yōu)化調(diào)整。將納米金均勻負(fù)載在Ti02纖維的表面,增強(qiáng)了復(fù)合纖維的光催化性能,并且討論了納米金負(fù)載量對(duì)復(fù)合纖維光催化活性的影響。制備了 g-C3N4/TiO2復(fù)合纖維,并研究了其在可見(jiàn)光下的光催化性能。將靜電紡絲得到的ZrO2前驅(qū)體纖維進(jìn)行高壓水蒸汽處理,有效去除有機(jī)物并在較低溫度實(shí)現(xiàn)結(jié)晶。將檸檬酸作配體制備前驅(qū)體,用離心甩絲法獲得了 NiO和Co304纖維,研究了其磁學(xué)和光催化性質(zhì)。
[Abstract]:One dimensional nanomaterials have obvious advantages relative to other nanomaterials, such as large length to diameter ratio, anisotropy, large specific surface area, electronic directional transmission and so on. It has a wide application in the fields of catalyst, electrode, supercapacitor, super hard composite material, sensor and so on. The preparation, morphology, structure, composition and properties of one-dimensional nanomaterials are made. Qualitative research is a very important research work. Metal oxide fiber, a compound made of metal elements and oxygen elements, is a great variety. In addition to several kinds of inert precious metals, other metals can form corresponding oxides, such as nickel oxide (NiO), titanium dioxide (Ti02), and two oxidation. Zirconium (Zr02), four oxidation three cobalt (Co304), etc. metal oxide has been widely studied because of its good electrical, light, thermal, force, magnetic, acoustic and other properties. Every oxide structure is not the same, which leads to the unique properties and the application is often very different. The methods of preparing one dimensional fiber are usually hydrothermal method, template method, solvent. The electrostatic spinning method is a new method for preparing fiber materials in recent years. By adjusting the properties of the sols, the process parameters and the environmental conditions, this method can get a variety of nanofibers with different morphology and diameter. The process of centrifugal spinning is simple, high yield, and easy to achieve mass production. The properties of the materials are not only related to their structure, but also related to the composition of the components and the state of crystallization..Ti02 is a commonly used photocatalytic material. The photocatalytic activity is limited by the limitation of the band gap and the high recombination rate of the photogenerate carrier. As an extremely important ultra high temperature insulation material, Zr02 is a very important material. In order to obtain high strength and low thermal conductivity, there is a great relationship between the crystalline form, crystallinity and grain size of its own. The study of NiO and Co304 fibers is less, and there are few reports on the preparation of two kinds of fibers. Based on this, the paper first prepared several oxide fibers by electrostatic spinning or centrifugal spinning, and then separately deposited the fibers. The main research content in this paper is as follows: the preparation and photocatalytic properties of 1.Ti02 composite fiber and its photocatalytic performance study by electrospinning to obtain T 02 nanofibers with uniform diameter, the diameter of fiber is about 500 nm, and Tur Kevich method obtained gold nanospheres with a diameter of 16 nm. Then the gold nanoparticles were loaded on the T 02 fiber by ligand exchange. The results showed that the gold nanoparticles in the Au/Ti02 composite fiber were evenly distributed on the surface of the fiber and the content was controllable. The load of various sizes (6 nm and 30 nm) could be prepared by this method. The photocatalytic activity of Au1/Ti02 composite fibers was significantly higher than that of P25 and pure Ti02 fibers. The photocatalytic activity of the composite fibers at 40 min was compared to 90%., and the photocatalytic activity of Au/Ti02 composite fibers with different gold content was compared at 40 min. The catalytic activity gradually becomes higher, and the photocatalytic activity is weakened until the content exceeds 1%. Under the conditions of ultraviolet and visible light, the photocatalytic effect of the composite fiber is best when the gold content is 1%. The UV visible diffuse reflectance spectrum, the fluorescence spectrum and the photoelectricity spectrum of the Au/Ti02 composite fibers with different gold content are tested, and the photocatalytic machine is studied. The results show that under ultraviolet light, the photoelectrons transfer from the guide band of Ti02 to the energy band of nanoscale gold, which can be effectively separated. Under the visible light, the nano gold can absorb visible light based on the surface plasmon resonance effect, and the thermal electrons can be transferred to the Ti02 guide band to participate in the photocatalytic reaction, thus effectively utilizing the visible light. When the content of nanoscale gold is larger, it may be used as a compound center, which will also cover the part of the surface of Ti02, and the photocatalytic efficiency of the composite fiber becomes lower. In addition, the graphite like carbon nitride (g-C3N4) nanoscale is prepared, and the layer structure and composition are proved by the tests of SEM, TEM, FT-IR and XRD. The deposition method is used to obtain the g-C3N4/Ti02. The composite fiber has been tested by photodegradation of methyl orange, which shows that the composite fiber has better photocatalytic effect under visible light. Meanwhile, the photocatalytic mechanism is discussed. The photoinduced electrons produced by g-C3N4 in visible light can be transferred to the guide band of TiO2, and the photoelectrons are effectively separated and more efficiently participated in the light. The preparation of catalytic reaction.2.Zr02 fiber, high pressure water vapor treatment and high temperature structure study by using sol-gel combined electrostatic spinning method to obtain the Zr02 precursor fiber, and then the fiber is treated with high pressure water vapor. After the fiber is treated with high pressure water vapor, the internal organic matter can be completely removed and can be at a lower temperature. Crystallization, forming a polycrystalline fiber composed of small grain. The effect of high pressure water vapor in the precursor fiber is not good. The solvent content in the precursor is too much, and the precursor fiber is pretreated at 300 C for 2 h and then the high pressure water steam treatment is the best. The effect of water and heat preservation time on fiber treatment is not obvious when the temperature is low. When the temperature is 300 or 400, the organic matter is more fully removed. The difference of heat preservation time (2 h, 5 h and 10 h) has no significant effect on the effect of high pressure water vapor treatment. The vapor pressure in the system is helpful to promote the crystallization of the precursor. The optimum condition is 400, 2 h and 30%., and the properties of the fiber after heat treatment at high temperature are also studied. The grain of the high pressure steam treated fiber is less than that of the untreated sample after heat treatment at 1000. The preparation and properties of.3.NiO and Co304 fibers were prepared by sol-gel method and centrifugation by sol-gel method and centrifugation. The diameter of the fiber was about 10 mu m. The precursor sol was prepared with citric acid as the ligand, and the ratio of nickel salt or cobalt salt to citric acid was found in the study. The ratio of.3.NiO and Co304 fiber was prepared by sol-gel method and centrifugation The spinnability of precursor sol has an important influence. The spinnability of precursor sol is the best when the ratio is 1.5. TG-DSC, FT-IR and XRD have been used to analyze the evolution process of precursor fibers at different heat treatment temperatures. It is found that the precursor fibers have experienced the removal of adsorbed water, organic matter decomposition and oxide crystallization in several stages of.TEM. The fiber composition was confirmed by the Raman analysis. The micromorphology of the fibers was further confirmed according to the SEM results. The results showed that the NiO fibers were solid structures and the Co304 fibers were hollow structures. The hysteresis loops of the two fibers were measured. It is proved that the NiO and Co304 fibers have weak ferromagnetism, and the antiferromagnetism of the bulk materials is different from that of the bulk materials. As the temperature increases, the magnetic saturation strength and coercive force are smaller,.NiO fibers also exhibit good photocatalytic activity for Congo red. In addition, a porous NiO/Co304 composite fiber has been prepared by similar methods, proving that it has a certain ferromagnetism. In this paper, T 02 and ZrO2 fibers are prepared by the electrospinning method in this paper. NiO and Co304 fibers were prepared by centrifugal shredding method. On this basis, the properties of the fibers were further optimized. The photocatalytic properties of the composite fibers were enhanced by loading the nano gold evenly on the surface of Ti02 fiber, and the influence of the nano gold load on the photocatalytic activity of the composite fibers was discussed. The g-C3N4/TiO2 composite was prepared. The photocatalytic properties of the fibers under visible light were studied. The ZrO2 precursor fibers obtained by electrostatic spinning were treated with high pressure water vapor to effectively remove organic compounds and crystallize at a lower temperature. NiO and Co304 fibers were obtained by using citric acid as ligands to prepare the precursors. The magnetic and photocatalytic properties of the fibers were studied by centrifugation.

【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：TQ343.5

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 翟林峰;史鐵鈞;于少明;;可紡性鋯溶膠的制備與應(yīng)用Ⅰ.氧化鋯連續(xù)纖維的制備[J];應(yīng)用化學(xué);2008年06期

2 潘梅,劉久榮,孟凡青,呂孟凱,袁多榮,許東;由醋酸鋯前驅(qū)體制備ZrO_2連續(xù)纖維的過(guò)程及研究[J];無(wú)機(jī)材料學(xué)報(bào);2001年04期

3 劉久榮,潘梅,許東,孟凡青,呂孟凱,袁多榮,王新強(qiáng),楊萍;由二氯氧鋯-醇-醋酸鹽體系制備氧化鋯纖維[J];硅酸鹽通報(bào);2001年03期

4 劉久榮,潘梅,許東,呂孟凱,袁多榮,王新強(qiáng),元增祥;Sol-gel法制備ZrO_2連續(xù)纖維的燒結(jié)過(guò)程的研究[J];山東工業(yè)大學(xué)學(xué)報(bào);2001年02期

相關(guān)博士學(xué)位論文 前2條

1 何順愛(ài);氧化鋯纖維和制品的制備及燒結(jié)研究[D];中國(guó)建筑材料科學(xué)研究總院;2008年

2 李建軍;氧化鋯基連續(xù)陶瓷纖維關(guān)鍵制備技術(shù)[D];山東大學(xué);2007年

相關(guān)碩士學(xué)位論文 前1條

1 王云燕;水熱法制備納米二氧化鋯及其形貌控制[D];南京理工大學(xué);2007年

，

本文編號(hào)：1798834