CdTe量子點(diǎn)復(fù)合材料的制備及其熒光性能研究
發(fā)布時(shí)間：2019-06-10 12:57
【摘要】：半導(dǎo)體量子點(diǎn)是一類尺寸小于10nm的納米晶,由于具有顯著的表面效應(yīng)、量子尺寸效應(yīng)等而使其具有比傳統(tǒng)有機(jī)染料更優(yōu)異的光學(xué)特性,在生物標(biāo)記、離子檢測、光電器件等方面應(yīng)用廣泛。水相法合成量子點(diǎn)方法簡單,毒性低,更經(jīng)濟(jì)。目前利用量子點(diǎn)對(duì)金屬離子靈敏的熒光猝滅響應(yīng),可將其作為離子探針檢測水溶液中的金屬離子。純量子點(diǎn)粉體的本征熱不穩(wěn)定性極大的限制了其在固體材料中的應(yīng)用,本論文采用靜電組裝法和離子交換原位合成法將CdTe量子點(diǎn)引入層狀材料麥羥硅鈉石(MD)中,得到性能優(yōu)異的CdTe/MD復(fù)合熒光粉體,進(jìn)一步通過熱熔共混的方法將其與聚乙烯(PE)、聚丙烯(PP)高分子材料復(fù)合,得到具有優(yōu)異熒光特性的高分子復(fù)合材料。另外,采用靜電紡絲法、原位聚合法,溶劑熱蒸發(fā)法將合成的CdTe量子點(diǎn)復(fù)合到聚甲基丙烯酸甲酯(PMMA)基體中,系統(tǒng)研究了不同工藝條件對(duì)CdTe/PMMA復(fù)合材料熒光性能的影響。研究結(jié)果如下：1.采用水相回流法合成了L-半胱氨酸修飾的CdTe量子點(diǎn),粒徑為2～4nm,可作為熒光探針檢測水溶液中的Cu2+濃度,線性范圍為400～4000nmol/L,檢測限為85nmol/L。對(duì)模擬水樣中Cu2+的測定值與實(shí)際加入值基本吻合。2.采用靜電組裝法和離子交換原位合成法均能成功將CdTe量子點(diǎn)引入MD層間制備出CdTe/MD復(fù)合物熒光粉體。MD層板的限域保護(hù)作用有效地抑制了CdTe量子點(diǎn)的團(tuán)聚,使其在粉體狀態(tài)仍表現(xiàn)出優(yōu)異的熒光性能和較好的熱穩(wěn)定性(1)采用靜電組裝法,當(dāng)以最大發(fā)射波長λem(max)為550nm左右的CdTe量子點(diǎn)為母液,物料比為V(CdTe)/m(MD)=50mL/0.5g時(shí),得到的CdTe/MD復(fù)合材料熒光強(qiáng)度最強(qiáng),其耐熱性也最任HRTEM表明CdTe量子點(diǎn)很好地分散于MD基質(zhì)中,不發(fā)生團(tuán)聚,XRD結(jié)果表明量子點(diǎn)的存在不影響MD的主體層板結(jié)構(gòu)。(2)采用離子交換原位合成法,當(dāng)回流時(shí)間為5min-24h,佳復(fù)合材料的最大發(fā)射波長λem(max)可在501-557nm范圍內(nèi)調(diào)諧,當(dāng)回流時(shí)間為30min時(shí),熒光最強(qiáng)。(3)將CdTe/MD復(fù)合材料粉體進(jìn)一步添加到聚乙烯、聚丙烯的熱塑中,得到CdTe/MD-PE, CdTe/MD-PP復(fù)合材料,材料熒光顏色可在黃色、橙黃色、橙紅色間調(diào)諧。3.采用靜電紡絲法制得CdTe/PMMA復(fù)合纖維,其直徑為2-3gm,且表面分布有直徑為100nm左右的孔,具有與初始量子點(diǎn)溶液基本相同的最大發(fā)射波長λem(max)。采用溶劑熱蒸發(fā)法制備出CdTe含量在2.12～6.10wt%的透明CdTe/PMMA熒光復(fù)合薄膜,其中6.1 0 wt%CdTe/PMMA復(fù)合物膜的熒光強(qiáng)度最大。TEM表明,CdTe量子點(diǎn)能均勻地分散于PMMA中；熒光分析和熒光壽命測試表明,與純的量子點(diǎn)粉體相比,PMMA基質(zhì)中CdTe量子點(diǎn)的熒光性能和光穩(wěn)定性均有很大的提高。熱重分析表明,CdTe量子點(diǎn)的存在對(duì)PMMA的熱穩(wěn)定性有所提高。當(dāng)改變CdTe量子點(diǎn)的最大發(fā)射波長λem(max)為539 nm,555 nm,566 nm和588nm時(shí),所制得的6.10wt% CdTe/PMMA復(fù)合物膜的最大發(fā)射波長λem(max)分別為538,553,565和584 nm,其熒光顏色可在綠色、黃綠色、黃色、橙色間調(diào)諧。
[Abstract]:The semiconductor quantum dots are a class of nanocrystals with a size of less than 10 nm. Due to the remarkable surface effect, quantum size effect, and the like, the semiconductor quantum dots have more excellent optical properties than the conventional organic dyes, and are widely applied in the fields of biological labeling, ion detection, photoelectric devices and the like. The method for synthesizing the quantum dots by the water phase method is simple, the toxicity is low, and the method is more economical. At present, the quantum dot is used for the sensitive fluorescence quenching of metal ions, which can be used as the ion probe to detect the metal ions in the aqueous solution. the intrinsic thermal instability of the pure quantum dot powder greatly limits the application of the pure quantum dot powder in the solid material, And the high-molecular composite material with excellent fluorescence property is obtained by compounding the polymer with the polyethylene (PE) and the polypropylene (PP) high-molecular material by a hot-melt blending method. In addition, the effects of different process conditions on the fluorescence properties of the CdTe/ PMMA composite were studied by means of electrospinning, in-situ polymerization, and solvent thermal evaporation. The results of the study are as follows:1. The CdTe quantum dot modified by L-cysteine was synthesized by the aqueous phase reflux method. The particle size was 2-4 nm. The concentration of Cu2 + in the aqueous solution can be detected as a fluorescent probe. The linear range is 400-4000 nmol/ L, and the detection limit is 85 nmol/ L. The measured value of Cu2 + in the simulated water sample is in agreement with the actual addition value. The CdTe/ MD composite phosphor powder can be prepared by introducing the CdTe quantum dots into the MD layer by adopting an electrostatic assembly method and an ion exchange in-situ synthesis method. the limited-domain protection effect of the MD layer effectively inhibits the agglomeration of the CdTe quantum dots so as to exhibit excellent fluorescence performance and better thermal stability in the powder state (1) adopting an electrostatic assembly method, and when the CdTe quantum point with the maximum emission wavelength (max) of about 550 nm is a mother liquid, When the material ratio is V (CdTe)/ m (MD) = 50 mL/ 0.5 g, the obtained CdTe/ MD composite material has the strongest fluorescence intensity, and the heat resistance is also the most HRTEM, which shows that the CdTe quantum dots are well dispersed in the MD matrix without agglomeration, and the XRD results show that the existence of the quantum dots does not affect the structure of the main body of the MD. (2) In situ synthesis with ion exchange, when the reflux time is 5 min to 24 h, the maximum emission wavelength of the good composite material (max) can be tuned in the range of 501-557 nm, and when the reflux time is 30 min, the fluorescence is the strongest. And (3) the CdTe/ MD composite material powder is further added into the thermoplastic of the polyethylene and the polypropylene to obtain the CdTe/ MD-PE and CdTe/ MD-PP composite material, and the fluorescent color of the material can be tuned between yellow, orange and orange. The CdTe/ PMMA composite fiber is prepared by the electrostatic spinning method, the diameter of the CdTe/ PMMA composite fiber is 2-3gm, and a hole with a diameter of about 100 nm is distributed on the surface, and the CdTe/ PMMA composite fiber has the same maximum emission wavelength (max) as that of the initial quantum dot solution. A transparent CdTe/ PMMA fluorescent composite film with a CdTe content of 2.12 to 6.10 wt% is prepared by a solvent thermal evaporation method, wherein the fluorescence intensity of the 6.1wt% CdTe/ PMMA composite film is the largest. TEM shows that the CdTe quantum dots can be uniformly dispersed in PMMA, and the fluorescence analysis and the fluorescence lifetime test show that the fluorescence and photostability of the CdTe quantum dots in the PMMA matrix are greatly improved compared with the pure quantum dot powder. The thermogravimetric analysis shows that the presence of CdTe quantum dots has improved the thermal stability of PMMA. When the maximum emission wavelength (max) of the CdTe quantum dots is changed to 539 nm,555 nm,566 nm and 588 nm, the maximum emission wavelength of the prepared 6.10 wt% CdTe/ PMMA composite film is 538,553,565 and 584 nm, respectively, and the fluorescence color thereof can be tuned between green, yellow, yellow, and orange.
【學(xué)位授予單位】：北京化工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TB33;TQ422
本文編號(hào)：2496470
[Abstract]:The semiconductor quantum dots are a class of nanocrystals with a size of less than 10 nm. Due to the remarkable surface effect, quantum size effect, and the like, the semiconductor quantum dots have more excellent optical properties than the conventional organic dyes, and are widely applied in the fields of biological labeling, ion detection, photoelectric devices and the like. The method for synthesizing the quantum dots by the water phase method is simple, the toxicity is low, and the method is more economical. At present, the quantum dot is used for the sensitive fluorescence quenching of metal ions, which can be used as the ion probe to detect the metal ions in the aqueous solution. the intrinsic thermal instability of the pure quantum dot powder greatly limits the application of the pure quantum dot powder in the solid material, And the high-molecular composite material with excellent fluorescence property is obtained by compounding the polymer with the polyethylene (PE) and the polypropylene (PP) high-molecular material by a hot-melt blending method. In addition, the effects of different process conditions on the fluorescence properties of the CdTe/ PMMA composite were studied by means of electrospinning, in-situ polymerization, and solvent thermal evaporation. The results of the study are as follows:1. The CdTe quantum dot modified by L-cysteine was synthesized by the aqueous phase reflux method. The particle size was 2-4 nm. The concentration of Cu2 + in the aqueous solution can be detected as a fluorescent probe. The linear range is 400-4000 nmol/ L, and the detection limit is 85 nmol/ L. The measured value of Cu2 + in the simulated water sample is in agreement with the actual addition value. The CdTe/ MD composite phosphor powder can be prepared by introducing the CdTe quantum dots into the MD layer by adopting an electrostatic assembly method and an ion exchange in-situ synthesis method. the limited-domain protection effect of the MD layer effectively inhibits the agglomeration of the CdTe quantum dots so as to exhibit excellent fluorescence performance and better thermal stability in the powder state (1) adopting an electrostatic assembly method, and when the CdTe quantum point with the maximum emission wavelength (max) of about 550 nm is a mother liquid, When the material ratio is V (CdTe)/ m (MD) = 50 mL/ 0.5 g, the obtained CdTe/ MD composite material has the strongest fluorescence intensity, and the heat resistance is also the most HRTEM, which shows that the CdTe quantum dots are well dispersed in the MD matrix without agglomeration, and the XRD results show that the existence of the quantum dots does not affect the structure of the main body of the MD. (2) In situ synthesis with ion exchange, when the reflux time is 5 min to 24 h, the maximum emission wavelength of the good composite material (max) can be tuned in the range of 501-557 nm, and when the reflux time is 30 min, the fluorescence is the strongest. And (3) the CdTe/ MD composite material powder is further added into the thermoplastic of the polyethylene and the polypropylene to obtain the CdTe/ MD-PE and CdTe/ MD-PP composite material, and the fluorescent color of the material can be tuned between yellow, orange and orange. The CdTe/ PMMA composite fiber is prepared by the electrostatic spinning method, the diameter of the CdTe/ PMMA composite fiber is 2-3gm, and a hole with a diameter of about 100 nm is distributed on the surface, and the CdTe/ PMMA composite fiber has the same maximum emission wavelength (max) as that of the initial quantum dot solution. A transparent CdTe/ PMMA fluorescent composite film with a CdTe content of 2.12 to 6.10 wt% is prepared by a solvent thermal evaporation method, wherein the fluorescence intensity of the 6.1wt% CdTe/ PMMA composite film is the largest. TEM shows that the CdTe quantum dots can be uniformly dispersed in PMMA, and the fluorescence analysis and the fluorescence lifetime test show that the fluorescence and photostability of the CdTe quantum dots in the PMMA matrix are greatly improved compared with the pure quantum dot powder. The thermogravimetric analysis shows that the presence of CdTe quantum dots has improved the thermal stability of PMMA. When the maximum emission wavelength (max) of the CdTe quantum dots is changed to 539 nm,555 nm,566 nm and 588 nm, the maximum emission wavelength of the prepared 6.10 wt% CdTe/ PMMA composite film is 538,553,565 and 584 nm, respectively, and the fluorescence color thereof can be tuned between green, yellow, yellow, and orange.
【學(xué)位授予單位】：北京化工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TB33;TQ422
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 張華,徐金鎖,唐頤,高滋;層狀磷酸鋯的合成與性質(zhì)研究[J];高等學(xué)校化學(xué)學(xué)報(bào);1997年02期
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