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1.
采用溶剂蒸发对流自组装法将单分散二氧化硅(SiO2)微球组装形成三维有序胶体晶体模板,以锗烷(GeH4)为先驱体气用等离子增强化学气相沉积法在350℃填充高折射率材料锗.获得了锗反蛋白石光子晶体.通过扫描电镜、X射线衍射仪对锗反蛋白石的形貌、成分、结构进行了表征.结果表明:锗在SiO2微球空隙内填充均匀,得到的锗为多晶态.锗反蛋白石光子晶体为三维有序多孔结构.等离子体增强化学气相沉积的潜在优势在于可实现材料的低温填充,从而以高分子材料为模板进行复型,得到多种结构的三维光子晶体.  相似文献   

2.
有序大孔二氧化硅微球的制备研究   总被引:1,自引:0,他引:1  
采用乳液聚合法合成了单分散改性聚苯乙烯(PS)乳胶粒,利用PS乳胶粒自组装制得胶体晶体(“蛋白石”)微球,通过溶胶-凝胶模板法制备了有序大孔SiO2(“反蛋白石”)微球,通过SEM对改性PS乳胶粒、胶体晶体微球和有序大孔SiO2微球表面形貌进行了表征。结果表明,改性PS乳胶粒呈单分散性,粒径为317 nm;胶体晶体微球表面PS乳胶粒排列有序;有序大孔SiO2微球表面呈有序多孔,其孔呈六边形,孔径分布均一,约为200 nm。  相似文献   

3.
首先合成顺丁烯二酸酐改性的β-环糊精,垂直沉积制备聚苯乙烯光子晶体模板。然后将改性环糊精与丙烯酸、过硫酸铵、N,N'-亚甲基双丙烯酰胺、诺氟沙星等混合的前驱液填入光子晶体模板中,引发交联聚合,得到蛋白石结构的凝胶光子晶体。再在二甲苯中超声除去聚苯乙烯光子晶体模板,用十二烷基硫酸钠的V(醋酸):V(甲醇)=1:9溶液除去分子印迹模板诺氟沙星,蒸馏水清洗后得到反蛋白石结构的分子印迹凝胶光子晶体。通过对比印迹凝胶光子晶体与非印迹凝胶光子晶体在同样条件下对诺氟沙星的响应性,发现印迹凝胶光子晶体能选择性地迅速响应溶液中的诺氟沙星,当诺氟沙星浓度从10-9 mol/L递增到10-4 mol/L时,其光子晶体的衍射峰位置从633 nm逐渐红移到722 nm,而非印迹凝胶光子晶体响应性很差。  相似文献   

4.
采用无皂乳液聚合方法自制的单分散聚苯乙烯(PS)微球乳液为原料,并以PS微球自组装制备了有序胶体晶体模板("蛋白石"),采用溶胶-凝胶模板法制备了三维有序大孔TiO2微球("反蛋白石"),其孔呈六边形,孔径分布均一,约为200 nm,运用SEM,XRD对其形貌特征及晶型进行表征。结果表明,采用表面含有羧基的单分散聚苯乙烯微球及高的硅油粘度制得的模板有序度高;控制煅烧温度可以改变有序大孔TiO2微球的晶型,当煅烧温度为500℃时,其晶型为锐钛型,当煅烧温度为700℃时,其晶型则为金红石型。  相似文献   

5.
单分散胶体颗粒的有序组装及其应用研究进展   总被引:1,自引:0,他引:1  
本文综述了近1~2年来课题组在单分散胶体微球有序组装及其应用方面的研究进展.其中包括250~1300 nm宽尺寸范围单分散二氧化硅胶体微球的重力沉降自组织;旨在提高光子晶体折射率反差的TiO2/SiO2复合胶体微球的有序组装;硬模板与催化材料一步复合的二元胶体体系颗粒的有序自组装;一种高效的聚苯乙烯胶体颗粒的批量组装技术;低体积分数聚苯乙烯胶体晶体的制备;以及聚苯乙烯胶粒晶体作为可调谐三维非线性光子晶体在高开关对比的光子晶体光开关方面的应用,和作为制备有序大孔材料硬模板在大分子催化方面的应用等.  相似文献   

6.
光子晶体水凝胶传感器在一定外界条件刺激下,其水凝胶体系会发生膨胀或收缩,进而引起光子晶体的光子带隙改变而产生响应。本文主要对光子晶体水凝胶传感器的原理及应用现状进行了综述,并提出了展望。  相似文献   

7.
先将单分散的聚苯乙烯微球通过垂直沉积法自组装得到聚苯乙烯光子晶体模板,再将水相合成法制备的巯基丙酸改性CdTe量子点与丙烯酸、丙烯酰胺、过硫酸铵、N,N’-亚甲基双丙烯酰胺等水凝胶前驱液混合填入聚苯乙烯光子晶体模板中,引发交联聚合,得到掺杂CdTe量子点的凝胶光子晶体。分别采用扫描电镜(SEM)、光纤光谱仪、固体荧光分光光度计对材料进行了表征,结果表明该材料既具有光子晶体的三维面心立方结构和光子带隙特征,又具有CdTe量子点荧光性能。  相似文献   

8.
利用SiO2胶体粒子构筑三维蛋白石光子晶体阵列,并将其嵌入聚二甲基硅氧烷(PDMS)弹性体内,制备了一种具有力致变色性能的透明光子晶体薄膜。采用SEM、光纤光谱仪、数码相机等对光子晶体薄膜进行了结构、光学性能的表征,并研究了其在防伪中的应用。结果表明:施加拉力时,该透明光子晶体薄膜显现结构色,并随拉伸量的增加发生持续蓝移,撤销拉力可逆回复至初始状态,且即使经历100次循环拉伸,光子晶体薄膜依旧保持稳定的光学性能。将光子晶体薄膜进行图案化设计,通过施加或撤销拉力可使隐藏于其中的图案快速显现或消失,在防伪领域具有广阔的应用前景。  相似文献   

9.
油性介质中组装二氧化硅胶体晶体薄膜   总被引:3,自引:1,他引:3  
许静  谢凯  龙永福  肖加余 《硅酸盐学报》2005,33(11):1348-1351
报道厂一种由粒径大于700nm的SiO2微球组装胶体晶体薄膜的方法。以一种密度较大的疏水性有机物替代水或醇类为分散剂,通过对SiO2微球表面进行疏水性处理改善其在油性介质中的分散性,采用改进的垂直沉积法在油性分散剂中制备SiO2胶体晶体。用扫描电子显微镜、红外光谱仪和紫外-可见光谱仪对SiO2胶体晶体薄膜的形貌、结构和光学性能进行了观察测试。结果表明;较大密度的分散剂能有效降低SiO2微球的沉降速度,组装成直径在700~2000nm范围的SiO2微球的胶体晶体。获得的SiO2光子晶体具有长程有序结构,并在近红外区具有显著的光子频率带隙。  相似文献   

10.
InP-SiO2三维光子晶体的制备   总被引:1,自引:1,他引:0  
用溶剂蒸发法将单分散SiO2微球组装成三维有序结构的胶体晶体,用金属有机化学气相沉积技术向SiO2胶体晶体中填充高折射率材料InP,获得了InP-SiO2两种介质复合的三维光子晶体,通过扫描电子显微镜、X射线衍射、能谱和紫外-可见光谱仪对InP-SiO2三维光子晶体的形貌、结构和光学性能进行了观察测试。研究结果表明:InP在SiO2微球空隙间具有较高的结晶质量,填充较致密均匀、与相同晶格周期的SiO2光子晶体相比,InP-SiO2光子晶体的反射光谱的峰值波长发生明显的红移。  相似文献   

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12.
Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.  相似文献   

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14.
Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.  相似文献   

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In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.  相似文献   

18.
Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.  相似文献   

19.
收集了2007年7月~2008年6月世界塑料工业的相关资料,介绍了2007~2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.  相似文献   

20.
收集了2005年7月~2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、通用热固性树脂(酚醛、聚氨酯、不饱和树脂、环氧树脂)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。  相似文献   

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