生物质碳量子点的制备及应用研究进展

碳量子点（Carbon Quantum Dots,CQDs）是一种新型生物荧光碳纳米材料,具有良好的生物相容性、水溶性、稳定的光电性质、强荧光性、低毒性、易于功能化等优质特性,受到研究者们的广泛关注。其中,采用生物质作为前驱体制备生物质碳量子点过程绿色环保,还可以赋予低价值的生物质废弃物更高的综合利用率。本文综述了生物质碳量子点的制备原料、制备方法以及在细胞成像、离子检测、能量储存等方面的应用。     

基于黄连的荧光碳点的合成及性能研究

为了设计一类具有良好荧光性能的碳纳米材料,本文以黄连为碳源,制备了绿色的荧光碳量子点,通过紫外光谱、红外光谱对其结构进行表征,此外,研究了碳量子点的抗盐、抗酸碱等性能,以及碳量子点对金属阳离子和氨基酸的响应性能。研究结果表明,黄连碳点在360nm处有最强的发射光谱,具有优秀的荧光性能,结构稳定,有良好的抗盐、抗酸碱性能,在抗金属阳离子、氨基酸干扰方面有良好的应用前景。     

碳量子点在光催化领域的应用

碳量子点(carbon quantum dots,CQDs)是一种新型的零维碳纳米材料,具有易制备、低毒、生物兼容性好,及良好的光稳定性等特点,在生物成像、传感器及电致发光器件等领域具有潜在的应用前景。除此之外,碳量子点的尺寸依赖性、上转换发光性质、响应波长从近红外区延伸到可见区等优点使其成为太阳能光催化材料领域的"新宠"。就碳量子点在光催化领域的应用进行了综述。     

荧光碳量子点的水热合成及其条件优化

以乙二胺四乙酸和L-半胱氨酸为原料,在高压反应釜中通过一步水热法合成了荧光碳量子点纳米材料,并使用荧光光谱仪研究了碳量子点溶液的荧光发射性能,同时考察了原料的质量比、水热反应温度以及水热反应时间对碳量子点荧光强度的影响。结果表明在乙二胺四乙酸与L-半胱氨酸质量比为5:1,反应温度为180℃,反应时间为8 h时为荧光碳量子点的最佳制备条件。     

基于黑米的荧光碳量子点的合成及性能表征

以黑米为碳源,采用热解-溶剂热组合法制备了蓝色荧光碳量子点,经透析纯化后对其性能进行表征。透射电镜表明制备的碳量子点在水溶液中分布均匀且尺寸约为3 nm,紫外-可见光谱表明碳量子点在240 nm和310 nm处有吸收峰,荧光光谱表明碳量子点在440 nm处有最大的发射光谱,且随着激发波长的红移而红移。研究表明该量子点在抗盐性和抗酸碱性方面性能优异。此外,我们还考察了碳量子点对金属离子的响应性能,结果表明该量子点在抗阳离子干扰方面有良好的应用价值。     

磁性荧光纳米材料的合成

磁/荧光纳米复合材料是一种多功能纳米材料,既具有优良的磁性又具备荧光性能,在化学、生物、医药等领域具有广泛的应用。本文通过氧化沉淀法制备了磁性Fe3O4纳米粒子,通过水热法制备了碳量子点。最后制备了磁性/荧光复合纳米材料,并对产物进行了表征。     

生物质基碳量子点研究现状及展望

碳量子点作为一种新型零维碳基纳米材料,相较于传统半导体量子点,因其低毒性、良好的生物相容性、成本低廉等优点,在传感检测、生物成像等领域得到极大发展。近年来,碳量子点的合成方法不断发展,其中,采用生物质基作为碳源的绿色合成方法,将天然原料或垃圾废弃物转化为量子点,可以有效降低生产成本,实现废弃资源的高效转化,是未来实现绿色化工与可持续发展的趋势。本文主要介绍了生物质基碳量子点的合成方法以及在生物医学领域应用的最新进展,通过对传统碳量子点和生物质基碳量子点比较,对生物质基碳量子点的应用前景和发展方向进行了展望。     

杂原子共掺杂碳量子点的制备及其性能表征

提取紫甘薯中红色素初品作为碳源,在水热条件下制备,经过柱层析、旋蒸、过滤等方法纯化后即得发蓝色荧光的碳量子点,并对其性能进行了表征。透射电镜表明碳量子点尺寸在10 nm左右,紫外光谱表明碳量子点在277 nm处有一个较大的吸收峰,荧光光谱表明所制备的碳量子点在440 nm处具有独立于激发波长的发射峰,且具有稳定的荧光特性。此外考察了碳量子点对金属离子的响应性能,结果表明该碳量子点在选择性检测Fe~(3+)方面具有潜在的应用价值。     

以梓树荚果为原料制备荧光碳量子点的研究

以梓树荚果为原料,通过高温反应釜等设备,将其制备成荧光碳量子点。通过单因素实验和正交实验来探究所制备的荧光碳量子点荧光强度达到最好效果的最适宜条件。结果显示最适宜的条件为:原料用量梓树荚果粉0.4 g与去离子水10 mL、碳化时间为180 min、碳化温度为220℃。我们希望通过本研究为以植物为原料制备荧光纳米材料提供了借鉴。     

以植物为碳源制备荧光碳量子点的研究

以植物为碳源,采用水热法制备稳定性好的水溶性碳量子点。通过荧光分光光度计对制备的碳量子点溶液的荧光性质进行了表征,研究了碳源用量、反应时间、反应温度、缓冲溶液pH值和激发波长对碳量子点溶液的荧光性质的影响,优化实验条件。实验结果表明,当碳源用量为2.0 g,反应温度为180℃,反应时间为9 h,缓冲溶液pH值为7.0,激发波长为370 nm时,制备的碳量子点溶液的荧光强度最强。本研究能为碳量子点的制备和应用提供一定的参考。     

Insect antifeedant properties of anthranoids from the genusVismia

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.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

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.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

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.     

2007～2008年世界塑料工业进展

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.     

2005～2006年国外塑料工业进展

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。