维生素A醋酸酯微胶囊化的制备工艺研究

研究了原料配方、乳化工艺条件及喷雾干燥操作参数对维生素A醋酸酯微胶囊产品性能的影响。通过实验设计得到优化乳化工艺条件为:壁材(明胶)与芯材(VA油)的最佳质量比为4:1,乳化的最佳温度为60℃,乳化液pH 4.5,乳化时间40 min,乳化剪切速度10 000 r×min~(-1)。最佳的喷雾干燥条件为进风温度120～140℃,进料流量20 mL×min~(-1),乳液固含量25%～30%。同时,对维生素A醋酸酯微胶囊外观、包埋度、含水量和储存稳定性等进行了表征。     

石油污染土壤生物修复菌剂的微胶囊包被研究

研究利用喷雾干燥法对革兰氏阴性菌进行微胶囊化处理，以微胶囊产品的菌种存活率和产品的产出率为两个主要考察指标，设计了四因素三水平的正交试验，通过正交试验分析，得出影响微胶囊菌种存活率及产品产出率的优化工艺条件为：进风温度160℃、进料速度12．50ml／min、主要壁材配比试剂a：试剂b为1：9、菌种用量为50ml时，微胶囊中菌种存活率可迭84．57％，产出率可达44．62％。微胶囊产品在室温条件下贮存6个月后，活菌数量仍有较大幅度增长，最佳实验条件下菌种增长量为149％。还对微胶囊产品性能进行了表征。     

超声波喷雾干燥微胶囊化橄榄油的存储稳定性研究

采用超声波喷雾干燥方法对橄榄油进行微胶囊化研究,探讨进风温度对橄榄油微胶囊含水量及包埋率的影响,进而评价微胶囊化橄榄油的存储稳定性。橄榄油的超声波喷雾微胶囊化研究结果显示：进风温度过高造成橄榄油微胶囊色泽加深,油脂析出,包埋率降低;进风温度过低导致橄榄油微胶囊干燥不充分,含水量较高。对喷雾干燥条件进行优化后获得橄榄油超声波喷雾微胶囊化条件：进风温度180℃,进料速率6 r/min。此条件下制备的橄榄油微胶囊包埋率可达98.2%。存储稳定性研究结果表明：橄榄油在不同光照、温度和湿度等条件下存储至30 d时,光照下微胶囊化橄榄油的过氧化值约是未包埋橄榄油的1/5,酸值约是未包埋橄榄油的1/3;避光下微胶囊化橄榄油过氧化值及酸值约是未包埋橄榄油的2/3;因温度升高,未包埋橄榄油氧化值增加1倍左右,酸值最大值可增加77.8%,而微胶囊化橄榄油过氧化值增加仅15%,酸值最大增加40.5%。微胶囊化橄榄油的过氧化值及酸值均低于未包埋橄榄油,微胶囊对橄榄油起到延缓氧化的作用,提高了橄榄油的存储稳定性。     

复合凝聚法制备避蚊胺微胶囊的研究

以明胶-阿拉伯胶为壁材,采用复合凝聚法制备避蚊胺微胶囊.考察了几种主要因素对微胶囊产品的影响,通过单因素实验以及正交实验得出较佳的工艺条件为:芯壁材比例1:1、反应时间40 min、反应温度40 ℃、搅拌转速2 000 r/min.避蚊胺的包埋率达到了80%.     

橘皮油微胶囊制备及其产品质量评价

橘皮油的易挥发、易氧化等特点使其难以长期保存。为了延长橘皮油的保质期并丰富其应用范围，本文利用微胶囊技术，以麦芽糊精和阿拉伯胶为复配壁材，分别采用喷雾干燥法和冷冻干燥法对橘皮油进行包埋，并对所得产品进行质量评价。喷雾干燥的最佳工艺参数为：进风温度194℃、进料速度90.2mL/min和料液固含量34.7%。冷冻干燥的工艺参数为冷冻温度-30℃、干燥室压力30Pa和干燥室温度30℃。在此工艺条件下，喷雾干燥法和冷冻干燥法制备的橘皮油微胶囊包埋率分别为90.17%和82.48%。喷雾干燥产品呈规则球形、质感细腻并且囊壁致密，而冷冻干燥产品呈不规则的薄片状，但水分含量较低并且流动性好。2种干燥产品都具有一定的耐热能力，可以减少芯材在贮存和使用过程中的受热损失。综合比较，喷雾干燥法比冷冻干燥法更适合应用于制备橘皮油微胶囊产品。     

共轭亚油酸粉末化微胶囊的制备

研究了喷雾干燥法制备共轭亚油酸微胶囊的工艺参数及配比条件。结果表明,最佳的工艺参数及配比条件为:乳液80℃热处理60 m in,乳化剂蔗糖酯加入量为水液的1%~1.5%,大豆分离蛋白与麦芽糊精质量比为1∶4,壁材中玉米糖浆含量38.5%,固形物含量16.7%,共轭亚油酸理论含量16%左右,进风温度130~150℃,进料流量(2.5~3.5)×150 mL/h,进料温度35℃,进风流量1.1 m3/m in左右,喷嘴压力180 kPa。制备出的共轭亚油酸微胶囊有较好的产品质量。     

嗜酸乳杆菌喷雾干燥技术的研究

研究利用喷雾干燥法对嗜酸乳杆菌进行微胶囊化处理，以微胶囊产品细菌存活率作为主要考察目标，设计了四因素三水平的正交试验。通过正交试验分析，得出微胶囊细菌存活率优化工艺条件为：进风温度140℃；进料速度14．58ml／min；主要壁材阿拉伯胶与麦芽糊精的配比为1：10；壁材浓度为20％。微胶囊内细菌的存活率可达63％，活菌数达到108cfu／ml数量级。并对微胶囊进行了表征。     

可再分散性乳胶粉含水率的影响因素研究

由可再分散性乳胶粉(SWF)制备的改性砂浆在建筑领域中的应用日趋广泛。为了得到性能较好的SWF产品,研究了喷雾干燥过程中进风温度、雾化轮转速、进料泵入口阀开度和出口温度等工艺条件对SWF产品性能(特别是含水率)的影响。研究结果表明,喷雾干燥最适宜的工艺条件是:进风温度为140～200℃,雾化轮转速为20000～30000r/min,进料泵入口阀开度为30%～40%和出口温度为90～110℃;由此生产出的SWF产品的各项性能均符合相关指标要求。     

喷雾干燥法制备β-环糊精/香兰素微胶囊

采用单因素实验对喷雾干燥法制备β-环糊精/香兰素微胶囊进行研究,以微胶囊的包埋率和装载量为指标优选出最佳的工艺条件为:ρ(β-环糊精)=79.5 g/L,n(香兰素)∶n(β-环糊精)=0.8∶1.0,V(无水乙醇)∶V(水)=1∶10,进风温度130℃,进风速度3.9 m/s,物料流量15 mL/min,得到产品包埋率和装载量分别是69.1%和10.6%。红外光谱结果表明,香兰素与β-环糊精存在分子间相互作用。热重-差热分析结果表明,微胶囊的形成提高了香兰素的热稳定性。粒度分析显示,在50 d存放期间,β-环糊精的平均粒径变化值为0.14～1.2μm,而产品的平均粒径变化值为0.011～0.22μm,后者比前者小,进一步印证了香兰素与β-环糊精形成了超分子微胶囊。     

缓释定向释放型IgY微胶囊的制备及其效果评价

目的制备缓释定向释放型IgY微胶囊,并评价其效果。方法采用喷雾干燥法,以明胶、海藻酸钠为微胶囊壁材,制备抗仔猪病原性腹泻IgY微胶囊。以IgY的活性、包封率、体外释放性能及稳定性为评价指标,通过单因素分析和L_9(3_4)正交试验,分别从成囊材料的配比对微胶囊性能的影响、制备微胶囊成囊乳化液的稳定性影响因素以及喷雾干燥条件3方面对IgY微胶囊制备条件进行优化,并评价微胶囊的IgY活性、包封率、在人工胃液(simulated gastric fluid,SGF)和人工肠液(simulated intestinal fluid,SIF)中的缓释效果及稳定性。结果筛选出的制备微胶囊的最佳工艺条件为:明胶浓度4%、海藻酸钠浓度0.75%,按IgY与明胶-海藻酸钠质量比为3∶4加入IgY,乳化后按进风温度170℃,进料速度10 ml/min,干燥时间10 s,出口温度70℃进行喷雾干燥。在此工艺条件下制备的IgY微胶囊包封率为77.4%,活性保持在85%以上;在SGF中2 h释放率为8.6%,在SIF中4 h释放率为81.2%;90℃加热30 s仍可保持50%以上的活性,常温(25~30℃)放置10个月活性仍保持在90%以上,4℃保存10个月活性仅下降5%。结论本工艺制备的明胶-海藻酸钠IgY微胶囊具有生物活性高,稳定性强的特点,且对特异性IgY具有缓释和靶向作用。     

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。