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壳聚糖是天然的抗菌材料,具有广谱抗菌性、生物相容性好、可降解,广泛应用于工农业、医药、化工、环境保护等领域。TiO_2具有优异的抗菌性、吸收紫外线、无毒等优良特性。用溶液扩散法制备纳米壳聚糖颗粒并负载纳米TiO_2制备复合抗菌材料。 相似文献
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以马铃薯淀粉为基材,壳聚糖和纳米TiO_2为增强相,研究壳聚糖和纳米TiO_2对马铃薯淀粉成膜性能的影响。通过溶液共混法将壳聚糖的乙酸溶液与马铃薯淀粉糊化液,按照4∶6的比例均匀混合,加入纳米Ti O2流延成膜,研究壳聚糖和纳米TiO_2对复合膜的阻氧性及透湿性的影响;用XRD、SEM表征复合膜的结构与形态。研究结果表明,马铃薯淀粉与壳聚糖、纳米TiO2组分成膜时具有良好的相容性;壳聚糖和纳米TiO_2能有效改善复合膜的水蒸气透过性和阻氧性;纳米TiO_2/壳聚糖/马铃薯淀粉复合膜较马铃薯淀粉单膜、马铃薯淀粉/壳聚糖复合膜、马铃薯淀粉/纳米TiO_2复合膜的阻氧性提高了43. 38%、7. 56%、19. 14%;水蒸气透过率降低了32. 41%、39. 18%、30. 89%。壳聚糖和纳米TiO_2添加到马铃薯淀粉液中共混制膜,能够增强复合膜的性能。 相似文献
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用纳米微粒直接分散法制备了纳米TiO2/水性聚氨酯复合膜,考察了纳米TiO2晶形(金红石型和锐钛矿型)对复合膜性能的影响。黏度分析表明,金红石型纳米TiO2增黏效果较好。粒径、SEM和AFM分析表明,添加纳米TiO2不影响聚氨酯乳液的稳定性,复合粒子仍然以纳米级存在,两种晶形的纳米TiO2均能均匀分散于复合膜中,并对复合膜表面的平整度无影响;接触角和卫生性能测试表明,两种晶形的复合膜都没有防水性,添加锐钛矿型纳米TiO2复合膜的卫生性能较好;机械性能和抗菌性测试表明,添加锐钛矿型纳米TiO2的复合膜具有更好的力学性能和抗菌性能。 相似文献
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用纳米微粒直接分散法制备了纳米TiO2/水性聚氨酯复合膜,考察了纳米TiO2晶型(金红石型和锐钛矿型)对复合膜性能的影响。粘度分析表明:金红石型纳米TiO2增粘效果较好。粒径、SEM和AFM分析表明:添加纳米TiO2不影响聚氨酯乳液的稳定性,复合粒子仍然以纳米级存在,两种晶型的纳米TiO2均能均匀分散于复合膜中,并对复合膜表面的平整度无影响;接触角和卫生性能测试表明:两种晶型的复合膜都没有防水性,添加锐钛矿型纳米TiO2复合膜的卫生性能较好;机械性能和抗菌性测试表明:添加锐钛矿型纳米TiO2的复合膜具有更好的力学性能和抗菌性能。 相似文献
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为了提高丁苯乳液涂膜力学性能,用硅烷偶联剂(KH-570)改性纳米TiO2,采用半连续种子乳液聚合法,制备TiO2/聚丁苯(PSB)复合乳液。采用FT-IR、TEM表征TiO2/PSB复合乳液乳胶粒子结构,结果表明合成了以TiO2为核的核壳结构纳米TiO2/PSB乳胶粒子。探讨了纳米TiO2、乳化剂、电解质、引发剂及增稠剂用量、聚合时间与温度、单体配比等对TiO2/PSB复合乳液性能的影响。确立了适宜的聚合工艺条件:纳米TiO2、乳化剂用量分别为总质量的0.5%和3.5%,电解质和引发剂用量为单体质量的0.4%,聚合温度和时间分别为64℃和3.5 h,可制备出高固高黏且性能优良的复合乳液。经纳米TiO2改性的PSB复合乳液涂膜性能较未改性的,在黏度、硬度、耐冲击性、耐洗刷性、附着力及耐水性等方面均有明显改善。 相似文献
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壳聚糖保鲜涂膜纳米SiO_x修饰工艺优化的研究 总被引:2,自引:1,他引:1
为了提高壳聚糖涂膜的力学性能和降低其透水率,实验先以十二烷基磺酸钠(SDS)活化纳米SiOx,随后将其加到壳聚糖乙酸溶液中,并用流延法制得分散比较均匀的壳聚糖纳米复合膜.此外采用二次回归旋转正交组合试验设计方法,优化了壳聚糖/纳米SiO(CTS/SiOx)复合涂膜的制备工艺条件,并通过红外(IR),X射线衍射(XRD)和电镜透射(TEM)手段对CTS/SiOx.复合涂膜的性能和结构进行袭征.优化结果表明,当壳聚糖(CTS)、活化纳米SiOx和单甘酯(Glyc)添加量分别为1.547 g、0.028 g和0.015 g时,CTS/SiOx,复合涂膜的性能达到最优,其拉伸强度和撕裂强度分别为54.85MPa和51.77kN·m-1,分别比未修饰壳聚糖单膜提高了63%和12%,而透水率却下降了73%.将制备的CTS/SiOx复合涂膜用于果蔬室温保鲜,保鲜质量和保鲜时间比对照组均有明显提高. 相似文献
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透水量的大小可以作为壳聚糖/纳米Ti O2复合膜保鲜效果好坏的标准。以透水量为目标函数,对壳聚糖用量、Ti O2用量和甘油用量进行L9(3)3三因素三水平的正交实验,实验结果表明:每100g复合膜溶液中壳聚糖2.0g,纳米Ti O20.03g,甘油2.5g,壳聚糖复合涂膜的透水量达到最低,在此含量下,将其应用于鲤鱼的保鲜,并对挥发性盐基氮、微生物指标、感官指标等进行测定,复合膜可以达到较好的保鲜效果。 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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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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. 相似文献
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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
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中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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
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中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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