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Ar等离子体改性PTFE膜接枝丙烯酸研究 总被引:1,自引:0,他引:1
研究利用Ar等离子体为引发手段对聚四氟乙烯(PTFE)膜进行表面处理,最终实现在PTFE膜表面接枝丙烯酸.通过XPS和ATR-FTIR对改性膜的表面进行表征,表明在PTFE膜的表面形成一层聚丙烯酸(pAAc)薄膜.PTFE-g-pAAc膜的表面亲水性及其表面稳定性比等离子改性PTFE膜(PTFE modified by plasma)具有较大的改善,克服了等离子体改性效果不稳定的缺点.本研究拓展了PTFE膜材料在其他各相关领域的应用,对其他高分子材料也有一定的借鉴意义. 相似文献
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远程氩等离子体改性膜固定化脲酶的研究 总被引:2,自引:0,他引:2
利用远程Ar等离子体技术引发聚四氟乙烯(PTFE)膜表面接枝丙烯酸,并以此膜为脲酶的固定化载体。研究结果表明:在放电压力20 Pa、放电功率100 W、放电时间100 s的等离子体处理条件和接枝温度70℃、接枝时间50 h、单体体积分数26%的接枝条件下,PTFE膜表面丙烯酸接枝量为131.7μg/cm2;固定化脲酶接枝密度随PTFE膜接枝丙烯酸(AA)量的增加几乎呈线性上升,固定化酶活性开始随PTFE膜接枝AA量的增加而增加,随后趋于平缓增加。同时评价了固定化酶膜的稳定性,并对接枝膜和固定化酶膜的结构进行了表征。 相似文献
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高密度聚乙烯表面光接枝丙烯酸行为研究 总被引:3,自引:0,他引:3
研究了以二苯甲酮为光敏剂时,紫外光辐照时间、温度、丙烯酸(AA)单体浓度、预覆液中光敏剂浓度等因素对高密度聚乙烯(HDPE)接枝率和接枝效率的影响,以及接枝HDPE膜的接触角与接枝率的关系。随辐照时间延长,HDPE的接枝率增加,4min时的接枝率为15%,膜表面对水的接触角由来接枝时的83°降到36°;随接枝时间的进一步延长,接枝率不断增加,但接触角变化不大。升高温度、增加单体浓度,可以促进接枝反应的进行,使接枝率增加。预覆液中光敏剂浓度也影响HDPE的接枝率和接枝效率。红外光谱(IR)结果表明,HDPE膜表面已接枝了PAA。差热分析(DSC)结果表明,接枝破坏了HDPE的结构规整性,影响其结晶度。 相似文献
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《现代化工》2017,(11)
为改善PTFE中空纤维膜表面亲水性能,扩大其在污水处理领域中的运用,采用含有磺酸基、氨基、羟基、醛基、羧基的溶液浸渍预处理,利用低温等离子体法对PTFE中空纤维膜进行表面亲水改性。SEM、ATR-FTIR分析结果表明,PTFE中空纤维膜经过不同亲水基团改性后,磺酸基、氨基、羟基、醛基、羧基成功地接枝到PTFE膜表面。改性后的PTFE中空纤维膜的接触角和出水渗透压有较大幅度下降,其中经羧基改性后的PTFE中空纤维膜接触角最低下降为52°,出水渗透压下降为0.18MPa。5种亲水基团中,改性PTFE中空纤维膜最佳的亲水基团为羧基,最佳的预处理溶液为丙烯酸。 相似文献
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利用氩等离子体对聚四氟乙烯膜进行预处理,经与空气接触后接枝丙烯酸。用碘化钠法测定了膜表面过氧基团的浓度,探讨了等离子体处理时间、放电功率对膜表面过氧基团浓度的影响;过氧基团的浓度对接枝率的影响。利用红外光谱和X射线光电子能谱图鉴定了接枝产物,对改性后薄膜的表面亲水性进行了测试。 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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Peter A. Edwards Grant Striemer Dean C. Webster 《Journal of Coatings Technology and Research》2005,2(7):517-527
Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins.
Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol.
The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and
cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on
the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to
determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model
amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate
functional group is more reactive than a glycidyl ether group.
Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago,
IL. 相似文献
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Dongjiang Yang Yao Xu Lei Zhang Shangru Zhai Dong Wu Yuhan Sun 《Journal of Coatings Technology and Research》2006,3(2):127-131
A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by 1H MAS NMR. For direct comparison purposes, an SiO2 coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N2 absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals. 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