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1.
以二苯醚和溴代十二烷为原料合成了由刚性基团连接的Gemini阴离子表面活性剂--双十二烷基二苯醚二磺酸钠(C12-DADS),用硅胶柱对其分离纯化,考察了该物质的性能,并与单烷基苯磺酸钠(C12-LAS)的性能进行了对比性的研究.结果表明:Gemini表面活性剂DADS的临界胶束浓度为6.32×10-6mol/L,比C12-LAS的临界胶束浓度低两个数量级;表面张力为42.02 mN·m-1,与C12-LAS相当;泡沫稳定性长达24 h,钙皂分散力为10.5,分解温度大于400 ℃,性能远优于C12-LAS.该表面活性剂具有较好的应用前景.  相似文献   

2.
双烷基二苯醚双磺酸盐是一种性能优异的双子表面活性剂,被广泛应用于日化、材料、印染等领域。为了进一步研究磺酸盐类表面活性剂结构与性能的关系,测定了单/双烷基二苯醚双磺酸钠(C_(12)-MADS/C_(12)-DADS)的胶束化热力学、润湿、泡沫和乳化性能,并与十二烷基苯磺酸钠(C_(12)-LAS)进行对比分析。结果表明,不同温度下的临界胶束浓度(cmc):C_(12)-DADS(1.49×10~(-4)~1.63×10~(-4)mol/L)C_(12)-MADS(3.40×10~(-4)~4.00×10~(-4)mol/L)C_(12)-LAS(1.80×10~(-3)~2.40×10~(-3)mol/L)。C_(12)-DADS的润湿性能优于C_(12)-MADS。此外,C_(12)-DADS具有较低的起泡能力和乳化能力。  相似文献   

3.
Gemini表面活性剂(一)   总被引:1,自引:2,他引:1  
陈荣圻 《印染》2005,31(23):46-49
Gemini表面活性剂由于其独特的结构,而具有优异的表面活性.其临界胶束浓度(CMC)较传统表面活性剂低数百倍,不仅应用浓度可大幅降低,而且具有传统表面活性剂不具备的性能.文中介绍了Gemini表面活性剂的研发现状,分子结构特点及表面行为,以及其优良性能.根据Gemini表面活性剂的性能,可将其分为阳离子型、阴离子型、非离子型和两性离子型,并详细阐述了合成、性能和应用.  相似文献   

4.
Gemini表面活性剂是一类含有双疏水基双亲水基的新型表面活性剂,表面活性高,临界胶束浓度低,Krafft点低,因此在增溶、杀菌、制备新材料等方面具有广阔的应用前景。本文综述了Gemini表面活性剂的研究进展、性能及应用,指出了今后的发展趋势。  相似文献   

5.
Gemini表面活性剂的研究进展及应用   总被引:1,自引:0,他引:1  
Gemini表面活性剂是一类含有双疏水基双亲水基的新型表面活性剂,表面活性高,临界胶束浓度低,Krafft点低,因此在增溶、杀菌、制备新材料等方面具有广阔的应用前景.本文综述了Gemini表面活性剂的研究进展、性能及应用,指出了今后的发展趋势.  相似文献   

6.
Gemini表面活性剂及其合成与应用   总被引:4,自引:1,他引:4  
Gemini表面活性剂由于独特的性能、优异的表面活性,它的临界胶束浓度cwc以及降低表面张力的效率均较传统表面活性剂低数百倍,不仅应用浓度大幅刚氏,而且具有传统表面活性剂不具备的性能,被誉为新一代的表面活性剂,成为表面活性剂研究开发的热点,目前正期待着大规模工业化生产.  相似文献   

7.
以脂肪醇(C_8、C_(12)和C_(16))和二苯醚为原料,在自制催化剂的催化下进行烷基化反应合成了烷基二苯醚并经减压蒸馏得到单烷基二苯醚。单烷基二苯醚经发烟硫酸(含20%游离SO3)磺化、Na OH水溶液中和后得到单烷基二苯醚双磺酸钠(MADS),产物用高效液相色谱、红外光谱以及电喷雾质谱进行了分析表征。研究了单烷基二苯醚双磺酸盐的表面性能及无机盐(Na Cl)对其表面性能的影响。结果表明,随着烷链长度的增加,单烷基二苯醚双磺酸钠的临界胶束浓度(cmc)逐渐减小,而临界胶束浓度处的表面张力值(γcmc)逐渐增加;随着Na Cl浓度的增加,单烷基二苯醚双磺酸钠的cmc及γcmc均降低。  相似文献   

8.
宋利  李雷  白红艳 《广西轻工业》2011,27(4):90-90,112
以分子内扭转电荷转移(TICT)尼罗红(NR)分子为探针,测定其在表面活性剂(C12TABr、SDS和C12E23)水溶液中的第二重荧光强度(Ia)随表面活性剂浓度(c)的变化趋势,依据Ia-c曲线的转折点可获得可靠的临界胶束浓度(cmc)值。从而,建立了一种利用尼罗红分子测定表面活性剂的cmc值的新方法。  相似文献   

9.
以脂肪醇、二苯醚和发烟硫酸为原料,经烷基化、磺化、中和反应合成了一系列烷基二苯醚双磺酸钠(C12ADPOS、C14ADPOS和C16ADPOS),并采用高效液相色谱(HPLC)对磺化产物进行了分析.测定了ADPOS的表面张力、乳化和泡沫性能.C12ADPOS、C14ADPOS和C16ADPOS的临界胶束浓度分别为2.16×10-4、5.98×10-5和6.84×10-5mol/L,临界胶束浓度时的表面张力分别为37.3、36.3和34.8 m N/m,泡沫和乳化能力随ADPOS碳链的增长先增大后减小.  相似文献   

10.
通过松香与环氧氯丙烷反应,合成了中间产物3-松香酰氧基-2-羟丙基氯,再与二乙醇胺反应,制备了3-松香酰氧基-2-羟丙基二乙醇胺,然后经盐酸催化,与环氧氯丙烷反应制得了二氯化-N,N'-二(3-松香酰氧基-2-羟丙基)四羟乙基异羟基丙二胺(阳离子Gemini表面活性剂).用FT-IR和DSC分别对产物进行了结构表征和热性能分析,同时研究了其水溶液性能.结果表明:阳离子表面活性剂的熔点为200.641℃.乳化力为34 min,临界胶束浓度为2.3x10<'-5>mol/L(电导率法测试).  相似文献   

11.
Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.  相似文献   

12.
An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.  相似文献   

13.
The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.  相似文献   

14.
The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.  相似文献   

15.
BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H2O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.  相似文献   

16.
17.
A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.  相似文献   

18.
19.
This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.  相似文献   

20.
<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the  相似文献   

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