首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
New stable silayl cationic surfactants have been studied for the destruction of toxic organophosphorus pesticides. Hexadecyl, dodecyl trimethyl silane ammonium chloride or iodide surfactants were synthesized and evaluated in the degradation of pesticides such as Diazinon, Malathion or Chlorpyrifos. The hydrolytic efficiency of each surfactant was tested by measuring the kinetics of model substrates cleavage under a pseudo-first order reaction. The iodo silayl based surfactants showed more destructive power than the chloro derivatives. Meanwhile, the hexadecyl moiety showed more effective pesticide degradation than the corresponding dodecyl moiety.
Abdelfattah M. Badawi (Corresponding author)Email:
Sahar M. AhmedEmail:
  相似文献   

2.
For the first time, a complex formed by polyaniline (in its organic metal form) and silver has been deposited on copper in nanoparticulate form. When depositing on Cu pads of printed circuit boards it efficiently protects against oxidation and preserves its solderability. The deposited layer has a thickness of only nominally 50 nm, containing the Organic Metal (conductive polymer), polyaniline, and silver. With >90% (by volume), polyaniline (PAni) is the major component of the deposited layer, Ag is present equivalent to a 4 nm thickness. The Pani–Ag complex is deposited on Cu in form of about 100 nm small particles. Morphology, electrochemical characteristics, anti-oxidation and solderability results are reported.
Bernhard WesslingEmail:
  相似文献   

3.
The degree of UV protection afforded by nano-ZnO in a polyurethane/acrylic clear topcoat was investigated. The influence of nano-ZnO concentration and dry film thickness on the optical properties (e.g., UV permeability and visible transmittance) of the coating was probed using a library of 28 samples that were prepared by high throughput techniques. A model for predicting the UV permeability of nano-ZnO filled coatings was developed and the nano-ZnO loading condition required to block >99% UV radiation was determined to be 2.0 g/m2. This model can be used to assist in the development of coatings and other polymeric systems embedded with nano-ZnO to protect the coating and underlying materials (i.e., substrate) from UV degradation.
Charles R. HegedusEmail:
  相似文献   

4.
Polyaniline/Pd nanoparticles were synthesized via ligand exchange. Pre-prepared water soluble starch/Pd nanoparticles were treated with polyaniline, and washed with water, leading to the small and well-dispersed polyaniline/Pd nanoparticles. The redox state of polyaniline was preserved during the ligand exchange reaction.
Toshikazu HiraoEmail:
  相似文献   

5.
The incorporation of metallic elements, such as gold, into porous polymeric foams is an important focus for inertial confinement fusion (ICF) experiments. Incorporation was attempted from copolymerization of new organogold(I) monomers and various co-monomers by three development methods. This report describes the preparation of new polymeric gold foams, polymerizable high internal phase emulsion (polyHIPE) foams, divinylbenzene (DVB) foams and acrylate foams (TMPTA foams). The resulting gold-doped foams are characterized by elemental analysis, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). A very homogeneous distribution of gold into the polymeric structure is obtained.
J. Thibonnet (Corresponding author)Email:
  相似文献   

6.
Three unsymmetrical bolaform surfactants with different aromatic rings and a ω-carboxyalkyl chain were synthesized and their molecular structures were characterized by ESI–MS and 1H NMR. The percentages of conversion of alkylation were judged by the iodine value measurements and the effect of reaction temperature on sulfonate content of synthesized products has also been discussed.
Yurong JiangEmail:
  相似文献   

7.
Linear alkylbenzene sulfonate (LAS) an ingredient of many household and industrial detergents can reach the environment after disposal of raw sewage. Its correct detection and quantification in different environmental samples is a critical issue for evaluating its environmental fate. This paper outlines a validation of an entire analytical procedure of LAS in environmental samples, including extraction, pre-concentration and HPLC detection and quantification with fluorescence detection.
C. BengoecheaEmail: Email:
  相似文献   

8.
The effect of the different binary aqueous organic solvents viz. 1,4-dioxane, acetonitrile, dimethylsulfoxide, ethylene glycol, and methanol, on the micelle formation and thermodynamics of a cationic surfactant cetyl triphenyl phosphonium bromide has been studied conductometrically at 298–318 K. From the conductivity data critical micelle concentration, degree of counter ion dissociation (α) and thermodynamic parameters of micellization have been determined. It is observed that micellization tendency of the surfactant decreases in the presence of binary aqueous solvents. The entropies of micellization are all positive, and they compensate the enthalpies of the process.
Kallol K. GhoshEmail:
  相似文献   

9.
Sodium Cardanol Sulfonate Surfactant from Cashew Nut Shell Liquid   总被引:1,自引:0,他引:1  
Sodium cardanol sulfonate surfactant was synthesized from cardanol from cashew nut shell liquid. Surfactant properties of cardanol sulfonate were determined and compared with dodecylbenzene sulfonate. Surface tension values were determined to be 32.25 mN/m for cardanol sulfonate at 20% w/v and 28.00 mN/m for dodecylbenzene sulfonate at 15% w/v. Critical micelle concentrations of dodecylbenzene sulfonate and cardanol sulfonate were found to be 0.435 and 0.372 mol/L, respectively. In comparison with dodecylbenzene sulfonate, the relative detergency of cardanol sulfonate was calculated to be 93.7% compared to dodecylbenzene sulfonate. Results suggest that cardanol sulfonate can be used as alternative anionic surfactant.
Sophon RoengsumranEmail:
  相似文献   

10.
An effective and economic two-step route was developed to synthesize the long alkyl chain betaine zwitterionic surfactant directly from natural fatty acids. The optimal processing conditions for synthesizing the intermediate and final product were probed and the yields of 96.4% and 88.3% were obtained for each step, respectively. The surface active behavior of the synthesized decylbetaine surfactant was investigated using the surface tension method. The related thermodynamic parameters were calculated and discussed. The fluorescence probe technology was applied to determine the micropolarity of decylbetaine micelles.
Yun Fang (Corresponding author)Email:
  相似文献   

11.
The wetting behavior of rhamnolipids produced by Pseudomonas aeruginosa LBI strain grown on waste oil substrate and sodium dodecyl sulfate (SDS) on glass, polyethylene terephthalate (PET), poly(vinyl chloride) (PVC), poly(ε-caprolactone) (PCL) and polymer blend (PVC–PCL) was investigated by the measuring contact angle of sessile drops, to determine the wetting characteristics of rhamnolipids. The comparison of the wetting profiles showed that at low SDS and rhamnolipid concentrations, the contact angle increased and when the concentration of the surfactant increased further, the contact angle decreased. The blend surface (PVC–PCL) showed better wettability than the homopolymers themselves and the blend changed the surface hydrophobicity of the polymer, making it more hydrophilic. The rhamnolipids produced by the LBI strain exhibited superior wetting abilities than the chemical surfactant SDS one. This is the first work that evaluates the wetting properties of rhamnolipids on polymer blends.
Jonas ContieroEmail:
  相似文献   

12.
We review the currently known methods of producing gold nitride and report on the influence of electrically isolated substrates on the growth of gold nitride films by reactive ion sputtering (RIS). It is found that isolation of the substrate decreases grain size and increases nitrogen content, the latter attributed to longer nitrogen ion lifetime on the surface of the growing film. The chemical reactivity of gold nitride is compared with that of pure gold films using the adsorption of 1-dodecyl mercaptan (CH3(CH2)11SH) as a model system and it is found that there is no significant difference between gold films and gold nitride in terms of Au–S binding. However, gold nitride nanoparticles are suggested to be worthy of further investigation in terms of their catalytic properties.
L. ŠillerEmail:
  相似文献   

13.
In this research, polyester fabrics were treated with three concentrations (10, 20 and 30 g/L) of macro- and microemulsions of silicones in water at 30 °C by the padding method. The treated fabrics were then dried/cured at 130 °C for 40 s. Some of the physical and chemical properties of the samples are discussed. The drapeability of treated samples was lower and found to depend on the silicone particle size. Moisture absorbency of treated samples was also lower. Colorimetric properties of softener treated fabrics were evaluated with a reflectance spectrophotometer. Scanning electron microscope (SEM) examinations showed an aggregation of silicone particles on the fiber surface.
Mazeyar ParvinzadehEmail:
  相似文献   

14.
Low molecular weight resins containing relatively high levels of acrylic acid were converted to oxidatively curable materials by reacting the carboxylic acid groups with oxazoline functional alkenes. The oxazolines were obtained by reacting fatty acid with 2-amino-2-methyl-1-propanol. The oxazolines were then reacted with the acrylic resins at elevated temperature. Relatively high yields of the desired reaction products were obtained in relatively short reaction times. The resulting resins were formulated into aqueous coatings and films were made over metal substrates. The films were cured oxidatively and evaluated for property development. The films had good general solvent resistance but poor resistance to dilute sodium hydroxide.
D. L. TrumboEmail:
  相似文献   

15.
Zeolite synthesis is driven by structure-directing agents, such as tetrapropyl ammonium ions (TPA+) for Silicalite-1 and ZSM-5. However, the guiding role of these organic templates in the complex assembly to highly ordered frameworks remains unclear, limiting the prospects for advanced material synthesis. In this work, both static ab initio and dynamic classical modeling techniques are employed to provide insight into the interactions between TPA+ and Silicalite-1 precursors. We find that as soon as the typical straight 10-ring channel of Silicalite-1 or ZSM-5 is formed from smaller oligomers, the TPA+ template is partially squeezed out of the resulting cavity. Partial retention of the template in the cavity is, however, indispensable to prevent collapse of the channel and subsequent hydrolysis.
Rutger A. van Santen (Corresponding author)Email:
  相似文献   

16.
Four ionic bolaamphiphiles were synthesized from four bolasingle systems and the surface properties of bolasingle systems and bola\oppositely charged conventional mixed surfactant systems were studied. Variations in the structure of the hydrophobic chain of bolaamphiphiles has a great influence on their antimicrobial activities. The bolaform surfactants prepared have significant antimicrobial and antifungal activities relative to their conventional analogues. The Г (saturated adsorption amount) and A min (minimum average area per surfactant molecule) of these bolaamphiphiles in both water and 0.1 M NaCl solutions were calculated and CMC of the mixed systems with oppositely charged conventional surfactants in both water and 0.1 M NaCl solutions were determined.
Hanan El-Sharkawy AliEmail:
  相似文献   

17.
Synthesis of nano crystalline zeolite Y from bentonite   总被引:1,自引:0,他引:1  
Zeolite Y was synthesized from bentonite via the hydrothermal method. The effects of various parameters on the synthesis were investigated. The samples were characterized by XRD, XRF, IR, DTG and wet chemical analysis. The results show that crystallization temperature, aging time and concentration of sodium hydroxide play important roles in the formation of the zeolite. P zeolite was the competitive phase and present in most of the products. However, under optimized conditions, such as crystallization temperature (97 °C), aging time (20 h), concentration of NaOH (3N), pure zeolite Y with high crystallinity was synthesized. The results showed that optimization of the process results in a commercial route to synthesis zeolite Y from bentonite.
N. GodazandehaEmail:
  相似文献   

18.
NMR chemical shifts and linewidth measurements were examined for mixtures of sodium 10-phenyldecanoate (Na ω-PhDec) in deuterated aqueous solutions in the presence of varying compositions of poly(ethylene oxide) (PEO) polymers of 2000 and 4000 molecular weight. In addition, variable temperature NMR spectra and NMR spin lattice relaxation times (T 1) were obtained for the PEO-4000/Na ω-PhDec system as a function of varying polymer concentrations. As expected, the polymer/surfactant systems exhibit the behaviour typical of that of an anionic surfactant/neutral polymer system with well defined critical aggregation concentrations (CMC) corresponding to the formation of polymer/surfactant complexes below the CMC of the free surfactant. The 1H-NMR linewidths acquired for the Na ω-PhDec/PEO-4000 system before and after the CMC region of the surfactant indicate that the maximum in the linewidth of the PEO proton peak is reached at approximately twice the CMC of the free surfactant. 2D-NMR NOESY measurements on this system exhibit cross peaks between the PEO protons and the protons on the surfactant backbone, consistent with the location of the phenyl group in the micellar interior. All these NMR experiments are interpreted in terms of the structure of the polymer/surfactant complexes as a function of the system composition.
Jan C. T. Kwak (Corresponding author)Email:
  相似文献   

19.
This research focused on developing alcohol-free biosurfactant-based microemulsions. Rhamnolipid-based mixtures were found to have double the solubilization parameter as compared to sodium bis(2-ethyl) dihexyl sulfosuccinate/sodium dihexyl sulfosuccinate/sodium mono- and dimethyl naphthalene sulfonate at the same total molar concentration. For the first time, a phase diagram was developed for surfactant mixtures containing soy methyl ester ethoxylate, rhamnolipid and oleyl alcohol with limonene oil. This phase diagram can be used as a guideline for selecting a surfactant system and surfactant ratio to formulate microemulsions with a given oil. In addition, the alcohol-free biosurfactant-based microemulsions required reasonable salinity values for limonene, making it viable in a variety of applications.
David A. Sabatini (Corresponding author)Email:
  相似文献   

20.
In this paper, the surfactant dodecylcysteine hydrochloride was synthesised. The surface parameters of the synthesised surfactant were studied using a surface tension technique. The surface parameters show a good surface activity of the prepared surfactant in aqueous solution. The self-assembling behaviour of the synthesised surfactant comparing with that of cysteine compound on the prepared gold nanoparticles was confirmed using transmission electron microscope (TEM) measurements. The effect of self-assembling of this surfactant on the size of gold nanoparticles was studied using TEM images. The antitumour activity of the prepared surfactant without and with the gold nanoparticles was investigated. The results show that the antitumour activity of the prepared surfactant was enhanced with the presences of the gold nanoparticles.
E. M. S. AzzamEmail:
  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号