Soap-based detergent formulations: VI. Alkylaryl sulfonamide derivatives as lime soap dispersing agents

Alkylbenzenes, such as industrial detergent alkylates, as well as pure 1-phenylalkanes whose side chain lengths varied C₈−C₁₂, were converted into the corresponding alkylbenzenensulfonyl chlorides with chlorosulfonic acid. Surface active sulfonamides were obtained from the reaction of the sulfonyl chlorides with various low mol wt aminosulfonic acids, such as N-methyltaurine, or with aminoalkyl esters of sulfuric acid, such as 2-aminoethyl hydrogen sulfate. The hydrolytic stability of the resulting surface active sulfonamide derivatives was investigated. As expected, the sulfonates were quite resistant to acid or alkaline hydrolysis, while the sulfates were more susceptible to hydrolysis. Hydrolytic stability of the sulfonamides was compared with that of the analogous fatty acid amide sulfactants. All of the compounds were excellent lime soap dispersing agents giving Borhetty-Bergman values of 4–10. The compounds were evaluated for detergency either alone or formulated either with tallow soap or with tallow soap and sodium silicate (Na₂O/SiO₂ ratio of 1∶1.6) The derivatives of the pure hydrocarbons which gave the best overall detergency were those of 1-phenyldecane and 1-phenyldodecane, whereas those of 1-phenyloctane exhibited poor detergency. This ranking was observed when the compounds were tested alone as well as when formulated. The sulfonamide derivatives of the detergent alkylate type of alkylbenzenes exhibited excellent detergency characteristics and showed substantial potentiation of detergency when mixed with soap or with a soap-sodium silicate blend. The detergency performance of some of these formulated detergents was equal to that of a commercial household detergent used as a control.     

Mixed sulfated tallow alkanolamides as lime soap dispersing agents

Sulfated alkanolamides of hydrogenated tallow fatty acids have been shown to possess excellent lime soap dispersing and detergent properties. However the high melting points of the alkanolamides and their relative insolubility in organic solvents such as dichloroethane make sulfation on an industrial scale awk ward. This difficulty has been overcome by the use of a eutectic mixture of the N-(2-hydroxypropyl)amide and N-(2-[2-hydroxyethoxy]ethyl)amide of unhydrogenated tallow fatty acids. The sulfation of such a mixture can be carried out at or slightly above room temperature, and only a small amount of a chlorinated solvent is required in order to keep the sulfation mixture fluid. The resulting sulfated mixed alkanolamide is an excellent lime soap dispersing agent, which is formulated readily with tallow soap and a glassy silicate into an effective heavy duty detergent.     

Metal cation complexes as dispersing agents for non-aqueous powder suspensions

Formulation of high solid load slurries is an important aspect in achieving dense, high quality ceramic green body shaping by additive manufacturing techniques. To this end, the understanding and control of interparticle interactions in non-aqueous organic slurry systems is imperative. With nanosized powders gaining increasing interest, particle stabilization by long-chain polymeric dispersants is undesirable due to the high exclusion volume associated and the subsequent decrease in the maximum solid load of the suspension. In this study, we focus on the stabilization mechanisms provided by metal cation complexes in methyl ethyl ketone and isopropanol-based spinel slurries. Special focus is given to chromium (III) 2-ethylhexanoate. Hemi-micelle formation at the powder surface in methyl ethyl ketone is suggested as a highly efficient stabilization mechanism. Complexes of metal dopant cations may open new pathways towards future advances in ceramic slurry formulation, especially in the field of additive manufacturing. Furthermore, the importance of solvation forces is discussed on the basis of the protic or aprotic character of the solvent used.     

Modern dispersing agents for polypropylene

Dispersing agents are becoming indispensable for the effective colouring of polypropylene. Reinhold Kling and Dr. Reiner Hess of Clariant GmbH describe the development of modern dispersing agents - micronized waxes and metallocene waxes.     

Water-soluble sulfonated amino-formaldehyde resins. II. Characteristics as dispersing agents

The use of sulfonated melamine–formaldehyde resins as dispersants with inorganic materials was investigated, and the effect of these dispersants on the rheology of cement pastes was studied. The improvement in compressive strength of sand and mortar was also investigated. Results show that these polyanionic resins are effective dispersing agents when they are mixed with inorganic materials. Significant improvements in the flow and compressive strength of these systems can be realized when small quantities of the water-soluble polymers are added. The effect of reaction conditions on the molecular structure and its effect on performance is discussed.     

Coal as a carbon source for carbon nanotube synthesis

This article reviews the recent advances on the various processes used in the synthesis of carbon nanotubes (CNTs) from different types of coal (anthracite, bituminous, etc.) and on the role played by coal as carbon source in the production of CNTs. The molecular solid coal is inexpensive and widely available in comparison to the most widely used solid carbon precursor, graphite (a lattice solid) and high purity hydrocarbon gas sources. An account is given on the different processes involved in the synthesis of various CNTs (single and multi-walled, bamboo-shaped, branched, etc.) from different types of coal (anthracite, bituminous, etc.). Both arc-discharge and thermal plasma jet produce high quality CNTs but fundamental disadvantages limit their use as large-scale synthesis routes. Chemical vapour deposition appears to be promising but further experimental work is necessary in order to develop an understanding of the complex factors governing the formation of different carbon nanomaterials from coal. Successful utilization of CNTs in various applications is strongly dependent on the development of simple, efficient and inexpensive technology for mass production and coal as a carbon source has the potential to meet the needs.     

Effects of dispersing agents on dispersity and mechanical properties of carbon black/PET

Three kinds of dispersing agents, all copolyesters, were synthesized from the polycondensation reaction of dimethyl terephthalate (DMT), dimethyl isophthalate (DMI), sebacic acid (SA), and 1,4-butandiol (BD). Copolyester from DMT, SA, and BD was designated as PBTS; from DMT, SA, DMI, and BD as PBTIS; and from DMT, DMI, and BD as PBTI. Carbon black masterbatches were prepared by mixing carbon black into the dispersing agents in a Brabender Plasticorder PLE331. Using single screw extruder, masterbatches were compounded with poly(ethylene terephthalate) in 3 wt% concentration and mechanical properties of the compounds were investigated. Gel permeation chromatography data implied that thermal degradation of polymeric dispersing agents was not very significant. Capillary rheometer tests showed that PBTI has the highest viscosity and shear sensitivity of the three dispersing agents. Volume resistivities of each masterbatch were increased as the rotor rpm of the Brabender and mixing time increased. Transmission electron micrographs showed that dispersion of carbon black was enhanced by increasing the melt viscosity of the dispersing agent. The performance and mechanical characteristics of carbon-black-filled PET compounds depends directly on the dispersion quality of the carbon black in the masterbatch. Mechanical properties of compounds were improved by increasing dispersion of carbon black and increasing numbers of rigid aromatic groups in the copolyester dispersing agent.     

Water-dispersible multiwalled carbon nanotube/iron oxide hybrids as contrast agents for cellular magnetic resonance imaging

Novel magnetic resonance imaging (MRI) contrast agents composed of multiwalled carbon nanotubes decorated with magnetic iron oxide nanoparticles were explored. They were functionalized with multilayer polyelectrolytes through layer-by-layer assembling and were shown to be hydrophilic, biocompatible, and have a high MRI contrast. A targeted ligand folic acid was chemically bonded to the functionalized nanotubes for specific targeting and imaging of cancer cells in MRI. The results demonstrate that the material can be used as ideal targeted imaging agents and is sufficient to obtain strong MRI contrast.     

耐火浇注料用分散剂进展

简要介绍了分散剂在耐火浇注料中的作用及作用机理,以及无机分散剂与有机分散剂的不同分散作用机理。着重介绍了有机分散剂的进展及各分散剂的化学结构式、性质与使用效果,并提出耐火浇注料用分散剂的发展方向。     

Anodic aqueous electrophoretic deposition of titanium dioxide using carboxylic acids as dispersing agents

The dispersion of anatase phase TiO₂ powder in aqueous suspensions was investigated by zeta-potential and agglomerate size analysis. The iso-electric point (IEP) of anatase was determined to be at pH 2.8 using monoprotic acids for pH adjustment. In comparison, it was found that the use of carboxylic acids, citric and oxalic, caused a decrease in zeta-potential through the adsorption of negatively charged groups to the particle surfaces. The use of these reagents was shown to enable effective anodic electrophoretic deposition (EPD) of TiO₂ onto graphite substrates at low pH levels with a decreased level of bubble damage in comparison with anodic EPD from basic suspensions. The results obtained demonstrate that the IEP of TiO₂ varies with the type of reagent used for pH adjustment. The low pH level of the IEP and the ability to decrease the zeta-potential through the use of carboxylic acids suggest that the anodic EPD of anatase is more readily facilitated than cathodic EPD.     

Anisotropic carbon nanotube papers fabricated from multiwalled carbon nanotube webs

We fabricated large-scale anisotropic carbon nanotube (CNT) paper sheets by stacking long-lasting multiwalled CNT (MWCNT) webs without using binder materials. The MWCNTs are highly aligned in the webs and they retain their alignment in the fabricated paper. Although MWCNTs are just connected by van der Waals force, tensile strength is as strong as 75.6 MPa. In addition, resistivity and thermal conductivity is as good as 2.5 × 10⁻³ Ω cm and 70 W/m K, respectively. The present high anisotropy ratios of 7.3 in resistivity and of 8.1 in thermal conductivity are due to the high alignment of the ultra-long MWCNTs which have lengths of millimeters. High-speed web drawing with a draw speed of over 10 m/s enables very rapid fabrication. The material properties of CNT structures can be measured by conventional methods for macroscopic samples rather than methods designed for nanomaterials. CNT web technology will enable CNTs to be used in new applications.     

Single-walled carbon nanotube/Nafion composites as methanol sensors

Single-walled carbon nanotube (SWCNT)/Nafion composite films were fabricated on an interdigitated electrode by using a simple casting method. Nafion acts as a polymer backbone to give stable and homogeneous cast thin films. The potential use of the composites as sensors of methanol concentration in water was investigated. The composites are operative even at ambient temperatures, and respond quickly to concentration changes. The resistance increases significantly with increasing concentration between 0.5 M and 4 M. The composites may be useful as a material to measure the concentration of methanol for direct fuel cells.     

A carbon nanotube film as a radio frequency filter

This paper proposes a new concept for the application of carbon nanotubes to electronic devices. A carbon nanotube (150-200 nm width, few μm length) film grown on a metal sensitized quartz surface was modeled using a two-pole lumped element equivalent circuit consisting of a capacitor, an inductor, and two resistors. The capacitor was in series with the inductor resulting in band-stop filter characteristics with a central frequency of 18 MHz. The reactive subcircuit was in parallel with one resistor and in series with the other. The magnitude of the parallel resistance had a large influence on the efficiency of the reactive elements and the filter quality factor. A two-dimensional carbon nanotube film is expected to be suitable in the design of miniaturized RF filters.     

Soap-based detergent formulations: II. Oxyethylated fatty amides as lime soap dispersing agents

Nonionic surface active agents with two oxyalkyl chains were prepared from the triethylamine catalyzed reaction of ethylene oxide with diethanolamides of palmitic, stearic and tallow fatty acids. The addition of 4 moles of ethylene oxide was required to render these diethanolamides water soluble, whereas 9 moles were required to make the corresponding monoethanolamide soluble. Efficiency of lime soap dispersion increased as oxyethyl chain length was increased. Best detergency of soap-nonionic combinations was achieved when the oxyethyl chain length was at the minimum required for water solubility. Theγ-hydroxyethanolamides and -diethanolamides were prepared by the uncatalyzed reaction of the corresponding amines withγ-stearolactone. These compounds became water soluble at lower levels of oxyethylation, but the lime soap dispersing power and detergency were not improved over those of corresponding compounds derived from stearic acid. Presented at the AOCS Meeting, Los Angeles, April 1972. E. Market. Nutr. Res. Div., ARS, USDA.     

Soap-based detergent formulations: VII. Sodium methyl alkylbenzoylsulfopropionates as lime soap dispersing agents

Research was performed on the development of lime soap dispersing agents derived from alkylbenzenes. The sulfonation with sodium bisulfite of a variety of methyl β-p-alkylbenzoylacrylates (III) produced adducts (I) whose detergent properties were studied. Yields were optimized, model compounds were synthesized, and products characterized by NMR spectroscopy. The sulfonated adduct (I-A) derived from a commercial mixture of alkylbenzenes can be formulated with tallow soap, sodium silicate, and sodium carboxy methylcellulose to give a product that is competitive with a standard linear alkylbenzenesulfonate-phosphate household detergent.     

乳胶漆助剂

乳胶漆助剂朱传　（北京东方化工厂）Ｔｈｅｗｅｔｔｉｎｇａｎｄｄｉｓｐｅｒｓｉｎｇａｇｅｎｔｓｉｎｌａｔｅｘｐａｉｎｔｓ￥ＺｈｕＣｈｕａｎ－ｑｉＡｂｓｔｒａｃｔ：Ａｓｅｒｉｅｓｃｏｕｒｓｅｉｎｌａｔｅｘｐａｉｎｔｓ．二、润湿剂和分散剂涂料产品中的色漆都...     

Functionalized polypropylenes as efficient dispersing agents for carbon nanotubes in a polypropylene matrix; application to electromagnetic interference (EMI) absorber materials

Carbon nanotubes (CNTs) have been dispersed within polypropylene with the purpose to prepare electromagnetic interference (EMI) absorbers. In order to limit the reflectivity of the electromagnetic waves at the interface of the materials while achieving good absorbing properties, the CNTs concentration must be kept low (<3 wt%) which means that a perfect dispersion must be ensured. Since CNTs do not disperse well within apolar polymer matrices such as polypropylene, two compatibilizers bearing aromatic moieties, i.e. pyrene and pyridine, able to develop π-π interactions with the CNTs have been synthesized starting from polypropylene grafted by maleic anhydride (PP-g-MA). A masterbatch is first prepared by dispersion of CNTs within the compatibilizers by melt-mixing and coprecipitation followed by further dispersion within the PP matrix. Rheological and electromagnetic characterizations of the nanocomposites have demonstrated the efficiency of these compatibilizers to promote the dispersion of CNTs in PP and the good EMI shielding effectiveness of the PP matrix at a low CNTs concentration (2 wt%).     

Liquefied petroleum gas containing sulfur as the carbon source for carbon nanotube forests

Carbon nanotube (CNT) forests were obtained from liquefied petroleum gas (LPG) as the carbon source in the floating catalyst process. The CNTs obtained in the forest had a thinner diameter and lower growth rate than those obtained with other carbon sources, which was attributed to the existence of sulfur in the LPG. The use of unpurified LPG provides a controllable way to synthesize a CNT forest at low cost.     

Strong,conductive carbon nanotube fibers as efficient hole collectors

We present the photovoltaic properties of heterojunctions made from single-walled carbon nanotube (SWNT) fibers and n-type silicon wafers. The use of the opaque SWNT fiber allows photo-generated holes to transport along the axis direction of the fiber. The heterojunction solar cells show conversion efficiencies of up to 3.1% (actual) and 10.6% (nominal) at AM1.5 condition. In addition, the use of strong, environmentally benign carbon nanotube fibers provides excellent structural stability of the photovoltaic devices.     

Electroless plated gold as a support for carbon nanotube electrodes

A monolayer of -NH₂ terminated 3-aminopropyltriethoxysilane (APS) was self-assembled onto a p-type silicon (1 0 0) substrate. This amine terminated silane monolayer provided an electrostatic point of attachment for citrate stabilised gold colloid nanoparticles, which act as ‘seed’ particles for the electroless deposition of gold, creating an electrolessly deposited gold layer on silicon. A -NH₂ terminated cysteamine monolayer was then deposited onto the gold layer and carbon nanotubes, with high carboxylic acid functionality, were immobilised via a condensation reaction. A redox active molecule ferrocenemethanol was then chemically attached to the immobilised carbon nanotubes. These nanostructures were used as working electrodes in cyclic voltammetry to observe the oxidation and reduction of ferrocene. Important electrochemical parameters such as electrode kinetics, electron transfer rate and surface concentration of the redox active molecules were obtained, providing information on the ability of electroless plated gold surfaces to act as supports for carbon nanotube-based electrodes. This information has also provided insights into the behaviour of vertically aligned carbon nanotubes immobilised on nanoscale gold wires, which have been previously fabricated using atomic force microscopy.