We have studied the self-assembly of amphiphilic dendrons extended with linear polyethylene oxide (PEO) chains and their ion complexes. Keeping dendron core PEO chain compatible allows for combination dendritic core-shell conventional blockcopolymer characteristics complex mesophase behavior. An unexpected sequence crystalline lamellar, cubic micellar (Pm3n), hexagonal columnar, continuous (Ia3d), lamellar mesophases is observed. Multiple phase behavior within single compounds study charge...

SiO 2 -based xerogels are highly porous materials that may enhance the performance of microelectronic devices due to their extremely low dielectric constants (ε=1.36–2.2). Conventional xerogel and aerogel manufacturing techniques include an expensive hazardous supercritical drying step deposit crack free, high porosity films. Ambient have recently been developed in this article, we discuss how process parameters ambient affect properties a spin-coated film. Successful spin-on deposition...

Several strategies are demonstrated for the use of additive‐driven chemistries that take place in only one type nanosized domains all‐organic and organic–inorganic hybrid block copolymer thin films. Such an approach is used to examine convergence “top–down” “bottom–up” fabrication via light‐driven processes. Characterization carried out with microscopies grazing‐incidence small‐angle X‐ray scattering (see Figure cover).

The deformation and fracture behavior of several dynamic vulcanizate blends isotactic polypropylene with ethylene-propylene-diene rubber (EPDM) was examined compared those uncrosslinked PP/EPDM. These were prepared by melt mixing in an internal mixer at 190°C a composition range 10–40 wt % EPDM rubber. variation yield stress, the strength fibrils craze, number density domains (morphology fixation) that are dominant factors for enhancing interfacial adhesion toughness evaluated. ductility...

Abstract Studies have been carried out at 2.38 MPa total pressure and 360 400°C of the synthesis ammonia over a triply‐promoted iron catalyst (United Catalysts Inc.). Runs were using gradientless reactor in steady‐state periodic modes, latter employing forced composition cycling. The had particle diameter 0.30 mm; resulting reaction rates free from transport intrusions. range mean compositions for measurements was 0.1 to 0.9 mole fraction hydrogen operation 0.5 0.9. cycle‐split ratio (used...

The etching of various xerogel films has been studied in high-density fluorocarbon plasmas. etch rate is part enhanced by the porosity. In discharges resulting low surface polymerization, such as CF4 or oxygen-rich plasmas, an additional enhancement up to 60% observed. When polymerization discharge increased, this disappears and becomes more suppressed. suppression pronounced for with a higher porosity larger pore size. X-ray photoelectron spectroscopy analysis on partially etched samples...

Study of melts rheological properties unvulcanized and dynamically vulcanized polypropylene (PP)/ethylene-propylene-diene rubber (EPDM) blends, at blending ratios 10–40 wt %, EPDM, are reported. Blends were prepared by melt mixing in an internal mixer 190°C parameters have been evaluated 220°C single screw capillary rheometer. Vulcanization was performed with dimethylol phenolic resin. The effects (i) blend composition; (ii) shear rate or stress on viscosity; (iii) sensitivity flow...

Tensile yield behavior of the blends polypropylene (PP) with ethylene-propylene-diene rubber (EPDM) is studied in blend composition range 0–40 wt % EPDM rubber. These were prepared a laboratory internal mixer by simultaneous blending and dynamic vulcanization. Vulcanization was performed dimethylol phenolic resin. For comparison, unvulcanized PP/EPDM also prepared. In comparison to blends, dynamically vulcanized showed higher stress modulus. The increase interfacial adhesion caused...

Abstract A computational study is reported of the behaviour three catalytic reaction models containing conventional adsorption, desorption, and surface steps under conditions forced composition cycling in a mixed reactor. The contained varying degrees non‐linearity. With long cycle periods, time‐average rate asymptotically approached quasi‐steady state. Time‐average was found to be bounded by asymptotes state slow cycling, relaxed steady rapid cycling. It concluded that approach used until...

Biodegradable polymers can potentially be combined with natural fibers to produce biodegradable composite materials. In this work, PLA (Polylactide) was used in combination Jute fabric generate bio-composite by compression molding technique. Various mechanical characterizations like tensile, flexural and impact properties of were determined. The result from testing showed that use PLA, increases the tensile strength modulus 23% 14% respectively. Flexural found increased 8% 102% However...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDensities and refractive indexes of aqueous zinc nitrate solutionsSurender K. Jain, Anil Ajay Gupta, Vijay V. SinghCite this: J. Chem. Eng. Data 1985, 30, 3, 301–304Publication Date (Print):July 1, 1985Publication History Published online1 May 2002Published inissue 1 July 1985https://pubs.acs.org/doi/10.1021/je00041a019https://doi.org/10.1021/je00041a019research-articleACS PublicationsRequest reuse permissionsArticle...

Abstract Adsorption studies of normal paraffins, monoolefins, and their mixtures on X-type zeolites are reported. isotherms at ambient temperature for single components, viz., n-octane, 1-octene, water, were measured in the vapor phase. measurements carried out liquid phase a specially designed cell. The various systems studied include n-octane/1-octene, n-decane/1-decene, n-undecane/1-undecene, n-dodecane/1-dodecene, n-dodecane/1-tetradecene. with Na+, K+, Ca2+, Sr2+, Ba2+, or as...

Abstract Batch equilibrium and kinetic studies were carried out for adsorption of water from aqueous solution isopropyl alcohol on 4A molecular sieves (cylindrical pellets 1.8 mm diameter). Equilibrium data obtained rectangular in shape. The capacity was about 0.25 g per gram dry adsorbent. This corresponds to 0.29g water/cm3 sieve pellets. effect temperature behavior not significant the range 20 70°C. at room temperature. Differential equations uptake by biporous cylindrical particles...

Abstract Experiments were carried out in which the reactants, nitrogen and hydrogen admitted to a fixed bed of triply‐promoted iron catalyst form concentration step‐functions. Temperature was about 400°C, total pressure 2.38 MPs. The stabilized with equimolal flows then stepped up pure or down nitrogen. From rate ammonia production, properties, temperature behaviour, it inferred that is dissolved by bulk phase catalyst. This result has important implications for general model transient...