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United States Patent Application: 0020053514 The microchannel device of claim 11, wherein an outermost layer of said polyelectrolyte layers disposed on a first portion of said microchannel surface of one said arm is negatively charged and an outermost layer of said polyelectrolyte layers disposed on a second portion of said microchannel surface of said one arm is positively charged. A polyelectrolyte layer is disposed as an outermost surface on the first microchannel wall portion and a second polyelectrolyte layer of opposite charge is exposed as an outermost surface on the second microchannel wall portion. At least one polyelectrolyte layer is formed on selected surfaces of the microchannel by exposing a selected portion of a first microchannel wall surface and a selected portion of the second microchannel wall surface of the microchannel to a first solution comprising first charge polyelectrolytes. appft1.uspto.gov /netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=/netahtml/PTO/srchnum.html&r=1&f=G&l=50&s1='20020053514'.PGNR.&OS=DN/20020053514&RS=DN/20020053514   (5586 words)

Polyelectrolyte - Wikipedia, the free encyclopedia Polyelectrolyte properties are thus similar to both electrolytes (salts) and polymers (high molecular weight compounds), and are sometimes called polysalts. A 'weak' polyelectrolyte, by constrast, has a dissociation constant (pKa or pKb) in the range of ~2 to ~10, meaning that it will be partially dissociated at intermediate pH. Although the statistical conformation of polyelectrolytes can be captured using variants of conventional polymer theory, it is in general quite computationally intensive to properly model polyelectrolyte chains, owing to the long-range nature of the Coulomb interaction. en.wikipedia.org /wiki/Polyelectrolyte   (810 words)

Patent 4274599: Ore grinding process including a grinding aid of an anionic polyelectrolyte Thus, it is critical in the practice of this invention that the amount of polyelectrolyte grinding aid employed be sufficient to reverse the trend towards a lower grinding efficiency as weight percent concentration of ore solids in the slurry is increased. Examples of polyelectrolytes of particular interest are the polymers of acrylic or methacrylic acid including the monovalent metal or ammonium salts thereof, e.g., sodium polyacrylate or acrylamide/acrylate copolymer which may be derived from the partial hydrolysis of polyacrylamide. Polyelectrolytes which are insoluble or non-dispersible in the medium are, of course, not within the scope of the invention. www.freepatentsonline.com /4274599.html   (5356 words)

美国专利申请公开说明书 20040149572 - Method of preparing free polyelectrolyte membranes   (Site not responding. Last check: 2007-10-22) The release stratum and the membrane stratum contain oppositely-charged polyelectrolytes that are associated. The oppositely-charged polyelectrolytes of the release stratum are selected to dissociate upon application of stimulus whereas those of the membrane stratum are selected to remain associated upon application of the stimulus. Thus, when the stimulus is applied the polyelectrolytes in release stratum dissociate and the membrane stratum is released from the substrate and is a free membrane. cxp.paterra.com /uspregrant20040149572cn.html   (105 words)

Vascular Smooth Muscle Cells on Polyelectrolyte Multilayers: Hydrophobicity-Directed Adhesion and Growth Polyelectrolyte multilayer films were employed to support attachment of cultured rat aortic smooth muscle A7r5 cells. Polyelectrolyte films were designed to examine the effect of surface charge and hydrophobicity on cell adhesion, morphology, and motility. Increasing the proportion of AEDAPS in the copolymer decreased the adhesion of cells to the surface. pubs.acs.org /cgi-bin/sample.cgi/bomaf6/2005/6/i01/abs/bm0497015.html   (284 words)

Thin films   (Site not responding. Last check: 2007-10-22) Adsorption of polyelectrolytes and polyelectrolyte-surfactant mixtures and the interactions between surfaces coated with such adsorbed layers were studied using a range of methods. The effect of various polyelectrolytes on interactions between cellulose surfaces was thoroughly investigated and of central importance for the PhD-thesis of Evgeni Poptoshev entitled "Polyelectrolyte Moderated Interactions between Glass and Cellulose Surfaces". This line of research will be extended in 2002 with an emphasis on how the polyelectrolyte charge density affects the adsorbed amount, amount of associated water, and the viscoelastic properties of the layer as deduced from the energy dissipation during oscillation of the probe crystal. www.surfchem.kth.se /yki/sfg/Research/Surface%20Interactions.HTML   (1042 words)

[No title] Thickness of brush layer on the surface of the spherical polyelectrolyte brushes measured as the function of the pH [3]. Polyelectrolyte chains hence can be used to modify the interaction of latex particles with given surfaces. The counterions of the polyelectrolyte chains are confined to the surface layer. www.uni-bayreuth.de /departments/pci/hauptteil_forschung_sub_spb.html   (736 words)

Yakov Lapitsky Mixing of oppositely charged surfactants and polyelectrolytes in aqueous solutions can lead to associative phase separation, where the concentrated phase assumes the form of a viscous liquid, gel, or precipitate. When drops of aqueous polyelectrolyte solution are mixed with an oppositely charged surfactant solution this phenomenon can lead to the formation of gel-like particles. The size of these particles reflects and is controlled by the initial size of the polyelectrolyte solution drops used in the preparation. www.kalergroup.che.udel.edu /Members/yakov_index.htm   (167 words)

Theses from Uppsala University : 1246 - Effects of polyelectrolyte conformation, charge density and ion specificity in ... Such knowledge is essential for understanding and regulatingthe interaction between polyelectrolytes as well as between polyelectrolytes and a drug substance in apharmaceutical formulation and for its fate in the human organism. The gel formation of the sulphated polyelectrolyte ê-carrageenan was found to be dependent on theextent of inter-chain helical association and thus the nature of the polyelectrolyte counterions. Increasing the polyelectrolyte chargedensity decreased the critical aggregation concentration, increased the degree of cooperativity andincreased the magnitude of ion specific effects. publications.uu.se /theses/abstract.xsql?lang=en&isbn=91-554-4724-4   (407 words)

Andrea Liu: Polyelectrolyte Solutions   (Site not responding. Last check: 2007-10-22) Polyelectrolytes are polymers with ionizable groups that can dissociate in solution, leaving ions of one sign bound to the chain and counterions in solution. As a result, synthetic polyelectrolytes are used in environmentally benign polymer processing, as rheology modifiers in food, and in a host of other applications. Chain structure is key to understanding the behavior of polymer solutions; indeed, the field of polymer physical chemistry is largely based on the study of chain structure and its consequences for static and dynamic properties. w3.chem.ucla.edu /~rmn/liu/poly.html   (270 words)

Polyelectrolyte Brush on Nanoporous Membrane Here polyelectrolyte brushes were grafted on a nanoporous membrane to regulate the substance permeation through the pores in response to pH, temperature, oxireduction, or photo-irradiation. In order to graft the polyelectrolyte chains to the surface, track-etch porous polycarbonate membrane (average pore diameter, 200 nm) was glow-discharged and poly(acrylic acid) was graft-polymerized on the membrane surface. The polyelectrolyte brushes were put in direct contact with their environment; this allowed them to respond quickly. www.foresight.org /Conferences/MNT05/Abstracts/Ito1abst.html   (294 words)

New polyelectrolyte inks create fine-scale structures through direct writing A careful balance is needed so that the extruded ink filament is elastic enough to maintain its shape while spanning the structure, but flexible enough to adhere to other filaments. Dispensed from a syringe by a computer-controlled, three-axis micropositioner, the polyelectrolyte ink exits the nozzle as a continuous filament that is deposited into a reservoir on the substrate surface, yielding a two-dimensional pattern. After the first layer is generated, the nozzle is raised and another layer is deposited. www.news.uiuc.edu /news/04/0324inks.html   (510 words)

Patent 4090013: Absorbent composition of matter In a preferred composition the poly-electrolyte is polyacrylic acid having 40-85% of its carboxylate groups neutralized, and the cation is aluminum and is present in the amount of 0.1-1.0 milliequivalents per gram of poly-electrolyte. Examplary of the sulfonic acid-containing polyelectrolytes are the homopolymers of monoethylenically unsaturated sulfonic acids (or salts thereof) and copolymers thereof with the aforementioned ethylenically unsaturated monomers. Exemplary of the sulfate-containing polyelectrolytes are those formed by reacting homopolymers and copolymers containing hydroxyl groups or residual polymer unsaturation with sulfur trioxide or sulfuric acid; for example, sulfated polyvinyl alcohol, sulfated hydroxyethyl acrylate, sulfated hydroxypropyl methacrylate. www.freepatentsonline.com /4090013.html   (4436 words)

Mats Dahlgren: How Polyelectrolytes Behave at Solid Surfaces - Summary of papers   (Site not responding. Last check: 2007-10-22) In paper I the adsorption of the polyelectrolyte MAPTAC (poly{[3-(2-methylpropionamido)propyl]trimethyl-ammonium chloride}) onto mica was studied under various conditions. The effects of changing the polyelectrolyte concentration on the surface forces were studied in paper II. XPS (ESCA) measurements show that at the cnp, the polyelectrolyte charges compensate the mica lattice charge to 80%, and above the cnp polyelectrolyte adsorption reaches the plateau in the adsorption isotherm, at which the charge compensation by the polyelectrolyte is 100%. www.homenet.se /matsd/thesis/peksmf.htm   (940 words)

Dr. Joseph B. Schlenoff's Homepage Polyelectrolytes offer great versatility as building blocks: their conformation is a sensitive function of solution ionic strength, which also regulates interaction between the charges on the backbone. When these and other experimental variables are added to the vast palette of polyelectrolyte architectures available for multilayer synthesis, a large parameter space for experimentation is created. Laurent, J.B. Schlenoff; Langmuir, 13, 1552 (1997), "Multilayer Assemblies of Redox Polyelectrolytes." www.chem.fsu.edu /schlenof   (750 words)

ScienceWeek   (Site not responding. Last check: 2007-10-22) It is already known that polyelectrolyte adsorption is governed by the charge reversal that appears on the film surface after each dipping step and that constitutes the buildup motor for the assembly. This regime is characterized by film thickness and the amount of adsorbed polyelectrolytes that increase more rapidly than linearly with the number of deposited layer pairs. The use of dye-conjugated polyelectrolytes now allows a direct three-dimensional visualization of the film construction by introducing fluorescent polyelectrolytes at different steps during the film buildup. www.scienceweek.com /2003/sw030919.htm   (5269 words)

Patent 4079029: Absorbent articles made from latexes of carboxylic synthetic polyelectrolyte containing n-substituted ... This invention relates to water swellable absorbent articles made from crosslinked polyelectrolytes, methods for their preparation, and to a composition consisting of polyelectrolytes containing a copolymerized crosslinker which is useful to make absorbent articles. It is sometimes desirable to add a small amount of a surfactant to the polyelectrolyte composition to aid in flowing on and removing the continuous film from the water impervious substrate. The swelled polyelectrolyte is then collected by filtration and the gel capacity is reported as grams of solution gelled per gram of polymer salt. www.freepatentsonline.com /4079029.html   (2006 words)

Research News   (Site not responding. Last check: 2007-10-22) As reported in the May 20 issue of Chemistry of Materials, the researchers formed the polyelectrolyte coatings by LBL deposition of poly(allylamine hydrochloride) (PAH) and poly(sodium 4-styrenesulfonate) (PSS) onto negatively charged polystyrene or silica colloids. Gelation and the formation of thin, thickness-defined hybrid organic/inorganic coatings were produced upon hydrolysis and condensation of the precursor. Water contained in the polyelectrolyte layers caused an in situ sol-gel process, leaving hybrid organic/inorganic coatings of a given thickness. www.mrs.org /publications/bulletin/researchnews/jul02/2.html   (385 words)

Polyelectrolyte NSOM Polyelectrolyte layer-by-layer (LbL) assembly has shown promise as a route for fabricating thin films with controlled thickness and designed functionality. This technique begins with a substrate with an excess surface charge on which alternating layers of polycations and polyanions are deposited by dipping the substrate into a dilute solution of the appropriate polyelectolyte salt. Since the polyelectrolyte requires that the properties defined on a nanoscale in an individual layer extend to the macroscale. www.chem.ucsb.edu /~buratto_group/PMNSOM.htm   (405 words)

Polyelectrolyte Brush on Nanoporous Membrane In the present investigation, we synthesized a polypeptide brush on a nanoporous polymeric membrane to have stimulus-sensitive gating of channel. It is known that the conformation of polyelectrolyte chain is dependent upon the environmental conditions such as pH and ionic strength. Previously we devised some porous membranes having polyelectrolyte brush on the surface, which was prepared by plasma polymerization. www.foresight.org /Conferences/MNT05/Papers/Ito1   (1158 words)

Boltac Industries - Products - The Jar Test The typical polyelectrolyte dose in most water treatment plants is around 0.1ppm. A 100ppm Polyelectrolyte solution should be kept no longer than two days and also stored in a dark, cool place or fridge. The Alum tank is 20% by volume Alum and the polyelectrolyte is at 0.2%. www.wave.co.nz /~boltac/jartest.htm   (962 words)

Thompson, Ansel Frederick (1967-10-30) The ultrafiltration of salt-polyelectrolyte solutions. ... The sodium chloride activity data were compared with the simple additivity rule or dissociation theory for the activity of simple salts in polyelectrolyte solutions and with theory based upon the cylindrical electrostatic model. Concentration polarization effects during filtration were eliminated only in the case of the lower polyelectrolyte concentrations studied and at relatively low filtration rates using high stirring speeds. At the solution-membrane interface, where the polyelectrolyte separation takes place, equilibration of the salt leads to an effective concentration equal to the equilibrium salt concentration; thus, the filtrate salt concentration is significantly greater than the salt concentration in the salt-polyelectrolyte solution being filtered. resolver.caltech.edu /CaltechETD:etd-10042002-160148   (350 words)

Examensarbeten på kemiinstitutionen   (Site not responding. Last check: 2007-10-22) Polyelectrolyte multilayer self-assembly is currently considered among the most powerful and flexible methods for surface engineering. One such system can be constructed on the basis of a weak polyelectrolyte (with pH dependant degree of ionization), which is sequentially adsorbed with a permanently charged polyelectrolyte of opposite charge. Previous investigations have shown that when the degree of charge and the structure of the building polyelectrolytes are mismatched the whole multilayer decomposes rather rapidly. www.kemi.kth.se /exjobb/multilayers/index.html   (213 words)

Thread connections reduce pump sizes: News from ITT Industries Jabsco, Rule and Flojet Polyelectrolyte mixtures are used in treatment of sewage and sludge or for the treatment of potable and process water for the removal of colloidal solid matter from liquids. Jabsco FIPs are widely used to transfer concentrated, wetted polyelectrolyte to a maturation tank for aging before use. The high concentration of long-chain-molecular polyelectrolyte mix is particularly susceptible to damage during transfer. www.engineeringtalk.com /news/jab/jab100.html   (332 words)

regine In the fotos you see the "new" thinner film thickness as darker spots which extend to a new homogeneous film thickness (see fotos).The studies reveal that the amplitude of the disjoining pressure oscillations are reduced with increasing ionic strength and decreasing degree of charge of the polelectrolyte chain. The results show that the jumps in film thickness and therefore the structuring is due to the electrostatic repulsions between the polyelectrolyte chains. A mesoscopic ordering of the polyelectrolyte chains in the film similar to that one found in aqueous semi-dilute polyelectrolyte solutions is assumed. www.tu-berlin.de /%7Einsi/ag_findenegg/regine/regine.html   (885 words)

Applied Enzyme Technology Ltd. Since AET was launched in 1994, the company has now identified a "next generation" of stabiliser molecules which give further stability to proteins and more versatility for the wider application of stabiliser formulations in industry. At AET we have been examining how certain interactions are generated between stabiliser molecules and proteins, how this effects their overall stability and how this can enable us to more accurately predict an optimal stabiliser formulation. From the research carried out at AET, it is apparent that the ratios of polyelectrolyte to polyalcohol are extremely important in the overall stabilisation of proteins. www.aetltd.com /tech/main.html   (518 words)

Monte Carlo Simulation Study of DNA Polyelectrolyte Properties in the Presence of Multivalent Polyamine Ions   (Site not responding. Last check: 2007-10-22) The question of the interaction between the DNA polyelectrolyte and complex multivalent polyamines such as spermidine is interesting also from a theoretical point of view. The interaction between a polyvalent counterion with three distributed charges and a polyelectrolyte surface, is weaker than that of a three-valent point charge counterion. The spermidine concentration near the DNA polyelectrolyte surface is lower for Mg as the competing counterion. www.fos.su.se /physical/sasha/spd/SPD.html   (6105 words)

NIST - Materials Science Engineering Laboratory - Polymers Division - Out from under the Radar Polyelectrolytes differ in chain dynamics and equilibrium structure from neutral polymers due to the presence of long-ranged electrostatic interactions. We have measured the statics and dynamics of labeled counterions and polyelectrolytes through the partial structure factors for a model system composed of poly(styrene sulfonate) (PSS) and counterions including sodium, magnesium, and tetramethylammonium (TMA+). An example of the dynamic structure factor for NaPSS in D2O taken for several values of the scattering wave vector (Q) is shown in Fig. polymers.msel.nist.gov /out-from-under-the-radar/Counterion-Polyelectrolyte-Dynamics-Neutron-Spin-Echo-Spectroscopy.html   (484 words)

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