Ion-exchange hollow fibers

An ion-exchange hollow fiber is prepared by introducing into the wall of the fiber polymerizable liquid monomers, and polymerizing the monomers therein to form solid, insoluble, crosslinked, ion-exchange resin particles which embed in the wall of the fiber. Excess particles blocking the central passage or bore of the fiber are removed by forcing liquid through the fiber. The fibers have high ion-exchange capacity, a practical wall permeability and good mechanical strength even with very thin wall dimensions. Experimental investigation of bundles of ion-exchange hollow fibers attached to a header assembly have shown the fiber to be very efficient in removing counterions from solution

Thermo and salt responsive poly(ionic liquid)s.

Poly(ionic liquid)s are defined as ionic liquids which feature polymerizable groups in either the cation, the anion, or both. The aim of this study is to synthesize a tributylhexyl phosphonium sulfopropyl acrylate (PSPA) poly(ionic liquid) (PIL) hydrogel and characterise its temperature and salt concentration induced shrinking. The gels were polymerised in circular moulds and were hydrated in deionized water (DI water). The percent shrinking upon exposure to a stimulus was calculated using the formula: %s = (Ai- Af)/Ai x 100, where Ai is the initial area of the swollen hydrogel and Af is the final area of the hydrogel after the application of the stimulus

Insoluble polyelectrolyte and ion-exchange hollow fiber impregnated therewith

The number of quaternary sites and ion exchange capacity of a polyquaternary, cross linked, insoluble copolymer of a vinyl pyridine and a dihalo organic compound is increased by about 15-35% by reaction of the polymer with an amine followed by quaternization, if required. The polymer forms spontaneously in the presence of a substrate such as within the pores of a hollow fiber. The improved resin impregnated fiber may be utilized to remove ions from waste or process steams

Ionic Liquids containing metallic nucleus

In this PhD thesis, new methods to solubilize metal salts in ionic liquids (ILs) were developed and the behavior of the new metal containing ILs was studied. To incorporate metals in ILs, till now, anions (chloride, bromide, dicyanamide) able to give strong complexes with metals or the introduction of specific functional groups on cation or anion able to interact with the metal cation have been used. In all these cases, chemical nature of metal is changed by the interaction with other atoms and formation of new chemical bonds. To have weakly coordinated or relatively “free” cations in ILs, new kind of salts, with very soft anions have been used. New metallic salts, with Tf2N- as anion, were dissolved in suitable ionic liquids obtaining high concentrated solutions. Experiments performed using different classes of ILs evidenced that ILs having the same anion of the added metal salt generally assure a relevant solubility. A new common anion effect was invoked. The physical-chemical properties of the metal containing solutions were determined as function of concentration and temperature. Moreover, new ILs bearing cations or anions able to interact with the metal center were synthesized. In this contest basic 1,4-diazabicyclo[2.2.2]octane (dabco) based ILs bearing different alkyl chains and having as counter anion dicyanamide were synthesized and characterized as well as imidazolium based ILs functionalized with hydroxyl substituted alkyl chains (glycerol) or polymerizable groups (allyl, vinyl and styril groups). The interaction between dicyanamide anion and metals, especially in copper-catalyzed reactions was investigated. Since the purity degree of ILs is very important for their application in synthesis, especially when ILs must be used in metal catalyzed reactions, or when kinetics studies have to be performed, a new cheap and easily accessible method to purify ILs from organic solvents and unreacted reagents was developed and applied. Highly “pure” ILs, so generated, were used in the kinetic study of oxidation reactions performed using with singlet oxygen

Two-photon or higher-order absorbing optical materials for generation of reactive species

Disclosed are highly efficient multiphoton absorbing compounds and methods of their use. The compounds generally include a bridge of pi-conjugated bonds connecting electron donating groups or electron accepting groups. The bridge may be substituted with a variety of substituents as well. Solubility, lipophilicity, absorption maxima and other characteristics of the compounds may be tailored by changing the electron donating groups or electron accepting groups, the substituents attached to or the length of the pi-conjugated bridge. Numerous photophysical and photochemical methods are enabled by converting these compounds to electronically excited states upon simultaneous absorption of at least two photons of radiation. The compounds have large two-photon or higher-order absorptivities such that upon absorption, one or more Lewis acidic species, Lewis basic species, radical species or ionic species are formed

Poly(ionic liquid) based dual responsive smart hydrogels

Poly(ionic liquid)s (PILs) are a subclass of ionic liquid that feature polymerizable groups either in the cation, the anion or both. Applications of these materials include solid ion conductors, CO2 absorption and energy storage. Furthermore, a branch of PILs feature lower critical solution temperature (LCST) behaviour, making them suitable for the synthesis of temperature responsive materials. The aim of this study was to synthesize thermo-responsive crosslinked PIL hydrogels based on phosphonium PILs. Moreover, taking into account that these PIL hydrogels consist of polyelectrolyte chains, the effect of added salt was also investigated

Ion-exchange hollow fibers

An ion-exchange hollow fiber is prepared by introducing into the wall of the fiber polymerizable liquid monomers, and polymerizing the monomers therein to form solid, insoluble, cross-linked, ion-exchange resin particles which embed in the wall of the fiber. Excess particles blocking the central passage or bore of the fiber are removed by forcing liquid through the fiber. The fibers have high ion-exchange capacity, a practical wall permeability and good mechanical strength even with very thin wall dimensions. Experimental investigation of bundles of ion-exchange hollow fibers attached to a header assembly have shown the fiber to be very efficient in removing counterions from solution

Ion-exchange hollow fibers

An ion-exchange hollow fiber is prepared by introducing into the wall of the fiber polymerizable liquid monomers, and polymerizing the monomers therein to form solid, insoluble, cross-linked, ion-exchange resin particles which embed in the wall of the fiber. Excess particles blocking the central passage or bore of the fiber are removed by forcing liquid through the fiber. The fibers have high ion-exchange capacity, a practical wall permeability and good mechanical strength even with very thin wall dimensions. Experimental investigation of bundles of ion-exchange hollow fibers attached to a header assembly have shown the fiber to be very efficient in removing counterions from solution