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The chemical analysis of egg-based wall paintings-the mezzo fresco technique-is an interesting topic in the characterisation of organic binders. A revised procedure for a dot-enzyme-linked immunosorbent assay (dot-ELISA) able to detect protein components of egg-based wall paintings is reported. In the new dot-ELISA procedure we succeeded in maximizing the(More)
When investigated under high concentration conditions, hyaluronan (HA) solutions in physiological saline are shown to generate stable superstructures. An abrupt change in the rheological properties observed on increasing the temperature suggests the breaking of certain cooperative bonds. The thermal disruption of the HA superstructure is accompanied by a(More)
We report the development of a new type of hydrogel in which a cosolvent has been added to the water component. The gel networks are based on the well-known poly(vinyl alcohol)-borate systems (PVA-borate). However, it is shown that the rheological and solubilizing properties of the hydrogels can be modified drastically by the addition of a cosolvent. The(More)
Chitosan is a linear chain polysaccharide comprising glucosamine and N -acetyl glucosamine residues joined together by β -1,4-glycosidic bonds. It is derived as an acids-soluble material by deacetylation of chitin, which is commonly found in the outer skeleton of crustaceans and in the cell walls of fungi. A variety of fundamental properties such as(More)
Calcium sulphate dihydrate nanocrystals of 25-100 nm width have been synthesized in 100% purity and yield by means of a method--the cryo-vacuum process--consisting of rapid freezing of quasi-saturated solutions and subsequent vacuum assisted sublimation of water. Transmission electron microscopy reveals both curled nano-lamellae and smaller, irregular(More)
The works of art and artifacts that constitute our cultural heritage are subject to deterioration, both from internal and from external factors. Surfaces that interact with the environment are the most prone to aging and decay; accordingly, soiling is a prime factor in the degradation of surfaces and the attendant disfigurement of a piece. Coatings that(More)
The synthesis and characterization of a novel series of polymer gels are reported. They are formed at ambient temperatures by bubbling CO(2) through solutions of polyallylamine (PAA; a latent gellant) in several organic liquids, including aliphatic alcohols and 1-methyl-2-pyrrolidone. The stabilities of the alcohol gels, as indicated by the (irreversible)(More)
The microstructure of aggregates formed by sodium dodecyl sulfate (SDS) and 1-pentanol in mixtures of water and a polar aprotic solvent (propylene carbonate, PC) was investigated by means of pulsed gradient spin-echo NMR, dynamic light scattering, viscosity, and conductivity measurements. PC partitions itself between micelles and aqueous bulk. The fraction(More)
A gel-like, high-viscosity polymeric dispersion (HVPD) based on cross-linked borate, partially hydrolyzed poly(vinyl acetate) (xPVAc, where x is the percent hydrolysis) is described. Unlike hydro-HVPDs prepared from poly(vinyl alcohol) (PVA) and borate, the liquid portion of these materials can be composed of up to 75% of an organic cosolvent because of the(More)