Irreversible swelling

A fine or coarse wrinkling due to irreversible swelling of a surface-dried film. 

Research on resin-bonded boards has used wood chips, or fibres, that are acetylated prior to composite manufacture. In almost all cases, acetylation has been achieved by using uncatalysed acetic anhydride. Significant improvements in dimensional stability proportional to the WPG of the wood particles have been reported when acetylated wood is used, and there is also a reduction in irreversible swelling (e.g. Bekere etal., 1978 Arora etal., 1981 Rowell etal., 1986a-e, 1989, 1990, 1991,1995 Yoshida etal., 1986 Youngquist etal., 1986a,b, 1988 Larsson and Tillman, 1989 Subiyanto etal., 1989 Vick etal., 1991 Clemons etal., 1992 Kajita and Imamura, 1993 Sasaki and Kawai,... 

The actual cause of membrane instability, whether due to an unstable chemical bond or to a gradual, irreversible swelling of the structure, has not been determined. 

In recent years the Coal Research Laboratory has been investigating the kinetics and isotherm behavior of methanol sorption on coal (6, 7, 10) along with the sorption of other vapors on coal (6) and of polar vapors on swelling gels (9, 10). Methanol sorption was shown to be reversible on coal, and its sorption behavior supports the model of coal as a gel or mixture of gels in its physical structure. All indications (I, 6, 7) are that its interaction is with specific and a fixed number of sites for a particular coal sample. Although the sorption of methanol is reversible, coal exhibits sorption behavior which is interpreted in terms of an irreversible swelling of the coal gel upon initial exposure to methanol vapor. As a result of these studies, an isotherm and experimental rate equation for the sorption and desorption were derived that fit the observed data. The isotherm derived for methanol sorption on coal was ... 

The hollow (PtS/AlA)4 microcapsules keep the original shape of cores and the integrity of their walls remains even after the removal of CaCOj. According to CLSM and AFM analysis both in wet (Fig. Ic) and in dry (Fig. 2a) states, the diameter of hollow (PtS/AlA)4 microcapsules is 3.0 0.2 pm and comparable to the diameter of initial matrix (Fig. la). Thus, it is necessary to note, that for the obtained (PtS/AIA)4 microcapsules, the effect of partial irreversible swelling is not observed, in contrast to the capsules made of similar polysaccharides and protein protamine but on different cores, as described in [5,9]. 

Irreversible swelling is a phenomenon principally observed with acrylic strong base anion exchange resins whereby upon undergoing their first few aqueous ion exchange cycles an irreversible expansion occurs of around 7—10% over and above the reversible volume changes which thereafter apply. 

According to the literature (see section S087 there) damage due to mineral acids can easily be recognized under the microscope by means of the irreversible swelling of the nylon fibres. Acid residues can also be detected microscopically by embedding the sample in 0.1% Methyl Orange solution (typical needle formation, see Section 8.5.2). 

Panel density (g/cm ) Measured wet (%) Measured dry (irreversible swelling) (%) Original IB, tensile perpendicular (kg/cm ) IB after a 2-h boil (kg/cm ) Cyclic test after five cycles measured (%)... 

Wood a mixed polymer with lignin as a structural component. Deposition of lignin in the cellulose matrix of the cell wall is called lignification. It is in principle comparable to an irreversible swelling. Cellulose and lignin are physically and chemically bound together in W. 

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