Recuperative Amino Acids Separation through Cellulose Derivative Membranes with Microporous Polypropylene Fiber Matrix

Abstract

The separation, concentration and transport of the amino acids through membranes have been continuously developed due to the multitude of interest amino acids of interest and the sources from which they must be recovered. At the same time, the types of membranes used in the sepa-ration of the amino acids are the most diverse: liquids, ion exchangers, inorganic, polymeric or composites. This paper addresses the recuperative separation of three amino acids (alanine, phe-nylalanine, and methionine) using membranes from cellulosic derivatives in polypropylene ma-trix. The microfiltration membranes (polypropylene hollow fibers) were impregnated with solu-tions of some cellulosic derivatives: cellulose acetate, 2-hydroxyethyl-cellulose, methyl 2-hydroxyethyl-celluloseand sodium carboxymethyl-cellulose. The obtained membranes were characterized in terms of the separation performance of the amino acids considered (retention, flux, and selectivity) and from a morphological and structural point of view: scanning electron microscopy (SEM), high resolution SEM (HR-SEM), Fourier transform infrared spectroscopy (FT-IR), energy dispersive spectroscopy (EDS) and thermal gravimetric analyzer (TGA). The re-sults obtained show that phenylalanine has the highest fluxes through all four types of mem-branes, followed by methionine and alanine. Of the four kinds of membrane, the most suitable for recuperative separation of the considered amino acids are those based on cellulose acetate and methyl 2-hydroxyethyl-cellulose.

Osmium Nanoparticles-Polypropylene Hollow Fiber Membranes Applied in Redox Processes

“…The fibers have a porosity of 40% [54,55] and a pore diameter of less than 0.2 µm [56] (Figure 2). This type of module with polypropylene hollow fiber membranes allows operation over the entire pH range, in oxidizing or reducing solutions at temperatures up to 100 • C without dimensional changes and can be sterilized by known physical-chemical methods [57][58][59]. Polypropylene hollow fiber membranes at a length of 700 mm and a diameter of 0.3 mm are assembled so as to achieve a filtering surface of 1 m 2 [52,54].…”

“…After the oxidation process, the reaction compartment underwent three stages of tartar: with nitrogen gas to remove residual oxygen, with hydrogen (at least two hours to reduce any traces of osmium tetroxides), and then with nitrogen to remove residual hydrogen. The filtration characteristics of polypropylene hollow fiber membranes [56][57][58][59][60][61][62][63][64] ensured the complete retention of osmium nanoparticles in the reaction compartment which could be followed by established analytical techniques [74][75][76][77][78].…”

Simultaneous Release of Silver Ions and 10–Undecenoic Acid from Silver Iron–Oxide Nanoparticles Impregnated Membranes

“…The general characteristics are presented in Table 3, determined by scanning electron microscopy (SEM), in section and on the surface intended for contact with the expected working environment [33], by measuring the thickness with a micrometer [34] and determining the porosity by gravimetric method [34,35]. The procedure of obtaining membranes ensures a good surface quality (without wrinkles, surface defects or polymer agglomerations), high porosity and relatively uniform thickness (Table 3).…”

Biomedical Applications of Quaternized Chitosan

“…Snyman et al (2003) studied the effect of extent of quaternization (22–48%) and molecular mass (100,000 g/mole) on the biological activity of synthesized TMC polymers. The outcomes suggested decreased mucoadhesiveness on increased quaternization of TMC polymers [ 35 , 102 ].…”