Biomedical polymers optical properties

PMMA is an interesting polymer which is widely used in architecture, railway, aerospace, automobile and biomedical sectors due to its good mechanical and optical properties (1,51). The low cost,... 

PMMA is widely used for biomedical implants, barriers, membranes, microlithography and optical applications. In fact, it was the first implanted biomedical polymer [46-49]. Table 2.8 illnstrates the properties of PMMA. 

Applications in the biomedical area are also very important. Contact lenses, transparent medical tubing, and films for packaging are just few examples. There is literally no area of our life that has not been positively affected by the usefulness of the optical properties of polymers. 

Azo-based chitosan derivative was prepared by Dutta et al. [97] using different reaction conditions with different characteristic features like crystallinity, good thermal and smface morphological behavior. The optical property measured by UV, AFM and photolmninescence spectra. Second harmonic generation (SHG) of polymers indicated that biopolymers may be considered as potential optical materials in biomedical held of applications. 

Optical properties of chitosan/myristic acid and chitosan/nicotinic acid derivatives show red shift. Chitosan/methoxycinnamaldehyde, the IV-substimted chitosan derivative showed fairly good photoluminescence (PL) properties, and introduces polymer conformations in organic and inorganic solvents (Fig. 10). The chiro-optical properties of chitosan-derivatives may draw the attention to biomedical apphcations [128, 129]. 

Knowledge of the swelling characteristics of a polymer is of utmost importance in biomedical and pharmaceutical applications since the equilibrium degree of swelling influences the solute diffusion coefficient through these hydrogels [1], the surface properties and surface mobility [1,2,8], the optical properties, especially in relation to contact lens applications, and the mechanical properties. 

Micron and nano-sized polymer particles have wide field of interest including industrial to biomedical applications. All this is due to the faster response to environmental change, which is again responsible for its minimum size, high surface to volume ratio, low surface tension, etc. Apart from that heterogeneous polymer blends of submicrometer scale containing nanoparticles of two different polymers exhibit better mechanical [1], optical and electro-optical properties [2]. 

Finally, for practical reasons it is useful to classify polymeric materials according to where and how they are employed. A common subdivision is that into structural polymers and functional polymers. Structural polymers are characterized by - and are used because of - their good mechanical, thermal, and chemical properties. Hence, they are primarily used as construction materials in addition to or in place of metals, ceramics, or wood in applications like plastics, fibers, films, elastomers, foams, paints, and adhesives. Functional polymers, in contrast, have completely different property profiles, for example, special electrical, optical, or biological properties. They can assume specific chemical or physical functions in devices for microelectronic, biomedical applications, analytics, synthesis, cosmetics, or hygiene. 

More recently, in the 1980s and 1990s new series of fused phenothiazine derivatives, the benzo[a,b or c]phenothiazines (BPHTs), were synthesized [3, 21 and references therein] and have received a great deal of attention, mainly because of their potential applications and their important biomedical properties [12-24]. Indeed, some BPHTs are coloured compounds and have been applied as polycyclic dyes or pigments for synthetic polymers, and also in optical recording media ([21] and references therein). Moreover, certain benzo [a or c]phenothiazine derivatives are potential anti-helmintics, possess an antiviral activity, for example inhibiting the multiplication of encephalomyocarditis viruses in tissue cultures ([21,22], and refer-... 

Ionizing radiation has been found to be widely applicable in modifying the structure and properties of polymers, and can be used to tailor the performance of either bulk materials or surfaces. Currently, there is a large interest in nanoscale materials since they have both fundamental interest and potential applications in areas such as biomedical sciences, electronics, optics, material sciences. New researches involve, as might be expected, the use of the radiation in the field of nanotechnologies. 

Synthetic polymers applied in everyday life rarely possess well-defined stereochemistries of their backbones. This sharply contrasts with the polymers made by Nature where perfect control is the norm. An exception is poly-L-lactide this polyester is frequently used in a variety of biomedical applications. By simply playing with the stereochemistry of the backbone, properties ranging from a semi-ciystalline, high melting polymer (poly-L-lactide) to an amorphous high Tg polymer (poly-mes o-lactide) can be achieved. The synthetic synthesis of such chiral polymers typically starts from optically pure monomers obtained form the chiral pool. The fermentation product L-lactic acid, for example, is the starting material for the synthesis of poly(L-lactide). 

Successful incorporation of magnetic nanoparticles into a conductive polymer matrix will definitely widen their applicability in the fields of electronics, biomedical dmg delivery, and optics. These doubly functionalized nanocomposites will exhibit the magnetic properties of the magnetic particles and the conducting properties of the conductive-polymer matrices. However, one of the challenges so far is the abihty to integrate a high... 

Over the past several decades, polylactide - i.e. poly(lactic acid) (PLA) - and its copolymers have attracted significant attention in environmental, biomedical, and pharmaceutical applications as well as alternatives to petro-based polymers [1-18], Plant-derived carbohydrates such as glucose, which is derived from corn, are most frequently used as raw materials of PLA. Among their applications as alternatives to petro-based polymers, packaging applications are the primary ones. Poly(lactic acid)s can be synthesized either by direct polycondensation of lactic acid (lUPAC name 2-hydroxypropanoic acid) or by ring-opening polymerization (ROP) of lactide (LA) (lUPAC name 3,6-dimethyl-l,4-dioxane-2,5-dione). Lactic acid is optically active and has two enantiomeric forms, that is, L- and D- (S- and R-). Lactide is a cyclic dimer of lactic acid that has three possible stereoisomers (i) L-lactide (LLA), which is composed of two L-lactic acids, (ii) D-lactide (DLA), which is composed of two D-lactic acids, and (iii) meso-lactide (MLA), which is composed of an L-lactic acid and a D-lactic acid. Due to the two enantiomeric forms of lactic acids, their homopolymers are stereoisomeric and their crystallizability, physical properties, and processability depend on their tacticity, optical purity, and molecular weight the latter two are dominant factors. 

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