Perspectives of Conductive Polymers Toward Smart Biomaterials for Tissue Engineering

Developing the stimuli-responsive biomaterials with tailor properties represents an important goal of the tissue-engineering community. Such biomaterial promises to become the conductive polymers (CPs), as a novel generation of organic materials that have both electrical and optical properties similar to those of metals and inorganic semiconductors but which also exhibit the attractive properties associated with conventional polymers, that is, easy synthesis and flexibility in processing. The fact that several tissues are responsive to electrical fields and stimuli has made conductive polymers attractive for various biological and medical applications. In this context, the chapter provides information on the basic properties of the conductive polymers and how these polymers can be optimized to generate specific properties for biomedical applications. The synthesis routes of novel materials and specific design techniques, as well as the mechanisms by which electrical conduction affects cells/tissues, are examined, and the significant impact of the conductive polymers in the biomedical field, that is, biosensors, tissue engineering, and neural probes, is demonstrated

Influence of structural and topogical connectivity indices on dielectric properties of blends based on quaternized polysulfones : theoretical approach

Cationic polysulfones containing quaternary ammonium side groups (PSFQ), synthesized by reaction of the chloromethylated polysulfone (CMPSF) with a tertiary amine, N,Ndimethylbutylamine (DMBA), are considered to be suitable for a wide range of applications from the electronic field. Additionally, quaternized polysulfone-based composites with optical and electrical properties represent a challenge for researchers. Therefore, it is of interest to find out whether PSFQ can be designed for specific applications in blends with polyvinyl alcohol (PVA) and to establish their impact on the different properties. Thus, in the present study the cationic polysulfone PSFQ was analyzed in combination with PVA, which is supposed to improve among the other properties, such as hydrophylicity, flexibility, and the optical ones [1].In this context, the thermoplastic characteristics (e.g.,the refractive index and dielectric constant)were evaluated using the structural and topological techniques of spatial arrangement of the constituent atoms from analyzed polymer [2], by means the zero-order connectivity indices and first-order connectivity indices

New approaches to design of blends based on quaternized polysulfones with optimized conductive properties

New blends based on quaternized polysulfones, namely quaternized polysulfone/polyvinyl alcohol and quaternized polysulfone/cellulose acetate phthalate, were investigated in terms of their electrical properties. The dielectric constants have low values for the studied blends, being dependent on the chemical characteristics of blends compounds, in relation with the charge transfer complex and free volume and, consequently, with packing of the polymer chains and of the polarizable groups per volume units. Moreover, the electrical conductivity of studied blends can be explained in terms of band conduction mechanisms, through band gap representation. This study analyzes the possibility of using blends based on quaternized polysulfones as possible candidates in electrotechnical industry. Additionally, the outcomes highlight the importance of new polymer blends for better electrical performances

Structure-rheology relationship in polysulfones with triphenylphosphonium pendant groups systems for engineering applications

Ionic polysulfones have received widespread attention for their promising roles in order to create new materials that can modulate the membrane properties. In this context, understanding of mechanisms developed in quaternized polysulfones with triphenylphosphonium pendant groups solutions, considering their specific interactions and the way in which these interactions affect their physical properties were evaluated by rheological investigations. Rheological behavior of this system, described by the non-linear flow curve, indicates the effect of the chemical structure of quaternized polysulfone, in order to facilitate the subsequently preparation of the active membranes. Thus, this study analyzes the processing-property relationship of solutions based on quaternized polysulfones and possibility of using it’s, with expected future developments in the engineering fields

Synergistic effects of structural characteristics of quaternized polysulfone/cellulose acetate phthalate blends on surface properties

An alternative in order to obtain of new complex polymeric materials is represented by the blending polymers, thus creating a balance between the properties of individual components. New quaternized polysulfones (PSFQ)/cellulose acetate phthalate (CAP) blends were investigated for establishing the structural and compositional characteristics with impact on the surface properties. In this context, the synergistic effects generated by the charged groups from the alkyl radical of the quaternized polysulfones, flexible and hydrophilic nature of CAP in casting solution of polysulfone significantly influenced the surface tension parameters, surface free energy, and topographic reorganization. Moreover, the CAP composition, as well as the history of the formed films provide the controlling surface properties and are responsible for performance properties of the final membranes. In order to understand the correlation between the structural particularities and the resulting properties a deep analysis of the morphology must be performed

Effects of tetraethyl orthosilicate introducing on the rheological properties of celulose acetate solution

The rheological behavior of cellulose acetate (CA)/tetraethyl orthosilicate (TEOS) solution in N,N-dimetilacetamida (DMAc) has been investigated as a function of TEOS content for different shear rates and temperatures. The shear-thinning behavior or so called “pseudoplastic” behavior of the CA pure solution may be caused, on the one hand, by the destruction of the polymer chains as the shear rate increases, and on the other hand, by the increasing of the chains orientation in the flow direction during the rotational measurements. Also, for CA/TEOS blend solutions the curves shape varies from one content to another, a decrease in viscosity as the content of TEOS increases being observed. This tendency, of viscosity decreasing, is mainly due to the formation of hydrogen bonds between -OH groups and Si-OH, characteristic to TEOS, which means that increase in TEOS content tends to form a stable gel network. Furthermore, as temperature increases the viscosity varies irregularly, this being a consequence of the conformational transitions occurring in the system. The incorporation of TEOS in CA solution was described from rheological point view with the aim to produce chemically and mechanically resistant hybrid films with highly degree of dispersed metal particles. Consequently, the present study represents the basis for obtaining hybrid membranes with specific properties, which will find application both in industrial and bioengineering field