Polymeric material, fibrillar

The preparation of nano-scaled polymeric assemblies such as nanofibers is one of the most useful methods to practically utilize polymeric materials as observed in the case of cellulose (Abe at al., 2007, Saito et al., 2006, Saito et al., 2007). For example, self-assembled fibrillar nanostructures from cellulose are promising materials for the practical applications in bio-related research fields such as tissue engineering (Isogai et al., 2011, Abdul Khalil et al., 2012). The efficient methods have also been developed for the preparation of chitin nanofibers. The conventional approaches to the production of chitin nanofibers are mainly performed upon top-down procedures that break down the starting bulk materials from chitin resources (Figure 2). 

The enormous scale of the challenge to build a truly biomimetic muscle can be appreciated by considering what is known about natural muscle structure. The contractions of these motors involve a highly complex and coordinated sequence of electrical, chemical, and physical phenomena within a composite, gel-like polymeric material that is known to possess a detailed hierarchical structure, stretching from the nano-scale assembly of proteins through the cellular fibrillar textures to the macroscopic tissue. The exact function of many of these features is still the subject of on-going research. In general, the skeletal muscles consist of tendons (non-active) and muscle belly (active). While tendons mainly provide muscle connectivity to hard bones,... 

The most important polymeric matrices are linear and cross-linked polyesters, epoxy resins and linear and cross-linked polyimides the most important reinforcements are high-performance polymeric fibres and filaments (for polymeric composites), filaments of refractory metals and inorganic materials (E-glass, A12C>3, B, BN, SiC and Carbon) and whiskers (fibrillar single crystals of A1203, B4C, WC, SiC and C, exclusively for reinforcement of metals). 

The polymorphism and morphology of cellulose precipitated from solutions in amine oxide by the slow diffusion of water vapors, was Investigated, as functions of the temperature of recrystallization and the degree of polymerization (DP) of the material to be recrystallized. At temperatures around 90°C, low DP cellulose crystallized almost exclusively as cellulose IV, whereas higher DP material was found in the form or cellulose II. Substantial differences were also found in the morphologies of the various samples with cellulose II, rod-like crystals were obtained with low DP material while a crystalline fibrillar gel precipitated when high DP scimples were recrystallized. In all cases, cellulose was obtained as a granular precipitate. 

Deposition occurs at nucleation sites on the electrode until the surface is cov-ered and subsequently (or at the same time) over the previously formed deposits because of their conductivity. The deposition on the bare electrode surface produces, up to a thickness of about 0.1 ixm, a material more dense than that produced on the preformed deposit, which is loose and fibrillar. The first polymer layer lies essentially flat on the electrode surface and the polymeric chains are well ordered up to a thickness of 5 nm [45]. 

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