Templated synthesis, polymeric template free method

Dopant-Free Template-Free Method PANI-NTs have been prepared by the oxidative polymerization of anihne with APS in water without added acid (Figure 2.18) [199,350,380,381]. This is a facile and efficient approach to synthesize PANI-NTs because it not only omits hard templates and post-treatment template removal, but also simplifies reagents. A modification of the dopant-free template-free method of PANI-NTs synthesis... 

Template-free techniques have been extensively studied for the fabrication of conducting polymer nanomaterials fabrication. Compared with hard and soft template methods, these methodologies provide a facile and practical route to produce pure, uniform, and high quality nanofibers. Template-free methods encompass various methods such as electrochemical synthesis, chemical polymerization, aqueous/organic interfacial polymerization, radi-olytic synthesis, and dispersion polymerization. 

Other methods Dilute polymerization, template-free method, rapidly mixed reaction, reverse emulsion polymerization, ultrasonic shake-up, radiolytic synthesis external template the morphology (shape, diameter) poorly or non-oriented ID nanostructures tures such as tubes, wiresZfibers, hoUow microspheres, nanowireZnanotube junctions and dendrites... 

The low affinity of sulfur for alkali metal ions, however, renders template effects of less consequence in the synthesis of polythia macrocycles. Thus, the competition between cycli-zation and linear polymerization is more statistically defined, with cyclization kinetically favored only at high dilution 64,65,66). Consequently, most of the synthetic methods for the synthesis of polythia rings involve high-dilution techniques coupled with relatively long reaction times. Historically, the study of the coordination chemistry of macrocyclic thioethers has been hindered by difficulties in the synthesis of the free ligands. The synthesis of [BJaneSa, first reported by Ochrymowycz and co-workers in 1977 101), illustrates this well. 

The chemical methods for the preparation of nanomaterial could be categorized as either template-directed or template-free. The template synthesis methods commonly used for the production of one-dimensional nanostructured PANI are further subdivided into hard template (physical template) synthesis and soft template (chemical template) synthesis approach according to the solubility of the templates in the reaction media. Non-template routes for the synthesis of one-dimensional nanostructured PANI such as rapid-mixing reaction method, radiolytic synthesis, interfacial polymerization, and sonochemical synthesis have also been reported [56], Other approaches like combined soft and hard template synthesis are also known. An overview of hard-template, soft-template, and template-free procedures are presented in the following paragraphs. 

The cost of the support element and the lengthy steps involved in zeolite film synthesis makes zeolite membranes very expensive compared to the well established polymeric membranes. MFI membranes are relatively expensive and their price (about 5.000 /m2) is typically due by 50% to the support and by 50 % to chemicals. Consequently the development of template-free synthesis on cheaper supports (multi-channels, ceramic foils/plates, capillaries, hollow fibers) is seriously considered, in parallel with the development of continuous, automatic, reliable, and reproducible production methods. 

Solid-State Mechanochemical Synthesis Facile template-free solid-state mechano-chemical synthesis of highly branched PANI-NFs with coralloid tree-like superstrueture, via the oxidative polymerization of aniline hydrochloride with FeCl3 6H2O, has been demonstrated [194]. The synthetic yield ( 8%) was comparable to that of the solution interfacial polymerization method. Solid-phase mechanochemical synthesis of branched PANI-NFs was also achieved by using anhydrous FeCl3 as the oxidant [195]. 

Purely interfacial polymerization is a template-free synthesis method allowing relatively high throughput to be reached (say, grams of nanofibers per run at laboratory scale). The different conditions of interfacial polymerization, such as the structure of the specific monomer and the eventual dopants, the... 

By integrating CNTs with PANi nanofibers, high density and high-suiface areas are possible that can lead to improvements in the conductivity and the development of electronic devices with superior properties [78]. The composites of PANi-CNT can be synthesized by various methods such as electrochemical processing, surfactant free aqueous polymerization, micelle-CNT hybrid template directed synthesis, inverse emulsion pathways, interfacial polymerization, plasma polymerization, in-situ and ex-situ polymerization. The details of these methods have been discussed by Oueiny et al. [8]. In-situ polymerization is one of the most important methods developed so far to integrate CNTs and polyaniline. Polymerization methods include stirring, static placement, sonication and emulsion polymerization [78]. 

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