Synthesis, structure, and properties of new Cu/polydiphenylamine metallopolymer nanocomposites

Abstract

EXPERIMENTALCommerically available solvents and chemicals were used without further purification unless other wise stated. Ammonium persulfate and toluene were additionally subjected to crystallization [16] and frac tional distillation [17], respectively. The monomer and other reagents were prepared as described earlier [13]. The oligomers of polydiphenylamine were synthesized by the interphase (water/toluene) oxidative polymeri zation of diphenylamine monomer ([M] = 0.2 M) using ammonium persulfate ([(NH 4 ) 2 S 2 O 8 ]/[M] = 1.25) and hydrochloric acid ([M]/[HCl] = 1/5) [13].The synthesis of Cu/polydiphenylamine nano composites was performed by dissolving diphe nylamine oligomers (2 wt %) in DMFA solution con taining 5-30 wt % of copper acetate monohydrate (with respect to M w of oligomers) followed by the removal of the solvent in vacua at 85°C. The residue was then treated at 150-350°C for 2-60 min under an Ar atmosphere using an automated IR heating machine [18].The FTIR spectra were recorded using a Specord M-82 spectrophotometer with Soft Spectra software package over the region 4000-400 cm -1 on samples prepared in KBr pellets. An X ray analysis of obtained materials was performed with a Rigaku dif fractometer in a continuous mode (FeK α source, Bragg-Brentano geometry). Transmission scanning microscopy (EM-301, acceleration voltage 60-80 kV, Phillips) was used to study the microstructure of Cu/polydiphenylamine nanocomposites, while atomic adsorption spectroscopy (AAS 30, Carl Zeiss Jena) was applied for quantitative copper analysis of the fabricated samples.A thermogravimetric analysis (TGA) was carried out using a Netzsch TG 209 F1 thermomicrobalance under the dynamic mode in a stream of nitrogen or air in the temperature range 30-820°C. The sample was thermostated first at 30°C for 15 min and then for the second time at 820°C for 30 min. The TG experimen tal parameters were as follows: a heating rate of 10°C/min, a nitrogen flow rate of 50 ml/min, a sample weight of 100 mg, and a standard alumina made cru cible.The calorimetric measurements were performed using a TA-4000 differential scanning calorimeter (Mettler) equipped with a DSC-30 heating cell at a heating rate of 10°C/min under N 2 in the temperature range 20-350°C. RESULTS AND DISCUSSIONA comparison of the IR spectra of the starting oli gomers and the obtained Cu/polydiphenylamine nanocomposites (Fig. 1) revealed an increase in the intensity of the adsorption bands associated with the deformation vibration of aromatic C-H groups (812 cm -1 ) and valent oscillations of C=N bonds in the quinonoid like structures (1650 cm -1 ) [13,[19][20][21] as a result of the growth of the polymeric chain and the increase in the oxidation level of the product.It was shown that the thermal Cu induced poly condensation [22] of crystalline oligomers of dipheny lamine is accompanied by a release of hydrogen, which consequently leads to the reduction of Cu 2+ ions to nanoscale particles of Cu 0 (Fig. 2a).Abstract-It was found that the Cu induced thermal polycondens...

Synthesis and Electrochemical Characterisation of Novel Hybrid Copper / Poly (diphenylamine) (PDPA) Nanocomposites

“…The polyaniline group of conducting polymeric materials has received ample attention because of its simple method of preparation and their electrical, electrochemical and optical properties. Furthermore, the poly (diphenylamine) (PDPA) is found to be a suitable material for the composite material preparation due to their characteristic properties different from polyaniline (PANI) [13][14][15][16][17][18][19][20][21].…”