Synthesis, characterisation, thermal and electrical behaviour of copper and copper sulphide-epoxy nanocomposites.

Nanozarah kuprum (Cu) dan kuprum sulfida (CuS) disintesis di dalam fasa akueus dan serta-merta dipindahkan ke fasa organik yang mengandungi epoksi melalui kaedah pemindahan fasa. Spektrum penyerapan UV-vis menunjukkan kehadiran Cu dan CuS. Penambahan diglisidil eter bisfenol A (DGEBA) ke dalam organosol masing-masing dan setelah penyingkiran pelarut memberikan nanokomposit Cu- dan CuS-epoksi. Komposit ini dimatangkan menggunakan 4,4’-metilenadianilina (MDA). Bagi Cu-epoksi, kecekapan pemindahan zarah yang tertinggi adalah ≈ 97.2% apabila sampel disediakan menggunakan 5 mL isopropanol (IPA). IPA turut memberi kesan terhadap saiz purata zarah. Copper (Cu) and copper sulphide (CuS) nanoparticles were synthesised in an aqueous phase and subsequently transferred into the organic phase containing epoxy via phase transfer technique. The UV-vis absorption spectra confirmed the existence of Cu and CuS. Incorporation of diglycidyl ether of bisphenol A (DGEBA) into the respective organosols and upon solvent removal afforded Cu- and CuS-epoxy nanocomposites. These composites were cured using 4,4’-methyelene-dianiline (MDA). In the case of Cu-epoxy, the highest particle transfer efficiency was at ≈ 97.2% when the samples were prepared with 5 mL isopropanol (IPA). IPA also exerts influence on the average particle size

Synthesis of Dispersed and Self-Assembled Metal Particles in Epoxy via Aqueous to Organic Phase Transfer Technique

A convenient and effective method of dispersing gold (Au), silver (Ag) and copper (Cu) particles in epoxy is described. Particles were synthesized in aqueous phase and subsequently dispersed in toluene-epoxy with or without the presence of curing agent. Sodium borohydride and 2-propanol were used as reducing and phase transfer agents respectively. The surface plasmon resonance (SPR) at ~ 540-620 nm, ~ 525 nm and ~450 nm confirms the presence of Cu, Au and Ag nanoparticles in the composites. No chemical interaction occurred between the metal particles and the epoxy or cured epoxy. Increase in epoxy content caused the size of the particles to decrease for all metals. The average particle size for Au, Ag and Cu in 1% and 10% epoxy are 3.9 nm and 2.5 nm, 10.1 nm and 3.2 nm as well as 8.1 nm and 5.9 nm respectively. Similar decreasing trend was also observed upon addition of curing agent. In all cases, metal nanoparticles exhibit self-assembly with inter-particle spacing of <10 nm. The absence of any curing peak in the DSC thermograms suggests that the composites are well cured before any of the DSC analyses were performed. The Tg of the metal-cured epoxy is higher than neat epoxy, that is 71.3 °C, 69.8 °C and 62.0 °C for Cu, Au and Ag respectively

Electrical and Thermal Behavior of Copper-Epoxy Nanocomposites Prepared via Aqueous to Organic Phase Transfer Technique

The preparation, electrical, and thermal behaviors of copper-epoxy nanocomposites are described. Cetyltrimethylammonium bromide- (CTAB-) stabilized copper (Cu) particles were synthesized via phase transfer technique. Isopropanol (IPA), sodium borohydride (NaBH4), and toluene solution of diglycidyl ether of bisphenol A (DGEBA) were used as transferring, reducing agent, and the organic phase, respectively. The UV-Vis absorbance spectra of all the sols prepared indicate that the presence of Cu particles with the particles transfer efficiency is ≥97%. The amount, size, and size distribution of particles in the organosol were dependent on the content of organic solute in the organosol. The composites were obtained upon drying the organosols and these were then subjected to further studies on the curing, thermal, and electrical characteristic. The presence of Cu fillers does not significantly affect the completeness of the composite curing process and only slightly reduce the thermal stability of the composites that is >300◦C. The highest conductivity value of the composites obtained is 3.06 × 10−2 S cm−1