Journal of Colloid and Interface Science 315 (2007) 747–752 www.elsevier.com/locate/jcis Copper phthalocyanine ﬁlms deposited by liquid–liquid inter recrystallization technique (LLIRCT) K.R. Patil a,∗ , S.D. Sathaye b , R. Hawaldar c , B.R. Sathe a , A.B. Mandale a , A. Mitra a a Center for Materials Characterization, National Chemical Laboratory, Pune 411008, India b 759/83 Deccan Gymkhana, Pune 411004, India c Center for Materials for Electronics, Panchawati, Pune 411008, India Received 29 December 2006; accepted 14 July 2007 Available online 21 July 2007 Abstract The simple recrystallization process is innovatively used to obtain the nanoparticles of copper phthalocyanine by a simp interface recrystallization technique (LLIRCT) has been employed successfully to produce small sized copper phthalocyan diameter between 3–5 nm. The TEM-SAED studies revealed the formation of 3–5 nm sized with β-phase dominated mixtu phthalocyanine nanoparticles. The XRD, SEM, and the UV–vis studies were further carried out to conﬁrm the formation o thin ﬁlms. The cyclic voltametry (CV) studies conclude that redox reaction is totally reversible one electron transfer process. The process is attributed to Cu(II)/Cu(I) redox reaction.  2007 Elsevier Inc. All rights reserved. Keywords: Nanoparticulate ﬁlms; Copper phthalocyanine; Cyclic voltametry 1. Introduction Development of processes involving organic thin ﬁlm de- vices are expected to have distinct advantages such as low cost of production, low power consumption, etc. However, the progress in this direction seems to be limited to the study of polymers and a few organic materials. This limitation occurs, mainly due to thermal stability of organic materials. Among the stable organic materials, metal phthalocyanines (MPc) are an important class of materials, which has attracted the atten- tion of researchers recently. Apartfrom thermal stability, the other advantages of this class are chemical stability, ease in puriﬁcation, etc.A thin ﬁlm is the most suitable form for de- vice applications of these materials. In this aspect of the prob- lem, MPc are studied in the thin ﬁlm form prepared mainly by vacuum evaporation technique and its modiﬁcations. The wet chemical techniques namely spin coating, dip coating, sol–gel method and the LB technique cannot be readily used because * Corresponding author. E-mail address: kr.patil@ncl.res.in (K.R. Patil). of the low solubility of MPc in common organic/inorganic vents. Several applications of MPc have been reported in the ature. The important among those are gas sensors [1,2], cations based on optical properties such as photoconduc etc.[3–5].The otherapplications in the ﬁelds of photonics and optoelectronics [6], organic light emitting diodes, et organic transistors [8] are well reported. Copper phthallocya- nine (CuPc) is perhaps the most studied material of this Mostof the times the CuPc is studied in the form of thin ﬁlms prepared by evaporation techniques. There are few ref- erences where LB technique is used to form the ﬁlms, where the host material, e.g., CuPc is modiﬁed to increase its s ity in organic solvents. The applications for sensors, cata etc.prefers small particle size. It is thought that nanoparticu- late ﬁlms of CuPc would enhance the scope for applicatio Energy intensive processes are not suitable to grow sma ulate ﬁlms. In the absence of low temperature, low energ methods for growing thin ﬁlms of CuPc in literature, we successfully attempted to develop a facile method to dep CuPc thin ﬁlms. Since the crystal structure and the morp of thin ﬁlms is dependant on the method of preparation a 0021-9797/$ – see front matter  2007 Elsevier Inc. All rights reserved. doi:10.1016/j.jcis.2007.07.031