依据聚乙烯吡咯烷酮(PVP)在水中的溶解度随温度升高而降低的特性,建立了将PVP保护的金、银、铂纳米粒子从水相转移到油相的简单而有效的相转移技术.方法是利用电化学还原法先于水溶液中制备粒度均匀的金属纳米粒子,然后向电化学合成后的金属纳米水溶胶中加入适量正丁醇,在搅拌条件下升温至80℃即可使金属纳米粒子从水相转移至有机相.纳米粒子的相转移效率很高,而且相转移后粒子在油相中分散很好,没有团聚现象发生.在此基础上进一步建立在油水混合体系电化学合成金属纳米粒子的实验方法,为收集纳米粒子和制备纳米粒子薄膜提供了新的有效途径.
A novel phase-transfer method was developed based on the decrease of PVP's solubility in water with increasing temperature,by means of which PVP-protected gold,silver and platinum nanoparticles can be conveniently transferred from aqueous phase to 1-butanol phase.Monodispersed metal nanoparticles were electrochemically synthesized at first in the aqueous,and then 1-butanol of appropriate volume was added to the aqueous phase.Heating the oil-water mixture to 80 ℃ under vigorous stirring would make metal nanoparticles leave the aqueous phase and enter into the 1-butanol phase,with high phasetransfer efficiency and without aggregation between nanoparticles.An electrochemical method to synthesize metal nanoparticles in the oil-water mixtures was further established,which provides a new path for collection of nanoparticles and preparation of metal nanofilms.
[1]Zhu J,L iu S,Palch ik O,et al.Shape-controlled syn-thesis of silver nanopartic les by pu lse sonoelectrochem i-calm ethods[J].Langmu ir,2000,16:6396~6399.
[2]W u Y,Yang P.D irect observation of vapor-liqu id-solidnanow ire growth[J].J.Am.Chem.Soc.,2001,123:3165~3166.
[3]Rodriguez-Sanchez L,B lanco M C,Lopez-Qu inteal MA.E lectrochem ical synthesis of silver nanopartic les[J].J.Phys.Chem.B,2000,104:9683~9688.
[4]Moham ed M B,Ism ailK Z,L ink S,et al.Therm al re-shap ing of gold nanorods in m icelles[J].J.Phys.Chem.B,1998,102:9370~9374.
[5]Sun Y,X ia Y.Shape-controlled synthesis of gold andsilver nanopartic les[J].Sc ience,2002,298:2176~2179.
[6]Y in B S(尹秉胜),M a H Y(马厚义),W ang S Y(王书运),et al.E lectrochem ical synthesis of silver nanop-artic les under protection of poly(N-vinylpyrrolidone)[J].J.Phys.Chem.B,2003,107:8898~8904.
[7]Huang S X(黄绍鑫),M a H Y(马厚义),Zhang X K(张晓凯),et al.E lectrochem ical synthesis of goldnanocrystals and the ir 1D and 2D organ ization[J].J.Phys.Chem.B,2005,109:19823~19830.
[8]ReetzM T,Helb igW.S ize-selective synthesis of nano-structured transition m etal c lusters[J].J.Am.Chem.Soc.,1994,116:7401~7402.
[9]Yu Y Y,Chang S S,Lee C L,et al.Gold nanorods:E lectrochem ical synthesis and optical properties[J].J.Phys.Chem B,1997,101:6661~6664.
[10]Yang J,De ivaraj T C,Too H P,et al.An alternativephase-transfer m ethod of preparing alkylam ine-stab i-lized p latinum nanopartic les[J].J.Phys.Chem.B,2004,108:2181~2185.
[11]W ang W,E frim a S,Regev O.D irecting oleate stab i-lized nanosized silver colloids into organ ic phases[J].Langmu ir,1998,14:602~610.
[12]Lala N,Lalbegi S P,Adyanthaya S D,et al.Phasetransfer of aqueous gold colloidal partic les capped w ithinc lusion comp lexes of cyc lodextrin and alkaneth iolmolecu les into Chloroform[J].Langmu ir,2001,17:3766~3768.
[13]Yao H,Momozawa O,Ham atan i T,et al.Stepw isesize-selective extraction of carboxylate-mod ified goldnanopartic les from an aqueous suspension into toluenew ith tetraoctylammon ium cations[J].Chem.M ater.,2001,13:4692~4697.
[14]L iu J,A lvarez J,OngW,et al.Phase transfer of hy-droph ilic,cyc lodextrin-mod ified gold nanopartic les tochloroform solutions[J].J.Am.Chem.Soc.,2001,123:11148~11154.
[15]W ilson O M,ScottR W J,Garc ia-M artinez J C,et al.Separation of dendrim er-encapsu lated Au and Ag nano-partic les by selective extraction[J].Chem.M ater.,2004,16:4202~4204.
[16]K im K S,Demberelnyamba D,Lee H.S ize-selectivesynthesis of gold and p latinum nanopartic les using no-vel th iol-functionalized ion ic liqu ids[J].Langmu ir,2004,20:556~560.
