Ứng dụng laser chế tạo và nghiên cứu thuộc tính quang học phi tuyến của một số hạt nano kim loại quý

DAI HOC QLOC CIA HA NOI TRUÒNC; DAI HOC KHOA HOC TU NHIÉN BÀO CÀO TÒNG KÉT DE TÀI KHOA HOC GÒNG NGHÉ TÉN DK lÀI UNG DUNG LASER CHE TAO VA NGHIÈN CUU TULỊC T Ì N H Q L A I N G HOC PHI TUYÉN CÙA MOT SO HAT NANO KIM LOAI QUY MA SO: QC.TD 10-04 CHI! TRÌ: TS PHAM NCUN HAI DON VI : TRNG DAI HOC KHOA HOC TU NHIÉN HANOI 2012 IVIL'C LUC • • Frane Danh sàch càn bo iham già thuc hién BAO CAO TOM T A T C À C KÉT QUA NGHIHN CL/U CHINH CUA DE TÀI NOI D U N d B A O C A O r Ò N G H O P 10 Chuang I : Che tao hat nano kim Ioai bang phuong phàp àn mòn laser l.Ca so ly thuyél va thuc nghiCMii cua phuong phàp àn mòn laser 10 1.1 Co che àn mịn laser 10 1.2 Mị hình hịa c a c h e àn mòn laser 11 1.3 Mò ta qu> Irình àn mịn laser tàm kim Ioai clung djch long 2.Xà\ dung he thiét hi àn mòn laser su dung laser Nd:YA(i Quanta Ra\ Pro 230 (USA) 16 2.1 hiét ké \ \à\ dung he àn mòn laser 2.2.Qu\ trinh thuc hién 16 23 3.Mot so két qua che tao hai nano kim Ioai bang àn mòn laser 2X 3.1 Che tao hat nano bac dung djch Trisodium cilratc (TSC) 29 3.2 Che tao hat nao \àng nuóc càt \à ethanol 33 3.3 Che tao hat nano dịng nuxVc càt nc khu ion \à cthanol 35 3.4 Che tao hat nano Plalin dung djch I risodium Citrate (TSC) 44 4.Nghién CUU ci\c \éu tò co anh huo'ng dén plurong phàp che tao hat nano bang àn mòn laser 49 4.1 Nghién ciVu anh hucrng cua thòng luong laser 50 4.2 Nghién cùu anh hu\yng cua hu'óe song laser 52 4.3 Nghién cuii anh hu'ong cua iiiòi iruo'ng chat long 54 5.1 licu ung eòng hu^yng plasmon \à diéu khién kich thuóc trung binh cua càc hat nano kim Ioai 69 C hirons II: N^hien ciìii thiioc tinh quang lioe cua mot so ha! nano kim Ioai C a s o ly thu\ét \ é nguòn gòc thuòc tinh quang hoc tu\én unii \a phi lu>én trén càu trùc nano kim Ioai ^^ Xà\ dirng phép phò phàt quang tir càu trùc nano kim Ioai 83 Nghién ciru phò phàt quang cùa hat nano vàng 88 Mot so két qua nghién ciru ùng dung 93 4.1 Hieu ung Raman tàng cuòng bé màt 93 4.2 Hieu ung quang phi tuyén SFG tàng cuòng trén càu trùc nano kim Ioai 101 Ketluàn 107 Tài lieu tham khào 108 Phu lue Phieu tóm tàt kct qua ticng Anh Phiéu dàng ki két qua nghién cùu cùa de tài Thuyet minh De cuong de tài Q(,TI) 10-04 Minh chùng két qua tao Minh chùng kct qua khoa hyc ng nghé 110 DANH SÀCH CÀN BĨ THAM GIÀ THUC HIÉN • • • Chù tri de tài: TS Pham Nguyén Hai, Chu nhiem Bo mòn Vat ly Chat ràn, Khoa Vat Ly, Triràng DHKHTN NhGng nguò'i thirc hien: 1/PGSTS Nguyen The Bình, Khoa Vat Ly, Trng DHKHTN Il TS Hoàng Chi Hiéu, Khoa Vat Ly, Truàng DHKHTN 3/ThS Ngun Thanh Dình Nghién cù-u sinh Khoa Vat Ly, Trng DHKHTN 4/ ThS Pham Vàn Thuònii, Hoc vién cao hoc, Khoa Vat L\\ Truònu DHKHTN 5/ThS Dò Vàn Tién, Hoc vién cao hoc, Khoa Vat L\\ Truàng DHKHTN 6/Trinh Thi I lue Hoc vién cao hoc, Khoa Vat Ly Truòng DHKHTN 7/Nguyèn Quang Dòng, Hoc vién cao hoc, Khoa Vat Ly, Tryòng DHKHTN 8/Duo-ng Thi Nguyet, Hoc vién cao hoc, Khoa Vat L\, Tru'àng DHKHTN Q/Vù Thi Khành Tlui, Hoc vién cao hoc, Khoa Vat L\\ Truòng DHKHTN BÀO C À O T O M T À T C À C K É T Q U A N G H I É N CU L C H I N H CUA DE TÀI I - Tén de tài Ung dung laser ehé tao ve) nghién ei'ru thuoe tinh quang hoc phi tuyén ciia mot so hat nano kim Ioai quy Ma so: QGTDIO-04 2-Muc tiéu: - Muc tiéu cua de tài phàt trién phuang phàp àn mòn laser che tao càc hat nano kim hai , tao mot quy trinh che tao hat nano kim Ioai hién dai bó xung thém vào càc phircnig phàp hién co va nghién ei'vu mot sé hieu ùng quang hoc phi tuyén trén càc càu trùc nano che tao du'crc du'ó'i fàc dung cua chimi laser ( V thè là: -Xày dung mot he thiét bj àn mòn laser su dung laser Nd:YAG Quanta Ra\ Pro 230 (USA) de che tao cac hat nano kim Ioai (Ag Au Cu ) hoàc bau dim -Nghién CUU qu\ irinh che tao cac hai nano kim Ioai (Ag Au Cu ) - Nghién cùu su dung hiéu mig ng luixvng Plasmon diéu khicn kich tluróc irung binh cua cac hai nano kim Ioai - Xà\' dung phép quang hoc phò hoc laser phi Ui>én Su dung he quang phò -laser nghién cuu cac ihuòc tinh quang hoc lu\'én tinh \ phi tu\ én cua mòl so càu trùc nano kim Ioai Uac hiéu ung co dinh hng ung dung ng nghé sinh hoc \ > té 3-Sàn pham du kién - Mot he lliiél hi fin mòn laser su dung laser Nd:YA(l Quanta Ra> Pro 23f) (LS.A) de che lao Ccìc hat nano kim Ioai (Ag Au Cu ) - Qu\ innli che lao cac hai nano kim Ioai (Ag Au Cu ) bang àn mòn laser - Mòl he quang phò hoc laser de nghién cùu cac ihuòc tinh quang hoc Ui\én linh \à phi Ui_\én cua mòl so cau trùc wdwo kim Ioai 4- Két qua (hii dune: 4.L Két qua \ é khoa hoc còni: ni^lic: Xà\ dung ihanh eòng dàu lién o \'icl nani mol he àn mon laser de che tao hai nano kim Ioai gòp plian bò xung phirong phàp che lao hai nano Ile thiél hi àn mịn laser su dung laser Nd:YACÌ Quanta Ra\ Pro 230 (USA) co ihé che tao cac hai nano kim Ioai (Ag Au Uu ) hoàc bàn dan Dà\ phuong phàp cho phép che tao hai nano càc mịi irucmg sach (nc càt ethanol ) va càc dung mịi hiJu co thàn thién vói mịi trng ma kha nàng ung dung y sinh mòi truàng Càc vàn de dà giài quyét: - Thiét ké he quang hoc thich hgp phuong phàp che tao hat nano bang àn mòn laser - Lua chon che dò laser thich hop phuong phàp che tao hai nano bang àn mòn laser 2/ Dà nghién cùu dua quy trinh thich hop de che tao hat nano kim Ioai bang àn mòn laser Vàn de dà giai quyét: -Tim hiéu co che àn mòn laser -Xàc dinh qu> Irinh tòi uu de che tao hai nano kim Ioai bang àn mòn laser -Xàc dinh anh huxmg cua mòi iruong chàl long irong phu(mg phàp che tao hai nano bànu àn mòn laser 3/ Dà nghién cùu hiéu ung ng huong Plasmon va diéu khién kich thc irung binh cua càc hai nano kim ioai bang hiéu ùng Vàn de dà giai quyét: Tini hiéu 1\ lhu\él eòng huong Plasmon bé mài àp dung cho càc hai nano kim Ioai Xàc dinh thòng luong laser, ihòi gian chiéu sàng laser, biróc song laser de diéu khiéii kich ihuóc hai nao kim Ioai 4/ Dà xày dung he thuòc tinh quang cua cac hai nano kich ihich bang laser nhàm khao sài phò hu\nh quang \ ihuòc linh quang hoc phi tu> én cua càu trùc nano Dà bu'óc dàu khao sài ung dung cua hai nano kim Ioai irong quang phò hoc laser cu the dà ihành eòng \ ice che tao càc càu iruc nano kim Ioai cho hiéu ung lan \a Raman tàng cuòng he mal (SliRS) Hiéu ùng quang hoc phi tuyén phàt so tòng tàng cuòng trén càu trùc nano kim Ioai cune dà duoc khao sài (Vie cong trinh dà eòng ho: 02 hai hào tap chi quòe té: (daiig ky 01) 1/ NgUNCii he Mmh \ u hi Kliaiih hu Ngu\cn Quang Dong Nguyen Thanh Dinh NuuNcn he An Trinh Thi I lue 'Treparafion ot nìctal natwparticlesfor surface enhanced Raman scattering hy laser ahlation" lOP science A\d Nat Sci Nanosci NanolechnoT3 (2012) 025016 21 Nauven The Minh Pham Nguyen Hai Ngu\cn Thanh Dinh \ g u \ e n The An Preparai ion ofAg nanoparticles in trisodium citrate (TSC) solution by pulsed laser ablalion submitcd to be published in Materials themistn and Physics Elsvier 02 bào cóng bó trén tap chi quóc già (dàng ki 01) 1/ Ngu\cn he Binh_ Pham Van hin Pham Thu Nga Nguyen Anh Tuan "Random laser in ZnO powder pumped hy picosecondpuldes " VNU Journal of Seience Mathematics - Physics 27 (201 1) 187-194 2/ Nguyen The Binh Nguyen Quang Dong Vu Thi Khanh Thu "Sur/ace-enhanced Raman scattering from a layer o/gold nanoparticles " VNU lournal of Science Mathemalics-Physics 26 (2()H)) 187-192 04 bào ềo hói nghi KH qiioc te: (dàng ky 02) dò 02 bào cào Hòi nghi quóc té du'o-c phan bicn in trén tap chi Advances in oplics photonics spectroscopy & Applications 1/ Pham Nguyen Hai Ngu\en The Binh Ngu\en Thanh Dinh Niiu\en Ouane Dona Vu Thi Khanh Thu Trinh I hi lue Production o/gold cnid sitver nanoparticles in clcan liquid amhience hy laser ahlation Advances in oplics pholonics speetroseop\ & Applications ISSN 18?9-4271 (2010) paoe 155-160 2/Nguyen The Binh Ngu>eii Thanh Dinh Nguyen Quang Dong.Vu Thi Khanh Ihu hinh Ihi lluc PhamNgu\en Hai Laser applicalioiì to produce copper ìianoparticles in some different liquids Ad\ances in oplics pholonics speetroscop\ & Applications ISSN 1859-4271 (2010) page 285-290 3/ Pham Neuven Hai Neu\cn Mie Binh NeuNcn Thanh Dinh \'u Ihi Khanh Thu Nauxen Quang Dong Trinh I hi Tlue Preparation of nohic nìclal nanoparticles The tirsi SCIIINCT: hy pulsed laser ahlation in aqueous solutions joinl (ierman-Vielnamese sxmposium on FRONTI T:RS IN MATERIALS - FMS 2010 - in lanoi'Vietnam in Uclober 2010 •//Nguyen The Binh Pham Nguyen Hai Ngu\en Hoang Hai Nguyen The An Preparation ofAg nanoparticles in trisodium cifrate (TSC) solution by laser ahlation and its antibaclerial application aguinst Escherichia coli The seeond s\mposium - FMS 201 I - in Irankfurt Cicman\ Ocloher 6-9th 201 02 bau cao Hoi njjhj KH tronfi nuóc: (dan*; ki 02) Trinh Thi lluc Ngu\en I hanli Diiih Ngu\cn Quang Dong Duong Thi Ngu>ct Ngu\en Ihe Binh Studymg the role of liquid environments Information of noble metal nanoparticles by laser ahlation Ky yéu Hoi nghi KH Truàng DHKITTN DHQGHN (Reeeived to be published in VNU Journal of Science Mathemalics-Physics ) 2/ Nguyen Thanh Dinh Trinh Thi Hue Vu Thi Khanh Thu Pham Thi Thanh Van Nguyen Quang Dong Nguyen The Binh Preparation of copper nanoparticles in water and acetone hy laser ahlation Ky yéu Hoi nghj KI I Truòng DI IKHTN, DI IQGHN (Reeeived to be published in VNU Journal of Seience Mathemalics-Physics ) 4.2 Két qua tao: Góp phan tao 07 thac sy dà hồn thành luan vàn (dàng ky 04): 1/TrinhThjThu Hue Ten de tài: « Vai Irị cua mịi trng chat long qu\ irinh che tao hai nano kim Kiai hhnsi phuang phàp àn mòn laser » Bào ve 1/201 Ngành: Val ly Chuyén ngành: Quang hoc Ma so: 60 44 1 2/Pham Thi Thanh Vàn \cn de tài: "l im hieu kha nàng che lao hai nant) dòng bang àn mon laser irong mòl so duna dich khàc nhau" Bao \è ^201 Ngành: Vài ly Chu\èn ngành: ()uang hoc Ma s6: 60 44 I 3/Duong Thi Ngu\et Tén de tài:« I lieu irng SHG tàng cuòng nhò plassmon bé mài trén càc càu trùc nano » Bao \ e 1/201 Ngành: Val ly Chu\én ngành: Quang hoc Ma so: 60 44 I 4/ Nguyén Quang Dòng de tài: Nghién cuu Plurong phap c|uang phò hoc Raman tàng cuòng bé mal Bao \é '201 Ngành; Vài K , Ghu\én ngành: Quang hoc Ma so: 60 44 1 5/ Dò Vàn Tuxén: Téli de lai: Khao sài hiéu ung phàt hịa ba bàc hai trén càu iriìc nano kim Ioai Bao \ c 201 I Ngành: Vài ly Chu\én ngành: Quang hoc Ma so: 60 44 li Tran I hi I hu_\ : Tén de tài: Nghién cuu mot so ihuòc linh quang cua hai nano kim Ioai quy Bao ve 3/2012 Ngành: Val ly Chuxén ngành: Quang hoc Ma so: 60 44 I Vù Thi Khanh Thu: Tén de tài : Khat) sài phò Raman tàng cuòng bé mài trén c\.w hai nano kim Ioai quy Bao ve 3?012 Ngành: Vài l\ C"hu\én nganh: Quang hoc Ma so: 6044 I Góp phan tao 01 Tién sy 1/NCS Nguyen Thanh Dình (2009-2912) Tén de lai: Nghién cuu mot so hiéu ung quang hoc phi tu\én trén càu trùc nano kim Ioai 4.3 Két qua nàng cao tiém lue khoa hoc ciia don vi: Viéc thuc hién càc muc tiéu cua de tài dà góp phàn xày dung mot hir&ng nghién ci'ru mài, tién tién a khoa Vat ly Tru-i'rng DHKHTN, DHQGHN, cu thè là: -Viéc xày dung mot he thiél hi àn mòn laser su dung laser Nd:YAG Quanta Ray Pro 230 (USA) de ehé tao càc hai nano kim Ioai (Ag Au Cu ) hoàc bàn dàn làm phàt trién phuong phàp àn mòn laser tao mot qu\ trinh che tao hai nano kim Ioai hién dai bò xung ihém \ càc phuong phàp hién co nuòe -Viéc xày dung càc ky ihuàl dac dùng quang phò hoc phi tuyén dàp ùng nhu càu nghién ciru cau trùc nano kim Ioai nói riéng va càc càu iriìc nano nói chung cua cac don \i nghién cùu nc nhu nu"(Vc ngồi Vói muc tiéu khòng nhùng co thè tàng cuòng nàng lue nghién cùu dàp ùng càc phép nghién cùu ùng dung \àl lieu nano dang co nhu càu ngày cao ma tàng cuòng nàng lue dao lao Irinh dò tién licn phù hop \ói chu Iruxnig \a> dung Dai hoc niihién cuu co iriiih dò quòc té cua dcrn \ i dang dal Thòi gian t h u c hién: 2()1()-2()12 Tong kinh phi : 400 triéu (dà hoàn thành càc chùng tu de quyét toàn \ ói lai \ u) C H I TRI DÉTAI KHOA V A T L Y Kv tèn Xàc nhan Uij^ ^ ^ ^ ^ «'^'U^Uc^T&OM T R D Ị N G DAI HOC KHOA HOC TU NHIÉN •MĨ MÌ\i TRNO fi S 1S K H Jmif'^' ^^^onnén dang plasma An mòn laser duge su dung nhiéu ITnh \uc nghién cùu \à co su lién he chat che vói ng nghé nani) Nò dugc ùng dung de tao màng mong cac hai nano, òng nano càc bon nano dà\ Si \à tao càu trùc nano \òi ihòi gian phàn giai \ugt qua giòi han nhiéu \a An mòn laser dugc su dung de che tao màng mong nò dugc thuc hién chàn khòng dòi mòi truòng trcy nhu Ar ha\ nhùng chàl dòng \ai Irị làc nhàn hồ hoc nhu Amoniac hồc Nilo An mịn laser thè thuc hién irong mịi truòng chat long de tao càc hai kich thuòc co nano KN ihuat àn mòn laser kha hùu hieu de tao càc hai nano cùa vat lieu bàn dàn va kim Ioai So \ ói càc phuong phap khàc àn mòn laser mot phuong phàp khà don gian càc hai nano dugc che tao khòng hi nhiém bàn boi chàl khu dàc bici eó thè diéu khién dugc kich thuòc hai / / Co che àn mòn laser Co hai qua trinh chi phòi gà\ qua Irinh àn mịn|^)|: - Qua trinh quang hồ: Dị qua trinh hàp thu photon de phà \ ò lién két hoà hoc phàn tu - Qua trinh quang nhiét: Dò qua trinh dot nòng vài lieu su hàp thu photon Doi vói laser boat dịng ò vùng hòng ngoai hoàc kha kién qua trinh quang nhiél chiém uu ihe h(rn.Vòi bue \ a laser \ung tu ngoai \a nàng lugng pholon lòn hon nàng lugng lién kcl hòa hoc phàn tu ihi qua irinh quang boa chiém uu thè hon Hai qua trinh na> déu miuNén nhàn gà> qua trinh àn mon I rcii tlii.ic le hai qua irmh nà> khòng làch neng lé ma co mòi lién he chat che \o\ 10 ,eeS, when the ethanol 'co e nt aUon l ' e a s c s I T'"""""''' '*""'" ''^ ""^'""^'^ bso-ption peak is shifted to longcT wave " n X T , ["T" T""^ '' '"'"^"' '"" ,o.r,ty of ethano, molecules caufc g r o : : r a r : : s t : t s - n T ^ ^ ^ l T o l r : ' ' ''"' ' " ' ' " ' " " WfiruMcfigt^ [rwni Fig, The absolution speetra ofgold nanoparticles colloid prepared in distilled water (a) solution of 30% ethanol (b) and solution of 60% ethanol (e) This resuits suggested that we can control average size and size distnbution of gold anoparticles by changing the concentration of ethanol in water We can also decrease mean ze ofgold nanoparticles in ethanol solution by laser-induced fragmentation Usmg seeond armonie 532nm wavelength of Nd:YAG laser corresponding to plasmon resonance absorption avelength ("-520nm) of gold nanoparticles we could decrease average diameter of gold anoparticles to few nanometers Fig shows TEM images and corresponding size distribution f gold nanoparticles prepared in ethanol 60% before and after 532nm irradiation The average ze ofgold nanoparticles is 9nmand3nm before and after 532nm irradiation respectively Fig, TEM images and corresponding size distribution ofgold nanoparticles in ethanol 60% before and after 532nm irradiation prepared 159 IV CONCLUSION Silver and gold nanoparticles were prepared successfuUy in several clean liquids such as eionized water, distilled water and ethanol soltions by pulsed laser ablation The mean size and ize distribution of gold nanoparticles in ethanol solutions could be controlied by changing oncentration of ethanol in water or irradiation of 532nm seeond harmonic wavelength of Id:YAG laser The resuits support a technique to control mean size and size distribution of letal nanoparticles by changing nature of liquid environment and by laser-induced ragmentation V ACKNOWLEDGMENTS This research was supported by the Project 43/2009/HD-NDT Vietnam-Russia and the project JGTD-10 04 of VNUHN Vietnam REFERENCES 1] Fumitaka Mafune, Jun-ya kohno Yoshihiro Takeda, Tamotsu Kondow, Journal of Physieal Chemistry fl, Voi 104 No 35(2000) 8333 2] R.MTilaki,A.Iraji zad and S.M Mahdavi Journal of Nanoparticle Research (2007) 9:853-860 3] Nguyen The Binh, Le Tu Quyen, Do Thi Ly, Trinh Th Hue, Tran Thi Ha, , VNU Joumal ofScence volume 24, No IS, 2008, p 284 [4] K Lance Kelly, Eduardo Coronado, Lin Lin Zhao, and George C Schatz / Phys Chem B 2003, 107, 668-677 [5] Jean-Philippe Sylvestre, Suzie Poulin Andre V Kabash.n, Edward Sacher M.chel Meun.er, and Media,/ Phvs Chem B 2004, 108, 16864 - 16869 (6] Fumitaka Mafune", Jun-ya Kohno, Yoshihiro Takeda, and Tamotsu Kondow / Phys Chem B Voi [7] JTdrei V^Kaba^shin, M Meunier J Photochemistry and Photobiology A:Chemistry (2006) 330-334 [8] P.V Kazakevich, A.V Simakin, V.V Voronov,G.A Shafeev, App Sur Science 252(2006) 4373^380 160 m uuc QUOC GIÀ HA NĨI VIETNAM NATIONAL UNIVERSITY, HANOI SSND865-B612 '^ j •v,ìv^ ^ • • ^ JOURNAL TOAN MATHEMAT Volume 27, No IS, 2011 VNU Joumal of Science Mathematics - Physics 27, No IS (20! 1, 51-56 ^ Preparation of copper nanoparticles in water and acetone by laser ablation Nguyen T^anh Dinh, Trinh Thi Hue, Vu Thi Khanh Thu, Pham Thi Thanh Van, Nguyen Quang Dong, Nguyen The Binh' Faculty of Physics, V^U University of Science, 334 Nguyen Trai, Hanoi Viemam Reeeived 8Juiy201l Abstract Using the Quanta Ray Pro 230 Nd:YAG laser, we produced copper nanoparticles in water and acetone by laser ablation The average size and optical properties of ihe nanoparticles were observed by a transmission electron microscopy (JEM 1010 - JEOL) and UV-visible 2450 spectrometer The average diameter of copper nanoparticles in water and acetone were 23 nm and nm, respectively The absorption specu-a of copper nanoparticles showed that there was no indication of copper oxide nanoparticles The experimental resuits showed advantages of the laser ablation method The resuits and discussions will be represented in this report Keywords: laser ablation, plasmon resonance, nanoparticles Introduction Metal nanoparticles are very attractive due to their unique physieal and chemical propenies They have a wide range of optical and electrical properties that originate from quantum confinement effects In recent years, copper nanoparticles have attracted great interest due to their potential applications in conductive films, lubrication nanofluids and catalysis Besides bulk materials, nanoparticles are efficient for catalysis applications because of their large surface to volume ratio In addition, copper nanoparticles embedded in a dielectric medium such as polymer matrices are useful materials for nonlinear optical devices [1,2] A number of methods, including microemulsion, reverse micelles and reduction of copper salts have been developed to prepare copper nanoparticles [3] Recently, the use of pulsed laser ablation of materials for preparation of silver and gold nanopareticles has been studied in our Quant um Optics Lab In this paper, we report the preparation of copper nanoparticles by laser ablation in distilled water and pure aceton The copper nanoparticles were produced with different laser powers The average size and size distribution of copper nanoparticles vsere observed to determine the optimal laser ablation process Corresponding author E-mail: thebinh@vnu.edu.vn 51 « r Z>« « «/ / n„JJo.r„a,ornane M.,H.„a,ic - , * , , , „ , , ;,„ ,saOU, A « Experimental Experimental setup was shown in Fi^ i Fig Experimental setup We placed a copper piate (99,9% in purity) in a glass euvette filed with lOml aqueous solution of surfactant The fundamental wavelength (1064 nm) of the Quanta Ray Pro 230 Nd: YAG laser was focused on the copper piate by a lens having the focal length of 150mm The laser was set in Q-switch mode to give laser pulse duration of ns, repetition rate of lOHz Copper nanoparticles were produced by laser ablation of copper piate immersed in water and acetone The vessel was placed on a horizontal platform, which executed repetitive circular motions at a Constant speed to prevent agglomeration of particles The solution becomes colored under action of the laser beam A small amount of the colored solution was e.xtracted for absorption measurement and TEM observation The absorption spectrum was measured by a Shimadzu LrV-2450 spectrometer The TEM micrograph was taken by a JEM 1010-JEOL The size of nanoparticles was determined by ImagieJ 1.37v software of Wayne Rasband (>Jationa] institutes of Health, USA) The size distribution was obtained by measuring the diameter of more than 500 particles and using Origin 7.5 software Resuits and discussion First, we studied to prepare copper nanoparticles in distilled water The ablation of copper was carried out with different laser powers and the same irradiation time The UV absorption speetra ofthe colloidal copper in water were shown in Fig.2 The characteristic absorption peak of copper nanoparticles around 630 nm appeared and shifted a little with the average laser powers of ablation In our experiments, thJs plasmon resonance absorption peak position was red-shifted from 629nm to 636nm when average laser power of ablation increased from 200mW to ÓOOmW According to Mie's theory the resonance peak of nanoparticles is red-shifted when their size increases [4] The resuits showed that the laser power density of ablation influences not only the abundance but also the size of nanoparticles There was no indication of the absorption around 800 nm, which is typical of copper oxide nanoparticles [5] ^- r Dinh et al / VNU Journal of Science Mathematics - Physics 27, J Na IS (2011) 51-56 53 3S-, 900 550 600 650 7C0 750 3CC wavelength (nm) Fig Absorption speetra of copper nanoparticles in distilled water with the different averjge laser powers '>00 m\V ( I j , 300 mW (2), 400 mW (3j, 500 mW (4), 600 mW (5) The copper nanoparticles produced in water with the average laser power of 200mW was observed by a transmission electron microscope (JEM 1010-JEOL) (Fi^.3) N5 ^ • ^ -K |:!H 1, a-iu (b) S-ca Iran) Fig TEM image (a) and size distribution (b) of copper nanopracticles produced by laser ablation in distilled water The TEM image and size distribution exhibit that the size ofthe particles is around 10-30nm It was found that the average particle diameter of copper nanoparticles is about 26 nm The copper nanoparticles colloids prepared in water remained stable for a week Then we carried out ablation of copper in acetone Figure illustrates absorption speetra ofthe colloidal copper which were produced in acetone with different laser powers 54 A^ T Dinh et at / VNV Journal of Science, Mathematics - Pt^sics 27 No JS nOUj 51-36 wavelength (nm) Fig Absorption speetra of copper nanoparticles in acetone with the different average laser powers 200 mW (a), 300 mW (b) 400 mW (e) The absorption peak appeared around 580 nm With laser power of 200 mW, the absorption spectrum has a net shape with peak at 578 nm The TEM image of copper nanoparticles produced in acetone with laser power of 200 mW was shown in Fig.5a Copper nanopaniclse are rather spherical in shape.The data of measured size ajid size distribution of copper nanoparticles were analyzed and given in Fig.5b It ìs observed that the diameter of copper nanoparticles concentrate in a range from to 12 nm The average size of copper nanoparticles is nm In comparison with the copper nanoparticles prepared in water, the diameter of nanoparticles is smaller and the size distribution is narrower " i t' • tr;'-^:V;-'- *?>- O ã ằ èLl^i^'410 nm i_J (b) S*;ô -wnj Fig TEM image (a) and size distribution (b) of copper nanopracticles produced by laser ablation in acetone Fig.6 gives a comparison between absorption speetra of Cu nanoparticles prepared in water ano acetone by laser ablation tising the same laser fluence and irradiation time ^ T Dinh et al / Vm Journal ofScienc Mathe soo «0 tóC '^atics - Physics 27, No ÌS(201lj 51-56 700 710 55 aoo wevaiftogth (nm) Fig Absorption speetra of copper nanopanicles in acetone (a) and water (b) with the average laser powers of 200 mW, irradiation time of 15 mins ^iJ^^ ^^'^Tn'"''' ' ^ ' ' ' ' ' ^^ ^"^ nanoparticles in water and acetone e.xhibit a ma^ximum peak at 578nm and 629nm respectively This result agrees with the average nanoparticle diameter observed Irom I bM im:ige, 26 nm and nm respectively, It is known that, in liquids, the nanoparticles are surface-charged Due to interaction of liquid environment molecules and surface-charged nanoparticles an electrical doublé layer surrounds the surface of the nanoparticles [6] Growth rate of nanoparticles depends on the number of particles formed in the first few laser pulses and molecular polarity of liquid environment Since the molecules of acetone has high dipole moment the electrical doublé layer surrounding nanoparticles restricted the grov/th mechanisms during ablation Hence, in acetone, copper nanopanicle diameter is smaller and size distribution is narrower than those in water Copper nanoparticles in acetone are stable even after more than two weeks Conclusion In the present work colloidal copper nanoparticles were synthesized successfuUy by pulsed laser ablation of copper targets in water and acetone Transmission electron microscopy was employed for characterization ofthe size and shape ofthe particles In both media the particles are rather spherical, and it has been found that the average diameters ofthe copper nanoparticles are 26 and nm in water and acetone respectively In addition, stability ofthe colloidal particles were also investigated The colloidal copper nanoparticles in acetone is stable during 20 days They were precipitated completely in water after days and colloidal copper nanoparticles change to o.xidized particles O.xidation of copper takes place due to the reaction of dissolved o.xygen in water with the colloidal copper nanoparticles This study also demonstrates a way to control the size of copper nanopanicles by changing the ablation medium 56 N.T Dinh et al / VNU Journal of Science, Mathematics - Physics 27, No, IS (2011) 51-56 Acknowledgement This research was supported by the NAFOSTED Grant No 103.02.51.09, Vietnam and the project QGTD 10.04 granted by VNU Hanoi References [I ] P.N Prasad, D.J Williams, Introduction to Nonlinear Optical Effects in Molecules and Polymers Wiicy, New York, (1991) [2] H.S Nalwa(Ed) Hanbook of Advanced Electronic and Phoionic Materials and Devices, Voi.9, Academic Press,New York,(2001) [3] KM.T\\dk:\, Applied Physics A UA\5-A\9{2^^1) [4] M.Saito, K.Yasukawa, T Umeda, Y.Aoi, Optical Materials 30 (2008) 1202 [5] E.K Athanassiou, RN Grass and W J Stark, Nanotechnology 17 (2006) 1668 [6] Mafune F Kohno, Y Takeda 2001 J Phys.Chem.B 105(2001), 9050 VNU Joumal ofScienr* w,, "i science, Mathematics - Physics 27, No 1S (2011)94-99 Studying the role of liquid environments in formation of noble metal nanoparticles by laser ablation Trinh Thi Hue, Nguyen Thanh Dinh, Nguyen Quang Dong Duong Thi Nguyet, Nguyen The Binh' Faculfy of Physics VNU University of Science, 334 Nguyen Trai, Hanoi, Vietnam ReceivedS July 2011 Abstract We studied the role ofthe aqueous solution in formation of noble metal nanoparticles by laser ablation The gold and Silver nanoparticles were produced in different liquids such as water ethanol solution of polyvinylpyrrolidone (PVP) Size and optical properties ofthe nanoparticles were characterized and observed by a transmission electron microscopy (JEM 1010 - JEOL) and UV-visible 2450 spectrometer In our experiments, we studied the effect of different solution to the average size and stability ofthe metal nanoparticles against coalescence Silver nanoparticles prepared in deionized water, ethanol and 0.005 M solution of PVP have average size of 14 nm, inm and I2nm respectively Meanwhile, average size ofgold nanoparticles are 21, 24 and 14 nm respectively The resuits and discussions will be represented in this report Keywords: laser ablation, plasmon resonance, nanoparticles Introduction Nanoparticles of noble metais have recently become the focus of research because of their unique properties, which are different from those of bulk materials They have a wide range of optical and electrical properties that originate from quantum confmement effects These properties depend on the size, shape and material of nanoparticles [1] Control of size and shape is very important for timing its properties The size induced properties of nanoparticles make them suitable for many applications in various areas such as catalysis, optics, and life environments [2] Numerous physieal and chemical methods have been employed to produce metal nanoparticles such as chemical reduction, ultrasonic reduction, radiolytic reduction, etc [3] Recently, laser ablation method has been developed to prepare nanoparticles wàth ease and without contamination by a reducing agent In laser ablation method the nucleation, growth, and aggregation mechanisms depend on several factors including laser tvavelength, pulse energy, pulse duration, repetition rate and nature of liquid environments [4] Liquid mvironment affect metal nanopaerticle formation mechanism and can be used to adjust the size and ihape of nanoparticles In this work we studied effects of the liquid environment such as water, :thanol and solution of PVP to optical properties, size distribution and aggregation of Au and Ag lanoparticles prepared by laser ablation Corresponding author E-mail: thcbinh@vnu.cdu.vn ^^ TT Hue et al / VNU Journal of Science Mathematics - Physics 27, No ÌS (201 Ij 94-99 Experimental We placed a metal piate (99.9 % in purity) in a glass euvette filled with 10 mi liquid The fundamental wavelength (1064 nm) ofthe Quanta Ray Pro 230 Nd:YAG laser in Q-switch mode was focused on the metal piate by a lens having the focal length of 150 mm The laser was set to give laser pulse with energy of 80 mJ, duration of ns and repetition rate of 10 FLz Metal nanoparticles were produced by laser ablation of metal piate immersed in different liquid environments such as water, ethanol, PVP solution The solution becomes colored under action ofthe laser beam A small amount of the colored solution was extracted for absorption measurement and TEM observation The absorption spectrum was measured by a Shimadzu UV-2450 spectromieter The TEM micrograph was taken by a JEM 1010-JEOL The size of nanoparticles was determined by ImagieJ 1.37v software of Wayne Rasband (>Jational institutes of Health, USA) The size distribution was obtained by measuring the diameter of more than 500 particles and using Origin 7.5 software Resuits and discussion Fig shows absorption speetra of silver nanoparticles produced in deionized water, ethanol and PVP solution 409 «ao WD wavetengttì (nm) Fi" Absorption speetra of Silver nanoparticles in deionizecTwater (a), ethanol (b) and 0.005 M solution of P\T (b) The speetra present absorption peaks at visible wavelengths P - ' ' - - - ^ , " „ ^ ; ° ' , ^ ^ , n ' o extinction speetra of sarnples that were prepared in deiomzed water, ethanol and «OO^M soluuc^ PVP present e.xtinetion peaks at 393 408 and 398 nm respeetwely, that can be - ' S ^ e ^o f J ^ ^ know^ surfaee plasmon resonanee of sphencal nanoparticles The resuits ^^o-d *at the o ^^^ e^inetion s p e e t L of silver n^opanicles m ethanol is broader ,n - P - o n w^^^ ^ ^ t J Z and 0.005M solution of PVP The extmction speetra of s.lver " ^ P ^ ^ ^ ^ ^ P ^ ' j J ^ e i e , ^ of is the n^owest Aeeordmg to ^ ^ ^ f ^ ^ ^ f r s ; ^ ^ ^ ^ ^ ^ ^ ^ the ma>dmum optieal extmction and the shape ot tne spec r v nanoparticles are rather sphencal m shape bince me incu ^^^ ^.|^.^^ 96 TT Hue et / VNU Journal of Science Mathematics - Physics 27, No ÌS(20Il) 9499 of the maximum of optical extinction is due to a change in the size of the particles In addition broademng of the extmction speetra in ethanol is related to the broad size distribution of the particles as confirmed by TEM images r Il (^^ tu Fig.2 TEM micrograph images and corresponding size distribution of silver nanoparticles prepared in deionized water(a), ethanol (b) and 0.005M solution of PVP(c) Fig 2a shows the TEM image and the size distribution of silver nanoparticles prepared in deionized water Their size distribution is broad with an average size of 14 run In ethanol, the size distribution is broadest with a mean diameter of 31 nm (Fig 2b) Meanwhile, Silver nanopanicles produced in the solution of PVP have mean diameters of 12 nm According to the Mie theory for sphere nanoparticles, the resonance plasmon absorption peak wavelength increasing with particle diameter The average diameters calculated by TEM images are in good agreement with the absorption speetra (fig.l) where the absorption peaks are red shifted when average size increase Fio Absorption specu-al ofgold nanoparticles in deionized'water (a), ethanol (b) and 0.005 M solution of P\T (e) We continued to carry out laser ablation ofgold Ln deionized water, ethanol and PVP solution Tììe absorption speetra, TEM images and size distributions of gold nanoparticles was showiì m Fig and '^ TTìe absorption speetra e.xhibits the characteristic peak of surface plasmon resonance at around 520 nm The wavelengths of these absorption peaks are 523 524 and 52Inm m de.omzed water, ethanol and 0.005M solution of PVP respectively TT Hue et al / VNU Journal of Science, Maihemat ics - Physics 27, No IS (201 Ij 94-99 97 (a) ã' ô • • " - - * - • IlOQ ! • •• idi !l!l ni liU llljluu «flL Fig TEM micrograph and corresponding size distribution ofgold nanopanicles prepared in deionized waterfa), ethanol (b) and 0.005M solution of PVP (e) As shown in Fig 4, the prepared gold nanopanicles are rather spherical in shape Mean size ofgold nanoparticles in deionized water, ethanol and 0.005 M solution of PVP are 21, 24 and 14 nm respectively The mechanism of pulsed laser ablation of metal in liquids could be explained by a model of Mafune and his coworkers [7] At first, pulsed laser beam ablates the target during laser irradiation Ablated materials, which are called piume, expand under liquid environment and disperse many produced species Dispersed materials include nanopanilces, small clusters, free atoms and ions For the first few pulses, only liquid medium surrounds the piume and metal species in piume nucleate to produce nanopanicles The nanopanicles disperse in liquid medium and provide nucleation centers for the next incoming metal species Plume-nanopanicle interaction takes place In this stage, two mechanisms contribute to the nucleation process The first mechanism is direct nucleation of metal in the condense plum^e similar to the first stage Another mechanism is addition ofthe metal species to the nanoparticles that produced before Vvhen both mechanisms occur, broad size distributions will be observed AH attractive and repulsive forces between piume species and nanopanicles such as attractive van der Waals forces and repulsive electrostatic forces due to the overlapping of electrical doublé layers take a very important role in formation and growth mechanism of nanopanicles It is known that, in liquids, the nanopanicles are surface charged Due to interaction of liquid environment molecules and surface-charged nanopanicles an electrical doublé la>er surrounds the surface of the nanoparticles [7] Growth rate of nanopanicles depends on the number of panicles formed in the first stage and molecular polarity of liquid environment Molecules with high dipole moment cause more packed and stronger bonds to the surface of the panicles The electrostatic repulsive force due to overlapping ofthe electrical doublé layer ofthe nanopanicles and species in the piume prevents fiirther growth It was demonstrated that in liquids surface of metal nanopanicles such as Au and Ag is charged negatively because of interaction with medium and different affm;r>' of electron to the surface [6,7] In water and ethanol the dissociation of OH group on metal nanopanicles resuits in surface charge and electrical doublé layer forms SLnce the molecule of water has higher dipole moment than pure ethanol, the electrostatic repulsive force restricts more effectively the growth mechanism As a result smaller Ag and Au nanoparticles and narrower size distribution were observed in water than those in pure ethanol In order to verify this argument, we canied out laser ablation of Au in solution of ethanol in water with diff"erent concentrations 98 TT « ^ „ , _ , „ , , , _ „^^^^^_^^ ^^^^^^ ^^ ^^ ^^^^^^^ ^^^^ wavtlengtn{nm) Fig, Th ab»,„,i„„ specra « J i * - - P - i c l s colloid p„pared in dis.ilied wa,„ , „ „ , „ , i „ r30% ethanol (b) and solution of 60% ethanol (e) Fig shows the absolution speetra of gold nanoparticles colloid prepared in distilled water solution of 30% ethanol and solution of 60% ethanol As obviously seen, when the ethanol concentration mcreases the absorption spectrum is broaden and absorption peak is shifted to lonoer wavelengths The weak electrical doublé layer due to low polarity of ethanol molecules cause growth and resuits m the size broadening We also carried out laser ablation ofAg and Au in distilled water to compare with deionised water TEM images and size distributions of Ag and Au nanoparticles prepared in distilled water were presented in Fig The average size of Ag and Au nanopanicles are nm and 13 nm respectively In comparison with nanoparticles prepared in deionised water, the average diameter ofAg and Au nanoparticles prepared in distilled water is smaJler and their size d'istributionls narrower These resuits eonflrm the role of ions in liquids environment during laser ablation process Co) \" :v!ililu li iilik lOQ ni Fig TFM images and size distributions ofAg (a) and Au (b) nanopanicles prepared in dislilled water The small size and narrow size distribution of Au and Ag nanopanicles prepared in solution PVP are explained by the role of C=0 group ofthe pol>Tner In the presence of P \ T - (C^^HgNOìa, the C=0 group interact with metal atoms on the surface of nanopanicles The oxygen atoms of C=0 group are attached to the metal atoms and create locai surface state that protect metal nanopanicles against growth and aggregation As a result, the metal nanoparticle size is small and dispersion decreases Conclusion The role ofthe liquid environment in preparation of metal nanoparticles by pulsed laser ablation was studied Silver and gold nanoparticles were prepared in different liquids sudi as deionized water, distilled water, ethanol and solution of PVP The TEM and spectral measurements were carried out to determine average size and size distribution of nanoparticles Our experimental resuits show that molecular polarity of liquid environment takes a very important role in nanoparticle formation and growth mechanism High polar molecules provide an electrical doublé layer, which prevents growth and aggregation This study support a technique to control average size and size distribution of metal nanoparticles by changing the nature of the liquid environment in pulsed laser ablation Acknowledgement This research was supported by the NAFOSTED Grant No 103.02.51.09, Vietnam and the project QGTD 10.04 granted by VNU Hanoi References rn U Kreibig, M Vollmer, Optical properties of metal clusters Springer Berlin, 1995 [2] Renat R Letfullin, Charles Joenathan, Thomas F George, Vladimir P Zharov, NanomedianeM^) (2006) 473 [3] Fumitaka Mafune, Jun-ya kohno Yoshihiro Takeda, Tamotsu Kondow, Journal of Physieal Chemistry B, Voi 104 No 35(2000) 8333 ^ [41 Nguyen The Binh, Le Tu Quyen, Do Thi Ly, Trinh Thi Hue, Tran Thi Ha Preparat.on ^"^ J^^^^^/'^^ control ofgold nanopanicles by laser ablation, VNU Journal of Science volume 24, No S (2008X ^84[51 C F Bohren, D.R Huffman, Absorption and Scattering of Light hy Small Particles, V ley, NV (1983) rean-Ph.hppe Sylvestre, Suzie Poulm, Andre V Kabash.n, Edward Sacher M.chel ^1eun.e^ an^^^^^^ H T Luong, Surface Chemistry of Gold Nanopan.cles Produced by Laser Ablation m Aqueous Med.a, J Phys Chem.B 108,(2004) 16864 [71 Maftine F Kohno, Y Takeda, J.P/T>-5.C/i^m.B 105 (2001)9050