本實驗利用晶種成長法分別製備出長寬比為2.5和4的金奈米棒，之後利用還原劑使其形變為啞鈴型金奈米棒。以此兩種金奈米棒做為模板合成金銀核殼型奈米粒子，先在75℃的環境下加入硝酸銀，之後加入還原劑Ascorbic acid (AA)將硝酸銀還原於金奈米棒上合成金銀核殼型奈米粒子，能分別形成銀殼長寬比為1.45的長方體、長邊為~75 nm、短邊為~57 nm的雙三角錐，而且我們發現其長寬比較短的金奈米棒生長銀殼的時間比較短。若是把界面活性劑中Br-換成Cl-反應時間會更為縮短。另外藉由在Hexadecyl trimethyl ammonium bromide (CTAB) 裡加入透明質酸 (Hyaluronic acid)之後加入還原劑AA將硝酸銀還原，則會生長成長度達數十微米的奈米銀線和奈米顆粒。但是當在溶液中加入其他金屬奈米粒子時，會抑制銀奈米線的形成。 An aspect ratio of 2.5 and 4 gold nanorods (NR) were prepared by seed-mediated growth method. gold nanodumbbell (ND) could be stabilized in the transfer process by adding AgNO3. Then Au-Ag core-shell (Au-Ag) nanorods could be synthesized from two kinds of nanorods and nanodumbbell. Adding AgNO3 at 75 ℃, and Ag+ was reduced on the surface of gold nanorods by ascorbic acid. We observed the 2.5 aspect ratio gold nanorods the reaction time is faster than orther nanorods. It can grow rectangular that silver shell aspect ratio is 1.45 and triangular bipyramid that long axis is ~75 nm, short axis is ~57 nm. If transferred into the solution of hexadecyl trimethyl ammonium chloride (CTAC), the reaction time can be shortened even more. Both silver nanoparticles and nanowires in several tens of micrometers could be obtained in the solution of HA and cationic surfactants at higher reaction temperatures. But, the formation of silver nanowires is easily inhibited in the presence of metal nanoparticles in the reaction solutions.
