pengnano 2 sblm uts.pdf

Teknik Fabrikasi Nanoteknologi 1 Semester Gasal 2022/2023 Dosen: Prastika K. Jiwanti Ph.D Program Studi Rekayasa Nanoteknologi Fakultas Teknologi Maju dan Multidisiplin Universitas Airlangga Outline (macam-macam jenis sintesis): 1. Sintesis Bottom-up 2. Sintesis Top-Down 3. Sinte...

Teknik Fabrikasi Nanoteknologi 1 Semester Gasal 2022/2023 Dosen: Prastika K. Jiwanti Ph.D Program Studi Rekayasa Nanoteknologi Fakultas Teknologi Maju dan Multidisiplin Universitas Airlangga Outline (macam-macam jenis sintesis): 1. Sintesis Bottom-up 2. Sintesis Top-Down 3. Sintesis kombinasi Bottom-up dan Top-down Ø Physical (Mechanical/Vapour) Ø Chemical Ø Biological Ø Hybrid High Energy Ball Milling simplest ways of making nanoparticles of some metals and alloys in the form of powder 100–1,100 oC Lower temperatures favour amorphous particle formation Co, Cr, W, Ni-Ti, Al-Fe and Ag-Fe are made nanocrystalline using ball mill Melt Mixing mixing the molten streams of metals at high velocity with turbulence. On mixing thoroughly, nanoparticles are found to have been formed. For example a molten stream of Cu-B and molten stream of Ti form nanoparticles of TiB2. Physical Vapour Deposition involves use of materials of interest as sources of evaporation, an inert gas or reactive gas for collisions with material vapour, a cold finger on which clusters or nanoparticles can condense, a scraper to scrape the nanoparticles and piston-anvil Vacuum chamber Ionized Cluster Beam Deposition v Developed by Takagi and Yamada around 1985 v Produce high quality single crystalline thin films v The set up consists of: 1. a source of evaporation, a nozzle through which material can expand into the chamber 2. an electron beam to ionize the clusters, 3. an arrangement to accelerate the clusters 4. a substrate on which nanoparticle film can be deposited Laser Vapourization (Ablation) vapourization of the material is effected using pulses of laser beam of high power. A powerful beam of laser evaporates the atoms from a solid source and atoms collide with inert gas atoms (or reactive gases) and cool on them forming clusters. Ex: SWCNT Sputter Deposition Sputter deposition is a widely used thin film deposition technique, specially to obtain stoichiometric thin films (i.e. without changing the composition of the original material) from target material. Target material may be some alloy, ceramic or compound. Sputtering is also effective in producing non porous compact films. It is a very good technique to deposit multilayer films for mirrors or magnetic films for spintronics applications. DC Sputtering RF Sputtering Magnetron Sputtering sputter target is held at high If the target to be sputtered is RF/DC sputtering rates negative voltage insulating, can further be increased and substrate may be at positive, it is difficult to use DC sputtering. by using magnetic field. ground or floating potential This is because it would mean the use of exceptionally By introducing gases like O2, high voltage (>106 V) to sustain N2, NH3, discharge between the CH4 and H2S, while metal electrodes. targets are sputtered, one can obtain metal oxides like Al2O3, nitrides like TiN and carbides like WC. This is known as ‘reactive sputtering’. ECR Plasma Deposition The plasma density can be further enhanced using microwave frequency and coupling the resonance frequency of electrons in magnetic field Ionization density using ECR plasma is about 2–3 orders of magnitude larger than that by DC, RF, Magnetron sputter Chemical Vapour Deposition (CVD) Chemical vapour deposition, a hybrid method using chemicals in vapour phase is conventionally used to obtain coatings of a variety of inorganic or organic materials. It is widely used in industry because of relatively simple instrumentation, ease of processing, possibility of depositing different types of materials and economical via- bility. Under certain deposition conditions nanocrystalline films or single crystalline films are possible Types: 1. Metallo Organic CVD (MOCVD), 2. Atomic Layer Epitaxy (ALE), 3. Vapour Phase Epitaxy (VPE), 4. Plasma Enhanced CVD (PECVD). 5. Micro wave-CVD (MVCVD) Chemical Vapour Deposition (CVD) https://www.youtube.com/watch?v=DF9YC4mXhJg Electric Arc Deposition This is one of the simplest and useful methods which leads to mass scale production of Fullerenes, carbon nanotubes Fullerenes are formed at low helium pressure and nanotubes are formed at high pressure. Also, fullerenes are obtained by purification of soot collected from inner walls of vacuum chamber, whereas nanotubes are found to be formed only at high He gas pressure and in the central portion of the cathode Ion Beam Techniques (Ion Implantation) possible to even obtain doped nanoparticles (i.e. nanoparticles in which some foreign atoms are intentionally introduced to alter the properties of the host material in the controlled fashion) using ion implantation. Molecular Beam Epitaxy (MBE) This technique can be used to deposit elemental or compound quantum dots, quantum wells as well as quantum wires in a very controlled manner. Making Nanoparticles Using Supersaturated Vapor A number of nanoparticle sources produce particles by mixing an atomic vapor of the material required with an inert gas at much lower temperature to produce a supersaturated vapor. Cu has a vapor pressure of about 15 mbar at 1200◦C; so if we generated a Cu vapor with a temperature 1200◦C and a pressure greater than 15 mbar, it would naturally con dense into Cu particles. Sources Producing Nanoparticle Beams in Vacuum Plasma, Spark, and Flame Metal Aerosol Sources Aerosol source Thermal Plasma source Flame synthesis: producing SiO2 Size Selection of Nanoparticles in Aerosols (a) Differential Mobility Analyzer (DMA) that determines particle size in an aerosol. The unfiltered particles are ionized using a radioactive source and then passed into a grounded cylinder with a high voltage pole in the middle. The electrostatic force on the particles produces a constant radial diffusion velocity that depends on particle size. Only particles of the correct size can escape through the exit aperture. The size can be selected by adjusting the pole voltage. (b) Condensation Particle Counter (CPC) that detects individual particles by passing them through a tube with controlled humidity in which the nanoparticles act as condensation nuclei for water. They can be grown t o a sufficient size so that each one produces a detectable flash of light when it passes through a focused laser beam and can be counted. The air introduced into both devices along with the aerosol is to ensure laminar flow.  Assignment: Make a table list of the advantages/disadvantages of nanomaterial syntesis method. Sources: books, journal articles, etc. References Sulabha K. Kulkarni. 2015. Nanotechnology principles and practices 3rd edition. Springer Chris Binns. 2010. Introduction to nanoscience and nanotechnology. John Willey & Sons, Inc. IOP Conf. Series: Materials Science and Engineering 263 (2017) 032019 doi:10.1088/1757-899X/263/3/032019 Teknik Fabrikasi Nanoteknologi 2 Prastika K. Jiwanti Ph.D Semester Gasal 2022/2023 Program Studi Rekayasa Nanoteknologi Fakultas Teknologi Maju dan Multidisiplin Universitas Airlangga Outline (macam-macam jenis sintesis): 1. Sintesis Bottom-up 2. Sintesis Top-Down 3. Sintesis kombinasi Bottom-up dan Top-down Ø Physical (Mechanical/Vapour) Ø Chemical Ø Biological Ø Hybrid Advantages ü Simple techniques ü Inexpensive, less instrumentation compared to many physical methods ü Low temperature (