The Experimental Research Of Using Micro-wave Methods To Prepare Nano-particles

Microwave exploits the new realm of the microwave chemistryin the application of chemistry. It can promote all kinds of chemicalreaction by reacting to chemical systems directly. Microwave is anelectromagnetic wave that includes the electric field and magneticfields. Its electric field can drive the charged particle migration orspinning. Because the electromagnetism in the microwave fieldchanges its directions from hundreds of millions to billions a second,usual molecular group such as liquid or solids, which can not keep upwith such a fast direction switch, will generate heat by friction. Theheating is caused by the movement of the numerator in itself, so it iscalled "inner heating". The inner heating has much superior, such as,it is quickly heated, the heating system temperature is even, and thepair pole moment of the molecule is big. Consequently heatingquicker, organic rate of reaction has a marked improvement at thistime.Currently the microwave mainly involves two aspects of theappliance in the realm of chemistry. The first aspect is to make use ofthe microwave to increase the rate of a chemical reaction. Because themicrowave heating is a kind of fast and whole method of heating, so itis called heating effect of microwave. The second aspect is to makeuse of the microwave to change reaction mechanism and get thelocalized material. The work of this thesis is on the other hand ofappliance of microwave, meanly making use of the microwave hoteffect system is to produce inorganic nanometer material. The nanometer material means the particle size of thin material iswithin the extent from 1nm to 100nm.Its size is larger than atomcluster, but smaller than micro powder. As a new function material,the way of producing nanometer material is becoming people's focusbecause it has many special characters which are different fromnormal materials. There are many ways to produce nanometer material and the newways are rising. Using microwave to produce nanometer is a newmethods rising in recent years. It is an effective method of producingnanometer material. Because it has much superiority such as the rateof a chemical reaction is very quickly, particle distributing issymmetrical. Along with the development of the modern industrial, high techof nanometer SnO2 is widely used. Currently it is mainly used as thenanometer SnO2 material for air, whites or light shades conductingmaterial and nanometer recombination light catalyst material. Italready displays the potential and huge market. The usual way ofproducing nanometer of SnO2 has two methods: water -heat method,sol-gel method. The microwave method is a useful method that can be used toproduce nanometer particle. The research is made in paper aboutproducing SnO2 and silver nanometer particle in microwave. To chose two samples in the nanometer SnO2 experiments. The sample A is at the middle fire condition (it equal to 472 Wmicrowave power) and heated for 15 minutes. The liquor is taken out. The sample B is heated for 30 minutes in the middle firecondition .The liquor is taken out. Finally, we find discover that the shape of the sample A isabnormal. Moreover there is conglutination between the particles andthe diameter is also a little bigger.However, the appearance of sampleB is clearer globosity. Its average diameter is about 40 nm, and thediameter of the particle distribute averagely.The particles don'tdisperse well perhaps because depositions come in being due to notanalyzing transmission electron microscope in time.If we add off-center washing, throw away the chlorine ion of the sample, thedisposition will not come in being, which makes the particle disperse. The reference [3] gives the result of producing silver nanometerin the microwave. We use ultraviolet ray besides the method referredin reference [3]. It means use microwave and ultraviolet ray toproduce silver nanometer particle. Moreover these two methods arecompared. Two samples are used in the experiment: The sample A is heated in fire for 18 minutes (after 8 minutes,the liquor is yellow. If continue heating, the color of liquor becomedark) (the liquor is gray).Take out the liquor. When the sample B is still in the midst fire, we use 80w mercurylight as ultraviolet ray (after heating 8 minutes, the color of the liquordoesn't change) for 18 minutes (The liquor is gray).Take out theliquor. As can been seen from the ultraviolet ray visible spectrum of twokinds of samples, the peak shape of two kinds of samples isfamiliarity and there is only an absorption peak. It means the silvernanometer particle is global granule.But the strength of peak of thesample A is higher than that of the sample B. Therefore the half peakwidth of the sample A is smaller than that of the sample B. It showsthat the diameter of the silver particle of the sample A distributes moreaveragely than the sample B. and the highest level of the absorptionpeak of two kinds of samples are about 400 nm. The analysis shows that silver nanometer particle is global. Itsradius is about 40 nm. However sample A distracts more well thansample B. Moreover the radius of the particle of sample A distributemore averagely than the sample B. It accords with the analysis resultof ultraviolet ray visible spectrum. A conclusion can be made in the paper by producing tin and twooxygen and silver nanometer particle: 1.If given proper microwave power and heating time, the tin and...