Nanotechnology in the High School Science Curriculum

1、Nanotechnology in the High School Science CurriculumKenneth Bowles- NBCTApopka High SchoolUCF- Science Instructional AnalysisOctober 5, 2004What Is All the Fuss About Nanotechnology?Any given search engine will produce 1.6 million hitsNanotechnology is on the way to becoming the FIRST trillion dolla

2、r market Nanotechnology influences almostevery facet of every day life such assecurity and medicine.Does Nanotechnology Address Teaching Standards?Physical science content standards 9-12Structure of atomsStructure and properties of matterChemical reactionsMotion and forcesConservation of energy and

3、increase in disorder (entropy)Interactions of energy and matter Does Nanotechnology Address Teaching Standards? Science and technology standardsAbilities of technological designUnderstanding about science and technology Science in personal and social perspectivesPersonal and community healthPopulati

4、on growthNatural resourcesEnvironmental qualityNatural and human-induced hazardsScience and technology in local, national, and global challengesDoes Nanotechnology Address Teaching Standards?History and nature of science standardsScience as a human endeavorNature of scientific knowledgeHistorical pe

5、rspective Does Nanotechnology Address Teaching Standards?Nanotechnology Idea Standard it can address The idea of “Nano” being small Structure of Atoms Nanomaterials have a high surface area(nanosensors for toxins) Structure and properties of matter, Personal and Community Health Synthesis of nanomat

6、erials and support chemistry (space propulsion) Chemical Reactions Shape Memory Alloys Motion and Forces, Abilities of technological design, Understanding about science and technology Nanocrystalline Solar Cells Conservation of Energy and increase in disorder (entropy), Interactions of energy and ma

7、tter, Natural Resources Nanocoatings resistive to bacteria and pollution Personal and Community Health, Population Growth, Environmental Quality, Natural and human-induced hazards iDoes Nanotechnology Address Teaching Standards?Nanotechnology Idea Standard it can address Nanomaterials, such as MR (m

8、agneto-rheological) fluids in security Science and technology in local, national, and global challenges Richard P. Feynmans talk, “There is plenty of room at the bottom”. Feynman had a vision. Science as a human endeavor, Nature of scientific knowledge, Historical perspective Nanocosmetics and nanoc

9、lothing Science as a human endeavor, Science and technology in local, national, and global challenges Nanotechnology and Science Ethics Science and technology in local, national, and global challenges, Science as a human endeavor, Historical perspective, Natural and human-induced hazards, Population

10、 Growth, Personal and Community Health Energy Capture and Storage Ever consider how much sunlight actually strikes the earth?On average every square yard of land exposed to the sun will receive 5 kW-hours of solar energy per day. So if you had an area covering 100 square yards you would generate 500

11、 kW-hours per day. Upon careful inspection of our energy bill we discover that the average U.S. household generates 500-1000 kW-hours of electrical energy in ONE MONTH. So if we could efficiently harness the suns energy there could be limitless energy for us to use. Ubiquitous?Alan Heeger, 2000 Nobe

12、l Prize winner in chemistry for the materials used in PDA screens. These materials conduct electricity and emit light.It was discovered that these SAME materials could absorb light and emit electricityGoal: inexpensive solar cells EVERYWHERE!It Is All About the Benjamins!Silicon is a costly semi-con

13、ductorSilicon is bulkySilicon is inflexibleTHREE time more expensive than fuel currently used on the power grid.Costs, due to scale, are going down by 7% per year, which is TOO slow. “More people have lost money in bets against silicon than I know,-Arno Penzias ( Nobel Prize winner in Physics) “But

14、then youre talking a HUGE possible payback: The power market is about $1 trillion.We Think It IS Achievable!Goal: To capture 10% of the incoming solar energy.Plan: To develop, using nanoparticles such as titanium dioxide, solar cells which are made from cheap plastics. These plastics are very flexib

15、le. The solar cell can even be printed out using an ink jet printer onto the plastic and rolled up during manufacturing. Applications of Thin Film Solar CellsThe idea is that these solar cells can be taken EVERYWHERE to supply a steady amount of electricity, reducing the need to PLUG IN for power.Ev

16、entually, we believe these materials might be able to be sprayed onto business tiles, vehicles, and billboards, and then wired up to electrodes. It might even be possible to eventually feed into the electric power grid.Manufacturing will come first, but then:?An Example of a Nanotechnology Experimen

17、t, Which Addresses the Standards: Constructing Nanocrystalline Solar Cells Using the Dye Extracted From CitrusFour main parts:NanolayerDyeElectrolyte2 electrodesNanocrystalline Solar CellsMain component: Fluorine doped tin oxide conductive glass slidesTest the slide with a multimeter to determine wh

18、ich side is conductiveSynthesis of the Nanotitanium SuspensionProcedure:Add 9 ml (in 1 ml increments) of nitric or acetic acid (ph3-4) to six grams of titanium dioxide in a mortar and pestle.Grinding for 30 minutes will produce a lump free paste.1 drop of a surfactant is then added ( triton X 100 or

19、 dish washing detergent).Suspension is then stored and allow to equilibrate for 15 minutes.Coating the CellAfter testing to determine which side is conductive, one of the glass slides is then masked off 1-2 mm on THREE sides with masking tape. This is to form a mold.A couple of drops if the titanium

20、 dioxide suspension is then added and distributed across the area of the mold with a glass rod.The slide is then set aside to dry for one minute.Calcination of the Solar CellsAfter the first slide has dried the tape can be removed.The titanium dioxide layer needs to be heat sintered and this can be

21、done by using a hot air gun that can reach a temperature of at least 450 degrees Celsius.This heating process should last 30 minutes.Dye PreparationCrush 5-6 fresh berries in a mortar and pestle with 2-ml of de-ionized water.The dye is then filter through tissue or a coffee filter and collected.As a

22、n optional method, the dye can be purified by crushing only 2-3 berries and adding 10-ml of methanol/acetic acid/water (25:4:21 by volume)Dye Absorption and Coating the Counter ElectrodeAllow the heat sintered slide to cool to room temperature.Once the slide has cooled, place the slide face down in

23、the filtered dye and allow the dye to be absorbed for 5 or more minutes.While the first slide is soaking, determine which side of the second slide is conducting.Place the second slide over an open flame and move back and forth.This will coat the second slide with a carbon catalyst layerAssembling th

24、e Solar CellAfter the first slide had absorbed the dye, it is quickly rinsed with ethanol to remove any water. It is then blotted dry with tissue paper.Quickly, the two slides are placed in an offset manner together so that the layers are touching. Binder clips can be used to keep the two slides tog

25、ether.One drop of a liquid iodide/iodine solution is then added between the slides. Capillary action will stain the entire inside of the slidesHow Does All This Work?The dye absorbs light and transfers excited electrons to the TiO2.The electron is quickly replaced by the electrolyte added.The electr

26、olyte in turns obtains an electron from the catalyst coated counter electrode.TiO2=electron acceptor; Iodide = electron donor;Dye = photochemical pumpClassroom Ideas For BiologyRe-creating photosynthesisStudying nature can gives us clues as to the nature of self-assemblyAnalyzing the potential using different types of citrusClassroom Ideas for ChemistrySolution chemistry making the