InDepthExtraLecture

Nanotechnology:TheBasicsWeek1

InDepthTopics1:Convertingamongsizeunits2:Estimatingthenumberofthings3:Estimatingthesurfaceareaofthings4:Thesizeofthingsonthenanoscale5:Atomsinacluster

Pleaserefertotheworksheet:week1indepthundercourseresources!!

ConvertingamongdifferentlengthunitsExample1: Youhavemeasuredthedimensionsofanatomicforcemicroscopesiliconprobetobearectangle35nanometersby1cm alongstripofsiliconthewidthofasiliconwafer.Thefabricationoftheproberequiresthatyouuselithographyofasiliconwafertocuttheseprobesfromthelargermaterial.HowmanyAFMprobescanyoumakefroma1cmsquarepieceofsilicon?

Example2: Ifyoucouldlaycarbonnanotubessidebyside,inasinglelayer,ontopofa4cmpostitnote,howmanywouldfit?CNTaretubes1nminwidthwithlengthsuptoamillimeterormore.Assumeherethattheyarestraight(whichtheywouldnotbeinreality)

FindingthenumberofobjectsExample3: Youhavemadehighlyuniform,spherical,particlesthatare5nanometersindiameter.Howmanyoftheseparticlesdoyouestimatewillfitinadrugdeliverydevicewitha10microliterinjectioncapability?Youdonotneedtoknowthedensity,butyoudoneedtoknowthat1milliliter=1cm3

Example4: Fortheobjectsdiscussedinexample3,howmanyoftheseparticleswouldweigh1gram?Inthiscaseyoudoneedtoknowthedensityis2g/cm3.

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FindingthesurfaceareaofobjectsExample5:Whatisthetotalsurfaceareain1.0gramofquartznanoparticlesthatare10.nmindiameter?Assumeadensityof1.2g/cm3.Howdoesthissurfaceareachangeiftheparticlesizedropsto1nmindiameter?[trytodothisforbothspheresandcubes]

Example6:Whatisthetotalsurfaceareain500.mggoldcatalyst(wellapproximatedbyasphere)thatis15nmindiameter?Notethatthedensityofgold,whichalsoholdsforthesecatalysts,is19.3g/cm3.Whathappenstothisnumberifyoushrinktheparticlediameterto1.5nm?

ThesizeofthingsonthenanoscaleExample7: Themoleculenaphthaleneiscomprisedofcarboncarbonbondsthatareontheorderof1.4angstroms.Basedonitsstructure,itlookstobeaflatovalmoleculethatlookstobeabout5angstromsonitslongaxis.Ifyouwere1nmtall,givesomeexamplesofobjectsthatwouldbeaboutthesamesizeasthismolecule.

Example8: Theproteinlysozymeisrelativelysmall,eggshapedwithdimensionsof3by2nm;itispartofthecellularmachinerythatdestroysmalfunctioningbiomolecules.Ifyouwere1nmtall,givesomeexamplesofobjectsthatwouldbeaboutthesamesizeasthisprotein.

Thenumberofatomsinaparticle(oneelement)Example9: Ifyouhadagoldclusterthatwasessentiallyspherical,and3nmindiameter,howmanyatomsofgoldwoulditcontain?

Example10:Aresearcherhasmadeagoldnanocrystal calledAu66where66referstothenumberofatomsinthegoldcluster.Canyouestimatethediameterofthenanocrystal?