teste1 Flashcards
Types of thin films
casting spin coating eletroquico ink-jet L LB LS SA LbL
Advantages de Castiing films
simples
good for studying
pouco material
Disadvanatges of casting thin films
low thickness control
low roughness control
hazardous material
hard to replicate
What happens in hot casting
As T increases so does grain size
A type of film categorization
UV
In UV categorization how does thinf iflm conductivity react with time of exposure and frequency
Conductivity incresases with light frequency and drecreases with exposure time, as does absorvance
During the spin coating procedure there are several factors that affect thickness:
vicosity concentration T vapor pressure humidity velocity of spin
relationship between thickness and velocity
Seee formula one
Advantages of spin coating
simples thickness control roughness control good quality reproducible good for studies low cost uniform
Disadvantages of spin coating
material waste dedicated suplies hazard not uniform for large areas roll-to roll incompatible
eletrochemical thin fils are sensitive to
time and heat
As time incresases in a eletrochemical film how does current density changes
decreases
Advantages of eletrochemical deposition
adjustible thicknesss and morphology low cost studies in situ reproducible robust green hybrid films low T effective
disadvantages
not easy to control thickness
hazard
dedicated equipment
multiple steps
ink jet disadvantages
dediacated equipment low efficiency ink must be replcaed ink can smudge slow
ink jet advantages
robust green roll to rol compatible ´ cheap reproducible studies hybrid light not volitile high quality
in order for a liquid or solid to be disolved in water what must happen
the energy loss of breaking H bonds must be compensated :
in OIL this would not happen
but in salt the ions will interact with the water molecules
hidrophobic interactions with water
as interações hidrofóbicas com a agua descrevem uma atração entre as moleculas hidrofobicas e as superficies de água
as moleculas de água vao formar estrutras em torno destas moléculas em que pelo menos um dos H bonds da agua irá estar direcionado
à moleculas fobica.
what is the diference between a hidrofobica surface and a hidrofilica surface
the hidrofilic will orient the water molecules
hidrofobic wil not
What happens when you have a molecule with both hidrofobic and hidrofilic parts
the fobic and filic parts are not cancelable. each part of the molecule will interact with water acordingly, but each part’s fobic or filic energy is reduced
what type of molecules are used for L films
anfifilicas
surface pressure formula
see formula 2
how dos surface pressure eveolve qith surface area in L films
see graph one
what distingushes each phase in L films
gas: no interactions between moleucles
liquid: interaction between the heads of the molecules
solid: heads and tails
What is indicative of the presence of the colapsed monolayer state in L films
a sudden increase of compressecibility
how does temperature affect the surface pressure vs area per molecule graph in L films
see graph 2
Possible use for L membranes
membrane cell simulation
