nanotechnology Flashcards
the application of nanoscience to develop new materials and products, involving manipulation of matter at nanometre scale
nanotechnology
the study of material and processes on nanometre scale
nanoscience
nanotechnology processing examples?
nanoscale rxn engineering, heat/mass transfer, homogenization, sel-assembly
nanotechnology food safety/biosecurity examples?
nanosensors, nanotracers
nanomaterials examples?
nanoparticles, nano-emulsions, nanocomposites, nanostructured materials
example of “old” nanotechnology?
Faraday’s gold, DNA structure discovery, drug delivery systems
examples of nano in food?
casein micelles and submicelles, fat crystal network
how is nanotech used in food packaging?
nanocomposites (strength, barrier), active packaging (anti-microbe), intelligent packaging (sense enviro)
nanocomposites made up of:
polymer matrix reinforced with nano-filler (fibre, platelet, particle with at least one dimension in nanometer scale)
examples of nanofillers?
layered inorgnic solids/clays like MMT (montmorillonite)
examples of bio-polymers:
polysacc, proteins, synth biopolymers (polylactic acid)
types of nanocomposites between polymers and layered silicates:
phase separated, intercalated, exfoliated
how is nanocomposite made?
polymer pellets+MMT powder–>extruder–>cooling roll–>solid sheets–>thermoforming thru pressing/drawing
how to calculate tortuosity factor?
= actual travel distance by penetrant / shortest travel distance in absence of any barrier
why use nanocomposites in food packaging?
^ moisture sensitivity, better barrier, flexibility, ^ thermal stability
is a higher Tortuosity factor better?
yes, has higher barrier properties
type of nanocomposite that has largest tortuosity factor?
exfoliated
how is nanolaminated emulsion created?
O/W emulsion stabilized by - charge protein, + charged biopolymer added to deposit on - charge droplet, coat w/ another - layer
by decreasing size of droplets, liquid can become solid _____
nanogel
significant increase in ___ content was found in vegetables wrapped in packaging materials made of ____ nanocomposites
silicon; MMT (montmorillonite)
smaller nanoparticles, ____ migratability
higher
___ nanoparticles become easily trapped in cationic charged mucus layer of GI, while ___ particles can escape
cationic; anionic
feeding rats with gold nanoparticles led to deposition of metals in:
kidney, liver, brain, other organs
potential toxicity of nanoparticles is based on?
oxidative stress it causes in cells–>potential for cancer, CNS, Parkinson’s, Alzheimers (smaller particles is more harmful); influence GI (insoluble), damage DNA (metal oxide)–>depend on chem composition
