Environmental Engineering Reference
In-Depth Information
13.2 Experimental
A series of bionanocomposites were prepared with variable wt% of nano-
i llers by using the solution technique. h e nanoparticles were dispersed in
double-distilled water by continuous stirring at 60
C for 30 minutes and
then the solution was treated with ultrasound (120W/180KHz) for 30 min-
utes. h en the biopolymer solution prepared in distilled water was added
to dif erent wt% i ller
solutions. h e viscous product obtained was i ltered
and washed with double-distilled water. h e bionanocomposites obtained
were dried in an oven for 24 hours. at a temperature of 50
°
C.
h e functionalization of MWCNT was done as per our earlier pub-
lication [22]. h e MWCNTs were treated with concentrated H
2
SO
4
and
HNO
3
in the volume ratio of 3:1 and sonicated by using ultrasonic cleaner
(120W/60KHz) at 40
°
C for 24 hours in a l ask. h e solution was diluted by
distilled water and i ltered. h e remaining residue was washed by distilled
water. h en the open ended tubes were polished with hydrogen peroxide
and H
2
SO
4
in volume ratio of 1:4 with stirring at 70
°
C for thirty minutes.
h e resulting solution was diluted by distilled water and centrifuged to
get f-MWCNT.
Starch/MWCNT nanocomposites i lm was prepared by a convenient
solution casting and evaporation method. h e f-MWCNTs were dispersed
in double-distilled water with stirring for ten minutes taking in a l ask.
Calculated amount of glycerol was added and homogenized in an ultra-
sonic bath for 30 minutes. h e required quantity of starch was added into
the l ask and the solution was charged by constant stirring with heating at
95
°
C for 30 minutes to form the plasticized starch. Oxygen permeability
of the bionanocomposite was measured with STM F 316-86 by using oxy-
gen permeation analyzer (PMI instrument, model GP-201-A, Texas, NY,
USA). For testing oxygen permeability the synthesized powdered bionano-
composites were converted into i lms of 5 mm thickness with the help of a
polymer press at a pressure of 9 tons. h e results were recorded as average
of the values obtained from i ve same samples.
°
13.3 Objective
Even though research activities have intensii ed over the last decade, there
is still a limited amount of literature on the applications of biopolymeric
nanocomposites-based primary, secondary and tertiary packaging. h is
indicates that an understanding on such bio-based nanocomposites as sus-
tainable packaging materials is very much still in its infancy and much is
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