Chemistry Reference
In-Depth Information
Fig. 3.19 Assembly of holographic flakes on paper-Fe
3
O
4
composites. a pHEMA matrices,
b pHEMA-co-MAA matrices, c pHEMA-co-MAA assembled to paper-Fe
3
O
4
composite in acetic
acid (1 %, v/v). Paper thicknesses were 0.50, 0.55, 1.10, 1.20 and 1.30 mm. Images were taken 6 h
after assembly
Fig. 3.20 Dyeing cellulose-based materials with Procion Black MX-K and Remazol Reactive
Black 5 at 24
C. a Procion Black MX-K without sodium carbonate, b Remazol Reactive Black 5
with sodium carbonate before rinsing. c Procion Black MX-K with sodium carbonate and urea
d Procion Black MX-K with sodium carbonate only
°
The composition of Procion MX-K was determined using thin-layer chroma-
tography. Thin layer chromatography (TLC) sheets precoated with Al were cut to
1
5 cm. The plates were marked with a line drawn 1 cm from the bottom of the
plate. Procion MX-K was diluted to 1 % (w/v) in DI water. A glass spotter
(i.e. capillary tube with
×
2 mm spots on
the plate. The plates were placed in a developing chamber saturated with the
following eluents: (i) Hexane, (ii) ethanol:water (1:1, v/v), (iii) acetone, (iv) ethanol
and acetone (1:1, v/v), and (v) acetone and ethanol (4:1, v/v) (Fig.
3.21
a
⌀
1 mm) was used to deposit the dye in 1
-
e). The
plate was removed when eluent front reached 25 mm from the plate top. Best TLC
results were obtained in acetone and ethanol mixture (1:1, v/v) (Fig.
3.21
e). Procion
MX-K dye consists of three or more single near primary colours; each supplier has
their own proprietary recipe. TLC showed that the colour composition of Procion
MX-K consisted of near primary
-
fibre reactive red, blue and yellow. Figure
3.21
f
illustrates the absorption UV-Vis spectrum, which showed that the dye predomi-
nantly consisted of blue hues. Light scattering on Fe
3
O
4
-paper composite and
Procion MX-K dyed
ection spectropho-
tometer: Both Fe
3
O
4
impregnation and Procion MX-K dyeing yielded suf
filter paper was determined using a re
fl
cient
reduction in background noise (Fig.
3.21
g). Both techniques can be adapted for
producing lateral-
ow test or multiplex assays, which can be integrated with
holographic sensors. In addition to paper strips, nitrocellulose membranes were
dyed using DEKA-L fabric dye. Nitrocellulose membranes were immersed in HCl
fl
