“…To increase the quantity of mobile paper constituents, the paper sample is placed in a UV-ozone cleaner (Jelight, UVO-cleaner model 42-220) for 2 or 10 min. Such treatment reduces the degree of polymerization of cellulose and other organic constituents, either by direct photolysis or photo-oxidative degradation, and creates reaction products of low molecular weight [38][39][40].…”
“…To increase the quantity of mobile paper constituents, the paper sample is placed in a UV-ozone cleaner (Jelight, UVO-cleaner model 42-220) for 2 or 10 min. Such treatment reduces the degree of polymerization of cellulose and other organic constituents, either by direct photolysis or photo-oxidative degradation, and creates reaction products of low molecular weight [38][39][40].…”
“…The band at 1640 cm −1 could be assigned to weakly adsorbed water. The bands in the 1462-1425 cm −1 domain are ascribed to asymmetric C-H stretching and bending vibration modes in the pyran ring The EB radiation at doses of 50 kGy is responsible for imidazolium ring scission, especially at C(2)-H and C(5)-H in the imidazolium ring, as determined from our previous research and from the reference literature for other more energetic irradiation types (X-ray, ) [27,28]. This scission could account for the formation of free radicals and imidazolium oligomers, but more important for this study is the hydroxylation of the imidazolium cation in the presence of trace amounts of absorbed water [16], which could explain the occurrence of a new band, centered at ∼ 3400 cm −1 (marked with asterisk in Figure 2(b)) in the FTIR spectrum of the EB-irradiated HMIMBF 4 .…”
Section: Resultsmentioning
confidence: 72%
“…All the cellulose samples shown in Figure 2(a) present in general two main absorbance regions. The first one, at low wavelengths in the 4000-1700 cm −1 range (Cel I ), comprises a few absorption bands such as the broad one from 3450-3400 cm −1 ascribed to -OH stretching; the overlapping ones from 2930-2910 cm −1 , ascribed to different C-H stretching modes from methyl and methylene groups; and those found at 1765-1715 cm −1 , ascribed to C=O resulting from the oxidation of the terminal -C-OH groups [24][25][26][27][28]. The second region, in the 1700-600 cm −1 domain (Cel II ), is more rich in absorption bands, including the fingerprint ones.…”
This paper presents a possible alternative to traditional cellulose nanofibers functionalization, by treatment of the material at low temperatures (25–35°C) with electron-beam irradiated 1-hexyl-3-methylimidazolium chloride ionic liquid. The treatment promotes decreasing the crystallinity of the cellulose with up to 45% and possible imidazolium moieties grafting to cellulose, as demonstrated from FTIR, XRD, and elemental analysis. The grafting determines water vapors uptake values with 50–70% lower and water vapors uptake rate with 50% lower than those of reference cellulose nanofibers. The grafting determined also improved adhesion of the cellulose nanofibers to HDPE, thus contributing to the obtaining of polymer matrix composites with improved properties.
“…8 ). These peaks found at approximately 399.9 eV and 288.4 eV (corresponding to the nitrogen and carbon atoms of the amide units) allowed us to clearly demonstrate the covalent linkages of the SP probes on the APTES-modified AAO channel via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) chemistry 44 . Fig.…”
In contrast to the conventional passive reaction to analytes, here, we create a proof-of-concept nanochannel system capable of on-demand recognition of the target to achieve an unbiased response. Inspired by light-activatable biological channelrhodopsin-2, photochromic spiropyran/anodic aluminium oxide nanochannel sensors are constructed to realize a light-controlled inert/active-switchable response to SO2 by ionic transport behaviour. We find that light can finely regulate the reactivity of the nanochannels for the on-demand detection of SO2. Pristine spiropyran/anodic aluminium oxide nanochannels are not reactive to SO2. After ultraviolet irradiation of the nanochannels, spiropyran isomerizes to merocyanine with a carbon‒carbon double bond nucleophilic site, which can react with SO2 to generate a new hydrophilic adduct. Benefiting from increasing asymmetric wettability, the proposed device exhibits a robust photoactivated detection performance in SO2 detection in the range from 10 nM to 1 mM achieved by monitoring the rectified current.
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