| 1. |
- Ahmed, Mohammad Tofayel, et al.
(författare)
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Fabrication of new multifunctional cotton-modal-recycled aramid blended protective textiles through deposition of a 3D-polymer coating : high fire retardant, water repellent and antibacterial properties
- 2020
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry. - 1144-0546 .- 1369-9261. ; 44:28, s. 12122-12133
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Tidskriftsartikel (refereegranskat)abstract
- This study reports a facile fabrication of multifunctional cotton-modal-recycled aramid blended protective textiles through the deposition of a three-dimensional tetrakis(hydroxymethyl)phosphonium chloride (THPC)-urea polymer coating. For this, blended fabrics with different compositions, weaving structures, thicknesses, GSMs and thread densities have been fabricated, followed by chemical deposition of the THPC-urea polymer coating on the fibrils of the yarn and then in the amorphous region through ammonia treatment. Full characterization of the resulting fabrics through SEM and FTIR allowed confirmation of the deposition of THPC-urea on each blended fabric. Treated and untreated samples were evaluated for their water repellency, flame retardance and antibacterial properties through diverse experimental tools. The results show that the lowest average char length (warp - 3.18 cm, weft - 2.84 cm) and radiant heat flux density (11.021 kW m-2), and highest LOI% (36.8%), were found in the 40%-cotton-30%-modal-30% aramid fabric, whereas the best thermal protective performance (t12- 4.0 s,t24- 5.9 s) was observed in the fabric with a high thickness and GSM. Regarding the water repellent properties, all treated samples showed superior water repellence properties expressed as water contact angle (thetaH2O) as high as 141.70 degrees to 151.50 degrees. Besides, the 3D polymer coating deposited on blended fabrics exhibited high antibacterial properties (99.90%) againstStaphylococcus aureusATCC 6538 andKlebsiella pneumoniaeATCC 4352 as calculated according to the KS K 0693:2016 method. These results herein provide fundamental grounds to design blended textiles with necessary functionalities for smart and protective applications.
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| 2. |
- Alammar, Tarek, et al.
(författare)
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Mechanochemical synthesis, luminescent and magnetic properties of lanthanide benzene-1,4-dicarboxylate coordination polymers (Ln(0.5)Gd(0.5))(2) (1,4-BDC)(3)(H2O)(4); Ln = Sm, Eu, Tb
- 2020
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry (RSC). - 1144-0546 .- 1369-9261. ; 44:3, s. 1054-1062
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Tidskriftsartikel (refereegranskat)abstract
- Mechanochemical reactions of benzene-1,4-dicarboxylate (BDC2-) and lanthanide carbonates, Ln(2)(CO3)(3)center dot xH(2)O (Ln = Sm, Eu, Gd, Tb) yield phase pure lanthanide coordination polymers, (Ln(0.5)Gd(0.5))(2)(1,4-BDC)(3)(H2O)(4) with Ln = Sm, Eu, Tb, which are isostructural with Tb-2(1,4-BDC)(3)(H2O)(4) as confirmed by powder X-ray diffraction and vibrational spectroscopy. Upon excitation with UV light all three compounds display strong emissions, characteristic for the respective optically active lanthanide ion, namely, red for Eu3+, green for Tb3+ and orange-red for Sm3+. In case of the Tb3+-containing compound, the energy difference between the triplet energy level of benzene-1,4-dicarboxylate ligand (BDC2-) allows for the most efficient BDC2--Tb3+ energy transfer. As a consequence, an intense green luminescence with rather long lifetime (0.81 ms) and high quantum yield (22%) is observed after allowed excitation of the BDC2- ligand. The compounds are paramagnetic with no onset of long range magnetic ordering down to liquid He temperatures.
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| 3. |
- Almkvist, Gunnar, et al.
(författare)
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Distribution of iron and sulfur and their speciation in relation to degradation processes in wood from the Swedish warship Vasa
- 2011
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry (RSC). - 1144-0546 .- 1369-9261. ; 35, s. 1491-1502
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Tidskriftsartikel (refereegranskat)abstract
- Wood samples from the Swedish warship Vasa were analysed by scanning electron microscopy and X-ray absorption spectroscopy with the focus on speciation and distribution of iron and sulfur compounds in the wood matrix. Both these elements were found at high concentration (10–100 mg/g) in the surface region as a result of former accumulation of iron sulfides, elemental sulfur and reduced organic sulfur species (ROSS). Below the surface region, iron was the dominating element (1–10 mg/g) present both as iron(II) and iron(III) compounds, which diffused into the wood matrix from corroding iron bolts and other iron items during the time in the sea (1628–1961). Electron microscopy results revealed that iron and sulfur are present in a variety of particles of different sizes and compositions in the surface region, in contrast to the interior where few particles were found. Here, the presence of iron compounds of nano-particle size inside the cell walls enables a close contact between the wood polymers and reactive oxygen species originating from reactions with iron compounds. The presence of ROSS seems to have played an important role as scavengers of reactive oxygen species. Samples with high iron : ROSS ratio displayed evident signs of degradation as indicated by depolymerisation of wood components accompanied by increased acidity due to low molecular organic acids. The observations strengthen the hypothesis of the pro-oxidative and antioxidant properties of iron and ROSS compounds, respectively, and that the chemical activities of these elements play crucial roles in the long term preservation of wooden maritime artefacts
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| 4. |
- Andreasson, Joakim, 1973, et al.
(författare)
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A simplicity-guided approach toward molecular set-reset memories
- 2010
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry (RSC). - 1369-9261 .- 1144-0546. ; 34:12, s. 2701-2703
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Tidskriftsartikel (refereegranskat)abstract
- Photochromic switches fulfill the general molecular design criteria for the surprisingly straightforward small-scale integration of seemingly complex set-reset latches. The implications of this re-interpretation are discussed with the example of a dithienylethene photochrome. The concept is shown to be valid for a multitude of well-introduced bistable switches with clearly differentiated output signals, e.g., optical signals for the presented example.
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| 5. |
- Arora, Kapildev K., et al.
(författare)
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Supramolecular synthesis of some molecular adducts of 4,4′-bipyridine N,N′-dioxide
- 2009
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Ingår i: New Journal of Chemistry. - 1144-0546 .- 1369-9261. ; 33:1, s. 57-63
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Tidskriftsartikel (refereegranskat)abstract
- Molecular adducts (1a–1e) of 4,4′-bipyridine N,N′-dioxide, 1, respectively with cyanuric acid, trithiocyanuric acid, 1,3,5-trihydroxybenzene (phloroglucinol), 1,3-dihydroxybenzene (resorcinol) and 1,2,4,5-benzenetetracarboxylic acid have been reported. The major interactions observed in the structures 1a–1e are N–H⋯O, N–H⋯S, O–H⋯O and C–H⋯O, in the form of homomeric and heteromeric patterns of the constituents, either as a single or cyclic hydrogen-bonded motifs. While in the adduct 1a, both homomeric and heteromeric units of both the constituents were observed, no heteromeric interactions were observed in 1b and 1c. In addition, in 1b, homomeric aggregation of molecules of 1 occurred in association with water molecules. However, while heteromeric interactions prevail between the constituents in 1d and 1e, only one of the co-crystallizing species gave homomeric interactions (4,4′-bipyridine N,N′-dioxide in 1d; 1,2,4,5-benzenetetracarboxylic acid in 1e). Further, in either type of the patterns, the cyclic motifs are formed as a pair-wise hydrogen bonds comprising of strong and weak hydrogen bonds (N–H⋯O/C–H⋯O or O–H⋯O/C–H⋯O). In three-dimensions, the ensembles of molecules yield planar sheets, ladders and pseudorotaxane type assemblies
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| 6. |
- Baryshnikov, Gleb V., et al.
(författare)
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A computational study of aromaticity and photophysical properties of unsymmetrical azatrioxa[8]circulenes
- 2017
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry. - 1144-0546 .- 1369-9261. ; 41:7, s. 2717-2723
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Tidskriftsartikel (refereegranskat)abstract
- Owing to their potential use in organic light-emitting diodes and field-effect transistors we present a theoretical study of a series of unsymmetrical azatrioxa[8]circulenes in order to explain the impact of outer substituents and benzoannelation on photophysical constants and aromaticity of these compounds in terms of spin-orbit coupling perturbation and magnetically-induced ring currents. It is argued that the S1-Tn inter-system crossing processes constitute the main deactivation pathways for the fluorescence quenching, something that is supported by a good agreement obtained with experimental data on fluorescence quantum yields. The concept of the gauge-including magnetically induced currents has been applied in order to estimate the role of substituents and benzoannelated fragments on the aromaticity and particularly on the overall balance between the diatropic “aromatic” and paratropic “antiaromatic” current strengths. While a variation of the substituents in the outer perimeter of the studied circulenes does not provide a clear effect on their aromaticity, it is demonstrated that an additional benzoannelation (π-extension) of the azatrioxa[8]circulene macrocycle induces a significant aromaticity enhancement.
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| 7. |
- Baryshnikov, Gleb V., et al.
(författare)
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Substituent-sensitive fluorescence of sequentially N-alkylated tetrabenzotetraaza[8]circulenes
- 2017
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry. - 1144-0546 .- 1369-9261. ; 41:15, s. 7621-7625
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Tidskriftsartikel (refereegranskat)abstract
- We explore the use of substituent-sensitive balance between fluorescence and non-radiative decay as a tool for optical tuning of promising materials for organic light emitting diode applications. A series of N-butylated tetrabenzotetraaza[8]circulenes is studied computationally in order to explain the gradual decrease of fluorescence intensity with the increase of the substituent number. The inter-system crossing probability is found to increase upon the gradual substitution of the circulene macrocycle as a result of the decrease of the S-1-T-1 energy gap due to the deformation of the tetrabenzotetraaza[8] circulenes and therefore the distortion of the pi-conjugation within the macrocycles. In contrast, the S-1-T-1 spin-orbit coupling matrix elements are quite insensitive to the number of outer substituents. As a result, the fluorescence-responsible pi pi(star) transition becomes less intense and the fluorescence rate constant decreases.
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| 8. |
- Bergdahl, Gizem Ertürk, et al.
(författare)
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Bisphosphonate Ligand Mediated Ultrasensitive Capacitive Protein Sensor : Complementary Match of Supramolecular and Dynamic Chemistry
- 2019
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry. - 1144-0546 .- 1369-9261. ; 43:2, s. 847-852
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Tidskriftsartikel (refereegranskat)abstract
- Modern healthcare demands rapid and accurate detection of proteins/enzymes at the ultratrace level. Herein we present a molecularly imprinted capacitive sensor for Trypsin, developed by microcontact imprinting. High affinity and selectivity was achieved by doping the prepolymerization mixture with a stoichiometric amount of methacrylamide-based bisphosphonate (BP) monomer. Taking advantage of the strong interaction of bisphosphonate with lysine/arginine residues on the surface of Trypsin, we have constructed a powerful polymeric sensor. The BP based sensor has the ability to recognize trypsin over other arginine-rich proteins, even in high ionic strength buffers with a sub-picomolar detection limit (pM). We believe that the combination of supramolecular chemistry, molecular imprinting and advanced instrumentation has a potential for future drug development and diagnostics that extends beyond biomolecular recognition.
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| 9. |
- Bernhardt, Paul V., et al.
(författare)
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Tailoring mixed-valence Co-III/Fe-II complexes for their potential use as sensitizers in dye sensitized solar cells
- 2008
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry (RSC). - 1144-0546 .- 1369-9261. ; 32:4, s. 705-711
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Tidskriftsartikel (refereegranskat)abstract
- Dinuclear class II Co-III/Fe-II mixed-valence complexes of type [LnCo (III)(mu-NC) Fe-II(CN)(3)L-2](m-) (where L-n represents a pentadentate macrocycle and L-2 a bpy ligand or two cyanides) have electronic properties that make them possible sensitizers in DSSC ( dye sensitized solar cells). For this purpose the new complex Na-2[{trans-L14COOCo III( m-NC)} Fe II( CN) 5] has been prepared and characterized by the usual methods and its sensitizer properties compared with those of the already known [{trans-L14COOCo (III)(mu-NC)}Fe-II(CN)(5)](2-)(CN)(3)(bipy)(eq,ax)](ClO4). The complex [{trans-L14COOCo (III)(mu-NC)}Fe-II(CN)(5)](2-) has been designed for the actuation of an electron injection from the cobalt centre on MMCT, while the [{trans-L14COOCo (III)(mu-NC)}Fe-II(CN)(3)(bipy)](+) structure can produce a tuned injection from the iron centre via an MLCT electronic state, as described for similar systems. The characterization on solid oxide semiconductor supports has been carried out for these two complexes and the results have been compared with the behaviour observed in aqueous solution and in solvents of varying polarities. Their use in DSSC has been checked and, while a sensitizer response is observed for [{trans-L14COOCo (III)(mu-NC)}Fe-II(CN)(5)](2-), complex [{trans-L14COOCoIII(mu-NC)}Fe-II(CN)(3)(bipy)(eq,ax)](+) does not produce any electrical current on illumination. The low efficiency of the built DSSC can be easily related both with the very low value of the extinction coefficient of the MMCT band responsible for the electron injection, and with the small driving force for the reduction of the complex with the standard I-2/I-3 (-) system used after electron injection.
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| 10. |
- Bhuyan, Prabal Dev, et al.
(författare)
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Ultrathin nanowire PdX2 (X = P, As) : stability, electronic transport and thermoelectric properties
- 2020
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry (RSC). - 1144-0546 .- 1369-9261. ; 44:36, s. 15617-15624
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Tidskriftsartikel (refereegranskat)abstract
- In the last few decades, the miniaturization of devices has been taking place and therefore the quest for new nanowires has become more significant. In the present study, we have investigated the geometry of new ultrathin nanowires (NWs) of PdP2 and PdAs2 that could be obtained experimentally. We have optimized the pentagonal structures of both the NWs and studied their dynamical stability using the phonon dispersion curve. The electronic band structure shows semiconducting behaviour of PdP2 NWs with a band gap of 380 meV and PdAs2 NWs with a band gap of 294 meV, with higher charge carrier mobility than that of their 2D counterparts. The NWs show a band gap of 840 meV and 740 meV for PdP2 and PdAs2, respectively, through hybrid potential calculations. The PdX2 structure shows a transition from semiconducting to semi-metallic behaviour at a compressive strain of 8% within a sustainable pressure of 0.2–0.3 GPa. A negative differential conductance (NDC) effect is observed in the current–voltage graph for both the NWs. The semi-metallic behaviour with an asymmetric density of states near the Fermi energy boosts the Seebeck co-efficient value and therefore the ZTe value is enhanced for both the nanowires. The strained PdP2 and PdAs2 NWs show ZTe values of 4.75 and 5.49, respectively. Our study stimulates the feasibility of both nanowires and thermoelectric applications for the conversion of waste heat into electricity.
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