Oxidation of industrially prepared carbon nanodiscs using a simple, versatile, and reproducible approach based on the Staudenmaier method yields a new hydrophilic form of nanocarbon. As a result of ...the strong acid treatment, which also enables the separation of carbon nanodiscs from the mixed starting material, the graphene planes detach from the discs, while the surface of the carbon nanodiscs is decorated with various oxygen-containing functional polar groups. Thus, the completely insoluble carbon nanodiscs are converted to a hydrophilic derivative dispersable in many polar solvents, including water. The new carbon structure is expected to have a wide range of applications in several fields including bioapplications. To this end, the functionalized carbon nanodiscs exhibit very low cytotoxicity, while they achieve high drug loadings, enabling their application as an effective drug nanocarrier. Furthermore, the carbon disks were evaluated as supports in nanobiocatalytic applications, increasing significantly the stability of the systems, due to carbon disks' nano-sized dimensions.
Hydrophilic oxidized carbon nanodiscs able to be used as drug delivery system and as support in nanobiocatalytic applications.
A lightweight, oxygen-rich carbon foam was prepared and doped with Pd/Hg alloy nanoparticles. The composite revealed high H2 sorption capacity (5 wt%) at room temperature and moderate pressure (2 ...MPa). The results were explained on the basis of the H2 spillover mechanism using Density Functional Theory.
Molecular dynamics simulations are performed on a lipid bilayer that consists of ceramide NS 24:0 in an attempt to examine several structural and physicochemical properties of the specific system. ...The simulations are carried out with five different force fields (OPLS, GROMOS, BERGER, CHARMM and GAFF) in order to evaluate and compare their performance in modelling lipid systems that contain ceramides. The examined properties include bilayer thickness, chain tilt, density profiles, order parameters, chain conformation, area per lipid and (intermolecular or intramolecular) hydrogen bonding between the head groups. Special focus is given to the lateral lipid arrangement. To this purpose, a method is proposed that utilises the radial distribution functions of the alkyl chains to derive quantitative information about the lateral lipid packing. In most cases, all force fields lead to similar results. For a few properties (e.g. intramolecular hydrogen bonding), there is some discrepancy between the force fields but the lack of respective experimental data does not allow an unambiguous conclusion on which force field is the most reliable.
In the past, sodium alanate, NaAlH
, has been widely investigated for its capability to store hydrogen, and its potential for improving storage properties through nanoconfinement in carbon scaffolds ...has been extensively studied. NaAlH
has recently been considered for Li-ion storage as a conversion-type anode in Li-ion batteries. Here, NaAlH
nanoconfined in carbon scaffolds as an anode material for Li-ion batteries is reported for the first time. Nanoconfined NaAlH
was prepared by melt infiltration into mesoporous carbon scaffolds. In the first cycle, the electrochemical reversibility of nanoconfined NaAlH
was improved from around 30 to 70% compared to that of nonconfined NaAlH
. Cyclic voltammetry revealed that nanoconfinement alters the conversion pathway, and operando powder X-ray diffraction showed that the conversion from NaAlH
into Na
AlH
is favored over the formation of LiNa
AlH
. The electrochemical reactivity of the carbon scaffolds has also been investigated to study their contribution to the overall capacity of the electrodes.
The microstructure evolution of confined glucose solutions in silica gels can provide insights into the effect of sugars in protecting living organisms under extreme dehydration conditions. Aqueous ...silica gels with relatively small pore sizes capable of deforming under changes in environmental conditions are used here as a model system. In situ monitoring of the dehydration process – with and without the presence of sugar molecules – by optical photography, gravimetric measurements, small-angle neutron scattering, and atomic force microscopy reveals that sugar plays a crucial role in the mechanics and protection of the gel. In the absence of sugar, dehydration leads to considerable degradation, whereas the incorporation of large doses of glucose maintains the stability and robustness of the structure. A model is proposed to explain the time dependence of the dehydration process.
A new Cu 2+ complex that was isolated from the initial use of 5-((pyridin-4-ylmethylene)amino)isophthalic acid (PEIPH 2 ) in 3d metal–organic framework (MOF) chemistry is reported. Complex {Cu 3 ...(PEIP) 2 (5-NH 2 -mBDC)(DMF)·7DMF} ∞ denoted as Cu-PEIP ·7DMF was isolated from the reaction of Cu(NO 3 ) 2 ·2.5H 2 O with PEIPH 2 in N , N -dimethylformamide (DMF) at 100 °C and contains both the PEIP 2− ligand and its 5-NH 2 -mBDC 2− fragment. After the structure and properties of Cu-PEIP were known an analogous complex was prepared by a rational synthetic method that involved the reaction of Cu(NO 3 ) 2 ·2.5H 2 O, 5-((pyridin-4-ylmethyl)amino)isophthalic acid (PIPH 2 – the reduced analogue of PEIPH 2 ) and 5-NH 2 -mBDCH 2 in DMF at 100 °C. Cu-PEIP comprises two paddle-wheel Cu 2 (COO) 4 units and exhibits a 3D-framework with a unique trinodal underlying network and point symbol (4.5 2 ) 4 (4 2 ·5 4 ·6 4 ·8 3 ·9 2 ) 2 (5 2 ·8 4 ). This network consists of pillared kgm-a layers containing a hexagonal shaped cavity with a relatively large diameter of ∼8–9 Å surrounded by six trigonal shaped ones with a smaller diameter of ∼4–5 Å and thus resembles the structure of HKUST-1. Gas sorption studies revealed that Cu-PEIP exhibits a 1785 m 2 g −1 BET area as well as high CO 2 sorption capacity (4.75 mmol g −1 at 273 K) and CO 2 /CH 4 selectivity (8.5 at zero coverage and 273 K).
A new Cu
2+
complex that was isolated from the initial use of 5-((pyridin-4-ylmethylene)amino)isophthalic acid (PEIPH
2
) in 3d metal-organic framework (MOF) chemistry is reported. Complex {Cu
3
...(PEIP)
2
(5-NH
2
-mBDC)(DMF)·7DMF}
∞
denoted as
Cu-PEIP
·7DMF was isolated from the reaction of Cu(NO
3
)
2
·2.5H
2
O with PEIPH
2
in
N
,
N
-dimethylformamide (DMF) at 100 °C and contains both the PEIP
2−
ligand and its 5-NH
2
-mBDC
2−
fragment. After the structure and properties of
Cu-PEIP
were known an analogous complex was prepared by a rational synthetic method that involved the reaction of Cu(NO
3
)
2
·2.5H
2
O, 5-((pyridin-4-ylmethyl)amino)isophthalic acid (PIPH
2
- the reduced analogue of PEIPH
2
) and 5-NH
2
-mBDCH
2
in DMF at 100 °C.
Cu-PEIP
comprises two paddle-wheel Cu
2
(COO)
4
units and exhibits a 3D-framework with a unique trinodal underlying network and point symbol (4.5
2
)
4
(4
2
·5
4
·6
4
·8
3
·9
2
)
2
(5
2
·8
4
). This network consists of pillared
kgm-a
layers containing a hexagonal shaped cavity with a relatively large diameter of ∼8-9 Å surrounded by six trigonal shaped ones with a smaller diameter of ∼4-5 Å and thus resembles the structure of HKUST-1. Gas sorption studies revealed that
Cu-PEIP
exhibits a 1785 m
2
g
−1
BET area as well as high CO
2
sorption capacity (4.75 mmol g
−1
at 273 K) and CO
2
/CH
4
selectivity (8.5 at zero coverage and 273 K).
A new microporous Cu
2+
MOF is reported containing a pyridyl-isophthalic acid Schiff base ligand which exhibits a significant BET area and high CO
2
sorptbion capacity.
Generation of valuable information about the biphasic geometrical configuration of porcine stratum corneum from Very Small Angle Neutron Scattering (VSANS) data and investigation of its effect on the ...corresponding effective diffusivity.
Spectra of porcine stratum corneum are mathematically transformed in order to obtain the corresponding auto-correlation function (ACF). Model stratum corneum structures, matching this experimentally determined ACF, are then produced based on the "brick-and-mortar" configuration. The effective diffusivity through these model domains is calculated using an appropriate numerical method.
The most appropriate geometry of porcine stratum corneum's lipid and protein phases in a "brick-and-mortar" configuration is quantitatively determined and correlated with the barrier properties (diffusivity) of the stratum corneum model structures.
The ACF analysis indicates the most appropriate values for the dimensions of the corneocyte thickness and the surrounding lipid gap, while the corneocyte length is estimated from the diffusion study.
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