scholarly journals Interaction between DNA and Trimethyl-Ammonium Bromides with Different Alkyl Chain Lengths

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Chao Cheng ◽  
Shi-Yong Ran
Keyword(s):  
Surfactant Concentration ◽  
Alkyl Chain ◽  
Scattering Method ◽  
High Concentration ◽  
Dna Structures ◽  
Dynamic Light Scattering Method ◽  
Atomic Force ◽  
Chain Lengths ◽  
Dna Complex ◽  
Long Alkyl Chain

The interaction betweenλ—DNA and cationic surfactants with varying alkyl chain lengths was investigated. By dynamic light scattering method, the trimethyl-ammonium bromides-DNA complex formation was shown to be dependent on the length of the surfactant’s alkyl chain. For surfactants with sufficient long alkyl chain (CTAB, TTAB, DTAB), the compacted particles exist with a size of ~60–110 nm at low surfactant concentrations. In contrast, high concentration of surfactants leads to aggregates with increased sizes. Atomic force microscope scanning also supports the above observation. Zeta potential measurements show that the potential of the particles decreases with the increase of surfactant concentration (CTAB, TTAB, DTAB), which contributes much to the coagulation of the particles. For OTAB, the surfactant with the shortest chain in this study, it cannot fully neutralize the charges of DNA molecules; consequently, the complex is looser than other surfactant-DNA structures.

Growth of Double-Chained Cationic Surfactant Films on Mica

2006 ◽  
Vol 59 (6) ◽  
pp. 381 ◽  
Author(s):  
Annabelle Blom ◽  
Gregory G. Warr ◽  
Erica J. Wanless
Keyword(s):  
Atomic Force Microscopy ◽  
Alkyl Chain ◽  
Effect Of Temperature ◽  
Equilibration Time ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Difference ◽  
Chain Lengths ◽  
Gel Transition

The evolution of adsorbed dialkyl chained quaternary ammonium surfactant films with different alkyl chain lengths has been observed in situ using atomic force microscopy (AFM). Both di-C12DAB and di-C14DAB form a cohesive bilayer immediately, which is observed to strengthen with equilibration time. The slow equilibrium of di-C16DAB allows examination of the film at less than saturated coverage and reveals growth of the bilayer through the nucleation and coalescence of patches. The difference in height between higher and lower regions is insufficient for bilayer and monolayer regions and the postulated structure is that of regions of bilayer with different packing densities. The effect of temperature on film morphologies near the gel transition is also examined.

scholarly journals The Effect of Concentration on the Cross-Linking and Gelling of Sodium Carbonate-Soluble Apple Pectins

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1635 ◽  
Author(s):  
Diana Gawkowska ◽  
Jolanta Cieśla ◽  
Artur Zdunek ◽  
Justyna Cybulska
Keyword(s):  
Light Scattering ◽  
Sodium Carbonate ◽  
Cross Linking ◽  
Scattering Method ◽  
Ph Measurements ◽  
Aggregation Index ◽  
Dynamic Light Scattering Method ◽  
Atomic Force ◽  
Low Degree ◽  
The Cross

The cross-linking and gelation of low-methoxy pectins are basic processes commonly used in different industries. The aim of this research was to evaluate the cross-linking process of the sodium carbonate-soluble pectins (named DASP) extracted from apples, characterized by a low degree of methylesterification as a function of its concentration in water (CDASP). The cross-linking process was studied with a dynamic light scattering method, atomic force microscope (AFM), viscosity and pH measurements. An increase in CDASP above 0.01% resulted in a decrease in the aggregation index (AI) and the change of its sign from positive to negative. The value of AI = 0 occurred at CDASP = 0.33 ± 0.04% and indicated the formation of a pectin network. An increase in CDASP caused the changes in viscosity of pectin solutions and the nanostructure of pectins spin-coated on mica observed with AFM, which confirmed results obtained. The hydrogen bonds were involved in the cross-linking process.

Template mediated crystal engineering

1994 ◽  
Vol 52 ◽  
pp. 480-481
Author(s):  
Brigid R. Heywood ◽  
S. Champ
Keyword(s):  
Crystal Engineering ◽  
Electrostatic Interactions ◽  
Alkyl Chain ◽  
Crystallographic Axis ◽  
Two Dimensional ◽  
Engineering Process ◽  
Solution Interface ◽  
Extensive Program ◽  
Geometric Homology ◽  
Long Alkyl Chain

Recent work on the crystallisation of inorganic crystals under compressed monomolecular surfactant films has shown that two dimensional templates can be used to promote the oriented nucleation of solids. When a suitable long alkyl chain surfactant is cast on the crystallisation media a monodispersied population of crystals forms exclusively at the monolayer/solution interface. Each crystal is aligned with a specific crystallographic axis perpendicular to the plane of the monolayer suggesting that nucleation is facilitated by recognition events between the nascent inorganic solid and the organic template.For example, monolayers of the long alkyl chain surfactant, stearic acid will promote the oriented nucleation of the calcium carbonate polymorph, calcite, on the (100) face, whereas compressed monolayers of n-eicosyl sulphate will induce calcite nucleation on the (001) face, (Figure 1 & 2). An extensive program of research has confirmed the general principle that molecular recognition events at the interface (including electrostatic interactions, geometric homology, stereochemical complementarity) can be used to promote the crystal engineering process.

X-ray Crystallographic Study of Alkylammonium Anthracene-9-carboxylates as a Model for Fibrous Structure of Binary Anthracene Salt Gels

2004 ◽  
Vol 69 (6) ◽  
pp. 1292-1300 ◽  
Author(s):  
Tahahiro Tani ◽  
Kazuki Sada ◽  
Masatsugu Ayabe ◽  
Yuya Iwashita ◽  
Takanori Kishida ◽  
...  
Keyword(s):  
Alkyl Chain ◽  
Columnar Structure ◽  
Hydrogen Bond Network ◽  
One Dimensional ◽  
X Ray ◽  
Crystallographic Study ◽  
Alkylammonium Salts ◽  
Bond Network ◽  
Fibrous Assemblies ◽  
Long Alkyl Chain

Crystal structure of hexylammonium anthracene-9-carboxylate was investigated. The salt was arranged by a one-dimensional hydrogen bond network to form a columnar structure in the crystalline state. This columnar structure should be the model of fibrous assemblies in the organogels of anthracene-9-carboxylate alkylammonium salts having a long alkyl chain.

scholarly journals Steady state charge conduction through solution processed liquid crystalline lanthanide bisphthalocyanine films

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1603-1615
Author(s):  
Chandana Pal ◽  
Isabelle Chambrier ◽  
Andrew N. Cammidge ◽  
A. K. Sharma ◽  
Asim K. Ray
Keyword(s):  
Metal Ions ◽  
Liquid Crystalline ◽  
Microscopy Study ◽  
Individual Characteristics ◽  
Central Metal ◽  
Force Microscopy ◽  
Atomic Force ◽  
Double Decker ◽  
Order Of Magnitude ◽  
Chain Lengths

In-plane electrical characteristics of non-peripherally octyl(C[Formula: see text]H[Formula: see text]- and hexyl(C[Formula: see text]H[Formula: see text]-substituted liquid crystalline (LC) double decker lanthanide bisphthalocyanine (LnPc[Formula: see text] complexes with central metal ions lutetium (Lu), and gadolinium (Gd) have been measured in thin film formulations on interdigitated gold (Au) electrodes for the applied voltage ([Formula: see text] range of [Formula: see text]. The conduction mechanism is found to be Ohmic within the bias of [Formula: see text] while the bulk limited Poole–Frenkel mechanism is responsible for the higher bias. The compounds show individual characteristics depending on the central metal ions, substituent chain lengths and their mesophases. Values of 67.55 [Formula: see text]cm[Formula: see text] and 42.31 [Formula: see text]cm[Formula: see text] have been obtained for room temperature in-plane Ohmic conductivity of as-deposited octyl lutetium (C[Formula: see text]LuPc[Formula: see text] and hexyl gadolinium (C[Formula: see text]GdPc[Formula: see text] films, respectively while C[Formula: see text]GdPc[Formula: see text] films exhibit nearly two orders of magnitude smaller conductivity. On annealing at 80[Formula: see text]C, Ohmic conductivities of C[Formula: see text]LuPc[Formula: see text] and C[Formula: see text]GdPc[Formula: see text] are found to have increased but the conductivity of C[Formula: see text]GdPc[Formula: see text] decreased by more than one order of magnitude to 1.5 [Formula: see text]cm[Formula: see text]. For physical interpretation of the charge transport behavior of these three molecules, their UV-vis optical absorption spectra in the solution and in as-deposited and annealed solid phases and atomic force microscopy study have been performed. It is believed that both orientation and positional reorganizations are responsible, depending upon the size of the central ion and side chain length.

scholarly journals Facile construction of a family of supramolecular gels with good levofloxacin hydrochloride loading capacity

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12641-12648
Author(s):  
Renyuan Chen ◽  
Caidie Xu ◽  
Yihao Lei ◽  
Hongxin Liu ◽  
Yabin Zhu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Alkyl Chain ◽  
Low Molecular Weight ◽  
Loading Capacity ◽  
Supramolecular Gels ◽  
Low Molecular Weight Gelators ◽  
Chain Lengths

A family of low molecular weight gelators with different alkyl chain lengths was constructed, having excellent gelation ability and antibiotic loading capacity. A low molecular weight hydrogelator was obtained by adjusting the length of alkyl chain.

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