scholarly journals Non-Conventional Features of Plant Oil-Based Acrylic Monomers in Emulsion Polymerization

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 2990 ◽  
Author(s):  
Ananiy Kohut ◽  
Stanislav Voronov ◽  
Zoriana Demchuk ◽  
Vasylyna Kirianchuk ◽  
Kyle Kingsley ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Physical And Mechanical Properties ◽  
Polymer Coatings ◽  
Van Der Waals Interactions ◽  
Vinyl Monomers ◽  
Plant Oil ◽  
Crosslinking Degree ◽  
One Step ◽  
And Control ◽  
Plant Sources

In recent years, polymer chemistry has experienced an intensive development of a new field regarding the synthesis of aliphatic and aromatic biobased monomers obtained from renewable plant sources. A one-step process for the synthesis of new vinyl monomers by the reaction of direct transesterification of plant oil triglycerides with N-(hydroxyethyl)acrylamide has been recently invented to yield plant oil-based monomers (POBMs). The features of the POBM chemical structure, containing both a polar (hydrophilic) fragment capable of electrostatic interactions, and hydrophobic acyl fatty acid moieties (C15-C17) capable of van der Waals interactions, ensures the participation of the POBMs fragments of polymers in intermolecular interactions before and during polymerization. The use of the POBMs with different unsaturations in copolymerization reactions with conventional vinyl monomers allows for obtaining copolymers with enhanced hydrophobicity, provides a mechanism of internal plasticization and control of crosslinking degree. Synthesized latexes and latex polymers are promising candidates for the formation of hydrophobic polymer coatings with controlled physical and mechanical properties through the targeted control of the content of different POBM units with different degrees of unsaturation in the latex polymers.

Surface Modification of Poly(Vinylchloride) for Manufacturing Advanced Catheters

2020 ◽  
Vol 27 (10) ◽  
pp. 1616-1633 ◽  
Author(s):  
Oana Cristina Duta ◽  
Aurel Mihail Ţîţu ◽  
Alexandru Marin ◽  
Anton Ficai ◽  
Denisa Ficai ◽  
...  
Keyword(s):  
Surface Modification ◽  
Chemical Modification ◽  
Medical Devices ◽  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Modern Medicine ◽  
Structural Failure ◽  
Chemical Grafting ◽  
One Step

Polymeric materials, due to their excellent physicochemical properties and versatility found applicability in multiples areas, including biomaterials used in tissue regeneration, prosthetics (hip, artificial valves), medical devices, controlled drug delivery systems, etc. Medical devices and their applications are very important in modern medicine and the need to develop new materials with improved properties or to improve the existent materials is increasing every day. Numerous reasearches are activated in this domain in order to obtain materials/surfaces that does not have drawbacks such as structural failure, calcifications, infections or thrombosis. One of the most used material is poly(vinylchloride) (PVC) due to its unique properties, availability and low cost. The most common method used for obtaining tubular devices that meet the requirements of medical use is the surface modification of polymers without changing their physical and mechanical properties, in bulk. PVC is a hydrophobic polymer and therefore many research studies were conducted in order to increase the hydrophilicity of the surface by chemical modification in order to improve biocompatibility, to enhance wettability, reduce friction or to make lubricious or antimicrobial coatings. Surface modification of PVC can be achieved by several strategies, in only one step or, in some cases, in two or more steps by applying several techniques consecutively to obtain the desired modification / performances. The most common processes used for modifying the surface of PVC devices are: plasma treatment, corona discharge, chemical grafting, electric discharge, vapour deposition of metals, flame treatment, direct chemical modification (oxidation, hydrolysis, etc.) or even some physical modification of the roughness of the surface.

scholarly journals Cold Plasma Deposition of Polymeric Nanoprotrusion, Nanoparticles, and Nanofilm Structures on a Slide Glass Surface

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 99
Author(s):  
Sun-Woo Yi ◽  
In-Keun Yu ◽  
Woon-Jung Kim ◽  
Seong-Ho Choi
Keyword(s):  
Contact Angle ◽  
Visible Light ◽  
Methyl Methacrylate ◽  
Cold Plasma ◽  
Plasma Deposition ◽  
Vinyl Monomers ◽  
Glass Slides ◽  
Structure Surface ◽  
One Step ◽  
Coated Surface

In this study, we coated the surface of glass slides with nanoprotrusion, nanoparticles, and nanofilm structures by one-step plasma deposition of three vinyl monomers. Three functional vinyl monomers with symmetrical polarity sites were used: methyl methacrylate (MMA), trifluoro methylmethacrylate (TFMA), and trimethylsilyl methyl methacrylate (TSMA). The TSMA/MMA (80/20, mol-%) nanoprotrusion-coated surface of slide glass was superhydrophobic, with a 153° contact angle. We also evaluated the transmittance (%) of the slide glass with nanoprotrusions in the infrared (IR) (940 nm), ultraviolet (365 nm) and visible light (380–700 nm) regions. The obtained nanoprotrusion structure surface of slide glass created by plasma deposition transmits more than 90% of visible light.

scholarly journals Dynamical strengthening of covalent and non-covalent molecular interactions by nuclear quantum effects at finite temperature

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Huziel E. Sauceda ◽  
Valentin Vassilev-Galindo ◽  
Stefan Chmiela ◽  
Klaus-Robert Müller ◽  
Alexandre Tkatchenko
Keyword(s):  
Finite Temperature ◽  
Electrostatic Interactions ◽  
Zero Point ◽  
Quantum Effects ◽  
Van Der Waals Interactions ◽  
Interatomic Distances ◽  
Point Energy ◽  
Molecular Bond ◽  
Energy Surfaces ◽  
Nuclear Quantum Effects

AbstractNuclear quantum effects (NQE) tend to generate delocalized molecular dynamics due to the inclusion of the zero point energy and its coupling with the anharmonicities in interatomic interactions. Here, we present evidence that NQE often enhance electronic interactions and, in turn, can result in dynamical molecular stabilization at finite temperature. The underlying physical mechanism promoted by NQE depends on the particular interaction under consideration. First, the effective reduction of interatomic distances between functional groups within a molecule can enhance the n → π* interaction by increasing the overlap between molecular orbitals or by strengthening electrostatic interactions between neighboring charge densities. Second, NQE can localize methyl rotors by temporarily changing molecular bond orders and leading to the emergence of localized transient rotor states. Third, for noncovalent van der Waals interactions the strengthening comes from the increase of the polarizability given the expanded average interatomic distances induced by NQE. The implications of these boosted interactions include counterintuitive hydroxyl–hydroxyl bonding, hindered methyl rotor dynamics, and molecular stiffening which generates smoother free-energy surfaces. Our findings yield new insights into the versatile role of nuclear quantum fluctuations in molecules and materials.

scholarly journals Calix[4]arene-Based MOFs Controlled by Length of Alkyldiammonium Guests

2014 ◽  
Vol 70 (a1) ◽  
pp. C1713-C1713
Author(s):  
Ki-Min Park ◽  
Eunji Lee ◽  
Huiyeong Ju ◽  
Suk-Hee Moon ◽  
Shim Sung Lee
Keyword(s):  
Electrostatic Interactions ◽  
Three Dimensional ◽  
Van Der Waals Interactions ◽  
Supramolecular Interactions ◽  
Solvothermal Reaction ◽  
Guest Molecules ◽  
Structural Framework ◽  
Guest Species ◽  
Dimensional Network ◽  
Alternative Conformation

Our interest in the development of MOFs with the cavities controlled by guest species has led us to investigate the MOFs based on calix[4]arene derivatives, in which metal ions link the calix unit to give the networks with the cavities accommodating several guest species, because the calix[4]arene-based MOFs contain porosity associated with both the ligand itself and the structural framework. In the present work, we employed a low rim-functionalized calix[4]arene tetraacetic acid (H4CTA) with 1,3-alternative conformation as a multidentate building block and alkyldiamines as the guest molecules. In the solvothermal reaction of H4CTA and Zn(II) ion in the presence of alkyldiamines, two types of new MOFs based on calix[4]arene tetraacetate (CTA4-) depending on the lengths of α,ω–alkyldiammonium guests have been synthesized by including suitable alkyldiammonium guests. Their single-crystal X-ray diffraction analyses reveal that the short alkyldiammonium guests such as ethyldiammonium, propyldiammonium, and butyldiammonium lead to form two-dimensional framework with the cavity consisting of two CTA4-and four Zn(II) ions whereas the alkyldiammonium guests such as heptyldiammonium, octyldiammonium, nonyldiammonium, and decyldiammonium give rise to generate three-dimensional network with the cavity surrounded by six CTA4-and four Zn(II) ions. The alkyldiammonium guests in both MOFs are well accommodated by each cavity via a variety of supramolecular interactions including electrostatic interactions, hydrogen bonds and van der Waals interactions. We will present and discuss a study on the syntheses and characterization of two new MOFs based on calix[4]arene derivative.

scholarly journals Study of the Adhesion Mechanism of Acidithiobacillus ferrooxidans to Pyrite in Fresh and Saline Water

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 306 ◽  
Author(s):  
Francisca San Martín ◽  
Claudio Aguilar
Keyword(s):  
Fresh Water ◽  
Electrostatic Interactions ◽  
Saline Water ◽  
Streaming Potential ◽  
Bacterial Attachment ◽  
Van Der Waals Interactions ◽  
Streaming Potentials ◽  
Ph Values ◽  
Na Ions ◽  
Kinetics Of

In the present work, the streaming potential of A. ferrooxidans and pyrite was measured in two environments: fresh and saline water (water with 35 g/L of NaCl) at different pH values. Also, attachment kinetics of A. ferrooxidans to pyrite was studied in fresh and saline water at pH 4. The results show that A. ferrooxidans and pyrite had lower streaming potentials (comparing absolute values) in saline water than in fresh water, indicating the compression in the electrical double layer caused by Cl− and Na+ ions. It was also determined that the bacteria had a higher level of attachment to pyrite in fresh water than in saline water. The high ionic strength of saline water reduced the attractive force between A. ferrooxidans and pyrite, which in turn reduced bacterial attachment. Electrostatic interactions were determined to be mainly repulsive, since the bacteria and mineral had the same charge at pH 4. Despite this, the bacteria adhered to pyrite, indicating that hydrophobic attraction forces and Lifshitz–van der Waals interactions were stronger than electrostatic interactions, which caused the adhesion of A. ferrooxidans to pyrite.

Enhancement and control of neuron adhesion on polydimethylsiloxane for cell microengineering using a functionalized triblock polymer

Lab on a Chip ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 3162-3167
Author(s):  
Wenming Liu ◽  
Kai Han ◽  
Meilin Sun ◽  
Jinyi Wang
Keyword(s):  
Triblock Polymer ◽  
One Step ◽  
And Control

We present a straightforward strategy to promote and engineer neuron adhesion on a polydimethylsiloxane substrate by a one-step modification using a functionalized triblock polymer.

scholarly journals Electrostatic shape control of a charged molecular membrane from ribbon to scroll

2019 ◽  
Vol 116 (44) ◽  
pp. 22030-22036 ◽  
Author(s):  
Changrui Gao ◽  
Sumit Kewalramani ◽  
Dulce Maria Valencia ◽  
Honghao Li ◽  
Joseph M. McCourt ◽  
...  
Keyword(s):  
Shape Control ◽  
Electrostatic Interactions ◽  
Debye Length ◽  
Electron Microscopies ◽  
Atomic Force ◽  
Length Relationship ◽  
Transmission Electron ◽  
Nacl Concentration ◽  
Large Length ◽  
And Control

Bilayers of amphiphiles can organize into spherical vesicles, nanotubes, planar, undulating, and helical nanoribbons, and scroll-like cochleates. These bilayer-related architectures interconvert under suitable conditions. Here, a charged, chiral amphiphile (palmitoyl-lysine, C16-K1) is used to elucidate the pathway for planar nanoribbon to cochleate transition induced by salt (NaCl) concentration. In situ small- and wide-angle X-ray scattering (SAXS/WAXS), atomic force and cryogenic transmission electron microscopies (AFM and cryo-TEM) tracked these transformations over angstrom to micrometer length scales. AFM reveals that the large length (L) to width (W) ratio nanoribbons (L/W > 10) convert to sheets (L/W → 1) before rolling into cochleates. A theoretical model based on electrostatic and surface energies shows that the nanoribbons convert to sheets via a first-order transition, at a critical Debye length, with 2 shallow minima of the order of thermal energy at L/W >> 1 and at L/W = 1. SAXS shows that interbilayer spacing (D) in the cochleates scales linearly with the Debye length, and ranges from 13 to 35 nm for NaCl concentrations from 100 to 5 mM. Theoretical arguments that include electrostatic and elastic energies explain the membrane rolling and the bilayer separation–Debye length relationship. These models suggest that the salt-induced ribbon to cochleate transition should be common to all charged bilayers possessing an intrinsic curvature, which in the present case originates from molecular chirality. Our studies show how electrostatic interactions can be tuned to attain and control cochleate structures, which have potential for encapsulating, and releasing macromolecules in a size-selective manner.

Polymorphism of Trimeric Perfluoro-ortho-phenylene Mercury, [Hg(o-C6F4)]3

2004 ◽  
Vol 59 (11-12) ◽  
pp. 1483-1487 ◽  
Author(s):  
Mason R. Haneline ◽  
François P. Gabbaï
Keyword(s):  
Single Crystal ◽  
Electrostatic Interactions ◽  
Van Der Waals ◽  
Relativistic Effects ◽  
Van Der Waals Interactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Π Interactions

Three new modifications of trimeric perfluoro-ortho-phenylene mercury (2) have been investigated by single crystal X-ray diffraction. In each of these modifications, the molecules of 2 form extended stacks. Within each stack, the successive molecules are parallel and separated by approximately 3.3 - 3.4 Å. The packing observed in the different structures is rationalized on the basis of secondary mercury-π interactions, mercuriophilic interactions and electrostatic interactions. Altogether, little preference is given for one particular type of interaction. The packing appears to be dominated by non-directional van der Waals interactions between molecules of 2 which are largely aromatic and whose overall polarizability is magnified by relativistic effects at the mercury(II) centers.

scholarly journals Effect of Lysyllysine on non-covalent hybridization of single walled carbon nanotube by single-stranded DNA homodimer: in silico approach

2019 ◽  
Vol 9 (4) ◽  
pp. 315-321
Author(s):  
Fateme Bagherolhashemi ◽  
Mohammad Reza Bozorgmehr ◽  
Mohammad Momen-Heravi
Keyword(s):  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
Electrostatic Interactions ◽  
Membered Ring ◽  
Binding Energies ◽  
Van Der Waals Interactions ◽  
Dynamics Simulation ◽  
Quantum Calculations ◽  
Single Walled Carbon Nanotube ◽  
Sensor Properties

Abstract In this work, the interactions between adenine–adenine di-nucleotide (DA2N) and carbon nanotube (CNT) in the presence of Lysyllysine (LL) was studied by the molecular dynamics simulation. Different carbon nanotubes including (5.5), (6.6) and (7.7) were used to investigate the effect of CNT type. The binding energies were calculated using the molecular mechanics-Poisson Bolzmann surface area method. The results showed that the contribution of the van der Waals interactions between DA2N and CNT was greater than that of the electrostatic interactions. The LL significantly enhanced the electrostatic interactions between the DA2N and CNT (6.6). The quantum calculations revealed that the sensor properties of the DA2N were not significantly affected by the CNT and LL. However, the five-membered ring of adenine played a more important role in the sensing properties of the DA2N. The obtained results are consistent with the previous experimental observations that can help to understand the molecular mechanism of the interaction of DA2N with CNT. Graphic abstract

Sign in / Sign up

Export Citation Format

Share Document