Effect of Surfactant Concentration on the Long-Term Properties of a Colloidal Chemical, Biological and Radiological (CBR) Decontamination Gel

Chemically, biologically, or radiologically contaminated surfaces can be treated using colloidal “vacuumable” gels containing alumina particles as a thickening agent, decontaminating solutions to inhibit/eliminate biological and chemical contaminants, and Pluronic PE 6200 as a surfactant to adjust the gel’s physicochemical properties. These gels have been shown to remain efficient even after prolonged storage. In the present study, the properties of gels with different surfactant concentrations were monitored over several months using rheological analyses, contact angle measurements, and ion chromatography. Results show that the surfactant reacts with the hypochlorite ions in the decontaminating solution. This leads to sedimentation, which modifies the rheological properties of the gel. Increasing the surfactant concentration ensures the physicochemical properties of the gel are preserved for longer, but because the surfactant reacts with the hypochlorite ions, the concentration of the latter decreases drastically and thus so do the decontamination properties of the gel. There is therefore a trade-off between the efficiency of the gel against chemical and biological contamination at a given time and how long its physicochemical properties are preserved, with the optimal balance depending on its intended use.

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Polydopamine Linking Substrate for AMPs: Characterisation and Stability on Ti6Al4V

Materials ◽

10.3390/ma13173714 ◽

2020 ◽

Vol 13 (17) ◽

pp. 3714

Author(s):

Zuzanna Trzcińska ◽

Marc Bruggeman ◽

Hanieh Ijakipour ◽

Nikolas J. Hodges ◽

James Bowen ◽

...

Keyword(s):

High Performance ◽

Release Profile ◽

Water Contact ◽

Force Microscopy ◽

Angle Measurements ◽

Atomic Force ◽

Contact Angle Measurements ◽

Titanium Alloy Ti6al4v ◽

Thickness Measurements

Infections are common complications in joint replacement surgeries. Eradicated infections can lead to implant failure. In this paper, analogues of the peptide KR-12 derived from the human cathelicidin LL-37 were designed, synthesised, and characterised. The designed antimicrobial peptides (AMPs) were attached to the surface of a titanium alloy, Ti6Al4V, by conjugation to a polydopamine linking substrate. The topography of the polydopamine coating was evaluated by electron microscopy and coating thickness measurements were performed with ellipsometry and Atomic Force Microscopy (AFM). The subsequently attached peptide stability was investigated with release profile studies in simulated body fluid, using both fluorescence imaging and High-Performance Liquid Chromatography (HPLC). Finally, the hydrophobicity of the coating was characterised by water contact angle measurements. The designed AMPs were shown to provide long-term bonding to the polydopamine-coated Ti6Al4V surfaces.

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Modification of Silicone Elastomers Using Silicone Comonomers Containing Hydrophilic Surface Active Endgroups

MRS Proceedings ◽

10.1557/opl.2014.11 ◽

2014 ◽

Vol 1626 ◽

Cited By ~ 2

Author(s):

Jonathan Goff ◽

Barry Arkles ◽

Santy Sulaiman

Keyword(s):

Contact Angle ◽

Mechanical Performance ◽

Silicone Elastomer ◽

Hydrophobic Contact ◽

Silicone Elastomers ◽

Angle Measurements ◽

Contact Angle Measurements ◽

Friction Measurements ◽

Time Frames

ABSTRACTA facile technique was developed for a long-term increase in silicone elastomer surface hydrophilicity, eliminating the need for post-cure surface treatment (e.g. oxygen plasma or surface grafting). Well-defined silicones (1-4 kDa) with a central vinyl functionality and discrete PEG2, PEG3 and tetrahydrofurfuryl (THF) pendant endgroups were synthesized, characterized and used as comonomers in addition-cure, platinum catalyzed 2-part silicone elastomer formulations. The modified silicone elastomers were optically clear and maintained the mechanical performance characteristic of this class of material with up to 20 wt.% comonomer in the 2-part formulation. Contact angle measurements of deionized water on the silicone elastomer surface showed improved wettability with comonomer content. The elastomer surface shifted from hydrophobic (contact angle ∼120°C) to hydrophilic (contact angle < 90°C) at ∼5 wt.% comonomer loadings for extended time frames (> 5 months). Coefficient of friction measurements of the modified silicone elastomers revealed an increase in surface lubricity with comonomer loadings.

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Engineered Pullulan-Collagen-Gold Nano Composite Improves Mesenchymal Stem Cells Neural Differentiation and Inflammatory Regulation

Cells ◽

10.3390/cells10123276 ◽

2021 ◽

Vol 10 (12) ◽

pp. 3276

Author(s):

Meng-Yin Yang ◽

Bai-Shuan Liu ◽

Hsiu-Yuan Huang ◽

Yi-Chin Yang ◽

Kai-Bo Chang ◽

...

Keyword(s):

Stem Cells ◽

Physicochemical Properties ◽

Neuronal Differentiation ◽

Nano Composite ◽

Angle Measurements ◽

Contact Angle Measurements ◽

Anti Inflammatory ◽

Inflammatory Regulation

Tissue repair engineering supported by nanoparticles and stem cells has been demonstrated as being an efficient strategy for promoting the healing potential during the regeneration of damaged tissues. In the current study, we prepared various nanomaterials including pure Pul, pure Col, Pul–Col, Pul–Au, Pul–Col–Au, and Col–Au to investigate their physicochemical properties, biocompatibility, biological functions, differentiation capacities, and anti-inflammatory abilities through in vitro and in vivo assessments. The physicochemical properties were characterized by SEM, DLS assay, contact angle measurements, UV-Vis spectra, FTIR spectra, SERS, and XPS analysis. The biocompatibility results demonstrated Pul–Col–Au enhanced cell viability, promoted anti-oxidative ability for MSCs and HSFs, and inhibited monocyte and platelet activation. Pul–Col–Au also induced the lowest cell apoptosis and facilitated the MMP activities. Moreover, we evaluated the efficacy of Pul–Col–Au in the enhancement of neuronal differentiation capacities for MSCs. Our animal models elucidated better biocompatibility, as well as the promotion of endothelialization after implanting Pul–Col–Au for a period of one month. The above evidence indicates the excellent biocompatibility, enhancement of neuronal differentiation, and anti-inflammatory capacities, suggesting that the combination of pullulan, collagen, and Au nanoparticles can be potential nanocomposites for neuronal repair, as well as skin tissue regeneration in any further clinical treatments.

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Polymer surface properties and their effect on the adhesion of Proteus mirabilis

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1243/095441103322060730 ◽

2003 ◽

Vol 217 (4) ◽

pp. 279-289 ◽

Cited By ~ 19

Author(s):

A Downer ◽

N Morris ◽

W J Feast ◽

D Stickler

Keyword(s):

Surface Properties ◽

Polymer Films ◽

Proteus Mirabilis ◽

Polymer Surface ◽

Poly Vinyl Alcohol ◽

Repulsive Interaction ◽

Bacterial Surface ◽

Angle Measurements ◽

Contact Angle Measurements

A problem encountered in patients undergoing long-term catheterization of the urinary tract is that of encrustation and blockage of the catheter by crystalline bacterial biofilms. This is principally caused by the action of the urease-producing pathogen Proteus mirabilis. A major aim of this work is to develop materials resistant to encrustation. Here, the effects of polymer surface properties on the adhesion of P. mirabilis are examined. Spin-coated polymer films were characterized through contact angle measurements to give the Lifschitz-van der Waals, electron acceptor and electron donor terms of the surface free energy, γsLW, γs+ and γs− respectively. A parallel-plate flow cell was used to assess adhesion to these polymer films of P. mirabilis suspended in an aqueous phosphate buffer, pH 7.4, ionic strength 0.26 mol/kg. P. mirabilis was found to adhere significantly less ( p<0.02) to films of agarose, poly(2-hydroxyethylmethacrylate) and cross-linked poly(vinyl alcohol) than to more hydrophobic materials. These polymer films were found to be strongly electron donating, i.e. possessing large γs−. Films examined using scanning electron microscopy mostly showed no evidence of roughness down to a scale of 1–10 μm. The better performance is thought to be due to a repulsive interaction with the bacterial surface caused by acid/base-type interactions.

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Plasma-Based Surface Modification of Polydimethylsiloxane for PDMS-PDMS Molding

ISRN Polymer Science ◽

10.5402/2012/767151 ◽

2012 ◽

Vol 2012 ◽

pp. 1-5 ◽

Cited By ~ 6

Author(s):

S. Lopera ◽

R. D. Mansano

Keyword(s):

Surface Modification ◽

Polymer Surface ◽

Rf Power ◽

Force Microscopy ◽

Angle Measurements ◽

Atomic Force ◽

Contact Angle Measurements ◽

Hydrogen Mixtures ◽

Pdms Molding

We present and compare two processes for plasma-based surface modification of Polydimethylsiloxane (PDMS) to achieve the antisticking behavior needed for PDMS-PDMS molding. The studied processes were oxygen plasma activation for vapor phase silanization and plasma polymerization with tetrafluoromethane/hydrogen mixtures under different processing conditions. We analyzed topography changes of the treated surfaces by atomic force microscopy and contact angle measurements. Plasma treatment were conducted in a parallel plate reactive ion etching reactor at a pressure of 300 mTorr, 30 Watts of RF power and a total flow rate of 30 sccm of a gas mixture. We found for both processes that short, low power, treatments are better to create long-term modifications of the chemistry of the polymer surface while longer processes or thicker films tend to degrade faster with the use leaving rough surfaces with higher adherence to the molded material.

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The effectiveness of granular chalk use for growing winter wheat on grey forest soil

Agrobìologìâ ◽

10.33245/2310-9270-2020-157-1-181-191 ◽

2020 ◽

pp. 181-191

Author(s):

M. Tkachenko ◽

N. Borys ◽

Ye. Kovalenko

Keyword(s):

Winter Wheat ◽

Physicochemical Properties ◽

Forest Soil ◽

Active Substance ◽

Mass Fraction ◽

Gray Forest Soil ◽

Mineral Fertilizers ◽

Acidic Soils ◽

Grey Forest Soil

The research aims to establish the eff ectiveness of granular chalk use produced by «Slavuta-Calcium» Ltd. under growing Poliska–90 winter wheat variety, changing the physicochemical properties of grey forest soil and the wheat productivity. It also aims to establish optimal dosis of «Slavuta-Calcium» granular chalk as the meliorant and mineral fertilizer for grey forest soil in the system of winter wheat fertilization. In the temporary fi eld studies, various doses of nutrients N60–90–120P30–45–60K60–90–120 combined with «Slavuta–Calcium» granular chalk in a dose of Ca230–460–690 kg/ha of the active substance were studied against the background of secondary plowing of rotation products – soybean biomass that averaged 2.34 t/ha. Granular chalk is a modern complex highly eff ective meliorant with the content of Ca – 37.7 and Mg – 0.2 %, the mass fraction of carbonates (CaCO3 + MgCO3) makes at least 95 %. It is characterized by a high level of solubility when interacting with moisture in soil. It has a form of white granules, the mass fraction of 4.0–6.0 mm in size granules makes not less than 90 % and the one of 1.0 mm in size makes less than 5 %. Reactivity – 97 %. The granular chalk is advisable to apply on acidic soils, as a highly concentrated calcium-magnesium fertilizer, with the former as the dominant fertilizer, to optimize the physicochemical properties of the soil, as well as the plant nutrition system, in particular, increasing the availability of an element for assimilation by plants and as long-term ameliorants. The eff ectiveness of the use of mineral fertilizers, in particular acidic nitrogen on highly and medium acidic soils, after chemical reclamation is increased by 30–50 %, and slightly acidic by 15–20 %. The increase in productivity of crops from the combined eff ects of nutrients and chalk granulated is usually higher than when separately applied. The eff ectiveness of the integrated action of these elements is manifested in the growth of plant productivity and the quality of the resulting products, as well as the optimization of physical chemical properties and soil buff ering in the long term. In order to optimize the physicochemical properties of the arable layer of gray forest soil and the productive nutrition of agricultural crops, winter wheat, in particular, biogenic elements should be used in doses N60-90-120P30-45- 60K60-90-120 with granulated chalk «Slavuta-Calcium» in doses of Ca230-460-690 kg/ha of active substance. Granulated chalk obtained as a result of industrial grinding of solid sedimentary carbonate rocks of natural origin, subsequently under the infl uence of the granulation process of the starting material contains Ca and Mg carbonates of at least 95 %, dense granules which facilitates convenient mechanized application, as well as chalk suitable for accurate metered application on the quest map. Key words: granular chalk, gray forest soil, chemical reclamation, crop productivity.

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Nanostructured Polymer Brushes With Reversibly Changing Properties

MRS Proceedings ◽

10.1557/proc-727-r2.5 ◽

2002 ◽

Vol 727 ◽

Author(s):

Denys Usov ◽

Manfred Stamm ◽

Sergiy Minko ◽

Christian Froeck ◽

Andreas Scholl ◽

...

Keyword(s):

Polymer Brushes ◽

Phase Segregation ◽

Water Contact ◽

Angle Measurements ◽

Nanostructured Polymer ◽

Contact Angle Measurements ◽

Vertical Segregation ◽

Oxygen Plasma Etching ◽

Grafting From ◽

Photoemission Electron

AbstractWe investigated the interplay between different mechanisms of the lateral and vertical segregation in the synthesized via “grafting from” approach symmetric A/B (where A and B are poly(styrene-co-2,3,4,5,6-pentafluorostyrene) and poly(methylmethacrylate), respectively) polymer brushes upon exposure to different solvents. We used X-ray photoemission electron spectroscopy and microscopy (X-PEEM), AFM, water contact angle measurements, and oxygen plasma etching to study morphology of the brushes. The ripple morphology after toluene (nonselective solvent) revealed elongated lamellar-like domains of A and B polymers alternating across the surface. The dimple-A morphology consisting of round clusters of the polymer A was observed after acetone (selective solvent for B). The top layer was enriched with the polymer B showing that the brush underwent both the lateral and vertical phase segregation. A qualitative agreement with predictions of SCF theory was found.

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Wrinkling Poly(trimethylene 2,5-Furanoate) Free-standing Films: Nanostructure Formation and Physical Properties

10.26434/chemrxiv.11867205.v1 ◽

2020 ◽

Author(s):

Michelina Soccio ◽

Nadia Lotti ◽

Andrea Munari ◽

Esther Rebollar ◽

Daniel E Martínez-Tong

Keyword(s):

Irradiation Time ◽

Polymer Surface ◽

Laser Source ◽

Free Standing ◽

Force Microscopy ◽

Nanostructure Formation ◽

Physicochemical Changes ◽

Angle Measurements ◽

Atomic Force ◽

Contact Angle Measurements

<p>Nanostructured wrinkles were developed on fully bio-based poly(trimethylene furanoate) (PTF) films by using the technique of Laser Induced Periodic Surface Structures (LIPSS). We investigated the effect of irradiation time on wrinkle formation using an UV pulsed laser source, at a fluence of 8 mJ/cm2. It was found that the pulse range between 600 and 4800 pulses allowed formation of periodic nanometric ripples. The nanostructured surface was studied using a combined macro- and nanoscale approach. We evaluated possible physicochemical changes taking place on the polymer surface after irradiation by infrared spectroscopy, contact angle measurements and atomic force microscopy. The macroscopic physicochemical properties of PTF showed almost no changes after nanostructure formation, differently from the results previously found for the terephthalic counterparts, as poly(ethyleneterephthalate), PET, and poly(trimethyleneterephthalate), PTT. The surface mechanical properties of the nanostructured PTF were found to be improved, as evidenced by nanomechanical force spectroscopy measurements. In particular, an increased Young’s modulus and higher stiffness for the nanostructured sample were measured. <br></p>

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