Opoka—Sediment Rock as New Type of Hybrid Mineral Filler for Polymer Composites

The work presents a comprehensive profile of the physicochemical characteristics of opoka sedimentary rock in the context of its use as a hybrid filler for thermoplastics. Determining the functional parameters of the studied filler was the main aim of this research. Thermal treatment leads to changes in its morphology and phase composition. A wide range of physicochemical techniques was used, such as low-temperature nitrogen adsorption, FT-IR, TGA, XRD, optical, and electron microscopy. The susceptibility of the material to micronisation was also tested (ball milling). Due to its widespread occurrence, opoka can be an attractive alternative to fillers such as silica or chalk. In order to verify this statement, polypropylene composites thereof were prepared by melt blending and injection molding, and studied by mechanical testing and microscopic imaging.

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Tailorable Synthesis of Highly Oxidized Graphene Oxides via an Environmentally-Friendly Electrochemical Process

Nanomaterials ◽

10.3390/nano10020239 ◽

2020 ◽

Vol 10 (2) ◽

pp. 239 ◽

Cited By ~ 3

Author(s):

Ana María Díez-Pascual ◽

Carlos Sainz-Urruela ◽

Cristina Vallés ◽

Soledad Vera-López ◽

María Paz San Andrés

Keyword(s):

Electrical Resistance ◽

Interlayer Spacing ◽

Electrochemical Process ◽

Attractive Alternative ◽

Mechanical And Thermal Properties ◽

Graphene Oxides ◽

Synthesis Conditions ◽

Oxidation Level ◽

Wide Range ◽

Ft Ir

Graphene oxide (GO) is an attractive alternative to graphene for many applications due to its captivating optical, chemical, and electrical characteristics. In this work, GO powders with a different amount of surface groups were synthesized from graphite via an electrochemical two-stage process. Many synthesis conditions were tried to maximize the oxidation level, and comprehensive characterization of the resulting samples was carried out via elemental analysis, microscopies (TEM, SEM, AFM), X-ray diffraction, FT-IR and Raman spectroscopies as well as electrical resistance measurements. SEM and TEM images corroborate that the electrochemical process used herein preserves the integrity of the graphene flakes, enabling to obtain large, uniform and well exfoliated GO sheets. The GOs display a wide range of C/O ratios, determined by the voltage and time of each stage as well as the electrolyte concentration, and an unprecedented minimum C/O value was obtained for the optimal conditions. FT-IR evidences strong intermolecular interactions between neighbouring oxygenated groups. The intensity ratio of D/G bands in the Raman spectra is high for samples prepared using concentrated H2SO4 as an electrolyte, indicative of many defects. Furthermore, these GOs exhibit smaller interlayer spacing than that expected according to their oxygen content, which suggests predominant oxidation on the flake edges. Results point out that the electrical resistance is conditioned mostly by the interlayer distance and not simply by the C/O ratio. The tuning of the oxidation level is useful for the design of GOs with tailorable structural, electrical, optical, mechanical, and thermal properties.

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Pharmaceutical Co-Crystals - Design, Development and Applications

Drug Delivery Letters ◽

10.2174/2210303109666191211145144 ◽

2020 ◽

Vol 10 (3) ◽

pp. 169-184

Author(s):

Rachna Anand ◽

Arun Kumar ◽

Arun Nanda

Keyword(s):

Physicochemical Properties ◽

Crystal Engineering ◽

Pharmacological Action ◽

Physicochemical Characteristics ◽

Research Area ◽

Dissolution Profile ◽

Design Development ◽

Drug Molecule ◽

Wide Range ◽

Major Factors

Background: Solubility and dissolution profile are the major factors which directly affect the biological activity of a drug and these factors are governed by the physicochemical properties of the drug. Crystal engineering is a newer and promising approach to improve physicochemical characteristics of a drug without any change in its pharmacological action through a selection of a wide range of easily available crystal formers. Objective: The goal of this review is to summarize the importance of crystal engineering in improving the physicochemical properties of a drug, methods of design, development, and applications of cocrystals along with future trends in research of pharmaceutical co-crystals. Co-crystallization can also be carried out for the molecules which lack ionizable functional groups, unlike salts which require ionizable groups. Conclusion: Co-crystals is an interesting and promising research area amongst pharmaceutical scientists to fine-tune the physicochemical properties of drug materials. Co-crystallization can be a tool to increase the lifecycle of an older drug molecule. Crystal engineering carries the potential of being an advantageous technique than any other approach used in the pharmaceutical industry. Crystal engineering offers a plethora of biopharmaceutical and physicochemical enhancements to a drug molecule without the need of any pharmacological change in the drug.

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Clinoptilolite as a natural, active zeolite catalyst for the chemical transformations of geraniol

Reaction Kinetics Mechanisms and Catalysis ◽

10.1007/s11144-021-02027-3 ◽

2021 ◽

Author(s):

Anna Fajdek-Bieda ◽

Agnieszka Wróblewska ◽

Piotr Miądlicki ◽

Jadwiga Tołpa ◽

Beata Michalkiewicz

Keyword(s):

Reaction Time ◽

Nitrogen Adsorption ◽

Carbon Chain ◽

Raw Material ◽

Chemical Transformations ◽

Renewable Biomass ◽

Ft Ir ◽

Catalyst Content ◽

Favorable Conditions ◽

Instrumental Methods

AbstractThis work presented the studies with the natural zeolite—clinoptilolite as the catalyst for the isomerization of geraniol. During the research, it turned out that the studied process is much more complicated, and not only isomerization takes place in it, but also dehydration, oxidation, dimerization, cyclization and fragmentation of the carbon chain. Geraniol is an organic raw material which can be obtained not only by a chemical synthesis but also from plants (renewable biomass) by distillation or extraction method, for example a source of geraniol can be a plant—geranium. Before catalytic tests clinoptilolite was characterized by the instrumental methods, such as: XRD, porosity studies—nitrogen adsorption at 77 K, SEM, EDXRF, and FT-IR. Gas chromatography analyses showed that the main products of geraniol isomerization process were 6,11-dimethyl-2,6,10-dodecatrien-1-ol and thumbergol. The selectivity of 6,11-dimethyl-2,6,10-dodecatrien-1-ol and thumbergol depended on the temperature, catalyst content and reaction time. These parameters were changed in the following ranges: 80–150 °C (temperature), 5–15 wt% (catalyst content) and 15–1440 min. (reaction time). The most favorable conditions for 6,11-dimethyl-2,6,10-dodecatrien-1-ol and thumbergol obtaining were: temperature 140 ºC, catalyst content 12.5 wt% and reaction time 180 min. At these conditions, the conversion of geraniol amounted to 98 mol%, and the selectivities of 6,11-dimethyl-2,6,10-dodecatrien-1-ol and thumbergol amounted to 14 and 47 mol%, respectively.

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Multidimensional Ln-Aminophthalate Photoluminescent Coordination Polymers

Materials ◽

10.3390/ma14071786 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1786

Author(s):

Carla Queirós ◽

Chen Sun ◽

Ana M. G. Silva ◽

Baltazar de Castro ◽

Juan Cabanillas-Gonzalez ◽

...

Keyword(s):

Water Content ◽

Coordination Polymers ◽

Metal Ion ◽

Low Cost ◽

Microwave Assisted Synthesis ◽

X Ray Diffraction ◽

X Ray ◽

Wide Range ◽

Ft Ir ◽

Ft Ir Spectroscopy

The development of straightforward reproducible methods for the preparation of new photoluminescent coordination polymers (CPs) is an important goal in luminescence and chemical sensing fields. Isophthalic acid derivatives have been reported for a wide range of applications, and in addition to their relatively low cost, have encouraged its use in the preparation of novel lanthanide-based coordination polymers (LnCPs). Considering that the photoluminescent properties of these CPs are highly dependent on the existence of water molecules in the crystal structure, our research efforts are now focused on the preparation of CP with the lowest water content possible, while considering a green chemistry approach. One- and two-dimensional (1D and 2D) LnCPs were prepared from 5-aminoisophthalic acid and Sm3+/Tb3+ using hydrothermal and/or microwave-assisted synthesis. The unprecedented LnCPs were characterized by single-crystal X-ray diffraction (SCRXD), powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM), and their photoluminescence (PL) properties were studied in the solid state, at room temperature, using the CPs as powders and encapsulated in poly(methyl methacrylate (PMMA) films, envisaging the potential preparation of devices for sensing. The materials revealed interesting PL properties that depend on the dimensionality, metal ion, co-ligand used and water content.

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NOHSO4/HF – A Novel Etching System for Crystalline Silicon

Zeitschrift für Naturforschung B ◽

10.1515/znb-2007-1110 ◽

2007 ◽

Vol 62 (11) ◽

pp. 1411-1421 ◽

Cited By ~ 12

Author(s):

Sebastian Patzig ◽

Gerhard Roewer ◽

Edwin Kroke ◽

Ingo över

Keyword(s):

Gas Phase ◽

Chemical Etching ◽

Silicon Surface ◽

Crystalline Silicon ◽

Etching Solution ◽

Wide Range ◽

Ft Ir ◽

Wet Chemical ◽

Wet Chemical Etching ◽

Etching System

Solutions consisting of HF - NOHSO4 - H2SO4 exhibit a strong reactivity towards crystalline silicon which is controlled by the concentrations of the reactive species HF and NO+. Selective isotropic and anisotropic wet chemical etching with these solutions allows to generate a wide range of silicon surface morphology patterns. Traces of Ag+ ions stimulate the reactivity and lead to the formation of planarized (polished) silicon surfaces. Analyses of the silicon surface, the etching solution and the gas phase were performed with scanning electron microscopy (SEM), DR/FT-IR (diffusive reflection Fourier transform infra-red), FT-IR, Raman and NMR spectroscopy, respectively. It was found that the resulting silicon surface is hydrogen-terminated. The gas phase contains predominantly SiF4, NO and N2O. Furthermore, NH4+ is produced in solution. The study has confirmed the crucial role of nitrosyl ions for isotropic wet chemical etching processes. The novel etching system is proposed as an effective new way for selective surface texturing of multi- and monocrystalline silicon. A high etching bath service lifetime, besides a low contamination of the etching solution with reaction products, provides ecological and economical advantages for the semiconductor and solar industry.

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Blocking of Bacterial Biofilm Formation by a Fish Protein Coating

Applied and Environmental Microbiology ◽

10.1128/aem.00279-08 ◽

2008 ◽

Vol 74 (11) ◽

pp. 3551-3558 ◽

Cited By ~ 16

Author(s):

Rebecca Munk Vejborg ◽

Per Klemm

Keyword(s):

Biofilm Formation ◽

Fish Muscle ◽

Physicochemical Characteristics ◽

Economic Problem ◽

Bacterial Attachment ◽

Bacterial Biofilm ◽

Adhesive Properties ◽

Muscle Extract ◽

Wide Range ◽

Inert Surfaces

ABSTRACT Bacterial biofilm formation on inert surfaces is a significant health and economic problem in a wide range of environmental, industrial, and medical areas. Bacterial adhesion is generally a prerequisite for this colonization process and, thus, represents an attractive target for the development of biofilm-preventive measures. We have previously found that the preconditioning of several different inert materials with an aqueous fish muscle extract, composed primarily of fish muscle α-tropomyosin, significantly discourages bacterial attachment and adhesion to these surfaces. Here, this proteinaceous coating is characterized with regards to its biofilm-reducing properties by using a range of urinary tract infectious isolates with various pathogenic and adhesive properties. The antiadhesive coating significantly reduced or delayed biofilm formation by all these isolates under every condition examined. The biofilm-reducing activity did, however, vary depending on the substratum physicochemical characteristics and the environmental conditions studied. These data illustrate the importance of protein conditioning layers with respect to bacterial biofilm formation and suggest that antiadhesive proteins may offer an attractive measure for reducing or delaying biofilm-associated infections.

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Synthesis of Silica Modified Large-Sized Hydroxyapatite Whiskers by a Hydrothermal Co-Precipitation Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.645-646.1339 ◽

2015 ◽

Vol 645-646 ◽

pp. 1339-1344 ◽

Cited By ~ 1

Author(s):

Yan Ting Yin ◽

Qing Hua Chen ◽

Ting Ting Yan ◽

Qing Hua Chen

Keyword(s):

Bone Repair ◽

Ethanol Solution ◽

Morphological Properties ◽

Precipitation Method ◽

X Ray Diffraction ◽

X Ray ◽

New Type ◽

Ft Ir ◽

Co Precipitation ◽

Surface Modified

The objective of this study was to develop a novel silica modified large-sized hydroxyapatite whiskers with improved properties for use in bone repair applications. Large-sized whiskers with a mean length of 250μm were obtained by a hydrothermal co-precipitation method at 150°C, 7.5Mpa in high-pressure reactor. Silica modified hydroxyapatite whiskers were prepared by dissolving TEOS in ethanol solution, then sintering with hydroxyapatite. The compositional and morphological properties of prepared whiskers were studied by means of x-ray diffraction (XRD), Fouier transform infrared (FT-IR), scanning electron microscopy (SEM). The results indicated the evidence of nanosilicon dioxide particles on the surface of HAP whiskers. The size of nanosilicon dioxide particles depends on dropping and stirring rate. Hence, this new type of silica modified large-sized hydroxyapatite whiskers is a valuable candidate for biomedical applications.Key words: hydroxyapatite, hydrothermal co-precipitation, surface modified, whiskers

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EXPRESS: On the Limit of Detection in Infrared Spectroscopic Imaging

Applied Spectroscopy ◽

10.1177/00037028211050961 ◽

2021 ◽

pp. 000370282110509

Author(s):

Laurin Lux ◽

Yamuna Dilip Phal ◽

Pei-Hsuan Hsieh ◽

Rohit Bhargava

Keyword(s):

Limit Of Detection ◽

Protein Microarray ◽

Spectroscopic Imaging ◽

Single Frequency ◽

Systematic Analysis ◽

Protein Mass ◽

Ir Imaging ◽

Wide Range ◽

Ft Ir ◽

Processing Techniques

Infrared (IR) spectroscopic imaging instrumentsâ performance can be characterized and optimized by an analysis of their limit of detection (LoD). Here we report a systematic analysis of the LoD for Fourier transform IR (FT-IR) and discrete frequency IR (DFIR) imaging spectrometers. In addition to traditional measurements of sample and blank data, we propose a decision theory perspective to pose the determination of LoD as a binary classiï¬cation problem under different assumptions of noise uniformity and correlation. We also examine three spectral analysis approaches, namely absorbance at a single frequency, sum of absorbance over selected frequencies and total spectral distance â to suit instruments that acquire discrete or contiguous spectral bandwidths. The analysis is validated by reï¬ning the fabrication of a bovine serum albumin protein microarray to provide eight uniform spots from 2.8 nL of solution for each concentration over a wide range (0.05 -10 mg/mL). Using scanning parameters that are typical for each instrument, we estimate a LoD of 0.16 mg/mL and 0.12 mg/mL for wideï¬eld and line scanning FT-IR imaging systems, respectively, usingthespectraldistanceapproach,and0.22mg/mLand0.15mg/mL using an optimal set of discrete frequencies. As expected, averaging and the use of post-processing techniques such as minimum noise fraction (MNF) transformation results in LoDs as low as 0.075 mg/mL that correspond to a spotted protein mass of 112 fg/pixel. We emphasize that these measurements were conducted at typical imaging parameters for each instrument and can be improved using the usual trading rules of IR spectroscopy. This systematic analysis and methodology for determining the LoD can allow for quantitative measures of conï¬dence in imaging an analyteâs concentration and a basis for further improving IR imaging technology.

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NUMERICAL ANALYSIS OF FLOW BEHAVIOR IN GAS-LIQUID CYLINDRICAL CYCLONE (GLCC©*) SEPARATORS WITH INLET DESIGN MODIFICATIONS

Journal of Energy Resources Technology ◽

10.1115/1.4051423 ◽

2021 ◽

pp. 1-27

Author(s):

Srinivas Swaroop Kolla ◽

Ram S. Mohan ◽

Ovadia Shoham

Keyword(s):

Numerical Study ◽

Flow Behavior ◽

Low Cost ◽

Field Application ◽

Attractive Alternative ◽

Inlet Section ◽

Wide Range ◽

Cylindrical Cyclone ◽

Light Oil ◽

Section Design

Abstract The Gas-Liquid Cylindrical Cyclone (GLCC©*) is a simple, compact and low-cost separator, which provides an economically attractive alternative to conventional gravity-based separators over a wide range of applications. More than 6,500 GLCC©'s have been installed in the field to date around the world over the past 2 decades. The GLCC© inlet section design is a key parameter, which is crucial for its performance and proper operation. The flow behavior in the GLCC© body is highly dependent on the fluid velocities generated at the reduced area nozzle inlet. An earlier study (Kolla et al. [1]) recommended design modifications to the inlet section, based on safety and structural robustness. It is important to ensure that these proposed configuration modifications do not adversely affect the flow behavior at the inlet and the overall performance of the GLCC©. This paper presents a numerical study utilizing specific GLCC© field application working under 3 different case studies representing the flow entering the GLCC, separating light oil, steam flooded wells in Minas, Indonesia. Commercially available Computational Fluid Dynamics (CFD) software is utilized to analyze the hydrodynamics of flow with the proposed modifications of the inlet section for GLCC© field applications.

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Synthesis of photoreactive solvent-free acrylic pressure-sensitive adhesives in the recovered system

Polish Journal of Chemical Technology ◽

10.2478/v10026-007-0014-y ◽

2007 ◽

Vol 9 (2) ◽

pp. 5-9 ◽

Cited By ~ 4

Author(s):

Roland Milker ◽

Zbigniew Czech ◽

Marta Wesołowska

Keyword(s):

Organic Solvent ◽

Solvent Free ◽

The Novel ◽

Pressure Sensitive Adhesive ◽

Adhesive Film ◽

Pressure Sensitive Adhesives ◽

Pressure Sensitive ◽

Wide Range ◽

Protective Films ◽

New Type

Synthesis of photoreactive solvent-free acrylic pressure-sensitive adhesives in the recovered system The present paper discloses a novel photoreactive solvent-free acrylic pressure-sensitive adhesive (PSA) systems, especially suitable for the so much adhesive film applications as the double-sided, single-sided or carrier-free technical tapes, self-adhesive labels, protective films, marking and sign films and wide range of medical products. The novel photoreactive solvent-free pressure-sensitive adhesives contain no volatile organic compounds (residue monomers or organic solvent) and comply with the environment and legislation. The synthesis of this new type of acrylic PSA is conducted in common practice by solvent polymerisation. After the organic solvent are removed, there remains a non-volatile, solvent-free highly viscous material, which can be processed on a hot-melt coating machine at the temperatures of about 100 to 140°C.

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