442 results match your criteria high-κ polymer

Chemically Stable Hafnium-Based Metal-Organic Framework for Highly Efficient CH/CH Separation under Humid Conditions.

ACS Appl Mater Interfaces 2021 Apr 13. Epub 2021 Apr 13.

State Key Laboratory of Silicon Materials, Department of Materials Science & Engineering, Zhejiang University, Hangzhou 310027, China.

Realization of ethane-selective porous materials for efficient ethane/ethylene (CH/CH) separation is an important task in the petrochemical industry. Although a number of CH-selective adsorbents have been realized, their adsorption capacity and selectivity might be mostly dampened under humid conditions due to structure decomposition or co-adsorption of water vapor. A desired material should have simultaneously high CH uptake and selectivity, excellent water stability, and ultralow water adsorption uptake for industrial applications, but such a material is elusive. Read More

View Article and Full-Text PDF

Directed evolution of feruloyl esterase from Lactobacillus acidophilus and its application for ferulic acid production.

Bioresour Technol 2021 Mar 17;332:124967. Epub 2021 Mar 17.

Laboratory of Biomanufacturing and Food Engineering, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China.

Producing ferulic acid (FA) from the natural substrate with feruloyl esterase is promising in industries, screening and engineering new enzymes with high efficiency to increase the FA yield is of great concern. Here, the feruloyl esterase of Lactobacillus acidophilus (FAELac) was heterologous expressed and the FAELac with different oligomerization states was separated. Interestingly, the activity of dimer was 37-fold higher than high-polymer. Read More

View Article and Full-Text PDF

Phase behavior of polymer-nanorod composites: A comparative study using PRISM theory and molecular dynamics simulations.

J Chem Phys 2021 Mar;154(12):124903

Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.

Well-dispersed composites of polymer and nanorods have many emerging applications and, therefore, are an important area of research. Polymer reference interaction site model (PRISM) theory and molecular dynamics simulations have become powerful tools in the study of the structure and phase behavior of polymer nanocomposites. In this work, we employ both PRISM theory and molecular dynamics simulations to determine the structure and spinodal phase diagram of 1% volume fraction of nanorods in a polymer melt. Read More

View Article and Full-Text PDF

Investigating crystallization tendency, miscibility, and molecular interactions of drug-polymer systems for the development of amorphous solid dispersions.

Drug Dev Ind Pharm 2021 Mar 2:1-30. Epub 2021 Mar 2.

School of Pharmacy and Health Professions, Creighton University, Omaha, NE, USA.

Crystallization tendencies, thermal analysis [i.e. glass transition temperature ()], crystallinity, and melting point depression, along with theoretical calculations such as solubility parameter, of five different drugs [i. Read More

View Article and Full-Text PDF

Application of Response Surface Methodology and Box-Behnken Design for the Optimization of the Stability of Fibrous Dispersion Used in Drilling and Completion Operations.

ACS Omega 2021 Feb 24;6(4):2513-2525. Epub 2021 Jan 24.

Department of Petroleum and Geological Engineering, University of Oklahoma, 100E. Boyd Street, Norman, Oklahoma 73019, United States.

Fibers are extensively used as a fluid additive in the oil and gas industry to improve hole-cleaning performance, control fluid filtration loss, and enhance hydraulic fracturing effectiveness. Generally, a small amount of fiber is dispersed in the base fluid to achieve the desired results without increasing the viscosity of the base fluid. Nevertheless, sustaining a uniform fiber dispersion can be challenging under wellbore conditions, which is essential for fibers' functionality. Read More

View Article and Full-Text PDF
February 2021

Polyhydroxyalkanoate nanoparticles produced by marine bacteria cultivated on cost effective Mediterranean algal hydrolysate media.

J Biotechnol 2021 Feb 22;328:95-105. Epub 2021 Jan 22.

Department of Botany and Microbiology, Faculty of Science, Alexandria University, Egypt. Electronic address:

Algae are omnipresent in all seas and oceans, which make thema target for many applications such as bio-fertilizers, fish feeding and removal of heavy metals. In the present study, different algal species were examined as sustainable alternatives substrates for PHA production by Halomonas sp. Several media simulations were utilized to achieve high polymer productivity. Read More

View Article and Full-Text PDF
February 2021

Next generation polyphosphazene immunoadjuvant: Synthesis, self-assembly and in vivo potency with human papillomavirus VLPs-based vaccine.

Nanomedicine 2021 Jan 18;33:102359. Epub 2021 Jan 18.

Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, United States. Electronic address:

Poly[di(carboxylatomethylphenoxy)phosphazene] (PCMP), a new member of polyphosphazene immunoadjuvant family, is synthesized. In vitro assessment of a new macromolecule revealed hydrolytic degradation profile and immunostimulatory activity comparable to its clinical stage homologue PCPP; however, PCMP was characterized by a beneficial reduced sensitivity to the ionic environment. In vivo evaluation of PCMP potency was conducted with human papillomavirus (HPV) virus-like particles (VLPs) based RG1-VLPs vaccine. Read More

View Article and Full-Text PDF
January 2021

Sintering Process Optimization for 3YSZ Ceramic 3D-Printed Objects Manufactured by Stereolithography.

Nanomaterials (Basel) 2021 Jan 14;11(1). Epub 2021 Jan 14.

Energy & Environmental Division, Korea Institute of Ceramic Engineering and Technology, 101, Soho-ro, Jinju 52851, Korea.

A 3YSZ (3 mol% yttria-stabilized zirconia) ceramic green body with 50 vol% of ceramic content was 3D-printed by supportless stereolithography under optimal drying, debinding, and sintering conditions in order to achieve high strength and density. The viscosity and flowability of the ceramic nanocomposite resins were optimized by adjusting the amounts of non-reactive diluents. The ceramic 3D-printed objects have a high polymer content compared to ceramics samples manufactured by conventional manufacturing processes, and the attraction between layers is weak because of the layer-by-layer additive method. Read More

View Article and Full-Text PDF
January 2021

Stratification of polymer-colloid mixtures via fast nonequilibrium evaporation.

Soft Matter 2020 Dec 14;16(45):10326-10333. Epub 2020 Oct 14.

Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.

In drying liquid films of polymer-colloid mixtures, stratification in which polymers are placed on top of larger colloids is studied. It is often presumed that the formation of segregated polymer-colloid layers is solely due to the proportion in size at fast evaporation as in binary colloid mixtures. By comparing experiments with a theoretical model, we found that the transition in viscosity near the drying interface was another important parameter for controlling the formation of stratified layers in polymer-colloid mixtures. Read More

View Article and Full-Text PDF
December 2020

Impact of polymer type, ASD loading and polymer-drug ratio on ASD tablet disintegration and drug release.

Int J Pharm 2021 Jan 12;592:120087. Epub 2020 Nov 12.

Small Molecule Pharmaceutical Sciences, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA. Electronic address:

Amorphous solid dispersion (ASD) has become an attractive strategy to enhance solubility and bioavailability of poorly water-soluble drugs. To facilitate oral administration, ASDs are commonly incorporated into tablets. Disintegration and drug release from ASD tablets are thus critical for achieving the inherent solubility advantage of amorphous drugs. Read More

View Article and Full-Text PDF
January 2021

Antimicrobial and anti-inflammatory thermo-reversible hydrogel for periodontal delivery.

Acta Biomater 2020 10 13;116:259-267. Epub 2020 Sep 13.

Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Department of Dentistry - Biomaterials, Philips van Leydenlaan 25, 6525 EX Nijmegen, the Netherlands. Electronic address:

In periodontal treatment, topical adjunctive therapy with antimicrobials or anti-inflammatory agents is frequently applied. However, currently available drug carrier biomaterials often exhibit poor perfusion into small crevices, such as the deep and irregular periodontal pockets, due to relatively high viscosity. Moreover, high polymer concentrations of the polymer can potentially be cytotoxic upon confined local administration. Read More

View Article and Full-Text PDF
October 2020

Screening lengths and osmotic compressibility of flexible polyelectrolytes in excess salt solutions.

Soft Matter 2020 Aug 15;16(31):7289-7298. Epub 2020 Jul 15.

Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany.

We report results of small angle neutron scattering measurements made on sodium polystyrene sulfonate in aqueous salt solutions. The correlation length (ξ) and osmotic compressibility are measured as a function of polymer (c) and added salt (c) concentrations, and the results are compared with scaling predictions and the random-phase approximation (RPA). In Dobrynin et al. Read More

View Article and Full-Text PDF

Formulation of polyphthalaldehyde microcapsules for immediate UV-light triggered release.

J Colloid Interface Sci 2020 Nov 23;579:645-653. Epub 2020 Jun 23.

Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, Sweden. Electronic address:

Triggered release from responsive drug reservoirs activated by remote stimuli is desired in a range of fields. Critical bottlenecks are cost-efficient formulation avenues applicable for industrial scale-up, viable triggers and immediate release rather than continuous release upon activation. UV-sensitive microcapsules based on self-immolating polymers in combination with thin shells and morphological weak spots should allow for immediate triggered release. Read More

View Article and Full-Text PDF
November 2020

A General Protocol for Electrospun Non-Woven Fabrics of Dialdehyde Cellulose and Poly(Vinyl Alcohol).

Nanomaterials (Basel) 2020 Apr 2;10(4). Epub 2020 Apr 2.

Division of Chemistry of Renewable Resources, Department of Chemistry, University of Natural Resources and Life Sciences, Tulln, Konrad-Lorenz Straße 24, 3430 Tulln, Austria.

In the past two decades, research on electrospinning has boomed due to its advantages of simple process, small fiber diameter, and special physical and chemical properties. The electrospun fibers are collected in a non-woven state in most cases (electrospun non-woven fabrics, ESNWs), which renders the electrospinning method an optimum approach for non-woven fabric manufacturing on the nano-scale. The present study establishes a convenient preparation procedure for converting water-soluble dialdehyde cellulose (DAC) into DAC-based electrospun non-woven fabrics (ESNWs) reinforced with poly(vinyl alcohol) (PVA). Read More

View Article and Full-Text PDF

Electrospinning and Post-Spun Chain Conformations of Synthetic, Hydrophobic Poly(-amino acid)s.

Polymers (Basel) 2020 Feb 4;12(2). Epub 2020 Feb 4.

Division of Synthetic Polymers, Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Tokida 3-15-1, Ueda 386-8567, Japan.

Electrospinning and post-spun conformations of hydrophobic poly(-amino acid)s are described in this study. The poly(-amino acid)s, poly(Gly), poly(L-Ala), poly(L-Val), and poly(L-Leu) were synthesized via corresponding -carboxy--amino acid anhydrides. The average molecular weight and degree of polymerization of these polymers were determined by -terminus labeling using 2,4-dinitrofluorobenzene and by viscometry in the case of poly(Gly). Read More

View Article and Full-Text PDF
February 2020

UV-Triggered On-Demand Temperature-Responsive Reversible and Irreversible Gelation of Cellulose Nanocrystals.

Biomacromolecules 2020 02 28;21(2):830-838. Epub 2020 Jan 28.

Department of Applied Physics , Aalto University School of Science , P. O. Box 15100, Espoo FI-00076 , Finland.

We show ionically cross-linked, temperature-responsive reversible or irreversible hydrogels of anionic cellulose nanocrystals (CNCs) and methacrylate terpolymers by mixing them homogeneously in the initially charge-neutral state of the polymer, which was subsequently switched to be cationic by cleaving side groups by UV irradiation. The polymer is a random terpolymer poly(di(ethylene glycol) methyl ether methacrylate)--poly(oligo(ethylene glycol) methyl ether methacrylate)--poly(2-((2-nitrobenzyl)oxycarbonyl)aminoethyl methacrylate), that is, PDEGMA--POEGMA--PNBOCAEMA. The PDEGMA and POEGMA repeating units lead to a lower critical solution temperature (LCST) behavior. Read More

View Article and Full-Text PDF
February 2020

Improvement of Rice Husk/HDPE Bio-Composites Interfacial properties by Silane Coupling Agent and Compatibilizer Complementary Modification.

Polymers (Basel) 2019 Nov 22;11(12). Epub 2019 Nov 22.

MOE Key Laboratory of Wooden Material Science and Application, Beijing Forestry University, Beijing 100083, China.

Composites using agricultural and forestry residues as raw materials with potentially high-performance, multifunctional and biodegradable ecological advantages, are viewed as very promising for new-generation lightweight and low-cost bio-based sustainable building materials. At present, the research on wood-plastic composite materials is relatively mature. However, it is still a challenge to effectively use other biomass and improve the interface of the high-polymer compound system. Read More

View Article and Full-Text PDF
November 2019

Revealing Adsorption Behaviors of Amphoteric Polyacrylamide on Cellulose Fibers and Impact on Dry Strength of Fiber Networks.

Polymers (Basel) 2019 Nov 15;11(11). Epub 2019 Nov 15.

Department of Chemical Engineering, University of New Brunswick, Fredericton, NB E3B 5A3, Canada.

Amphoteric polyacrylamide (AmPAM) has been widely used in a variety of industrial areas and the adsorption behavior of AmPAM plays a crucial role in its applications. In this study, a series of AmPAMs with various molecular weights (MW) were synthesized; and their impact on dry strength of fiber networks or paper was assessed. The results showed that the optimal MW of AmPAM for strength enhancement ranged between 300 and 500 k. Read More

View Article and Full-Text PDF
November 2019

Effect of Polymer Permeability and Solvent Removal Rate on Forming Implants: Drug Burst Release and Microstructure.

Pharmaceutics 2019 Oct 10;11(10). Epub 2019 Oct 10.

Department of Pharmaceutics, School of Pharmacy, China Medical University, Liaoning 110122, China.

To explore the mechanism of drug release and depot formation of in situ forming implants (ISFIs), osthole-loaded ISFIs were prepared by dissolving polylactide, poly(lactide--glycolide), polycaprolactone, or poly(trimethylene carbonate) in different organic solvents, including -methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), and triacetin (TA). Drug release, polymer degradation, solvent removal rate and depot microstructure were examined. The burst release effect could be reduced by using solvents exhibit slow forming phase inversion and less permeable polymers. Read More

View Article and Full-Text PDF
October 2019

Mechanistic Insights into the Effect of Polymer Regioregularity on the Thermal Stability of Polymer Solar Cells.

ACS Appl Mater Interfaces 2019 Oct 21;11(43):40310-40319. Epub 2019 Oct 21.

Institute of Nuclear Energy Research , Longtan, Taoyaun 32546 , Taiwan.

Thermal stability is a bottleneck toward commercialization of polymer solar cells (PSCs). The effect of PCBM aggregation on a multilength scale on the bulk-heterojunction (BHJ) structure, performance, and thermal stability of PSCs is studied here by grazing-incidence small- and wide-angle X-ray scattering. The evolution of hierarchical BHJ structures of a blend film tuned by regioregularity of polymers from the as-cast state to the thermally unstable state is systematically investigated. Read More

View Article and Full-Text PDF
October 2019

Acoustically responsive polydopamine nanodroplets: A novel theranostic agent.

Ultrason Sonochem 2020 Jan 6;60:104782. Epub 2019 Sep 6.

Institute of Biomedical Engineering, Old Road Campus Research Building, University of Oxford, Oxford OX3 7DQ, UK; Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, China; School of Chemistry, Clayton Campus, Monash University Victoria, 3800, Australia. Electronic address:

Ultrasound-induced cavitation has been used as a tool of enhancing extravasation and tissue penetration of anticancer agents in tumours. Initiating cavitation in tissue however, requires high acoustic intensities that are neither safe nor easy to achieve with current clinical systems. The use of cavitation nuclei can however lower the acoustic intensities required to initiate cavitation and the resulting bio-effects in situ. Read More

View Article and Full-Text PDF
January 2020

Influence of Nanopillar Arrays on Fibroblast Motility, Adhesion, and Migration Mechanisms.

Small 2019 10 29;15(43):e1902514. Epub 2019 Aug 29.

Department of Physics, Norwegian University of Science and Technology (NTNU), 7491, Trondheim, Norway.

Surfaces decorated with high aspect ratio nanostructures are a promising tool to study cellular processes and design novel devices to control cellular behavior. However, little is known about the dynamics of cellular phenomenon such as adhesion, spreading, and migration on such surfaces. In particular, how these are influenced by the surface properties. Read More

View Article and Full-Text PDF
October 2019

Insight into the Dissolution Molecular Mechanism of Ternary Solid Dispersions by Combined Experiments and Molecular Simulations.

AAPS PharmSciTech 2019 Aug 5;20(7):274. Epub 2019 Aug 5.

State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese, Medical Sciences (ICMS), University of Macau, Macau, China.

With the increase concern of solubilization for insoluble drug, ternary solid dispersion (SD) formulations developed more rapidly than binary systems. However, rational formulation design of ternary systems and their dissolution molecular mechanism were still under development. Current research aimed to develop the effective ternary formulations and investigate their molecular mechanism by integrated experimental and modeling techniques. Read More

View Article and Full-Text PDF

[Advances on the study of movable artificial vertebral body].

Zhongguo Gu Shang 2019 Jul;32(7):677-682

The Second Department of Orthopaedics, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi, China;

At present, artificial vertebral implants have proven to be effective in the treatment of spinal tumors, infections, fractures and other diseases. However, the fusion artificial vertebral body can cause adjacent intervertebral joint degeneration and loss of original physiological curvature and activity. The movable artificial vertebral body can, to some extent, restore the normal physiological movement and reduce biomechanical changes of the spine, reducing the occurrence of complication. Read More

View Article and Full-Text PDF

High Polymer Mass Densities at the Mouths of Carbon Nanotubes (CNTs) Control the Diffusion of Small Molecules through CNT-Based Polymer Nanocomposite Membranes.

J Phys Chem B 2019 08 30;123(31):6892-6900. Epub 2019 Jul 30.

Department of Chemical Engineering , University of Patras & FORTH/ICE-HT , Patras GR 26504 , Greece.

Detailed molecular dynamics (MD) simulations of model single-walled carbon nanotube (CNT) membranes based on atactic poly(methyl methacrylate) (aPMMA) indicate that PMMA chains significantly penetrate nanotubes through their faces. They predict very high-density values of the polymer in the interfacial area around the CNT mouths that can exceed by 50% the density of the bulk polymer at the same thermodynamic conditions. This dramatically decreases the diffusivity of relatively small penetrants (in our study, water molecules) in the nanocomposite membrane, because of the exceedingly long times needed by these small molecules to diffuse through such a dense interfacial layer before accessing the interior of the nanotubes where they can travel really fast. Read More

View Article and Full-Text PDF

Mapping the phase behavior of coacervate-driven self-assembly in diblock copolyelectrolytes.

Soft Matter 2019 Jun;15(25):5116-5127

Department of Chemical and Biomolecular Engineering, 600 S. Mathews Ave., Urbana, IL, USA.

Oppositely-charged polymers can undergo an associative phase separation process known as complex coacervation, which is driven by the electrostatic attraction between the two polymer species. This driving force for phase separation can be harnessed to drive self-assembly, via pairs of block copolyelectrolytes with opposite charge and thus favorable coulombic interactions. There are few predictions of coacervate self-assembly phase behavior due to the wide variety of molecular and environmental parameters, along with fundamental theoretical challenges. Read More

View Article and Full-Text PDF

Three-dimensional simulations of undulatory and amoeboid swimmers in viscoelastic fluids.

Soft Matter 2019 Jun;15(24):4836-4855

Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA.

Microorganisms often move through viscoelastic environments, as biological fluids frequently have a rich microstructure owing to the presence of large polymeric molecules. Research on the effect of fluid elasticity on the swimming kinematics of these organisms has usually been focused on those that move via cilia or flagellum. Experimentally, Shen (X. Read More

View Article and Full-Text PDF

High Dielectric Constant and Low Dielectric Loss via Poly(vinyl alcohol)/TiCT MXene Nanocomposites.

ACS Appl Mater Interfaces 2019 May 7;11(20):18599-18608. Epub 2019 May 7.

Department of Chemical and Petroleum Engineering , University of Calgary , 2500 University Dr NW , Calgary T2N 1N4 , Canada.

As a new class of two-dimensional materials, the MXene family has triggered attention because of its unique electrical and mechanical properties. MXene's excellent electrical conductivity and hydrophilicity make it an ideal option for polymer nanocomposite fabrication. For the first time, polymer nanocomposites of polyvinyl alcohol (PVA)/TiCT (MXene) were used for charge storage applications in the X-band frequency range (8. Read More

View Article and Full-Text PDF

Determination of Micro-Quantities of DNA Using DNAse and Fluorescence of Hoechst 33258 and Light-Scattering.

J Fluoresc 2019 Mar 27;29(2):479-484. Epub 2019 Feb 27.

Institute of Cell Biophysics of PSC of RAS, Pushchino, Moscow Region, Russian Federation, 142290.

The DNA hydrolysis by deoxyribonuclease (DNAse I) in aqueous solution was studied, using fluorescence spectroscopy and high-sensitive light-scattering detection. Specific hydrolysis of high-polymer DNA or fragmented DNA by the enzyme led to a strong decrease in the fluorescence of the Hoechst dye. The hydrolysis of mitochondrial DNA was accompanied by a decrease in the fluorescence of the dye only in 1. Read More

View Article and Full-Text PDF

Creating a synthetic platform for the encapsulation of nanocrystals with covalently bound polymer shells.

Nanoscale 2019 Mar 13;11(9):3847-3854. Epub 2019 Feb 13.

Institute of Physical Chemistry, Fraunhofer CAN, Grindelallee 117, 20146 Hamburg, Germany.

We present a platform for the encapsulation of superparamagnetic iron oxide nanocrystals (SPIONs) with a highly stable diblock copolymer shell allowing a homogeneous dispersion of the nanocrystals into a polymer matrix in the resulting nanocomposites. High polymer shell stability was achieved by crosslinking the inner polydiene shell for example in a persulfate based redox process. The advantage of this crosslinking reaction is the avoidance of heat and UV light for the initiation, making it suitable for heat or UV sensitive systems. Read More

View Article and Full-Text PDF