108,550 results match your criteria films supramolecular

Biodegradation of bisphenol-A polycarbonate plastic by Pseudoxanthomonas sp. strain NyZ600.

J Hazard Mater 2021 Mar 31;416:125775. Epub 2021 Mar 31.

State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address:

Bisphenol-A polycarbonate (PC) is a widely used engineering thermoplastic and its release has caused damage to the ecosystem. Microbial degradation of plastic represents a sustainable approach for PC reduction. In this study, a bacterial strain designated Pseudoxanthomonas sp. Read More

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Preparation and characterization of cross-linked starch nanocrystals and self-reinforced starch-based nanocomposite films.

Int J Biol Macromol 2021 Apr 7. Epub 2021 Apr 7.

College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China. Electronic address:

In this study, starch-based nanocomposite films reinforced by cross-linked starch nanocrystals (CSNCs) were successfully prepared. CSNCs were obtained by cross-linking reaction between starch nanocrystals (SNCs) and sodium hexametaphosphate (SHMP). Through the characterization and comparison of SNCs and CSNCs in microscopic morphology, degree of substitution, swelling degree, XRD spectrum, and FTIR spectrum, the successful progress of the cross-linking reaction was confirmed. Read More

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A robotic system for spine surgery positioning and pedicle screw placement.

Int J Med Robot 2021 Apr 9. Epub 2021 Apr 9.

School of Mechanical Engineering and Automation, Beihang University, Beijing, China.

Background: In recent years, surgeons have explored minimally invasive methods of percutaneous pedicle screw implantation, which can effectively reduce human injury. This paper presents an accurate and efficient positioning method and robot system for percutaneous needle placement under c-arm fluoroscopy.

Methods: A simple five degree of freedom (DOF) robot with an unique end-effector is designed to perform perspective calibration and image space registration. Read More

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Rapidly deployable and morphable 3D mesostructures with applications in multimodal biomedical devices.

Proc Natl Acad Sci U S A 2021 Mar;118(11)

Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208;

Structures that significantly and rapidly change their shapes and sizes upon external stimuli have widespread applications in a diversity of areas. The ability to miniaturize these deployable and morphable structures is essential for applications in fields that require high-spatial resolution or minimal invasiveness, such as biomechanics sensing, surgery, and biopsy. Despite intensive studies on the actuation mechanisms and material/structure strategies, it remains challenging to realize deployable and morphable structures in high-performance inorganic materials at small scales (e. Read More

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Magneto-optical effects in hyperbolic metamaterials based on ordered arrays of bisegmented gold/nickel nanorods.

Nanotechnology 2021 Apr 9. Epub 2021 Apr 9.

Physics, Moscow State University, Moskva, RUSSIAN FEDERATION.

Hyperbolic metamaterials (HMM) based on multilayered metal/dielectric films or ordered arrays of metal nanorods in dielectric matrix are extremely attractive optical materials for manipulating over the parameters of the light flow. One of the most promising tools for tuning the optical properties of metamaterials in situ is application of external magnetic field. However, for the case of HMM based on the ordered arrays of magneto-plasmonic nanostructures, this effect has not been clearly demonstrated up to now. Read More

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Antioxidant films and coatings based on starch and phenolics from Spondias purpurea L.

Int J Biol Macromol 2021 Apr 6. Epub 2021 Apr 6.

Laboratory of Polymers and Materials Innovation, Department of Organic and Inorganic Chemistry, Sciences Center, Federal University of Ceará, Campus of Pici, 60440-900 Fortaleza, CE, Brazil. Electronic address:

The objective of this study was to prepare, for the first time, active films and coatings from fruit starch (SPFS) and phenolic stem bark extract (SBPE) from Spondias purpurea L. Starch film formulations were prepared with different SBPE contents (5-20 wt% on starch), then cast and dried into films. SBPE showed higher antioxidant activity and antimicrobial activity against both Gram-negative and Gram-positive bacteria. Read More

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Chitosan derivatives-based films as pH-sensitive drug delivery systems with enhanced antioxidant and antibacterial properties.

Int J Biol Macromol 2021 Apr 6. Epub 2021 Apr 6.

Laboratory of Enzyme Engineering and Microbiology, National School of Engineering of Sfax (ENIS), University of Sfax, P.O. Box 1173, Sfax 3038, Tunisia; Department of Life Sciences, Faculty of Science of Gabes, Omar Ibn Khattab Street, Gabes 6029, Tunisia. Electronic address:

The purpose of this study was to develop and characterize chitosan (Ch)-based films incorporated with varying molecular weight (Mw) and acetylation degree (AD) chitosan-depolymerization-products (CDP), to be applied as drug delivery materials. As compared to Ch-film, optical and antioxidant potentials of Ch/CDP-based films were improved, particularly using low Mw and AD-CDP. Whereas, films water resistance, mechanical and antibacterial properties increased as CDP-Mw increased and AD decreased. Read More

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Properties of degradable polyhydroxyalkanoates with different monomer compositions.

Int J Biol Macromol 2021 Apr 6. Epub 2021 Apr 6.

Siberian Federal University, 79 Svobodnyi av., Krasnoyarsk 660041, Russia; Institute of Biophysics SB RAS, Federal Research Center "Krasnoyarsk Science Center SB RAS", 50/50Akademgorodok, Krasnoyarsk 660036, Russia.

Purpose: To synthesize and investigate polyhydroxyalkanoates (PHAs) with different monomer composition and percentages and polymer films prepared from them.

Results: Various PHAs: homopolymer poly-3-hydroxybutyrate P(3HB) and 2-, 3-, and 4-component copolymers comprising various combinations of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), 4-hydroxybutyrate (4HB), and 3-hydroxyhexanoate (3HHx) monomers were synthesized under specialized conditions. Relationships were found between the monomer composition of PHAs and their molecular-weight and thermal properties and degree of crystallinity. Read More

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Tuning J-aggregate Formation and Emission Efficiency in Cationic Diazapentacenium Dyes.

Chemistry 2021 Apr 9. Epub 2021 Apr 9.

University of Coimbra, Chemistry Department, Rua larga, 3004 535, Coimbra, PORTUGAL.

Enhancement of the luminescence efficiency of two new diazapentacenium salts ( D1 and D2 ) of more than 55 for D1 and 22 times for D2 ) in poor solvents, acetonitrile and/or dichloromethane, was observed and rationalized as formation of emissive J-aggregates. Both compounds displaying 4- n -decylphenyl substituents at the 7,14-carbons and phenyl ( D1 ) or 2,6-difluorophenyl ( D2 ) substituents at the quaternary nitrogens in 5,12-positions have been synthetized in a two-step procedure involving a two-fold Buchwald-Hartwig-type CN cross-coupling and an electrophilic Friedel-Crafts-type cyclization. The optical properties of the dicationic diazapentacenium salts in various solvents and in thin films have been investigated by steady-state and time-resolved absorption and photoluminescence spectroscopies. Read More

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Fragile-Tough Mechanical Reversion of Silk Materials via Tuning Supramolecular Assembly.

ACS Biomater Sci Eng 2021 Apr 9. Epub 2021 Apr 9.

Department of Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States.

Regenerated silk nanofibers are interesting as protein-based material building blocks due to their unique structure and biological origin. Here, a new strategy based on control of supramolecular assembly was developed to regulate interactions among silk nanofibers by changing the solvent, achieving tough mechanical features for silk films. Formic acid was used to replace water related to charge repulsion of silk nanofibers in solution, inducing interactions among the nanofibers. Read More

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Influence of Anionic Surfactants on the Fundamental Properties of Polymer/Reduced Graphene Oxide Nanocomposite Films.

ACS Appl Mater Interfaces 2021 Apr 9. Epub 2021 Apr 9.

Cluster for Advanced Macromolecular Design (CAMD), School of Chemical Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia.

Surfactants are frequently employed in the fabrication of polymer/graphene-based nanocomposites via emulsion techniques. However, the impact of surfactants on the electrical and mechanical properties of such nanocomposite films remains to be explored. We have systematically studied the impact of two anionic surfactants [sodium dodecyl sulfate (SDS) and sodium dodecyl benzene sulfonate (SDBS)] on intrinsic properties of the nanocomposite films comprising reduced graphene oxide in a matrix of poly(styrene---butyl acrylate). Read More

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BSA/Silver Nanoparticle-Loaded Hydrogel Film for Local Photothermal Treatment of Skin Cancer.

Pharm Res 2021 Apr 9. Epub 2021 Apr 9.

College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, 501 Jinju Daero, Jinju, Gyeongnam, 52828, Republic of Korea.

Purpose: To develop a hydrogel film containing bovine serum albumin (BSA)-coated silver nanoparticles (BSA/AgNP) and evaluate its applicability for topical photothermal treatment (PTT) of skin cancer.

Methods: BSA/AgNP-loaded hydrogel films were prepared and their swelling, bioadhesive, mechanical, and photothermal properties were characterized in vitro and in vivo.

Results: The synthesized BSA/AgNP exhibited a narrow size distribution with good size stability and, notably, possessed great photothermal activity that could stably maintain through repetitive laser irradiation. Read More

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Printing Methods in the Production of Orodispersible Films.

AAPS PharmSciTech 2021 Apr 9;22(3):129. Epub 2021 Apr 9.

Department of Pharmaceutics, JSS College of Pharmacy, JSS Academy of Higher Education and Research (JSSAHER), Sri Shivarathreeshwara Nagar, Mysore, 570 015, India.

Orodispersible film (ODF) formulations are promising and progressive drug delivery systems that are widely accepted by subjects across all the age groups. They are traditionally fabricated using the most popular yet conventional method called solvent casting method. The most modern and evolving method is based on printing technologies and such printed products are generally termed as printed orodispersible films (POFs). Read More

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Synthesis of Polymer Brushes Via SI-PET-RAFT for Photodynamic Inactivation of Bacteria.

Macromol Rapid Commun 2021 Apr 8:e2100106. Epub 2021 Apr 8.

School of Chemical Engineering, Australian Centre for NanoMedicine, Cluster for Advanced Macromolecular Design, The University of New South Wales, Sydney, New South Wales, 2052, Australia.

Biofilms are a persistent issue in healthcare and industry. Once formed, the eradication of biofilms is challenging as the extracellular polymeric matrix provides protection against harsh environmental conditions and physically enhances resistance to antimicrobials. The fabrication of polymer brush coatings provides a versatile approach to modify the surface to resist the formation of biofilms. Read More

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Microscopic evidence of strong interactions between chemical vapor deposited 2D MoS film and SiO growth template.

Nano Converg 2021 Apr 9;8(1):11. Epub 2021 Apr 9.

Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Republic of Korea.

Two-dimensional MoS film can grow on oxide substrates including AlO and SiO. However, it cannot grow usually on non-oxide substrates such as a bare Si wafer using chemical vapor deposition. To address this issue, we prepared as-synthesized and transferred MoS (AS-MoS and TR-MoS) films on SiO/Si substrates and studied the effect of the SiO layer on the atomic and electronic structure of the MoS films using spherical aberration-corrected scanning transition electron microscopy (STEM) and electron energy loss spectroscopy (EELS). Read More

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Magnetically switchable soft suction grippers.

Extreme Mech Lett 2021 Apr 5;44:101263. Epub 2021 Mar 5.

Faculty of Medicine and Health Technology, Tampere University, 33720 Tampere, Finland.

Grasping is one of the key tasks for robots. Gripping fragile and complex three-dimensional (3D) objects without applying excessive contact forces has been a challenge for traditional rigid robot grippers. To solve this challenge, soft robotic grippers have been recently proposed for applying small forces and for conforming to complex 3D object shapes passively and easily. Read More

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Nanoscaled ZnO films used as enhanced substrates for fluorescence detection of dyes.

Chin Phys B 2012 Mar;21(3)

Department of Physics, University of Science and Technology of China, Hefei 230026, China.

The ability of nanoscaled ZnO films to enhance fluorescence was studied. We found that the fluorescence intensities of Cy5, rhodamine 6G, and fluorescein can be enhanced about 10-fold on nanoscaled ZnO films as compared to that on glass substrates. The lifetimes of all samples were measured, and no obvious change in lifetime was observed for dyes on different substrates. Read More

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Polymorphism and structure formation in copper phthalocyanine thin films.

J Appl Crystallogr 2021 Feb 1;54(Pt 1):203-210. Epub 2021 Feb 1.

Institute for Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.

Many polymorphic crystal structures of copper phthalocyanine (CuPc) have been reported over the past few decades, but despite its manifold applicability, the structure of the frequently mentioned α polymorph remained unclear. The base-centered unit cell (space group 2/) suggested in 1966 was ruled out in 2003 and was replaced by a primitive triclinic unit cell (space group 1). This study proves unequivocally that both α structures coexist in vacuum-deposited CuPc thin films on native silicon oxide by reciprocal space mapping using synchrotron radiation in grazing incidence. Read More

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February 2021

Grain-boundary segregation of magnesium in doped cuprous oxide and impact on electrical transport properties.

Sci Rep 2021 Apr 8;11(1):7788. Epub 2021 Apr 8.

Département de Physique, CESAM/Q-MAT, SPIN, Université de Liège, 4000, Liège, Belgium.

In this study, we report the segregation of magnesium in the grain boundaries of magnesium-doped cuprous oxide (CuO:Mg) thin films as revealed by atom probe tomography and the consequences of the dopant presence on the temperature-dependent Hall effect properties. The incorporation of magnesium as a divalent cation was achieved by aerosol-assisted metal organic chemical vapour deposition, followed by thermal treatments under oxidizing conditions. We observe that, in comparison with intrinsic cuprous oxide, the electronic transport is improved in CuO:Mg with a reduction of resistivity to 13. Read More

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Seeded 2D epitaxy of large-area single-crystal films of the van der Waals semiconductor 2H MoTe.

Science 2021 Apr;372(6538):195-200

State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China.

The integration of two-dimensional (2D) van der Waals semiconductors into silicon electronics technology will require the production of large-scale, uniform, and highly crystalline films. We report a route for synthesizing wafer-scale single-crystalline 2H molybdenum ditelluride (MoTe) semiconductors on an amorphous insulating substrate. In-plane 2D-epitaxy growth by tellurizing was triggered from a deliberately implanted single seed crystal. Read More

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Hyperspectral interference tomography of nacre.

Proc Natl Acad Sci U S A 2021 Apr;118(15)

Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI 53706;

Structural characterization of biologically formed materials is essential for understanding biological phenomena and their enviro-nment, and for generating new bio-inspired engineering concepts. For example, nacre-the inner lining of some mollusk shells-encodes local environmental conditions throughout its formation and has exceptional strength due to its nanoscale brick-and-mortar structure. This layered structure, comprising alternating transparent aragonite (CaCO) tablets and thinner organic polymer layers, also results in stunning interference colors. Read More

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Role of support in tuning the properties of single atom catalysts: Cu, Ag, Au, Ni, Pd, and Pt adsorption on SiO/Ru, SiO/Pt, and SiO/Si ultrathin films.

J Chem Phys 2021 Apr;154(13):134706

Dipartimento di Scienza dei Materiali, Università degli Studi Milano-Bicocca, via R. Cozzi, 55-20125 Milano, Italy.

The role of the support in tuning the properties of transition metal (TM) atoms is studied by means of density functional theory calculations. We have considered the adsorption of Cu, Ag, Au, Ni, Pd, and Pt atoms on crystalline silica bilayers, either free-standing or supported on Ru(0001) and Pt(111) metal surfaces. These systems have been compared with an hydroxylated SiO/Si(100) film simulating the native oxide formed on a silicon wafer. Read More

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Six years of solar UV-B manipulations affect growth of Sphagnum and vascular plants in a Tierra del Fuego peatland.

New Phytol 2003 Nov;160(2):379-389

The Ecology Center, Utah State University, Logan, UT 84322-5205, USA.

•  Tierra del Fuego is subject to increases in solar UV-B radiation in the austral spring and summer due to ozone depletion. •  Plastic films were used to filter solar UV-B radiation over peatland plots through six field seasons, resulting in near-ambient (c. 90%) and reduced (c. Read More

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November 2003

Enhanced crystallization of solution-processed perovskite using urea as an additive for large-grain MAPbI3 perovskite solar cells.

Nanotechnology 2021 Apr 8. Epub 2021 Apr 8.

Renmin University of China, Beijing, 100872, CHINA.

The perovskite crystal quality plays an important role in perovskite solar cells, given that multiple grain boundaries and trap states in the perovskite films hamper further enhancement in the solar cell efficiency. Using the solution method to prepare perovskite films with large grains and high coverage requires further improvements. Herein, we introduce Lewis base urea as an additive into the precursor of perovskite to control the crystallization dynamics, allowing for large-grain crystal growth. Read More

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Spiropyran-based photoswitchable acrylic nanofibers: A stimuli-responsive substrate for light controlled C6 glioma cells attachment/detachment.

Colloids Surf B Biointerfaces 2021 Apr 1;203:111731. Epub 2021 Apr 1.

Polymer Science Department, Iran Polymer & Petrochemical Institute, P.O. Box: 14965/115, 14977-13115 Tehran, Iran. Electronic address:

Reversible and remote cell manipulation with high spatiotemporal precision is now a highly attractive subject in various biological applications such as tissue engineering and cell-matrix interaction. Herein, photoresponsive poly(methyl methacrylate-co-hydroxy ethyl methacrylate-co-spiropyran ethyl acrylate) terpolymer (MHSP) was prepared using emulsion polymerization and the corresponding nanofibers (MHSP@NF) and film (MHSP@F) were prepared using electrospinning and drop-casting techniques, respectively. Structure of MHSP@NF with cylindrical cross-section and uniform diameter size of 169 nm were characterized by H-NMR and SEM analyses. Read More

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Monitoring the infection process of Rhizopus stolonifer on strawberry fruit during storage using films based on chitosan/polyvinyl alcohol/polyvinylpyrrolidone and plant extracts.

Int J Biol Macromol 2021 Apr 5. Epub 2021 Apr 5.

Biotechnology, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Colonia Vicentina, México D. F. 09340, Mexico.

Different formulations based on nanoparticles of chitosan-plant extracts were evaluated to detect the infection process from the earliest stage of the fungus Rhizopus stolonifer on strawberry fruit during storage. Chitosan/polyvinyl alcohol (Ch/PVA) and chitosan/polyvinylpyrrolidone (Ch/PVP) films enriched with nanoparticles (NPs) of chitosan blended with plant extracts were prepared. They were placed inside a plastic package containing inoculated fruits and stored at 25 °C for 72 h. Read More

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Excess Polymer in Single-Walled Carbon Nanotube Thin-Film Transistors: Its Removal Prior to Fabrication Is Unnecessary.

ACS Nano 2021 Apr 8. Epub 2021 Apr 8.

Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur, Ottawa, Ontario, Canada K1N 6N5.

Ultrapure semiconducting single-walled carbon nanotube (sc-SWNT) dispersions produced through conjugated polymer sorting are ideal candidates for the fabrication of solution-processed organic electronic devices on a commercial scale. Protocols for sorting and dispersing ultrapure sc-SWNTs with conjugated polymers for thin-film transistor (TFT) applications have been well refined. Conventional wisdom dictates that removal of excess unbound polymer through filtration or centrifugation is necessary to produce high-performance TFTs. Read More

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The Unusual Photochromic and Hydrochromic Switching Behavior of Cellulose-Embedded 1,8-Naphthalimide-Viologen Derivatives in the Solid-State.

Chemistry 2021 Apr 8. Epub 2021 Apr 8.

Northwestern University, Department of Chemistry, 2145 Sheridan Rd., 60208, Evanston, UNITED STATES.

Stimuli-responsive chromic materials such as photochromes, hydrochromes, thermochromes, and electrochromes have a long history of capturing the attention of scientists due to their potential industrial applications and novelty in popular culture. However, hybrid chromic materials that combine two or more stimuli-triggered color changing properties are not so well known. Herein, we report a design strategy that has led to a series of emissive 1,8-naphthalimide-viologen dyads which exhibit unusual dual photochromic and hydrochromic switching behavior in the solid-state when embedded in a cellulose matrix. Read More

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A computational lens into how music characterizes genre in film.

PLoS One 2021 8;16(4):e0249957. Epub 2021 Apr 8.

Department of Computer Science, University of Southern California, Los Angeles, CA, United States of America.

Film music varies tremendously across genre in order to bring about different responses in an audience. For instance, composers may evoke passion in a romantic scene with lush string passages or inspire fear throughout horror films with inharmonious drones. This study investigates such phenomena through a quantitative evaluation of music that is associated with different film genres. Read More

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Foam Silica Films Synthesized by Calcium Chloride-Assisted Emulsification.

Langmuir 2021 Apr 8. Epub 2021 Apr 8.

Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire des Multimatériaux et Interfaces, F-69622 Villeurbanne, France.

The development of porous films with an accessible high specific surface area is important for designing new adsorbents, sensors, or catalyst supports. Here, we describe a simple method to prepare a silica foam coating using a calcium chloride-assisted evaporation-induced emulsification method. An alcoholic silica sol containing calcium chloride and a poly(ethylene oxide)-based polymer is deposited on a substrate by dipping. Read More

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