Journal articles: 'Polymer micro-beads'

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Debasis Nayak and Saravanan Kaliyaperumal. "Development and effect of drug release from simvastatin loaded sodium alginate micro beads." World Journal of Biology Pharmacy and Health Sciences 12, no. 3 (December 30, 2022): 348–58. http://dx.doi.org/10.30574/wjbphs.2022.12.3.0259.

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The objective of the present study was to prepare the microbeads of Simvastatin loaded with sodium alginate to provide control release of drug delivery system. So, the design of drug delivery system was to improve and enhance the bioavailability of drug. The Simvastatin loaded microbeads were prepared by the ionic gelation method using polymer such as sodium alginate as a natural substance. Simvastatin loaded sodium alginate microbeads were formulated by different cross linking agent like CaCl₂, BaCl₂, ZnCl₂ and FeCl₃ in different ratio. The microbeads were spherical, free flowing exhibited drug content uniformity and high drug encapsulation efficiency. The swelling and drug release behavior depends upon amount of cross linking agent used in the microbeads. This released the drug up to 24 hours where beads released the drug up to 6 hours. The FTIR analysis of drug, polymers and the optimized formulation indicated the compatibility of the drug with the polymers. The DSC studies confirmed the drug polymer interaction in the microspheres. The SEM studies influence the rate of drug release from the microbeads. The present study concludes that the swelling and In-vitro release behavior of Simvastatin loaded sodium alginate microbeads can be considered as a promising control release drug delivery system.

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Zourob, Mohammed, Stephan Mohr, Andrew G. Mayes, Alexandra Macaskill, Natalia Pérez-Moral, Peter R. Fielden, and Nicholas J. Goddard. "A micro-reactor for preparing uniform molecularly imprinted polymer beads." Lab on a Chip 6, no. 2 (2006): 296. http://dx.doi.org/10.1039/b513195b.

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Vakifahmetoglu, Cekdar, Marco Balliana, and Paolo Colombo. "Ceramic foams and micro-beads from emulsions of a preceramic polymer." Journal of the European Ceramic Society 31, no. 8 (July 2011): 1481–90. http://dx.doi.org/10.1016/j.jeurceramsoc.2011.02.012.

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Descamps, Lucie, Marie-Charlotte Audry, Jordyn Howard, Samir Mekkaoui, Clément Albin, David Barthelemy, Léa Payen, et al. "Self-Assembled Permanent Micro-Magnets in a Polymer-Based Microfluidic Device for Magnetic Cell Sorting." Cells 10, no. 7 (July 9, 2021): 1734. http://dx.doi.org/10.3390/cells10071734.

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Magnetophoresis-based microfluidic devices offer simple and reliable manipulation of micro-scale objects and provide a large panel of applications, from selective trapping to high-throughput sorting. However, the fabrication and integration of micro-scale magnets in microsystems involve complex and expensive processes. Here we report on an inexpensive and easy-to-handle fabrication process of micrometer-scale permanent magnets, based on the self-organization of NdFeB particles in a polymer matrix (polydimethylsiloxane, PDMS). A study of the inner structure by X-ray tomography revealed a chain-like organization of the particles leading to an array of hard magnetic microstructures with a mean diameter of 4 µm. The magnetic performance of the self-assembled micro-magnets was first estimated by COMSOL simulations. The micro-magnets were then integrated into a microfluidic device where they act as micro-traps. The magnetic forces exerted by the micro-magnets on superparamagnetic beads were measured by colloidal probe atomic force microscopy (AFM) and in operando in the microfluidic system. Forces as high as several nanonewtons were reached. Adding an external millimeter-sized magnet allowed target magnetization and the interaction range to be increased. Then, the integrated micro-magnets were used to study the magnetophoretic trapping efficiency of magnetic beads, providing efficiencies of 100% at 0.5 mL/h and 75% at 1 mL/h. Finally, the micro-magnets were implemented for cell sorting by performing white blood cell depletion.

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Croft, Charles F., M. Inês G. S. Almeida, and Spas D. Kolev. "Development of micro polymer inclusion beads (µPIBs) for the extraction of lanthanum." Separation and Purification Technology 285 (March 2022): 120342. http://dx.doi.org/10.1016/j.seppur.2021.120342.

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Sun, Kun, Junqi Chen, Hong Zhao, Weifeng Sun, Yinsheng Chen, and Zhongming Luo. "Dynamic Thermomechanical Analysis on Water Tree Resistance of Crosslinked Polyethylene." Materials 12, no. 5 (March 5, 2019): 746. http://dx.doi.org/10.3390/ma12050746.

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The water tree resistance of crosslinked polyethylene (XLPE) initiated by ultraviolet (UV) irradiation technique is investigated through a water blade electrode method, and the effects of the mechanism of UV irradiation crosslinking on inhibiting water tree growth are revealed with dynamic thermomechanical analysis (DMA). The accelerated water tree aging experiment shows that UV irradiation crosslinking inhibits the growth rate of water trees, and the water tree length and width is reduced with the increase of the crosslinking degree of XLPE. The DMA result demonstrates that the molecular activity of the amorphous phase in XLPE as represented by polyethylene β-relaxation is gradually intensified with the increase of the crosslinking reaction. Combined with the fatigue mechanism of water tree growth in semi-crystalline polymers, it is suggested that the UV irradiation crosslinking reaction can significantly improve the anti-water-tree performance of linear low-density polyethylene (LLDPE). The crosslinking bond in the amorphous phase of UV-photoinitiated crosslinking polyethylene can produce a large number of cross-connected polymer chains, by which the length of fiber is obviously increased, leading to an reduced force from the micro-water beads onto the crack tip and thus decreasing the rate of the material being destroyed by micro-water beads.

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Georgescu, Constantin, Lorena Deleanu, and Mihail Botan. "Dry sliding of composites with PBT matrix and micro glass beads on steel." Industrial Lubrication and Tribology 66, no. 3 (April 8, 2014): 424–33. http://dx.doi.org/10.1108/ilt-03-2012-0026.

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Purpose – This research aims to characterize the tribological behavior of polybutylene terephthalate (PBT) and PBT composites with micro glass beads (MGB) on steel, in dry conditions and on a block-on-ring tester, pointing out the influence of sliding distance and speed. The tribology of PBT and its composites is still in an early stage because this thermoplastic polyester requires accurate technological and thermal treatment. Design/methodology/approach – The composites were produced by ICEFS Savinesti Romania and contain PBT grade Crastin6130NC010 (as supplied by Du Pont), 0.5 […] 1.0 per cent (weight) Relamyd B-2Nf (polyamide grade produced by ICEFS, for a better dispersion of MGB), 1 per cent (weight) black carbon for technological and tribological reasons and different micro glass beads (MGB) concentrations (10.0 and 20.0 per cent weight). Tests were done for different sliding distances (2,500, 5,000 and 7,500 m) and speeds (0.5, 1.0 and 1.5 m/s) and a normal load of 5 N. Findings – The friction coefficient and the wear parameter (as mass loss of polymeric blocks) pointed out a good tribological behavior for these composites. Scanning electron microscope (SEM) images revealed particular aspects of PBT local transfer on steel. Also, 10 per cent MGB in PBT reduces wear, especially for longer distances (75,000 m) and higher speeds (0.5 and 0.75 m/s); the friction coefficient is only slightly increased up to 0.23, being less influenced by the speed and the sliding distance as compared to neat polymer. Originality/value – PBT and PBT composites could become challengers for replacing materials in applications similar to tested ones. Even the neat polymer exhibits a good tribological behavior. The composites have a lower sensibility to higher speeds and sliding distances for the applied load.

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Oya, Asao, and Naoto Kasahara. "Preparation of thin carbon fibers from phenol–formaldehyde polymer micro-beads dispersed in polyethylene matrix." Carbon 38, no. 8 (2000): 1141–44. http://dx.doi.org/10.1016/s0008-6223(99)00232-8.

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Moritsugu, Masaki, Tomonari Ogata, Seiji Kurihara, and Takamasa Nonaka. "Synthesis of Photo-Cross Linking Polymer Beads and Application for Micro Fabrication of Periodic Structure." Molecular Crystals and Liquid Crystals 443, no. 1 (December 2005): 117–26. http://dx.doi.org/10.1080/15421400500247334.

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Haimhoffer, Ádám, Alexandra Vas, Gabriella Árvai, Éva Fenyvesi, László Jicsinszky, István Budai, Attila Bényei, et al. "Investigation of the Drug Carrier Properties of Insoluble Cyclodextrin Polymer Microspheres." Biomolecules 12, no. 7 (July 2, 2022): 931. http://dx.doi.org/10.3390/biom12070931.

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The investigation of the usability of solid insoluble β-cyclodextrin polymers (βCDP) in micro-sized, controlled drug delivery systems has only recently attracted interest. Our aim was to form complexes with poorly soluble active pharmaceutical ingredients (APIs) with two types of βCDP for drug delivery applications. Solid insoluble cyclodextrin polymer of irregular shape (βCDPIS) and cyclodextrin microbeads (βCDPB) were used in the experiments. Morphology, surface area, size distribution and swelling capacity of carriers were investigated. We created complexes with two APIs, curcumin and estradiol, and applied powder X-ray diffraction, FTIR and thermal analysis (TGA/DSC) to prove the complexation. Finally, the dissolution, biocompatibility and permeation of APIs on Caco-2 cells were investigated. The size of the beads was larger than 100 µm, their shape was spherical and surfaces were smooth; while the βCDPIS particles were around 4 µm with irregular shape and surface. None of the polymers showed any cytotoxic effect on Caco-2 cells. Both carriers were able to extract curcumin and estradiol from aqueous solutions, and the dissolution test showed prolonged estradiol release. Caco-2 permeability tests were in accordance with the complexation abilities and dissolution of the complexes. This study offers useful data for further pharmaceutical applications of insoluble cyclodextrin polymers.

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Dev Prakash and Rishi Kumar. "A review on natural polymer locust bean gum." World Journal of Biology Pharmacy and Health Sciences 13, no. 1 (January 30, 2023): 277–83. http://dx.doi.org/10.30574/wjbphs.2023.13.1.0031.

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Locust bean pods were utilized as cattle feed for a very long time but now its seed endosperm powder is utilized as locust bean gum in various industries such as food, cosmetic, pharmaceutical, textile, paint, mining, oil drilling and construction industries for its thickening and stabilizing properties. In pharmaceutical industries, locust bean gum is used in the production of solid monolithic matrix systems, films, beads, micro-particles, nano-particles, inhalable and injectable systems, as well as in viscous liquid and gel formulations. Locust bean gum is used as an additive in food industry due to its thickening and stabilizing property. Its application for bakery purposes results in higher baked product yields; it improves the final texture and adds viscosity in dough. Addition of guar gum in cookies dough improves the machinability of the dough which helps in the better handling of dough with minimum requirement of energy and time.

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Bozhinova, D., B. Galunsky, G. Yueping, M. Franzreb, R. Köster, and V. Kasche. "Evaluation of magnetic polymer micro-beads as carriers of immobilised biocatalysts for selective and stereoselective transformations." Biotechnology Letters 26, no. 4 (February 2004): 343–50. http://dx.doi.org/10.1023/b:bile.0000015471.18648.40.

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13

Drago, Claudia, and Guntram Weithoff. "Variable Fitness Response of Two Rotifer Species Exposed to Microplastics Particles: The Role of Food Quantity and Quality." Toxics 9, no. 11 (November 13, 2021): 305. http://dx.doi.org/10.3390/toxics9110305.

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Plastic pollution is an increasing environmental problem, but a comprehensive understanding of its effect in the environment is still missing. The wide variety of size, shape, and polymer composition of plastics impedes an adequate risk assessment. We investigated the effect of differently sized polystyrene beads (1-, 3-, 6-µm; PS) and polyamide fragments (5–25 µm, PA) and non-plastics items such as silica beads (3-µm, SiO2) on the population growth, reproduction (egg ratio), and survival of two common aquatic micro invertebrates: the rotifer species Brachionus calyciflorus and Brachionus fernandoi. The MPs were combined with food quantity, limiting and saturating food concentration, and with food of different quality. We found variable fitness responses with a significant effect of 3-µm PS on the population growth rate in both rotifer species with respect to food quantity. An interaction between the food quality and the MPs treatments was found in the reproduction of B. calyciflorus. PA and SiO2 beads had no effect on fitness response. This study provides further evidence of the indirect effect of MPs in planktonic rotifers and the importance of testing different environmental conditions that could influence the effect of MPs.

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Duty, Chad E., Vlastimil Kunc, Brett Compton, Brian Post, Donald Erdman, Rachel Smith, Randall Lind, Peter Lloyd, and Lonnie Love. "Structure and mechanical behavior of Big Area Additive Manufacturing (BAAM) materials." Rapid Prototyping Journal 23, no. 1 (January 16, 2017): 181–89. http://dx.doi.org/10.1108/rpj-12-2015-0183.

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Purpose This paper aims to investigate the deposited structure and mechanical performance of printed materials obtained during initial development of the Big Area Additive Manufacturing (BAAM) system at Oak Ridge National Laboratory. Issues unique to large-scale polymer deposition are identified and presented to reduce the learning curve for the development of similar systems. Design/methodology/approach Although the BAAM’s individual extruded bead is 10-20× larger (∼9 mm) than the typical small-scale systems, the overall characteristics of the deposited material are very similar. This study relates the structure of BAAM materials to the material composition, deposition parameters and resulting mechanical performance. Findings Materials investigated during initial trials are suitable for stiffness-limited applications. The strength of printed materials can be significantly reduced by voids and imperfect fusion between layers. Deposited material was found to have voids between adjacent beads and micro-porosity within a given bead. Failure generally occurs at interfaces between adjacent beads and successive layers, indicating imperfect contact area and polymer fusion. Practical implications The incorporation of second-phase reinforcement in printed materials can significantly improve stiffness but can result in notable anisotropy that needs to be accounted for in the design of BAAM-printed structures. Originality/value This initial evaluation of BAAM-deposited structures and mechanical performance will guide the current research effort for improving interlaminar strength and process control.

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Paraskevopoulou, Patrina, Despoina Chriti, Grigorios Raptopoulos, and George C. Anyfantis. "Synthetic Polymer Aerogels in Particulate Form." Materials 12, no. 9 (May 10, 2019): 1543. http://dx.doi.org/10.3390/ma12091543.

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Aerogels have been defined as solid colloidal or polymeric networks of nanoparticles that are expanded throughout their entire volume by a gas. They have high surface areas, low thermal conductivities, low dielectric constants, and high acoustic attenuation, all of which are very attractive properties for applications that range from thermal and acoustic insulation to dielectrics to drug delivery. However, one of the most important impediments to that potential has been that most efforts have been concentrated on monolithic aerogels, which are prone to defects and their production requires long and costly processing. An alternative approach is to consider manufacturing aerogels in particulate form. Recognizing that need, the European Commission funded “NanoHybrids”, a 3.5 years project under the Horizon 2020 framework with 12 industrial and academic partners aiming at aerogel particles from bio- and synthetic polymers. Biopolymer aerogels in particulate form have been reviewed recently. This mini-review focuses on the emerging field of particulate aerogels from synthetic polymers. That category includes mostly polyurea aerogels, but also some isolated cases of polyimide and phenolic resin aerogels. Particulate aerogels covered include powders, micro granules and spherical millimeter-size beads. For the benefit of the reader, in addition to the literature, some new results from our laboratory concerning polyurea particle aerogels are also included.

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Hoai, Nguyen To, Dong-Keun Yoo, and Dukjoon Kim. "Batch and column separation characteristics of copper-imprinted porous polymer micro-beads synthesized by a direct imprinting method." Journal of Hazardous Materials 173, no. 1-3 (January 15, 2010): 462–67. http://dx.doi.org/10.1016/j.jhazmat.2009.08.107.

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Shi, Jun, Li Zhang, Yingliang Liu, Shengang Xu, and Shaokui Cao. "Biomineralized organic–inorganic hybrids aiming for smart drug delivery." Pure and Applied Chemistry 86, no. 5 (May 19, 2014): 671–83. http://dx.doi.org/10.1515/pac-2013-0112.

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AbstractOrganic–inorganic hybrid materials have received great interest in the last 10 years in the controlled drug delivery area because of their excellent biocompatible, biomimetic, and pH-sensitive properties. Biomineralization is a biomineral-inspired route to prepare novel organic–inorganic hybrids, which involves a diffusion-controlled deposition of inorganic minerals within porous polymeric matrices. Proper combination of controlled biomineralization technique with the rational choice of polymer templates would lead to the successful development of smart self-assembled drug carriers. The present work mainly summarizes our recent work about the biomineralized organic–inorganic hybrid materials aiming for smart drug delivery including hybrid beads, membranes, and micro/nano gels. Furthermore, prospect for future development of the smart organic–inorganic hybrids is also discussed.

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Wang, Haoran, Takuya Mabuchi, Jiayuan Ji, Sheng-Feng Huang, and Takashi Tokumasu. "Molecular Dynamics Study on the Microscopic Mechanism of Mechanical Properties of Nafion Membrane." ECS Meeting Abstracts MA2022-02, no. 41 (October 9, 2022): 1531. http://dx.doi.org/10.1149/ma2022-02411531mtgabs.

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As the core component of new energy vehicles, the safe operation of polymer electrolyte fuel cells has become more important with the rapid development of the new energy field. Since polymer electrolyte membrane (PEM) works at a hydrated environment, the mechanical properties of its hydrated state must remain stable. At present, studies have shown that the increase of water content will reduce the mechanical properties of materials, such as the decrease of Young's modulus, but the microscopic mechanism has not been elucidated. This presents a challenge to the work to develop novel PEMs. We tried to use the method of coarse-grained (CG) molecular dynamics (MD) simulation to study the microscopic mechanism of the mechanical properties of basic PEM Nafion membrane under different water content conditions. The purpose of this study is to seek to demonstrate the microscopic mechanism by which macroscopic mechanical properties are determined from the MD perspective, thereby providing general guidance for the future development of novel PEMs. More specifically, we tested the Nafion membrane (CG model with 4 beads on the main chain and 2 beads on the side chain) under tensile and compressive stress (strain 0-0.5) at different water contents (2-14). Quantified micro-parameters make it possible to establish macro-micro relationships. Considering that our chosen Nafion is the basic model, it may have good generality to other complex models. At the macroscopic level, our results show that increasing the water content reduces Young's modulus of the material. The decreasing rate of Young's modulus shows a slowing trend. This is in good agreement with previous research. At the microscopic level, our results show that the coordination number between any two types of atoms except water molecules within the same volume decreases with increasing water content, suggesting that the increase in water molecules forces other atoms to away from each other, thereby increasing the spacing between molecules. Therefore, the dominant force on this distance scale, that is, the electrostatic attraction between positive and negative ions is reduced. We have a reason to think that this is the main micromechanical factor to change macroscopic mechanical properties. In addition, the results of polymer chain entanglement parameters show that the degree of entanglement of polymer chains deepened with the increase of water content. The complex entangled structure will increase the difficulty of the polymer deformation. We believe that this is one of the micromechanical factors to decrease the Young's modulus. The study of these mechanisms may help in the development of new Nafion materials.

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Gao, Jin, Taiyang Zhu, Zhi Zhang, Yuan Kong, and Xin Zhang. "Research on Interface Modification and Thermal Insulation/Anticorrosive Properties of Vacuum Ceramic Bead Coating." Coatings 12, no. 3 (February 24, 2022): 304. http://dx.doi.org/10.3390/coatings12030304.

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The thermal insulation effect of the coating was closely related to the content of the thermal insulation filler, but too much filler would cause interfacial compatibility problems of various substances in the coating, micro-defects in the coating, and affect the anti–corrosion performance of the coating. Therefore, solving the interface problem was the key to preparing a coating with heat insulation and anticorrosion functions. In this study, organic–inorganic hybrid polymer was used to modify the surface of vacuum ceramic microbeads, and epoxy–silicone resin was used as the film–forming material to prepare a heat-insulating and anticorrosive coating that can withstand 200 °C. The SEM morphology showed that the interface compatibility of the vacuum ceramic beads modified by the organic–inorganic hybrid agent and the film-forming material were improved, the dispersibility was significantly improved, and the beads were tightly arranged; the thermal conductivity of the coating reached 0.1587 W/(m·K), which decreased by 50% after adding 20% ceramic beads, ANSYS finite element simulation showed that the coating has good thermal insulation performance; after the coating underwent a thermal aging test at 200 °C for 600 h, the microstructure was dense, and the low-frequency impedance modulus was still around 109 Ω·cm2. There was no obvious defect in the microstructure after the alternating cold and heat test for 600 h; the low-frequency impedance modulus was still above 108 Ω·cm2, and the low-frequency impedance modulus of the coating was 1010 Ω·cm2 after the 130d immersion test, indicating that the coating had good heat resistance and anti-corrosion performance.

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Verma, Pawan, Taruna Bansala, Sampat Singh Chauhan, Devendra Kumar, Suleyman Deveci, and S. Kumar. "Electromagnetic interference shielding performance of carbon nanostructure reinforced, 3D printed polymer composites." Journal of Materials Science 56, no. 20 (April 7, 2021): 11769–88. http://dx.doi.org/10.1007/s10853-021-05985-0.

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Abstract We report the electrical, mechanical and electromagnetic interference (EMI) shielding performance of polypropylene random copolymer (PPR)/multi-wall carbon nanotube (MWCNT) nanocomposites enabled via customized fused filament fabrication process. The electro-conductive PPR/MWCNT filament feedstocks were fabricated via shear-induced melt-blending process that allows 3D printing of nanoengineered composites even at higher MWCNT loading (up to 8 wt%). The uniform dispersion of MWCNTs in PPR matrix confirmed via Raman spectroscopy and scanning electron microscopy facilitates better mechanical, electrical and EMI shielding performance. The results furthermore show enhanced shielding properties and higher attenuation for the nanocomposites printed in 90° direction (~ − 37 dB for 8 wt% MWCNT loading). Effective interfacial adhesion between the beads with lesser extent of voids (confirmed via micro-computed tomography) endorsed low transmission loss in nanocomposites printed in 90° direction compared to samples printed in 0° direction. Surface architected structure (frustum shape) reveals higher specific shielding effectiveness (maximum ~ − 40 dBg−1cm3, + 38%) over the plain structure. The realization of excellent shielding effectiveness (~ 99.9% attenuation) of additive manufacturing-enabled PPR/MWCNT nanocomposites demonstrates their potential for lightweight and strong EMI shields. Graphical Abstract

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Nath, Bipul, and Santimoni Saikia. "Characterization and Screening of a Novel Multiparticulate Pulsatile Delivery of Aceclofenac." International Journal of Pharmaceutical Sciences and Nanotechnology 9, no. 5 (September 30, 2016): 3494–501. http://dx.doi.org/10.37285/ijpsn.2016.9.5.7.

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In the present investigation, sodium alginate based multiparticulate system overcoated with time and pH dependent polymer was studied in the form of oral pulsatile system to achieve pulsatile with sustained release of aceclofenac for chronotherapy of rheumatoid arthritis seven batches of micro beads with varying concentration of sodium alginate (2-5 %) were prepared by ionotropic-gelation method using CaCl2 as cross-linking agent. The prepared Ca-alginate beads were coated with 5% Eudragit L100 and filled into pulsatile capsule with varying proportion of plugging materials. Drug loaded microbeads were investigated for physicochemical properties and drug release characteristics. The mean particle sizes of drug-loaded microbeads were found to be in the range 596±1.1 to 860 ± 1.2 micron and %DEE in the range of 65-85%. FT-IR and DSC studies revealed the absence of drug polymer interactions. The release of aceclofenac from formulations F1 to F7 in buffer media (pH 6.8) at the end of 5h was 65.6, 60.7, 55.7, 41.2, 39.2, 27 and 25% respectively. Pulsatile system filled with eudragit coated Ca-alginate microbeads (F2) showed better drug content, particle size, surface topography, in-vitro drug release in a controlled manner. Different plugging materials like Sterculia gum, HPMC K4M and Carbopol were used in the design of pulsatile capsule. The pulsatile system remained intact in buffer pH 1.2 for 2 hours due to enteric coat of the system with HPMCP. The enteric coat dissolved when the pH of medium was changed to 7.4. The pulsatile system developed with Sterculia gum as plugging material showed satisfactory lag period when compared to HPMC and Carbopol.

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Won, Ji Yeong, and Junhong Min. "Highly sensitive Escherichia coli O157:H7 detection in a large volume sample using a conical polymer tube chamber consisting of micro-glass beads." Biosensors and Bioelectronics 26, no. 1 (September 15, 2010): 112–17. http://dx.doi.org/10.1016/j.bios.2010.05.025.

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Sayah, Neshat, and Douglas E. Smith. "Effect of Process Parameters on Void Distribution, Volume Fraction, and Sphericity within the Bead Microstructure of Large-Area Additive Manufacturing Polymer Composites." Polymers 14, no. 23 (November 24, 2022): 5107. http://dx.doi.org/10.3390/polym14235107.

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Short carbon fiber-reinforced composite materials produced by large-area additive manufacturing (LAAM) are attractive due to their lightweight, favorable mechanical properties, multifunctional applications, and low manufacturing costs. However, the physical and mechanical properties of short carbon-fiber-reinforced composites 3D printed via LAAM systems remain below expectations due in part to the void formation within the bead microstructure. This study aimed to assess void characteristics including volume fraction and sphericity within the microstructure of 13 wt% short carbon fiber acrylonitrile butadiene styrene (SCF/ABS). Our study evaluated SCF/ABS as a pellet, a single freely extruded strand, a regularly deposited single bead, and a single bead manufactured with a roller during the printing process using a high-resolution 3D micro-computed tomography (µCT) system. Micro voids were shown to exist within the microstructure of the SCF/ABS pellet and tended to become more prevalent in a single freely extruded strand which showed the highest void volume fraction among all the samples studied. Results also showed that deposition on the print bed reduced the void volume fraction and applying a roller during the printing process caused a further reduction in the void volume fraction. This study also reports the void’s shape within the microstructure in terms of sphericity which indicated that SCF/ABS single freely extruded strands had the highest mean void sphericity (voids tend to be more spherical). Moreover, this study evaluated the effect of printing process parameters, including nozzle temperature, extrusion speed and nozzle height above the printing table on the void volume fraction and sphericity within the microstructure of regularly deposited single beads.

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Bhoj, Ananth N., and Mark J. Kushner. "Repetitively pulsed atmospheric pressure discharge treatment of rough polymer surfaces: II. Treatment of micro-beads in He/NH3/H2O and He/O2/H2O mixtures." Plasma Sources Science and Technology 17, no. 3 (July 31, 2008): 035025. http://dx.doi.org/10.1088/0963-0252/17/3/035025.

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Absar, Saheem, Mujibur Khan, Kyle Edwards, and Jeffrey Neumann. "Investigation of synthesis and processing of cellulose, cellulose acetate and poly(ethylene oxide) nanofibers incorporating anti-cancer/tumor drug cis-diammineplatinum (II) dichloride using electrospinning techniques." Journal of Polymer Engineering 35, no. 9 (November 1, 2015): 867–78. http://dx.doi.org/10.1515/polyeng-2015-0057.

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Abstract A model anti-cancer/tumor drug cis-diammineplatinum (II) dichloride (cisplatin) was loaded into micro- and nanofibers of cellulose, cellulose acetate (CA) and poly(ethylene oxide) (PEO), using various electrospinning techniques. Single-nozzle electrospinning was used to fabricate neat fibers of each category. Drug loading in cellulose fibers was performed using single-nozzle electrospinning. Encapsulation of cisplatin in CA and PEO-based fibers was performed using coaxial electrospinning. Morphological analysis of the fibers was performed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The various categories of fibers exhibited diverse morphological features depending on the material compositions and applied process parameters. The drug-loaded cellulose nanofibers showed attached particles on the surface. These particles were composed of both the polymer and the drug. The CA-cisplatin fibers exhibited drug encapsulation within various diverse morphological conformations: hierarchical structures such as straw-sheaf-shaped particles, dendritic branched nanofibers and swollen fibers with large beads. However, in the case of PEO fibers, drug encapsulation was observed inside repeating dumbbell-shaped structures. Morphological development of the fibers and corresponding mode of drug encapsulation were correlated with process parameters such as applied voltage, concentrations and relative feed rates of the solutions and conductivities of the solvents.

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Descamps, Lucie, Damien Le Roy, Caterina Tomba, and Anne-laure Deman. "Magnetic Polymers for Magnetophoretic Separation in Microfluidic Devices." Magnetochemistry 7, no. 7 (July 8, 2021): 100. http://dx.doi.org/10.3390/magnetochemistry7070100.

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Magnetophoresis offers many advantages for manipulating magnetic targets in microsystems. The integration of micro-flux concentrators and micro-magnets allows achieving large field gradients and therefore large reachable magnetic forces. However, the associated fabrication techniques are often complex and costly, and besides, they put specific constraints on the geometries. Magnetic composite polymers provide a promising alternative in terms of simplicity and fabrication costs, and they open new perspectives for the microstructuring, design, and integration of magnetic functions. In this review, we propose a state of the art of research works implementing magnetic polymers to trap or sort magnetic micro-beads or magnetically labeled cells in microfluidic devices.

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Wu, Meiyan, Wangfang Deng, Yidong Zhang, Chao Chen, Zhexuan Liu, Pedram Fatehi, and Bin Li. "Facile Fabrication of Cellulose Nanofibrils/Chitosan Beads as the Potential pH-Sensitive Drug Carriers." Polymers 14, no. 11 (June 4, 2022): 2286. http://dx.doi.org/10.3390/polym14112286.

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It is highly desirable to develop a safe, highly efficient, and biodegradable drug carrier with an enhanced drug transport efficiency. Cellulose nanofibrils (CNF) and chitosan (CS) composite hydrogels are promising candidate carriers with biological compatibility and non-cytotoxicity. Herein, the CNF/CS composite beads were prepared by dissolving cellulose and CS in LiBr molten salt hydrate and regenerating in ethanol. This preparation method is facile and efficient, and the obtained porous CNF/CS beads with the weight ratio of 8:2 exhibited a large specific surface area, uniform micro-nano-sized pores, strong mechanical property, and water absorption-resistance. Moreover, these beads as drug (tetracycline hydrochloride, TH) carriers showed a higher encapsulation efficiency (47.4%) at the TH concentration of 5 mg/mL in 24 h, and a higher drug loading rate (12.0%) than pure CNF and other CNF/CS beads prepared with different ratios. In addition, the TH releasing behavior of CNF/CS (8:2) beads fitted well into the zero-order, first-order, and Higuchi models under an acid condition, indicating that the drug release of these pH-sensitive beads was mainly affected by drug concentration under an acid condition. Therefore, these CNF/CS beads have great potential to be used as drug carriers for medical applications.

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Kanehira, Masafumi, Werner J. Finger, Naohiko Iwasaki, Natthavoot Koottathape, and Hidekazu Takahashi. "Morphological Features of Composite Resin Surfaces after Two- and Three-Body Wear Simulation." World Journal of Dentistry 3, no. 3 (2012): 221–28. http://dx.doi.org/10.5005/jp-journals-10015-1160.

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ABSTRACT Purpose To investigate morphological surface features of different composite resins after 30,000 sliding wear cycles under two- and three-body wear action. Materials and methods The morphology of worn surfaces of four nanofiller containing composite resins, Filtek Supreme XT (FIL), MI Flow (MFL), Venus Diamond (VED) and Venus Pearl (VEP) were investigated and compared with three conventional composites as references, microfilled Durafill VS (DUR), microhybrid Filtek Z250 (Z250) and hybrid-type Clearfil AP-X (APX). Plane surfaces of the polymerized and water-saturated materials (n = 5) were tested in a custom-built pin-on-disk wear machine fitted with a zirconia ball, 4 mm in diameter, serving as the antagonist ‘cusp’ and loading the specimen at 15° angulation for 3.7 mm long sliding paths (50 N load, 1.2 Hz, 30,000 cycles) either in water, simulating two-body wear, or in slurries of PMMA beads or poppy seed, simulating three-body wear. Random samples of each material were selected and sputter-coated with gold for inspection of the wear patterns using scanning electron microscopy. Results Under two-body wear action all materials showed cracking as indicator of fatigue. MFL and VEP with prepolymer particles were least affected. Similarly, surfaces after three-body wearing with PMMA bead slurry revealed crack formation for five of the composites tested. The micro-hybrid Z250 and the nanofilled FIL displayed compressed and shallow delaminated areas. With poppy seed slurry as the third-body medium DUR was deeply destructed. Also the nanohybrid VED with a small fraction of up to 20 ƒÝm large ground glass fillers revealed deep cracks, whereas small delamination areas characterized the hybrid composite APX. Z250 as well as FIL, MFL and VEP were smoothly abraded without showing signs of cracking or delamination. Conclusion Composite resin surfaces, worn under two-body sliding showed mainly crack formation as an expression of fatigue. Similarly, three-body abrasion with a PMMA bead slurry revealed surface cracks to various extent and delamination, which is also an expression of fatigue related damage. With fine-ground poppy seed slurry only the microfilled composite with large prepolymer particles showed catastrophic failure. In all other cases the small poppy seed fragments in the slurry abraded the surfaces, removing polymer or fine particle loaded matrix uniformly. Supposedly, poppy seed slurry is a suitable third-body medium, simulating occlusal wear produced by food, rich in fibers or grain. How to cite this article Koottathape N, Takahashi H, Iwasaki N, Kanehira M, Finger WJ. Morphological Features of Composite Resin Surfaces after Two- and Three-Body Wear Simulation. World J Dent 2012;3(3):221-228.

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PLAVSIC, M. B., I. PAJIC-LIJAKOVIC, and M. M. PLAVSIC. "COMPACTIVITY OF CELL COLONIES-RELATIONS BETWEEN LIVING CELLS INSIDE POLYMER HYDROGEL BEADS." International Journal of Modern Physics B 24, no. 06n07 (March 20, 2010): 813–24. http://dx.doi.org/10.1142/s0217979210064459.

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The system of living cells closed in a polymer bead as a matrix is considered in formalism of lattice model extended with compactivity concept developed for complex systems in statistical mechanics of jammed state of matter. Possibility of extension of Edwards concept of compactivity developed for hard irregular grains with friction to living cell systems, is considered if function of cell interactions and properties. Existence of critical points in the course of cell colony grow related to their self assembling and response to polymer hydrogel micro-environment resistance, is analyzed in function of cell volume fraction growth. Based on the theory and experiments it is related to characteristic values of compactivity in analogy to phase transition temperatures. Interpretation of data from literature on cancer cell cluster growth suppression under pressure of microenvironment on the base of model proposed is offered.

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Favella, Patrizia, Susanne Sihler, Heinz Raber, Ann-Kathrin Kissmann, Markus Krämer, Valerie Amann, Dennis Kubiczek, et al. "Albumin Microspheres as “Trans-Ferry-Beads” for Easy Cell Passaging in Cell Culture Technology." Gels 7, no. 4 (October 21, 2021): 176. http://dx.doi.org/10.3390/gels7040176.

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Protein hydrogels represent ideal materials for advanced cell culture applications, including 3D-cultivation of even fastidious cells. Key properties of fully functional and, at the same time, economically successful cell culture materials are excellent biocompatibility and advanced fabrication processes allowing their easy production even on a large scale based on affordable compounds. Chemical crosslinking of bovine serum albumin (BSA) with N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (EDC) in a water-in-oil emulsion with isoparaffinic oil as the continuous phase and sorbitan monooleate as surfactant generates micro-meter-scale spherical particles. They allow a significant simplification of an indispensable and laborious step in traditional cell culture workflows. This cell passaging (or splitting) to fresh culture vessels/flasks conventionally requires harsh trypsinization, which can be omitted by using the “trans-ferry-beads” presented here. When added to different pre-cultivated adherent cell lines, the beads are efficiently boarded by cells as passengers and can be easily transferred afterward for the embarkment of novel flasks. After this procedure, cells are perfectly viable and show normal growth behavior. Thus, the trans-ferry-beads not only may become extremely affordable as a final product but also may generally replace trypsinization in conventional cell culture, thereby opening new routes for the establishment of optimized and resource-efficient workflows in biological and medical cell culture laboratories.

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Farah, Shady, Oren Aviv, Mahran Daif, Konda Reddy Kunduru, Natalia Laout, Stanislav Ratner, Nurit Beyth, and Abraham J. Domb. "N -bromo-hydantoin grafted polystyrene beads: Synthesis and nano-micro beads characteristics for achieving controlled release of active oxidative bromine and extended microbial inactivation efficiency." Journal of Polymer Science Part A: Polymer Chemistry 54, no. 5 (October 5, 2015): 596–610. http://dx.doi.org/10.1002/pola.27894.

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Partovinia, Ali, and Elham Vatankhah. "Experimental investigation into size and sphericity of alginate micro-beads produced by electrospraying technique: Operational condition optimization." Carbohydrate Polymers 209 (April 2019): 389–99. http://dx.doi.org/10.1016/j.carbpol.2019.01.019.

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Lee, Jonghwi, and Albert F. Yee. "Micro-mechanical deformation mechanisms in the fracture of hybrid-particulate composites based on glass beads, rubber and epoxies." Polymer Engineering & Science 40, no. 12 (December 2000): 2457–70. http://dx.doi.org/10.1002/pen.11377.

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Kawabata, Nariyoshi, Yuya Tsuchida, Yutaka Nakamori, and Mitsunobu Kitamura. "Adsorption of phenol on clustered micro-sphere porous beads made of cross-linked poly-4-vinylpyridine." Reactive and Functional Polymers 66, no. 12 (December 2006): 1641–48. http://dx.doi.org/10.1016/j.reactfunctpolym.2006.06.008.

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Sèbe, Gilles, Anne Simon, Benjamin Dhuiège, and Chrystel Faure. "Cu2+-loaded cellulose micro-beads applied to the direct patterning of metallic surfaces using a fast and convenient process." Carbohydrate Polymers 207 (March 2019): 492–501. http://dx.doi.org/10.1016/j.carbpol.2018.12.024.

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Zhang, Qingle, Yiqing Shao, Chengmeizi Wang, Lu Wang, Huimin Zhou, and Xin Xia. "Preparation of fluorine-free anti-acid and breathable composite fabric based on modified SBS/pitch electrospun nanofibers." Textile Research Journal 91, no. 13-14 (January 20, 2021): 1535–45. http://dx.doi.org/10.1177/0040517520982588.

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To develop a fluorine-free material of acidproof and breathable fabric, styrene–butadiene–styrene (SBS) blended with pitch was directly deposited on polyester/cotton blended fabric through electrospinning to fabricate a nanofibrous membrane composite fabric. Acrylic acid (AA) and methyl methacrylate (MMA) were used to graft SBS to improve compatibility between SBS and pitch, and the modified temperatures were set at 40°C, 60°C and 80°C. The effects of different grafting monomers and temperatures on the properties of SBS/pitch membrane composite fabrics were explored by Fourier transform infrared spectral analysis; morphological structures, acid-resistant properties and breathability (vapor permeability and air permeability) were also examined. The results showed that modified SBS/pitch membrane composite fabrics possessed good acid resistance and modest breathability. SBS-g-MMA/pitch (means SBS grafted by MMA) exhibited the highest acid resistance due to more evenly distributed beads than original SBS/pitch membrane composite fabrics and higher roughness than SBS-g-AA/pitch (means SBS grafted by AA) membrane composite fabrics. By systematically changing the grafting temperature, SBS-g-MMA/pitch membrane composite fabrics for which SBS was grafted by MMA at 80°C presented appropriate air permeability (120.5 mm/s), modest water vapor transport rate (13,656.45 g/(m2·d)), good tensile strength (1203 N) and bursting strength (616 N), and the best acid resistance (143°); meanwhile the acid penetration level reached level 3, which was attributed to the low surface energy caused by the fused ring from the pitch and the rough surface caused by the micro-beads in the nanofibers. The obtained modified SBS/pitch membrane composite fabric could be potentially applied in acidproof fabrics.

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Teng, Xin, Xingyu Ding, Zhuxin She, Yi Li, and Xiaohui Xiong. "Preparation of Functionalized Magnetic Polystyrene Microspheres and Their Application in Food Safety Detection." Polymers 15, no. 1 (December 25, 2022): 77. http://dx.doi.org/10.3390/polym15010077.

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Based on the specific binding of sulfonic acid groups to melamine, β-agonists and other compounds, Fe3O4 nano-magnetic beads were coated with polystyrene using an improved micro-suspension emulsion polymerization method, thus forming core–shell magnetic polystyrene microspheres (Fe3O4@PS) with Fe3O4 as the core and polystyrene as the shell. These functionalized microspheres, which can be used as magnetic solid-phase extraction (MSPE) adsorbent, were prepared after further sulfonation. These microspheres were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size analysis and saturation magnetization measurement. The results showed that these sulfonated magnetic polystyrene microspheres had favorable sphericity. The particle size of these microspheres ranged from 1μm to 10μm. Additionally, these microspheres had good dispersion and magnetic responses in both inorganic and organic solvents. Moreover, these functionalized magnetic polystyrene microspheres were tested and evaluated by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The results indicated that these sulfonated magnetic polystyrene microspheres (Fe3O4@SPS) could effectively adsorb such illegal additives as β-agonists and melamine in the food matrix.

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Brattekås, Bergit, Tore L. Føyen, Trond Vabø, Håkon Haugland, Simon I. Reite, Anders S. Saunes, and Martin A. Fernø. "Dos and Don’ts When Developing a System to Investigate Spontaneous Imbibition in Unconsolicdated Porous Media." E3S Web of Conferences 89 (2019): 01005. http://dx.doi.org/10.1051/e3sconf/20198901005.

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This paper describes the development of a consistent model system to measure spontaneous imbibition and determine saturation functions in unconsolidated porous media. Sand grains or glass beads were packed in up to 0.5 m long, transparent glass tubes with optical access to local saturation development during spontaneous imbibition processes. The Two Ends Open-Free spontaneous imbibition (TEOFSI) boundary condition was used, where one end face is exposed to the wetting ﬂuid and the other end to the non-wetting ﬂuid. Dynamic measurement of the advancing displacement front and volumetric production from each open end-face enabled estimation of capillary pressure and relative permeability for the system. A range of wetting- and non-wetting phase viscosities and viscosity ratios was used during spontaneous imbibition in unconsolidated sand or glass packs. Wetting phase (water) viscosity was increased using water soluble glycerol or polymers. Air or mineral oil of varying composition provided a wide range of non-wetting phase viscosities. High permeable systems are extremely sensitive to laboratory properties, which may dominate the viscous resistance and determine ﬂow behaviour. Systematic discrepancies observed in early testing indicated that end effects were present, even in long systems, in the ﬁlters at each end of the glass tube to maintain the grains or beads in place. Different ﬁlters were tested (no ﬁlter, glass, paper and micro-porous discs) to determine the impact of the ﬁlter on spontaneous imbibition. In addition to slower oil recovery than anticipated, developmentof a non-uniform displacement front was observed, demonstrating the large inﬂuence from minute heterogeneities within the packs, and at the end faces. A standard sand grain packing procedure, using a custom-designed packing device, was therefore developed to ensure homogeneous properties throughout theporous media, and limited the spread in porosity and permeability values. Homogeneous sand packs with reproducible properties are necessary, to systematically investigate ﬂow parameters and changes in wettability in unconsolidated porous media.

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Stavarache, Cristina Elena, Adi Ghebaur, Sorina Dinescu, Iuliana Samoilă, Eugeniu Vasile, George Mihail Vlasceanu, Horia Iovu, and Sorina Alexandra Gârea. "5-Aminosalicylic Acid Loaded Chitosan-Carrageenan Hydrogel Beads with Potential Application for the Treatment of Inflammatory Bowel Disease." Polymers 13, no. 15 (July 27, 2021): 2463. http://dx.doi.org/10.3390/polym13152463.

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The aim of our work is to prepare mucoadhesive particles with biopolymers and 5-Aminosalicylic acid (5ASA) using the ionotropic gelation technique to ensure a controlled drug release at the colon level with potential applications in the treatment of intestinal bowel disease (IBD). The preparation of particles through the crosslinking of Chitosan (CS) with sodium tripolyphosphate (TPP) using different mass ratios and the influence of the k-Carrageenan (kCG) layer were studied. UV–VIS spectrometry was employed to assess encapsulation efficiency and drug release profile of 5ASA. The particles were investigated using FT-IR spectrometry for chemical characterization and the DLS results highlighted a monodisperse particle size distribution. The morphology of the polymeric beads was investigated using micro-computer tomography (µCT) and Scanning Electron Microscopy (SEM). Particles based on Chitosan and k-Carrageenan were able to incorporate and preserve 5ASA in an acidic and alkaline medium. The 5ASA loaded polymeric particles obtained after immersion for 1 h in kCG solution exhibited the lowest release rate in pH = 1.2. Biocompatibility studies performed on all of the particles displayed a good viability for the CCD 841 CoN cells and low cytotoxicity. All of the results have shown that these new biomaterials could be a versatile platform of targeted carriers with potential applications in inflammatory bowel disease treatment.

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Kadikova, Irina F., Ekaterina A. Morozova, Tatyana V. Yuryeva, Irina A. Grigorieva, and Vladimir A. Yuryev. "Glass depolymerization in the process of long-term corrosion: A study of deteriorating semiopaque turquoise glass beads using micro-FTIR spectroscopy." Materials Research Express 7, no. 2 (February 24, 2020): 025203. http://dx.doi.org/10.1088/2053-1591/ab7510.

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Ye, Lei. "Molecularly Imprinted Micro- and Nano-Particles by Precipitation Polymerization." MRS Proceedings 787 (2003). http://dx.doi.org/10.1557/proc-787-g7.3.

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ABSTRACTMolecularly imprinted micro- and nano-particles can be conveniently prepared using precipitation polymerization method. By controlling the initial reaction composition, the resulting polymer particles may be obtained as uniform beads that display favourable binding characteristics. Incorporation of a novel reporter element resulted in an imprinted scintillation polymer that displayed an enhanced signalling efficiency.

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"Ecotoxicity of Microplastics in Freshwater Biota." International Journal of Innovative Technology and Exploring Engineering 9, no. 3 (January 10, 2020): 2610–13. http://dx.doi.org/10.35940/ijitee.c8582.019320.

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Micro plastics are primarily classified as individual pieces of synthetic material made of wide range of organic polymers which is generally called as ‘plastic’. Micro plastics are generally preproduction pellets, micro beads, polymer fibers and degraded micro plastic. Micro plastics make up to as much as 85 percentage of the plastic pollution in the shorelines. This large percentage in the total number of pollutant causes ecological stress caused by the biomagnifications along the food chain. Estimations show that globally majority of micro plastics comes from the runoff of 10 rivers along which includes the Ganges and Indus. To understand the role rivers, play as micro plastic carriers from land to oceans, the sampling of micro plastic is done at the relatively less populated part of Noyyal river and test are carried out to identify presence of micro plastic in the sample. Visual Identification method was used to identify the micro plastic components with relative ease and economy.

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McLachlan, D. "The defouling of membranes using polymer beads containing magnetic micro particles." Water SA 36, no. 5 (November 16, 2010). http://dx.doi.org/10.4314/wsa.v36i5.61997.

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Maixnerová, Lucie, Alexandar Horvitz, Gabriela Kuncová, Michal Přibyl, Marek Šebela, and Martin Koštejn. "Enzymatic sensor of putrescine with optical oxygen transducer – mathematical model of responses of sensitive layer." Chemical Papers 69, no. 1 (January 1, 2015). http://dx.doi.org/10.1515/chempap-2015-0041.

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AbstractA biosensor for putrescine containing a sensing layer with an optical oxygen probe based on ruthenium complex and the enzyme diamine oxidase from pea is described. The diamine oxidase was pre-immobilised on broken micro-beads modified with a ferrofluid. The pre-immobilised enzyme and ruthenium complex were both incorporated into the UV-cured inorganic-organic hybrid polymer ORMOCER

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Kaliyaperumal, Viswanathan, Azhahianambi Palavesam, Arul Kumar Kandasamy, Vijaya Shanthi Ramalingam, Chitra Karuppan, Madhan Nithiyanantham, Indira Harikrishnan, Dhinakarraj Gopal, Raman Muthusamy, and Senthil Kumar Tuticorin Maragatham Alagesan. "Development of Garlic Oral Beads using Garlic Nanoparticles and Studies on their Protective Effects Against Avian Coccidiosis." Nano LIFE 12, no. 01 (October 15, 2021). http://dx.doi.org/10.1142/s1793984421500070.

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In this paper, new oral beads were developed for poultry applications using garlic nanoparticles (NPs). The NPs were synthesized using water in oil micro-emulsion method and it was confirmed using energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The biocompatibility was evaluated by using the chicken blood, chicken intestinal cell line and the results indicated that the particles are highly safe. The oral beads were formulated using hydroxyl propyl methyl cellulose phthalate as polymer protective layer and specifically dissolved in pH 6.5 and released the NPs at the intestine. To study their impacts, the chickens were fed with beads starting day 3 after hatching, and their weight was recorded. To study the anti-parasitic effect, the chickens were challenged with Eimeria species. The active treatments with oral beads effectively cure the intestinal damages triggered by the Eimeria species and improved the chicken weight. The prophylactic treatment 100% protects chicken against Eimeria infection and increased the body weight.

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"00/03280 Preparation of thin carbon fibers from phenolformaldehyde polymer micro-beads dispersed in polyethylene matrix." Fuel and Energy Abstracts 41, no. 6 (November 2000): 369. http://dx.doi.org/10.1016/s0140-6701(00)94355-8.

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Kritzinger, Ané, Andrew Forbes, and Patricia B. C. Forbes. "Optical trapping and fluorescence control with vectorial structured light." Scientific Reports 12, no. 1 (October 21, 2022). http://dx.doi.org/10.1038/s41598-022-21224-1.

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AbstractHere we functionalized micro-scaled polymer beads with nano-scaled quantum dots and demonstrate optical trapping and tweezing, with in-situ fluorescence measurement, in an all-digital all-optical configuration. We outline the chemistry required to facilitate this, from deactivating the optical trapping environment to size, adhesion and agglomeration control. We introduce a novel holographic optical trapping set-up that leverages on vectorially structured light, allowing for the delivery of tuneable forms of light from purely scalar to purely vector, including propagation invariant flat-top beams for uniform illumination and tailored intensity gradient landscapes. Finally, we show how this has the potential to quench bleaching in a single wavelength trap by linear (spatial mode) rather than non-linear effects, advancing the nascent field of optics for chemistry.

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Kusari, Upal, Zhihao Bao, Cai Ye, Gul Ahmad, Kenneth H. Sandhage, and Larry G. Sneddon. "Template Routes to Non-Oxide Ceramic Nano- and Micro-Structures." MRS Proceedings 921 (2006). http://dx.doi.org/10.1557/proc-0921-t04-10.

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AbstractNon-oxide ceramic materials like boron carbide and silicon carbide are technologically relevant as advanced high temperature materials, while boron nitride is a thermally robust low-k insulating material with electronic applications. Efficient routes to boron carbide, boron nitride, and silicon carbide ceramic nanostructures have been developed which employ molecular and polymeric precursors, including the boron carbide precursor 6, 6'-bis(decaboranyl)hexane, the boron nitride precursor polyborazylene, and a commercially available silicon carbide precursor allylhydridopolycarbosilane(AHPCS), in conjunction with colloidal silica and biological silica “diatom” templates. Layered submicron-sized ordered void structures with three-dimensional periodicity and tunable length scales were fabricated by the melt infiltration of the precursors into ordered colloidal silica bead templates. Pyrolytic ceramic conversion followed by dissolution of the silica beads by chemical treatment with aqueous HF or NaOH generated highly uniform ceramic structures with thicknesses up to 50μm and ordered voids ranging in diameter from 50-150 nm. Following on earlier work by Sandhage who generated polymer and oxide ceramic structures, vacuum filtration of the ceramic precursor solutions through bioclastic silica diatom frustule templates generated polymer coated replicas of their 3-D micro- and nanostructures. Subsequent pyrolysis and dissolution of the frustules in 48% HF yielded free-standing ceramic structures with fine features on length scales of 60-200 nm. This technique therefore provides a large scale route to nano- and micro structured non-oxide ceramic materials. Structural control of the end products was achieved by changing the concentration of the precursor solution, pore size and/or the frustule template. Characterization by XRD, DRIFT, SEM, TEM and possible uses of these uniform nano- and micro-structured ceramics will be discussed.

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Mahadevan, Gomathi, and Suresh Valiyaveettil. "Understanding the interactions of poly(methyl methacrylate) and poly(vinyl chloride) nanoparticles with BHK-21 cell line." Scientific Reports 11, no. 1 (January 22, 2021). http://dx.doi.org/10.1038/s41598-020-80708-0.

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AbstractMicroplastic and nanoplastic particles are prevalent in the environment and are beginning to enter the living system through multiple channels. Currently, little is known about the impact of plastic nanoparticles in living organisms. In order to investigate the health impact of micro- and nanoparticles of common polymers in a systematic way, luminescent plastic nanoparticles from two common polymers, polyvinyl chloride (PVC) and poly (methyl methacrylate) (PMMA) with relatively narrow size distribution are prepared using a nanoprecipitation method. As a model system, BHK-21 cells were exposed to polymer nanoparticles to understand the mode of uptake, internalization and biochemical changes inside the cells. The cellular effects of the nanoparticles were evaluated by monitoring the changes in cell viability, cell morphology, concentrations of reactive oxygen species (ROS), adenine triphosphate (ATP) and lactate dehydrogenase at different concentrations of the nanoparticles and time of exposure. PVC and PMMA nanoparticles induced a reduction in the cell viability along with a reduction of ATP and increase of ROS concentrations in a dose- and time-dependent manner. The plastic nanoparticles are internalized into the cell via endocytosis, as confirmed by Dynasore inhibition assay and colocalization with latex beads. Our findings suggest that plastic nanoparticle internalization could perturb cellular physiology and affect cell survival under laboratory conditions.

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Deshmukh, Prasad, Mukund Tawar, Vaishnavi Chandak, Rachana Hallale, Alisha Hirani, and Omkar Rajurkar. "Preparation and Evaluation of Hydrogel Alginate Beads of Rifaximin." Asian Journal of Research in Pharmaceutical Sciences, November 22, 2022, 285–90. http://dx.doi.org/10.52711/2231-5659.2022.00049.

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Any optimal medication delivery system provides a therapeutic amount of medicine to the correct spot in the body to achieve quick reaction and maintain the desired drug concentration. Intravenous drug infusion at the site of action over a desired time period can provide this optimal drug delivery. In recent years, scientists and engineers have developed rate-controlled oral medication delivery devices. These formulations provide the medicine at a controlled and predetermined rate, keeping its therapeutically effective concentration in circulation. Most restricted substances are pills. After carrying out the drug release of prepared hydrogel alginate microbeads, it was discovered that the drug release (%) was found to be in the range of 0.81 to 4.81% for the time period of 03 hours. This finding was made possible by the fact that the drug release (%) was found to be in the range of 0.81 to 4.81%. According to the data on drug release, it was discovered that the batch of fz4 had the highest sustained drug release in comparison to the other batches. According to the pattern of drug release, the rate of drug release slows down as the concentration of polymer in the formulation increases. This formulation prolongs medication release, increasing bioavailability and therapeutic activity. Sodium alginate micro beads with a release modifier could be employed as a medication carrier. The industrial-scale process needs a pilot study.

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Journal articles on the topic 'Polymer micro-beads'

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