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Thematische Bibliographien / Macromolecular surfactants / Zeitschriftenartikel

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Zeitschriftenartikel zum Thema „Macromolecular surfactants“

Autor: Grafiati

Veröffentlicht am 29. Juni 2021

Zuletzt aktualisiert am 9. Februar 2022

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1

Durand, Alain, und Emmanuelle Marie. „Macromolecular surfactants for miniemulsion polymerization“. Advances in Colloid and Interface Science 150, Nr. 2 (September 2009): 90–105. http://dx.doi.org/10.1016/j.cis.2009.07.002.

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2

Schädler, V., P. Lindner, U. Wiesner und E. Mendes. „Ionic and Zwitterionic Model Macromolecular Surfactants“. Journal of Physical Chemistry B 102, Nr. 38 (September 1998): 7316–18. http://dx.doi.org/10.1021/jp982041b.

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3

Garti, Nissim, und Abraham Aserin. „Double emulsions stabilized by macromolecular surfactants“. Advances in Colloid and Interface Science 65 (Mai 1996): 37–69. http://dx.doi.org/10.1016/0001-8686(95)00289-8.

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4

Kudaibergenov, Sarkyt E. „Macromolecular complexes of polyampholytes“. Pure and Applied Chemistry 92, Nr. 6 (25.06.2020): 839–57. http://dx.doi.org/10.1515/pac-2019-1104.

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AbstractThe macromolecular complexes of random, regular, graft, block and dendritic polyampholytes with respect to transition metal ions, surfactants, dyes, polyelectrolytes, and proteins are discussed in this review. Application aspects of macromolecular complexes of polyampholytes in biotechnology, medicine, nanotechnology, catalysis are demonstrated.

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5

Mendes, E., V. Schädler, C. M. Marques, P. Lindner und U. Wiesner. „Electrostatics in the self-assembly of macromolecular surfactants“. Europhysics Letters (EPL) 40, Nr. 5 (01.12.1997): 521–26. http://dx.doi.org/10.1209/epl/i1997-00498-4.

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6

Joram, Anju, Rashmi Sharma und Arun K. Sharma. „Synthesis, Spectral and Thermo-Gravimetric Analysis of Novel Macromolecular Organo-Copper Surfactants“. Open Chemistry Journal 5, Nr. 1 (30.11.2018): 145–57. http://dx.doi.org/10.2174/1874842201805010145.

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Background: The present paper highlights: Synthesis of copper surfactants derived from edible oils i.e. Groundnut & Sesame and non-edible oils i.e. Neem & Karanj. Methods: Spectral studies (IR, NMR) have been carried out to understand the structural insight of the surfactants synthesized. Results and Conclusion: Thermogravimetric analysis of copper surfactants derived from Groundnut, Sesame, Neem & Karanj has been done to confirm the thermal decomposition/stability. Kinetic parameter i.e. activation energy and thermodynamic parameters i.e. Gibbs free energy, entropy and enthalpy were calculated by five different well-known equations namely Freeman Carroll, Coats - Redfern, Horowitz – Metzger, Broido, and Piloyan –Novikova.

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Jacobs, Jaco, Nicholas Gathergood, Johan P. A. Heuts und Andreas Heise. „Amphiphilic glycosylated block copolypeptides as macromolecular surfactants in the emulsion polymerization of styrene“. Polymer Chemistry 6, Nr. 25 (2015): 4634–40. http://dx.doi.org/10.1039/c5py00548e.

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Bio-inspired amphiphilic block copolymer surfactants fully derived from amino acids and sugars are synthesised. The materials are successfully employed in the synthesis of polystyrene latexes by emulsion polymerization.

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Schädler, V., C. Nardin, U. Wiesner und E. Mendes. „Micellization of Model Macromolecular Surfactants as Studied by Static Light Scattering“. Journal of Physical Chemistry B 104, Nr. 21 (Juni 2000): 5049–52. http://dx.doi.org/10.1021/jp9937205.

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9

Coulembier, Olivier, Jessica Ghisdal, Philippe Degée und Philippe Dubois. „Benzyl β-malolactonate: synthesis, copolymerization and design of novel biodegradable macromolecular surfactants“. Arkivoc 2007, Nr. 10 (02.12.2006): 57–70. http://dx.doi.org/10.3998/ark.5550190.0008.a07.

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10

Kaewprapan, Kulthida, Francis Baros, Emmanuelle Marie, Pranee Inprakhon und Alain Durand. „Macromolecular surfactants synthesized by lipase-catalyzed transesterification of dextran with vinyl decanoate“. Carbohydrate Polymers 88, Nr. 1 (März 2012): 313–20. http://dx.doi.org/10.1016/j.carbpol.2011.12.010.

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11

Liu, Lian, Xingmei Lu, Yingjun Cai, Yong Zheng und Suojiang Zhang. „Influence of Additives on the Speciation, Morphology, and Nanocrystallinity of Aluminium Electrodeposition“. Australian Journal of Chemistry 65, Nr. 11 (2012): 1523. http://dx.doi.org/10.1071/ch12305.

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The effects of various additives, including alkali metal chlorides, rare earth chlorides, small organic molecules, and surfactants on the electrodeposition of aluminium were investigated. The analytical techniques of cyclic voltammetry, potentiostatic coulometry, scanning electron microscope, and X-ray diffraction were applied to determine the speciation, morphology, and nanocrystallinity. It was found that additives significantly influence the morphology and grain parameters of the aluminium deposits. Inorganic additives and macromolecular surfactants play a prominent role in altering the speciation of aluminium. Small organic molecules (including surfactants) with simple structures have almost no effect on the aluminium separation process, but have a role in densification and homogenisation. In addition, the grain size can be adjusted after adding various additives, and then nanocrystallinity can be achieved. In conclusion, the effect of additive on the aluminium deposit can be predicted by cyclic voltammetry, which is a clue for smart-design on technological conditions of aluminium electrodeposition.

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12

Lee, Ji Ha, Hayata Matsumoto, Shota Fujii, Rintaro Takahashi und Kazuo Sakurai. „Monodisperse micelles composed of poly(ethylene glycol) attached surfactants: platonic nature in a macromolecular aggregate“. Soft Matter 15, Nr. 27 (2019): 5371–74. http://dx.doi.org/10.1039/c9sm00943d.

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Among the many studies on micelles, dating back more than 100 years, we first found a series of monodisperse micelles: spherical micelles made from calix[4]arene surfactants exhibited monodispersity in aggregation number (N_agg) with values of 4, 6, 8, 12, and 20.

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Dymytriuk, T. M., D. P. Savitskyi und A. S. Makarov. „The Influence of Molecular Weight Hydroxypropylcellulose on Rheological Properties of Aqua-Ethanol-Coal Suspensions“. Фізика і хімія твердого тіла 16, Nr. 4 (15.12.2015): 722–25. http://dx.doi.org/10.15330/pcss.16.4.722-725.

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The rheological properties of aqua-ethanol-coal of varying degrees coal metamorphism, stabilized by macromolecular surfactants was studied by rotational viscometry. It was found that including of hydroxypropylcellulose as a stabilizer for dispersions of coal and water-ethanol mixtures, increasing their stability. It is shown that with increasing molecular weight of hydroxypropylcellulose viscosity of disperse systems increases, regardless of the degree of coal metamorphism. With increasing concentrations of the polymer injected more than 0.01 % of coal the viscosity of the systems increases sharply.

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14

Korth, Bryan D., Pei Keng, Inbo Shim, Steven E. Bowles, Chuanbing Tang, Tomasz Kowalewski, Kenneth W. Nebesny und Jeffrey Pyun. „Polymer-Coated Ferromagnetic Colloids from Well-Defined Macromolecular Surfactants and Assembly into Nanoparticle Chains“. Journal of the American Chemical Society 128, Nr. 20 (Mai 2006): 6562–63. http://dx.doi.org/10.1021/ja0609147.

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15

Kancharla, Samhitha, Nathan A. Zoyhofski, Lucas Bufalini, Boris F. Chatelais und Paschalis Alexandridis. „Association between Nonionic Amphiphilic Polymer and Ionic Surfactant in Aqueous Solutions: Effect of Polymer Hydrophobicity and Micellization“. Polymers 12, Nr. 8 (15.08.2020): 1831. http://dx.doi.org/10.3390/polym12081831.

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The interaction in aqueous solutions of surfactants with amphiphilic polymers can be more complex than the surfactant interactions with homopolymers. Interactions between the common ionic surfactant sodium dodecyl sulfate (SDS) and nonionic amphiphilic polymers of the poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO-PPO-PEO) type have been probed utilizing a variety of experimental techniques. The polymer amphiphiles studied here are Pluronic F127 (EO100PO65EO100) and Pluronic P123 (EO19PO69EO19), having the same length PPO block but different length PEO blocks and, accordingly, very different critical micellization concentrations (CMC). With increasing surfactant concentration in aqueous solutions of fixed polymer content, SDS interacts with unassociated PEO-PPO-PEO molecules to first form SDS-rich SDS/Pluronic assemblies and then free SDS micelles. SDS interacts with micellized PEO-PPO-PEO to form Pluronic-rich SDS/Pluronic assemblies, which upon further increase in surfactant concentration, break down and transition into SDS-rich SDS/Pluronic assemblies, followed by free SDS micelle formation. The SDS-rich SDS/Pluronic assemblies exhibit polyelectrolyte characteristics. The interactions and mode of association between nonionic macromolecular amphiphiles and short-chain ionic amphiphiles are affected by the polymer hydrophobicity and its concentration in the aqueous solution. For example, SDS binds to Pluronic F127 micelles at much lower concentrations (~0.01 mM) when compared to Pluronic P123 micelles (~1 mM). The critical association concentration (CAC) values of SDS in aqueous PEO-PPO-PEO solutions are much lower than CAC in aqueous PEO homopolymer solutions.

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16

Mathieu, K., J. De Winter, C. Jérôme und A. Debuigne. „Simultaneous synthesis and chemical functionalization of emulsion-templated porous polymers using nitroxide-terminated macromolecular surfactants“. Polymer Chemistry 8, Nr. 11 (2017): 1850–61. http://dx.doi.org/10.1039/c7py00128b.

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17

Gordon, Virginia C. „The Scientific Basis of the EYTEX™ System“. Alternatives to Laboratory Animals 20, Nr. 4 (Oktober 1992): 537–48. http://dx.doi.org/10.1177/026119299202000406.

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The EYTEX™ system is an in vitro method for predicting in vivo ocular irritation via a target biomacromolecular approach. EYTEX™ uses changes of relevant macromolecules upon exposure to chemicals and formulations to predict in vivo irritancy and toxicity endpoints. The EYTEX™ system is based on alterations in the conformation and hydration of an ordered macromolecular matrix. An oligomeric protein with a molar mass of approximately 300,000g/mol is the major active component of the reagent. This oligomer, characterised by 12 subunits, associates itself into strands which are then incorporated into a gel network. This network also includes smaller proteins, peptides, amino acids, aminoglycans and mucopolysaccharides, which contribute to the overall response of the macromolecular matrix to a diverse array of test compounds, such as acids, bases, salts, solvents, surfactants, lubricants, preservatives, emulsions, dyes, amines, amides and many others. The method has been extensively evaluated using chemicals and formulations from diverse classes and with different ranges of toxicity, representing various mechanisms of ocular toxicity. Results using the in vitro test correlate broadly with the Draize in vivo eye irritancy test results. Quantification of the EYTEX™ method is based on measurement of changes in optical density of the matrix, which are sensitive to the conformation and hydration of protein, as well as the order in the matrix. These changes, which occur when the matrix is exposed to chemicals and formulations, can be used to predict in vivo ocular irritancy. Calibrators and controls provide assay standardisation with a 4–8% coefficient of variation. Multiple dose and time variables relating to irritancy potential can be assessed and compared with Draize in vivo results. The EYTEX™ system provides a comprehensive set of four protocols suitable for analysing chemicals and formulations with varying degrees and mechanisms of ocular irritancy.

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18

Su, Hao, Yiwen Li, Kan Yue, Zhao Wang, Pengtao Lu, Xueyan Feng, Xue-Hui Dong, Shuo Zhang, Stephen Z. D. Cheng und Wen-Bin Zhang. „Macromolecular structure evolution toward giant molecules of complex structure: tandem synthesis of asymmetric giant gemini surfactants“. Polymer Chemistry 5, Nr. 11 (2014): 3697. http://dx.doi.org/10.1039/c4py00107a.

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19

Li, Yunbo, Xudong Chen, Mingqiu Zhang, Weiang Luo, Jin Yang und Fangming Zhu. „Macromolecular Aggregation of Aqueous Polyacrylic Acid in the Presence of Surfactants Revealed by Resonance Rayleigh Scattering“. Macromolecules 41, Nr. 13 (Juli 2008): 4873–80. http://dx.doi.org/10.1021/ma702800p.

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20

Li, Yunbo, Xudong Chen, Mingqiu Zhang, Weiang Luo, Jin Yang und Fangming Zhu. „Macromolecular Aggregation of Aqueous Polyacrylic Acid in the Presence of Surfactants Revealed by Resonance Rayleigh Scattering“. Macromolecules 41, Nr. 19 (14.10.2008): 7257. http://dx.doi.org/10.1021/ma801834c.

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21

Tymchuk, A. F., A. O. Grossu und A. V. Babenko. „STUDY OF THE SOLUBILIZING CAPACITY OF POLYMER-COLLOID COMPLEXES FORMED WITH SODIUM ALGINATE AND CHLORIDE HEXADECYLPYRIDINIUM“. Odesa National University Herald. Chemistry 26, Nr. 2(78) (31.07.2021): 40–47. http://dx.doi.org/10.18524/2304-0947.2021.2(78).233827.

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It was examined the behavior of systems which contain surfactants and biopolymers is considered by the example of cationic surfactants and sodium alginate. The rheological and surface-active properties of the systems have been experimentally investigated. It was found that the presence of oppositely charged surfactants in the solution significantly affects the properties of sodium alginate, due to the fact that associates or polymer-colloidal complexes are formed in the solution. Their formation significantly affects the solubilizing ability in relation to non-polar liquids. Hydrodynamic parameters of macromolecules of sodium alginate in comparison with macromolecules of chitosan correspond to the conformation of the loose ball. The state of the SN is determined by the pH of the medium and temperature. The increase in temperature leads to a violation of the structure of the chain, its destruction and a subsequent decrease in viscosity. At a temperature of 293K, the macromolecule is in a more ordered state. In the alkaline environment there is a change in the conformation of the macromolecule. As a result of this change, the viscosity naturally increases. This is explained by the fact that in an alkaline environment, the macromolecule acquires an excess negative charge, there is a repulsion of the carboxyl groups of the same name in the chain links. The macromolecule acquires an expanded configuration. The viscosity increases. In acidic environment, sodium alginate has almost zero charge as a result of protonation of carboxyl groups. The molecule acquires the conformation of a loose ball with the lowest value of viscosity. The isoelectric state of the alginate macromolecule is observed in the pH range of 5.5 to 6.0. The described state of the macromolecule in solution is confirmed by our calculations. The interaction of surface-active cations with carboxyl groups of SN leads first to the formation of associates, then to polymer-colloidal complexes. The association as a result of electrostatic interaction of active groups is enhanced by the hydrophobic interaction of hydrocarbon fragments of surfactant molecules with each other and with the alginate matrix. The association ends with the formation of a polymer-colloidal complex.

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Babak, V. G. „Thermodynamic and kinetic aspects of the stabilization of microscopic liquid films by the adsorbed layers of macromolecular surfactants“. Langmuir 3, Nr. 5 (September 1987): 612–20. http://dx.doi.org/10.1021/la00077a003.

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23

Shahzadi, Iram, Mulazim Hussain Asim, Aida Dizdarević, Julian Dominik Wolf, Markus Kurpiers, Barbara Matuszczak und Andreas Bernkop-Schnürch. „Arginine-based cationic surfactants: Biodegradable auxiliary agents for the formation of hydrophobic ion pairs with hydrophilic macromolecular drugs“. Journal of Colloid and Interface Science 552 (September 2019): 287–94. http://dx.doi.org/10.1016/j.jcis.2019.05.057.

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24

Aguirre-Ramírez, M., H. Silva-Jiménez, I. M. Banat und M. A. Díaz De Rienzo. „Surfactants: physicochemical interactions with biological macromolecules“. Biotechnology Letters 43, Nr. 3 (03.02.2021): 523–35. http://dx.doi.org/10.1007/s10529-020-03054-1.

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AbstractMacromolecules are essential cellular components in biological systems responsible for performing a large number of functions that are necessary for growth and perseverance of living organisms. Proteins, lipids and carbohydrates are three major classes of biological macromolecules. To predict the structure, function, and behaviour of any cluster of macromolecules, it is necessary to understand the interaction between them and other components through basic principles of chemistry and physics. An important number of macromolecules are present in mixtures with surfactants, where a combination of hydrophobic and electrostatic interactions is responsible for the specific properties of any solution. It has been demonstrated that surfactants can help the formation of helices in some proteins thereby promoting protein structure formation. On the other hand, there is extensive research towards the use of surfactants to solubilize drugs and pharmaceuticals; therefore, it is evident that the interaction between surfactants with macromolecules is important for many applications which includes environmental processes and the pharmaceutical industry. In this review, we describe the properties of different types of surfactants that are relevant for their physicochemical interactions with biological macromolecules, from macromolecules–surfactant complexes to hydrophobic and electrostatic interactions.

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Danino, Dganit, Yeshayahu Talmon und Jenny Hinshaw. „Digital imaging: an advanced tool for cryo-TEM studies“. Microscopy and Microanalysis 7, S2 (August 2001): 828–29. http://dx.doi.org/10.1017/s143192760003021x.

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Direct-imaging cryo-electron microscopy combined with CCD cameras provide a powerful tool for studying macromolecular assemblies in the 2 to 300 nm range, which form in biological systems, biomedical solutions, surfactants, microemulsions and a host of other diverse systems. The CCD cameras are especially advantageous for identifying rare assemblies, studying specific assembly details (figures A and B) and transient structures forming during dynamic processes and phase transformations (figures C-E). This setup is also beneficial for exploring coexistence of structures and studying highly radiation-sensitive systems such as oil-continuous solutions. Information on internal ordering is also readily obtained (figure A).Continuous CCD application at low dose conditions provides numerous significant advantages over classical imaging on photographic plates. First, it allows a preview of the exact area to be recorded (search and focus modes), concentration on specific interesting features and adjustment of microscope parameters for optimal imaging (focus mode), at very low exposures and with minimal radiation damage.

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Lemos, Leandro, Luis Silva, Maria Silva, Jorge Amim, Jane Coimbra und Luis Minim. „Application of a macromolecular micellar system formed by the P123 triblock copolymer for determination of copper concentrations“. Open Chemistry 8, Nr. 2 (01.04.2010): 258–63. http://dx.doi.org/10.2478/s11532-010-0008-0.

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AbstractThis work proposes a method for determination Cu(II) concentrations, based on the formation of a copper-1-nitroso-2-naphthol complex, in the presence of micelles; formed by a triblock copolymer, made up of two blocks of polyethylene oxide (PEO), and one block of polypropylene oxide (PPO). The insoluble copper complexes, are concentrated inside the hydrophobic micelle core; formed by the PPO block. For a solution containing 0.200 mg L−1 Cu(II), the proposed method had a relative standard deviation of 2.0% (n = 3); an absolute error from 0.11 to 0.39 mg L−1; and a linear calibration range, from 0.200 to 0.800 mg L−1. Detection and quantification limits, were 43.1 mg L−1 and 144 mg L−1, respectively. We show that there is excellent agreement, between the results obtained using our novel method; and those obtained using flame atomic absorption spectrometry: In the determination of Cu(II) concentrations, in Brazilian sugar-cane spirits. The proposed method, is the first to apply macromolecular micelle systems, to the determination of copper concentrations; and improves upon the results obtained using molecular surfactants. This method is environmentally friendly (since it does not use any organic solvents for extraction), and the triblock copolymer is biodegradable and non-toxic.

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Lacroix-Desmazes, Patrick, Pascal Andre, Joseph M. Desimone, Anne-Val�rie Ruzette und Bernard Boutevin. „Macromolecular surfactants for supercritical carbon dioxide applications: Synthesis and characterization of fluorinated block copolymers prepared by nitroxide-mediated radical polymerization“. Journal of Polymer Science Part A: Polymer Chemistry 42, Nr. 14 (2004): 3537–52. http://dx.doi.org/10.1002/pola.20193.

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28

Madbouly, Samy A. „Waterborne Polyurethane Dispersions and Thin Films: Biodegradation and Antimicrobial Behaviors“. Molecules 26, Nr. 4 (11.02.2021): 961. http://dx.doi.org/10.3390/molecules26040961.

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Biodegradable and antimicrobial waterborne polyurethane dispersions (PUDs) and their casted solid films have recently emerged as important alternatives to their solvent-based and non-biodegradable counterparts for various applications due to their versatility, health, and environmental friendliness. The nanoscale morphology of the PUDs, dispersion stability, and the thermomechanical properties of the solid films obtained from the solvent cast process are strongly dependent on several important parameters, such as the preparation method, polyols, diisocyanates, solid content, chain extension, and temperature. The biodegradability, biocompatibility, antimicrobial properties and biomedical applications can be tailored based on the nature of the polyols, polarity, as well as structure and concentration of the internal surfactants (anionic or cationic). This review article provides an important quantitative experimental basis and structure evolution for the development and synthesis of biodegradable waterborne PUDs and their solid films, with prescribed macromolecular properties and new functions, with the aim of understanding the relationships between polymer structure, properties, and performance. The review article will also summarize the important variables that control the thermomechanical properties and biodegradation kinetics, as well as antimicrobial and biocompatibility behaviors of aqueous PUDs and their films, for certain industrial and biomedical applications.

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Li, Jingyan, und Cristina Sabliov. „PLA/PLGA nanoparticles for delivery of drugs across the blood-brain barrier“. Nanotechnology Reviews 2, Nr. 3 (01.06.2013): 241–57. http://dx.doi.org/10.1515/ntrev-2012-0084.

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AbstractThe blood-brain barrier (BBB), which protects the central nervous system (CNS) from unnecessary substances, is a challenging obstacle in the treatment of CNS disease. Many therapeutic agents such as hydrophilic and macromolecular drugs cannot overcome the BBB. One promising solution is the employment of polymeric nanoparticles (NPs) such as poly (lactic-co-glycolic acid) (PLGA) NPs as drug carrier. Over the past few years, significant breakthroughs have been made in developing suitable PLGA and poly (lactic acid) (PLA) NPs for drug delivery across the BBB. Recent advances on PLGA/PLA NPs enhanced neural delivery of drugs are reviewed in this paper. Both in vitro and in vivo studies are included. In these papers, enhanced cellular uptake and therapeutic efficacy of drugs delivered with modified PLGA/PLA NPs compared with free drugs or drugs delivered by unmodified PLGA/PLA NPs were shown; no significant in vitro cytotoxicity was observed for PLGA/PLA NPs. Surface modification of PLGA/PLA NPs by coating with surfactants/polymers or covalently conjugating the NPs with targeting ligands has been confirmed to enhance drug delivery across the BBB. Most unmodified PLGA NPs showed low brain uptake (<1%), which indirectly confirms the safety of PLGA/PLA NPs used for other purposes than treating CNS diseases.

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Islam, Molla Rafiquel, Elianne Dahan, Sundar Saimani und Pudupadi R. Sundararajan. „Preclusion of nano scale self-assembly in block-selective non-aqueous solvents for rod–coil and coil–rod–coil macromolecular surfactants based on perylene tetracarboxylic diimide“. European Polymer Journal 48, Nr. 9 (September 2012): 1538–54. http://dx.doi.org/10.1016/j.eurpolymj.2012.06.008.

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31

Morales-Torres, Sergio, Hana Jirglová, Luisa M. Pastrana-Martínez und Francisco J. Maldonado-Hódar. „Influence of Electrostatic Interactions During the Resorcinol-Formaldehyde Polymerization on the Characteristics of Mo-Doped Carbon Gels“. Processes 8, Nr. 6 (26.06.2020): 746. http://dx.doi.org/10.3390/pr8060746.

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The resorcinol (R)-formaldehyde (F) polymerization was carried out in different experimental conditions to obtain RF/Mo doped carbon xerogels with different morphology, porosity and nature and dispersion of metal. Attractive or repulsive electrostatic interactions were forced in the starting aqueous solution of RF-monomers using different synthesis conditions, namely, combinations of cationic or anionic surfactants, Mo-precursors and pH values. The results showed that when both cationic surfactant and Mo-precursor were used at neutral pH, attractive interactions with the anionic RF-macromolecules are favored during polymerization and the final carbon xerogel exhibited the most developed porosity and the strongest Mo-organic phase interaction, leading to deeper Mo-phase reduction during carbonization and the formation of highly-dispersed crystalline nanoparticles of Mo2C. On the contrary, the use of both anionic surfactant and Mo-precursor leads to repulsive interactions, which generates less porous carbon gels with a Mo-phase formed by large MoO3 platelet structures and low Mo-surface contents. RF/Mo-doped gels with intermediate properties were obtained by combining cationic and anionic surfactants, metal precursors or both. After carbonization, the obtained materials would be suitable to be used directly as catalysts with different physicochemical properties and active phases.

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Abhishek S., Patil, Shaikh Bilal J., Bhosale Ankush S., Raut Indrayani D. und Nitalikar Manojkumar M. „NIOSOMES: A PROMISING DRUG DELIVERY CARRIER“. International Journal of Pharmaceutical Sciences and Medicine 6, Nr. 6 (30.06.2021): 15–27. http://dx.doi.org/10.47760/ijpsm.2021.v06i06.002.

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Niosomes are non-ionic surfactant-based multilamellar or unilamellar vesicles in which an aqueous solute solution is completely encapsulated by a membrane formed by surfactant macromolecules organised as a bilayer. Because vesicles are made up of a bilayer of non-ionic surface-active substances, the term "Niosomes" was coined (non-ionic surfactants). Niosomes are an unique drug delivery technology that encapsulates the medication in a vesicle. Ionic drug carriers are hazardous and inappropriate, whereas niosomal drug carriers are less dangerous. Niosomes do not require any specific handling or storage conditions.Niosomes have shown to be a promising drug carrier, with the potential to minimise medication side effects and improve therapeutic efficacy in a variety of disorders. Drug insolubility, instability, limited bioavailability, and fast degradation are all issues that niosomes address. The benefits, preparations, assessment, and medicinal uses of niosomes are discussed in this review article.

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C, Naveen, Kiran kumar Y, Venkateshwar Rao P und T. Rama Rao. „Chemical Enhancers in Buccal and Sublingual Delivery“. International Journal of Pharmaceutical Sciences and Nanotechnology 4, Nr. 1 (31.05.2011): 1307–19. http://dx.doi.org/10.37285/ijpsn.2011.4.1.3.

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Rapid developments in the field of molecular biology and gene technology resulted in generation of many macromolecular drugs with superior pharmacological efficacy, site specificity and devoid of toxic effects. However, the major problem for the oral delivery of these therapeutic agents is their extensive presystemic metabolism, instability in acidic environment resulting into inadequate and erratic oral absorption. Parenteral route of administration is the only established route that overcomes all these drawbacks associated with these orally less/inefficient drugs. But, these formulations are costly, have least patient compliance and require repeated administration. The buccal delivery system found to be most convenient and easily accessible site for the delivery of such therapeutic agents. This route provides direct access to the systemic circulation through the internal jugular vein thus avoiding the hepatic first-pass effect and degradation in the gastrointestinal tract, ease of administration, and the ability to terminate delivery when required. The epithelium that lines the oral mucosa is a very effective barrier that restricts the membrane permeation for many drugs administered via this route, and can be a limiting factor to the absorption of drugs. The use of penetration enhancers is one approach for improving buccal drug delivery. This requisite has fostered the study of penetration enhancers that will safely alter the permeability restrictions of the buccal mucosa. This review describes various classes of transmucosal chemical permeation enhancers such as bile salts, surfactants, fatty acids and their derivatives, chelators, cyclodextrins and chitosan along with their mechanism of action. Even though these enhancers influence drug delivery, further exploration of these compounds is required to understand their modifying action on the properties of buccal mucosa.

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Grijalvo, Santiago, Gustavo Puras, Jon Zárate, Myriam Sainz-Ramos, Nuseibah A. L. Qtaish, Tania López, Mohamed Mashal et al. „Cationic Niosomes as Non-Viral Vehicles for Nucleic Acids: Challenges and Opportunities in Gene Delivery“. Pharmaceutics 11, Nr. 2 (22.01.2019): 50. http://dx.doi.org/10.3390/pharmaceutics11020050.

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Cationic niosomes have become important non-viral vehicles for transporting a good number of small drug molecules and macromolecules. Growing interest shown by these colloidal nanoparticles in therapy is determined by their structural similarities to liposomes. Cationic niosomes are usually obtained from the self-assembly of non-ionic surfactant molecules. This process can be governed not only by the nature of such surfactants but also by others factors like the presence of additives, formulation preparation and properties of the encapsulated hydrophobic or hydrophilic molecules. This review is aimed at providing recent information for using cationic niosomes for gene delivery purposes with particular emphasis on improving the transportation of antisense oligonucleotides (ASOs), small interference RNAs (siRNAs), aptamers and plasmids (pDNA).

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Clarke, M. S., und P. L. McNeil. „Syringe loading introduces macromolecules into living mammalian cell cytosol“. Journal of Cell Science 102, Nr. 3 (01.07.1992): 533–41. http://dx.doi.org/10.1242/jcs.102.3.533.

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We describe a simple, efficient, gentle and inexpensive technique for the introduction of normally impermeant macromolecules into the cytosol of living mammalian cells growing in suspension or attached to the culturing substratum. Loading is achieved by the production of transient, survivable plasma membrane disruptions as cells are passed back and forth through a standard syringe needle or similar narrow orifice. The loading volume required, which contains cells and the macromolecule to be loaded, can be as little as 5 microliters, thus minimizing the use of valuable reagents. In addition, we report that the surfactant molecule, Pluronic F-68, is capable of altering the physical properties of the plasma membrane in such a way as to increase loading efficiency and the long-term survivability of cells loaded by this and other mechanically based cell-loading techniques.

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Kolesnikov, A. V., und I. V. Tsyganova. „Investigation of flocculant influence on the kinetic parameters of copper recovery in aqueous solution with metal zinc“. Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy, Nr. 3 (19.06.2019): 4–11. http://dx.doi.org/10.17073/0021-3438-2019-3-4-11.

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We studied a number of models for the description of copper reduction by fine zinc powder in aqueous solutions. The experimentswere carried out in devices with a magnetic stirrer at mixing speeds of 40–150 rpm and temperatures of 15–50 °C. We investigated the influence exerted on the process by macromolecular flocculants such as non-ionic magnafloc 333, cationic besflok 6645 and anionic besfloc 4034. Under industrial conditions, these flocculants are used at the hydrolytic solution purification stage and then they are fed to cementing purification together with the clarified solution. Aqueous flocculant solutions of 2,5 g/l containing 2–4 g/l of zinc dust and 50–200 mg/l of flocculant were used in the experiments. Copper content in the initial and final solutions was quantitatively determined by spectrophotometric analysis with the preliminary copper transfer to the ammonia complex. Experiment duration varied from 1 to 8 min. The degree of copper reduction from solutions was 10–90 %. It was found that at low mixing rates the process kinetics can be described by the kinetic equation of the first order. At high speeds, the kinetics of the studied heterogeneous reactionwith added flocculants is more adequately described by the velocity change equation as a square root of the process duration. It wasshown that the highest constant of cementation rate is observed in experiments without the addition of surfactants. Anionic flocculant slows down the cementation process to a lesser extent than cationic one, which is consistent with the theory of electrochemical processes and shows that the discharge of copper cations under these conditions limits the cementation process. Regularities revealed in the studied process remain as temperature increases. It was noted that the addition of high-molecular substances with a relative molecular mass of 20 million in an amount of 50–200 mg/l inhibit the cementation process. This fact must be taken into account in industrial conditions where cementing purification from copper and other impurities is carried out from flocculant-containing solutions.

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Twarog, Caroline, Sarinj Fattah, Joanne Heade, Sam Maher, Elias Fattal und David J. Brayden. „Intestinal Permeation Enhancers for Oral Delivery of Macromolecules: A Comparison between Salcaprozate Sodium (SNAC) and Sodium Caprate (C10)“. Pharmaceutics 11, Nr. 2 (13.02.2019): 78. http://dx.doi.org/10.3390/pharmaceutics11020078.

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Salcaprozate sodium (SNAC) and sodium caprate (C10) are two of the most advanced intestinal permeation enhancers (PEs) that have been tested in clinical trials for oral delivery of macromolecules. Their effects on intestinal epithelia were studied for over 30 years, yet there is still debate over their mechanisms of action. C10 acts via openings of epithelial tight junctions and/or membrane perturbation, while for decades SNAC was thought to increase passive transcellular permeation across small intestinal epithelia based on increased lipophilicity arising from non-covalent macromolecule complexation. More recently, an additional mechanism for SNAC associated with a pH-elevating, monomer-inducing, and pepsin-inhibiting effect in the stomach for oral delivery of semaglutide was advocated. Comparing the two surfactants, we found equivocal evidence for discrete mechanisms at the level of epithelial interactions in the small intestine, especially at the high doses used in vivo. Evidence that one agent is more efficacious compared to the other is not convincing, with tablets containing these PEs inducing single-digit highly variable increases in oral bioavailability of payloads in human trials, although this may be adequate for potent macromolecules. Regarding safety, SNAC has generally regarded as safe (GRAS) status and is Food and Drug Administration (FDA)-approved as a medical food (Eligen®-Vitamin B12, Emisphere, Roseland, NJ, USA), whereas C10 has a long history of use in man, and has food additive status. Evidence for co-absorption of microorganisms in the presence of either SNAC or C10 has not emerged from clinical trials to date, and long-term effects from repeat dosing beyond six months have yet to be assessed. Since there are no obvious scientific reasons to prefer SNAC over C10 in orally delivering a poorly permeable macromolecule, then formulation, manufacturing, and commercial considerations are the key drivers in decision-making.

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Joondan, Nausheen, Sabina J. Laulloo, Prakashanand Caumul und Prashant S. Kharkar. „Antioxidant, Antidiabetic and Anticancer Activities of L-Phenylalanine and L-Tyrosine Ester Surfactants: In Vitro and In Silico Studies of their Interactions with Macromolecules as Plausible Mode of Action for their Biological Properties“. Current Bioactive Compounds 15, Nr. 6 (23.01.2020): 610–22. http://dx.doi.org/10.2174/1573407214666180829125309.

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Background: Aromatic amino acid-based surfactants have been found to have interesting biological properties such as antibacterial and hemolytic activities. Recently, we have reported the antibacterial activity of a range of ester hydrochloride surfactants derived from L-Phenylalanine and LTyrosine. This study aims at assessing the antioxidant, α-glycosidase inhibitory and cytotoxic activities of a series of L-Phenylalanine and L-Tyrosine ester hydrochlorides. Molecular docking and BSA binding studies were also carried out in order to investigate their potential therapeutic targets. Methods: L-Phenylalanine and L-Tyrosine surfactants were tested as potential lipophilic antioxidants using the DPPH and ABTS assays. These surfactants were also tested for their α-glycosidase inhibitory activity using 4-nitrophenyl α -D-glucopyranoside (pNPG) as substrate. Their cytotoxicity effects were screened using HeLa and KB cell lines. Glide version 5.7 as implemented in Schrödinger suite 2013-1, was used for performing docking studies of L-Phenylalanine and L-Tyrosine dodecyl esters. The interaction of the ester hydrochlorides of L-Phenylalanine and L-Tyrosine with bovine serum albumin (BSA) was investigated using fluorometric titration. Results: The presence of the phenolic moiety in L-Tyrosine-based surfactants was found to enhance the antioxidant and α-glucosidase inhibitory activities compared to the L-Phenylalanine derivatives. The α- glucosidase and anticancer activities of the phenylalanine surfactants were found to increase with chain length up to C12 above which the activities exhibited a downward trend. In the case of the tyrosine series, an increase in chain length from C8 to C14 was found to decrease the α-glucosidase inhibitory activity and increase the anticancer activity of the surfactants. Binding studies with bovine serum albumin showed that the tyrosine surfactants displayed greater affinity for the serum albumin, owing to the presence of the phenolic group which altered the orientation of the surfactant molecule within the hydrophobic core of BSA. Conclusion: L-Tyrosine esters having a phenolic moiety were found to possess enhanced biological activity in terms of both the antioxidant and antidiabetic activities as well as also bind more strongly to Bovine serum albumin. Molecular docking studies of the phenylalanine and tyrosine surfactants of similar chain length with target proteins showed direct correlation with their anticancer and antidiabetic activity. Therefore, the findings show that these aromatic based surfactants derived from L-Tyrosine can act as promising antioxidant, antidiabetic and anticancer agents, and they can also be efficiently transported and eliminated in the body, making them useful candidates for drug designs.

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Ivanov, Ivo, Ivanka Tsacheva, Vishnia Stoyanova, Miroslav Nikolov, Magdalena I. Tchorbadjieva, Svetla Petrova, Latchezar Christov, Ventsislava Georgieva und George Georgiev. „Chaperone-Like Effect of Polyzwitterions on the Interaction of C1q with IgG“. Zeitschrift für Naturforschung C 64, Nr. 1-2 (01.06.2009): 149–54. http://dx.doi.org/10.1515/znc-2009-1-224.

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The amphiphilic polyzwitterion (PZ) poly(ethylene oxide-b-N,N-dimethyl(methacryloyloxyethyl) ammonium propanesulfonate), zwitterionic surfactant (ZS) n-dodecyl- N,N-dimethyl-3-ammonium-1-propanesulfonate, and zwitterionic monomer (ZM) N,Ndimethyl( methacryloyloxyethyl)ammonium propanesulfonate were analyzed for their suggested chaperone-like effect on the interaction of C1q and IgG. Our results proved that the PZ retarded the C1q interaction with IgG, demonstrating a specific protein-folding helper effect. The ZS enhanced this interaction, when the ZS concentration was lower than the critical micelle concentration (CMC), and retarded it, when the ZS concentration was above the CMC. The ZM, with no self-assembling ability, did not influence this interaction. These results support the hypothesis of a hydrophobic interaction between Pts and hydrophobic domains of partly denatured protein molecules. The amphiphilic self-assemblies, formed by polyzwitterionic macromolecules or zwitterionic surfactants, have the ability to transform the hydrophobic domains of the protein molecules into hydrophilic ones, covering them with their hydrophilic parts.

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Yong-Zheng, Tang, Tang Ye-Cang, Luo Shi-Zhong, Fu Zhong und Zhang Wen-Min. „Microwave Preparation of Narrowly Distributed Surfactant-free Macromolecular Nanospheres“. Acta Physico-Chimica Sinica 14, Nr. 07 (1998): 620–23. http://dx.doi.org/10.3866/pku.whxb19980709.

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Hawgood, S. „Pulmonary surfactant apoproteins: a review of protein and genomic structure“. American Journal of Physiology-Lung Cellular and Molecular Physiology 257, Nr. 2 (01.08.1989): L13—L22. http://dx.doi.org/10.1152/ajplung.1989.257.2.l13.

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In recent years, as the complexity of the surfactant system has become more apparent, investigators with an increasingly diverse set of skills have been attracted to the study of this secretory product of the alveolar epithelium. In addition to advancing our knowledge of the mechanisms underlying the mechanical stability of the lung, recent studies of the surfactant system have also contributed information to less organ-specific biological phenomena such as exocytosis, endocytosis, cell differentiation and lipid-protein interactions in biomembranes. Pulmonary surfactant is not composed of a single class of molecules but, rather, is a collection of interrelated macromolecular lipoprotein complexes that differ in composition, structure, and function. The purpose of this review is to describe the structure of the lung-specific proteins that are associated with the phospholipids of surfactant in the alveolar space. The organization of the genes for the surfactant proteins is outlined and the affects of these proteins on the properties of phospholipid membranes are discussed.

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Yang, Xue, Ze Quan Liu und Qiang Zhang. „A Progress in Development and Application of Size Exclusion Chromatograph/Multi-Angle Laser Light Scattering“. Advanced Materials Research 936 (Juni 2014): 1597–602. http://dx.doi.org/10.4028/www.scientific.net/amr.936.1597.

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This paper reveals the development and significance of size exclusion chromatograph/multi-angle laser light scattering(SEC-MALLS) for determination of the molecular weight and characterization of the molecular weight distribution. This technque has been applied in many aspects, such as biology, polymer and carboxylate surfactant. It has made a big contribution to study the property of macromolecular substances.

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Koval, A. S., S. V. Birukova und Y. V. Voyda. „The quality assurance of the medicinal composition using the “Antimicrobial activity” indicator“. Management, economy and quality assurance in pharmacy, Nr. 1(65) (15.03.2021): 27–34. http://dx.doi.org/10.24959/uekj.21.2.

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The aim of the work is to determine the spectrum and strenght of antimicrobial activity of the studied compositions, to compare them with the activity of substancesand to select the most optimal concentration for further combination with each other. Topicality. Nowadays, one of the most common skin diseases is acne and demodicosis, the manifestations of which can be mild (comedones in seborrheic areas), more noticeable (papules-pustular rash) and severe (large cyanotic infiltrative elements in the back, prone to abscessing and scarring). The prevalence of acne and demodicosis currently reaches 90%. With these skin pathologies, it is desirable to use safe and effective drugs for external therapy, which provide rapid improvement of the skin (reduction of inflammation without side effects) to obtain a rapid and high-quality therapeutic effect. In the course of our research, we selected 3 active pharmaceutical ingredients (APIs): metronidazole, benzyl benzoate and benzoyl peroxide - according to the purpose of ICD-10 and their effectiveness in these pathologies. Mild medicines have an advantage over dermatological diseases such as acne and demodicosis because the use of soft medicines is local, namely a targeted effect on the microbial microflora. At present for production of soft medicines for local application such substances as macromolecular compounds are widely used, plasticizers, surfactants,etc. When creating a drug composition, a study was conducted aimed at obtaining soft medicines with certain consumer properties, in particular physicochemical (pH, osmotic activity, homogeneity,etc.) , physical and mechanical properties (rheological parameters). Materials for the study – soft medicines based on cetyl alcohol, Emulgade Sucro Plus, Polyvinylpyrrolidone, Carboxymethylcellulose, Tween 80, Triethanolamine, Propylene glycol, vaseline oil, which as (API) contains metronidazole, benzoyl peroxide, benzylbenzene. The specific antimicrobial activity of the samples was tested in accordance with Order № 167 of the Ministry of Health of Ukraine dated 05.04.2007 by the standard macromethod of serial dilutions in liquid nutrient medium and by the method of diffusion into agar. The minimum inhibitory concentration (MIC) of API (substrates) was determined. Results. The studied compositions of soft medicines and substrates revealed to presence of antibacterial (bacteriostatic) action against the test strains of microorganisms. Conclusions. The test of the compositions of soft medicines and the substance revealed the presence of a slight antibacterial (bacteriostatic) effect against the test strains of microorganisms. Key words: antimicrobial activity; active pharmaceutical ingredients (API); excipients; soft dosage form

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Evdokimov, A. O., A. M. Bukanov, L. R. Lyusova und A. V. Petrogradsky. „THE INFLUENCE OF RESIDUE EMULSIFIER AMOUNTS ON PROPERTIES OF NITRILE RUBBERS AND ELASTOMERIC MATERIALS BASED ON THEM“. Fine Chemical Technologies 13, Nr. 5 (28.10.2018): 58–66. http://dx.doi.org/10.32362/2410-6593-2018-13-5-58-66.

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The paper considers the properties of a number of commercially available Russian nitrilebutadiene rubbers (NBR) containing approximately the equal acrylonitrile amount (from 26 to 33%) in the macromolecule, but differing in the method of synthesis and isolation. The assessment ofthe influence of residual emulsifier content and also such surfactants as rosin and stearic acid introduced as technological additives on some NBR properties was performed. The technological properties of model compounds based on these NBR, in particular, Mooney viscosity, minimal and maximal torques during curing, and scorching time were determined. It was shown that both residual emulsifier amounts and introduced surfactants decrease the viscosity of the compounds and increase the curing time. It was noted that rosin acts in a different manner in comparison with stearic acid. In particular, stearic acid acting as an interstructural plasticizer affects viscosity decrease in a greater degree. The mechanical performance of vulcanizatesbased on rubber compounds considered in the paper was also determined. It was shown that the surfactants effect on the mechanical properties is negligible and is within the measurement accuracy. Nevertheless, the NBRs obtained with various emulsifiers differ essentially and can’t be replaceable without revising both the rubber compounds recipes and processing parameters. The vulcanizates resistance to some organic solvents and water was also studied. It was shown that the acrylonitrile content in the rubber macromolecule is the key factor affecting the resistance to non-polar solvents. At the same time it was found that the vulcanizates containing residual emulsifier amounts tend to the swelling index increase. In general, the surfactants effect on the swelling index is ambiguous, and it requires deeper research.

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Quintella, Cristina M., Cristiane C. Gonçalves, Iuri Pepe, Angelo M. V. Lima und Ana Paula S. Musse. „Automated system to acquire fluorescence, polarization and anisotropy maps within liquid flows“. Journal of Automated Methods and Management in Chemistry 24, Nr. 2 (2002): 31–39. http://dx.doi.org/10.1155/s146392460200007x.

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Maps of polarization and anisotropy can be helpful for flow analysis systems (FIA, CFA, etc.) with reactions dependent on the intermolecular alignment as well as for dispersion control. Maps can be acquired manually, but when a scan over a sample area is required, the acquisition becomes tiresome and has low precision. The paper describes an automatic flexible system for high-precision sample positioning with closed loop self control, remote data acquisition and storage controlled by a BASIC program. The system was developed to acquire maps up to 850 mm2of the sample (liquid flows, solids, interfaces, etc.), with up to 100 μm2precision. To evaluate the equipment, performance is presented as the scan of a thin liquid film of monoethylene glycol (MEG) flowing on borosilicate. Tests were performed with and without surfactantes at submicellar concentrations: two concentrations of sodium dodecyl sulphate (SDS) and one of polyethylene oxide (PEO). For pure MEG, the intermolecular alignment initially increased, then decreased. When SDS was added, both polarization and anisotropy only increased progressively with the flow. This might be explained by the surfactant decrease of interfacial interaction. When PEO was added, both polarization and anisotropy decreased pronouncedly over the entire map, which might be due to macromolecular aggregates within the bulk generating misaligned molecular domains. The system presented as sample positioning repeatability of 0.1% and a high polarization reproducibility (error margin < 6 in 1000).

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Ramalho, Joao Batista, Natalie Ramos und Elizabete Lucas. „The Influence of Some Interfacial Properties of PEO-b-PPO Copolymers on Dewatering of Water-in-Oil Asphaltene Model Emulsions“. Chemistry & Chemical Technology 3, Nr. 1 (15.03.2009): 53–58. http://dx.doi.org/10.23939/chcht03.01.053.

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Three different macromolecular structures of poly(ethylene oxide-b-propylene oxide) copolymers, used in formulations of commercial demulsifiers for breaking water-in-crude oil emulsions, were investigated. The interfacial activity (), the lower interfacial tension (m), the critical micelle concentration (CMC), the interfacial concentration (Γ) and the molecular area (A) adsorbed at the interface of the surfactant solutions were evaluated. These results were correlated to surfactant performance in coalescing three different asphaltene model emulsions. The PEO-b-PPO commercial demulsifiers, that were capable to dewater asphaltene model emulsions, exhibited interfacial activity to the oil-water interface, reduced the interfacial tension to low values, reached the CMC at low concentration and presented low molecular area adsorbed at the interface.

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Swerin, Agne, und Isabel Mira. „Ink-jettable paper-based sensor for charged macromolecules and surfactants“. Sensors and Actuators B: Chemical 195 (Mai 2014): 389–95. http://dx.doi.org/10.1016/j.snb.2014.01.064.

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Lee, Lay-Theng, und Bernard Cabane. „Effects of Surfactants on Thermally Collapsed Poly(N-isopropylacrylamide) Macromolecules“. Macromolecules 30, Nr. 21 (Oktober 1997): 6559–66. http://dx.doi.org/10.1021/ma9704469.

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Elliott, S., S. M. Burrows, C. Deal, X. Liu, M. Long, O. Ogunro, L. M. Russell und O. Wingenter. „Prospects for simulating macromolecular surfactant chemistry at the ocean–atmosphere boundary“. Environmental Research Letters 9, Nr. 6 (01.05.2014): 064012. http://dx.doi.org/10.1088/1748-9326/9/6/064012.

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Hall, Denver G. „Thermodynamics of ionic surfactant binding to macromolecules in solution“. Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases 81, Nr. 4 (1985): 885. http://dx.doi.org/10.1039/f19858100885.

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