Статті в журналах: "Polymer stretching during formation"

1

Wang, Yu, Wenjie Sun, Song Liu, Huajian Ji, Xin Chen, Huihao Zhu, Haili Zhao, Yulu Ma, and Linsheng Xie. "The Formation of a Highly Oriented Structure and Improvement of Properties in PP/PA6 Polymer Blends during Extrusion-Stretching." Polymers 12, no. 4 (April 10, 2020): 878. http://dx.doi.org/10.3390/polym12040878.

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During the “slit die extrusion-hot stretching” process, highly oriented polyamide 6 (PA6) dispersed phase was produced and retained in the polypropylene (PP) matrix directly. By adjusting the stretching forces, the PA6 spherical phase evolved into the ellipsoid, rod-like microfibril with a decreasing average diameter; then, the PA6 microfibrils broke. Moreover, the effects of the PA6 phases formed in the process of the microfibrillation on PP’s crystallization behaviors were studied systematically. As the stretching forces increased, the crystallization ability and orientation degree of PP crystals improved significantly. Differential scanning calorimetry and polarizing optical microscopy confirmed the formation of PP spherulite, fan-shaped lamellae and a transcrystalline layer under the induction of the PA6 phases with different morphology. In the PP/PA6 microfibrilar composites (MFCs), PP crystals showed smaller average size, more crystals and stronger interface adhesion due to more excellent heterogeneous nucleation ability of the PA6 microfibrils, which made contributions to the improvement of the melt elasticity responses and oxygen barrier properties of the PP/PA6 polymer blends.

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Komaladewi, Anak Agung Istri Agung Sri, Putu Teta Prihartini Aryanti, Graecia Lugito, I. Wayan Surata, and I. Gede Wenten. "Recent progress in microfiltration polypropylene membrane fabrication by stretching method." E3S Web of Conferences 67 (2018): 03018. http://dx.doi.org/10.1051/e3sconf/20186703018.

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Microfiltration polypropylene (MF-PP) membrane has been widely used in many industries due to their excellent combination of good separation performances and low production cost. In addition to membrane configuration, the structure of MF-PP membrane also plays an important role in separation performance. MF-PP membrane is commonly produced by thermal induced phase separation (TIPS) and stretching. TIPS is the simplest one where the polymer is dissolved in a solvent at a decent temperature and then cooled to induce phase separation which leads to the formation of microporous structure. However, this method is limited by the nature of PP that is difficult to dissolve in organic solvents and the solvent-contaminated effluent produced during the fabrication process. Therefore, the stretching method is more favorably used. The Stretching method involves four processing stages in sequence (i.e. melt-extrusion, annealing, stretching, and heat setting). Polymer composition, extrusion draw ratio, as well as stretching rate and temperature, are important parameters that significantly affect the pore structures evolved and thus the properties as well as the performances of MF-PP membrane. In this paper, the recent development of MF-PP fabrication by stretching methods as well as the parameters involved in each method will be reviewed and discussed comprehensively.

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Kulichikhin, Valery, Ivan Skvortsov, Andrey Subbotin, Sergey Kotomin, and Alexander Malkin. "A Novel Technique for Fiber Formation: Mechanotropic Spinning—Principle and Realization." Polymers 10, no. 8 (August 2, 2018): 856. http://dx.doi.org/10.3390/polym10080856.

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We present basic experimental data and the theoretical background of a novel technique for fiber spinning from polymer solutions. The principal feature of the advanced process is realization of phase separation with detachment of a solvent, accompanied by the orientation of macromolecules, under the action of high extension rates. This is similar in some respects to dry spinning, though the driving force is not diffusion with subsequent evaporation of a solvent but redistribution of polymer-solvent interactions in favor of polymer-polymer and solvent-solvent ones governed by mechanical stresses. A promise of this approach has been demonstrated by experiments performed with polyacrylonitrile solutions in different solvents and solutions of the rigid-chain aromatic polyamide. We examined mechanotropic fiber spinning in model experiments with stretching jets from a drop of polymer solution in different conditions, and then demonstrated the possibility of realizing this process in the stable long-term continuous mode. During extension, phase separation happens throughout the whole section of a jet, as was confirmed by visual observation. Then a solvent diffuses on a jet surface, forming a liquid shell on the oriented fiber. Instability of this cover due to surface tension leads either to formation of separate solvent drops “seating” on the fiber or to the flow of a solvent down to the Taylor cone. The separate liquid droplets can be easily taken off a fiber. The physics underlying this process is related to the analysis of the influence of macromolecule coil-to-stretched chain transition on the intermolecular interaction.

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4

Chen, Liang Yu, Chung Cheng Su, and Ren Haw Chen. "Influences of Process Conditions on Stretching Characteristics of Crystalline Polymer Film." Advanced Materials Research 939 (May 2014): 342–48. http://dx.doi.org/10.4028/www.scientific.net/amr.939.342.

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Developing the interior structures of polymer films is essential for creating novel functions of such films. This study investigates the effects of extension parameters and processing procedures on the super-structure of a polypropylene (PP) film. An biaxial extension device is also designed and fabricated to analyze the effects of annealing, extension temperature, extension rate and other parameters on the super-structures of PP films. Based on super-structure analyses, the relationships between extension parameters and film structures are determined, and an extension process that involves a second time stretching procedure is suggested. Experimental results indicate that void structures can be generated by biaxial extension at the interface between the crystalline and amorphous regions in a film. The mechanical strength of the film is also affected by stretching and become highly oriented. Although a low extension temperature can increase the number of void structures generated at a low extension ratio, structure sizes are dispersed. Additionally, voids with uniform size can be obtained when the film is stretched at a high temperature; however, it needs a high extension ratio to promote the formation of void structures. As for annealing treatment, when the annealing temperature increased, the size and quantity of the spherulites that were formed in films by annealing also increased, but these films tend to have similar sizes and numbers of void structures. Based on the experimental results, this study also describes how parameters influence the void structures of a PP film created during the extension process. Analysis results further demonstrate how extension parameters and processing procedures can be adjusted to improve the fabrication of PP films.

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Ding, Lei, Daoxin Zhang, Tong Wu, Feng Yang, Fang Lan, Ya Cao та Ming Xiang. "Three-dimensional crystal structure evolution and micropore formation of β-iPP during biaxial stretching". Polymer 196 (травень 2020): 122471. http://dx.doi.org/10.1016/j.polymer.2020.122471.

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Wu, Gao-Gao, Wen-Bo Chen, Chao Ding, Li-Yang Xu, Zheng-Ying Liu, Wei Yang та Ming-Bo Yang. "Pore formation mechanism of oriented β polypropylene cast films during stretching and optimization of stretching methods: In-situ SAXS and WAXD studies". Polymer 163 (лютий 2019): 86–95. http://dx.doi.org/10.1016/j.polymer.2018.12.051.

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Costine, Allan, Phillip Fawell, Andrew Chryss, Stuart Dahl, and John Bellwood. "Development of Test Procedures Based on Chaotic Advection for Assessing Polymer Performance in High-Solids Tailings Applications." Processes 8, no. 6 (June 24, 2020): 731. http://dx.doi.org/10.3390/pr8060731.

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Post-thickener polymer addition to initiate rapid tailings dewatering has gained considerable interest for tailings storage facility (TSF) management. However, the highly viscous and non-Newtonian rheology of dense suspensions presents unique challenges for mixing with polymer solutions. Such mixing is highly inefficient, often resulting in polymer overdosing and wide variations in deposited tailings characteristics, with the potential to significantly compromise TSF performance. In this study, a new type of mixer based on the principles of chaotic advection was used for treating kaolin suspensions with high molecular weight (MW) anionic copolymer solutions. Chaotic advection imparts efficient mixing by gently stretching and folding flows in a controlled manner, as opposed to random, high-shear flows associated with turbulent mixing, and this lower shear stress allows for the controlled formation of larger aggregate structures with vastly improved dewatering characteristics. A pre-conditioning pipe reactor prior to this mixer can also be advantageous in terms of providing a short burst of high shear for initial polymer distribution. Seven acrylamide/acrylate copolymers of a fixed anionic charge density (30%) spanning a distinct MW range, as characterized by intrinsic viscosity, were applied at elevated dosages to high-solids (20–30 wt %) kaolin suspensions in continuous flow through the chaotic mixer described above. Medium-to-high MW polymers were generally preferred, with further increases in MW resulting in significantly diminished dewatering outcomes. Direct analysis of polymer solution properties through oscillatory rheology gave a better indication of a polymer’s potential performance compared with intrinsic viscosity, offering a more robust basis for polymer selection. This represented the first systematic study into the effects of polymer properties on deposition behavior after dosing at high solids, which was only possible through the ability to apply controlled shear across the entire suspension during sample preparation.

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8

Jinnai, Hiroshi. "Electron microscopy for polymer structures." Microscopy 71, Supplement_1 (February 18, 2022): i148—i164. http://dx.doi.org/10.1093/jmicro/dfab057.

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Abstract This paper reviews recent advances and perspectives of electron microscopy and its application to polymer hierarchical structures. Of the various kinds of hierarchical polymer structures, we placed particular emphasis on polymer nanocomposites and polymer crystals based mainly on our recent results. In those nanocomposites, the chemical bonding between the nanometer-size fillers and rubber matrix, a key contributor to the mechanical properties of the material, has been investigated by combining scanning transmission electron microscopy (STEM) with electron energy-loss spectroscopy (EELS). The position-dependent EELS spectrum with high spatial resolution of STEM successfully provided revealed the presence/absence of the chemical bonds across the interface. The mechanical properties and fracture mechanism of nanocomposites have been studied by combining structural observations made using transmission electron microscopy (TEM) with simulations. They have been further investigated using in situ TEM with a newly designed stretching holder, in which morphological changes, including cavity formation, were visualized and analyzed in terms of local strain distribution. The fracture processes of nanocomposite have been observed at nanometer resolution. The fundamental reinforcement mechanisms have been elucidated from morphological studies of nanocomposites under tensile deformation and during the fracture process. Moreover, nano-diffraction imaging, a position-resolved electron diffraction imaging with STEM, has been applied to a polymer crystal to evaluate the orientation of lamellar crystals at nanometer resolution. All these recent successes with radiation-sensitive polymer materials stemmed from developments made in electron optics and super-sensitive cameras used for advanced electron microscopy.

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9

Maksimova, O. G., A. V. Maksimov, V. V. Smirnov, V. I. Egorov, S. V. Osipov, and E. V. Menshikov. "Study of adsorption effect on orientational and relaxation properties of finite polymer chains near the solid surface." Journal of Physics: Conference Series 2103, no. 1 (November 1, 2021): 012236. http://dx.doi.org/10.1088/1742-6596/2103/1/012236.

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Abstract To study dynamic properties of a polymer coating, we consider a polymer chain with finite length. We take into account a chain bending rigidity and assume that the chain is located near an adsorbing flat surface of a solid. One part of the chain is fixed on the surface, and the second one remains free. It is supposed that the cause of chain stretching is the internal effective mean (molecular) field formed as a result of intermolecular interactions with free ends of other chains. Kinetic equations based on the Kubo method are obtained to calculate the relaxation time of the segments. The dependences of the long-range orientational order parameter and relaxation time on the adsorption parameter, the mean field coefficient and chain bending rigidity parameters are calculated. It is shown that a first-order phase transition occurs at the critical point, which is associated with a drastic change in the degree of the chain elongation. We discovered the “critical deceleration” effect, which consists in a sharp increase in the relaxation time near the critical point during the formation of surface polymer layers on the surface of a solid.

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10

Fortunato, Cavallini, De Bellis, Marra, Tamburrano, Sarto, and Sarto. "Phase Inversion in PVDF Films with Enhanced Piezoresponse Through Spin-Coating and Quenching." Polymers 11, no. 7 (June 28, 2019): 1096. http://dx.doi.org/10.3390/polym11071096.

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In the present work, poly(vinylidene fluoride) (PVDF) films were produced by spin-coating, and applying different conditions of quenching, in order to investigate the dominant mechanism of the β-phase formation. The influence of the polymer/solvent mass ratio of the solution, the rotational speed of the spin-coater and the crystallization temperature of the film on both the β-phase content and the piezoelectric coefficient (d33) were investigated. This study demonstrates that the highest values of d33 are obtained when thinner films, produced with a lower concentration of polymer in the solvent (i.e., 20 wt.%), go through quenching in water, at room temperature. Whereas, in the case of higher polymer concentration (i.e., 30 wt.%), the best value of d33 (~30 pm/V) was obtained through quenching in liquid nitrogen, at the temperature of 77 K. We believe that in the former case, phase inversion is mainly originated by electrostatic interaction of PVDF with the polar molecules of water, due to the low viscosity of the polymer solution. On the contrary, in the latter case, due to higher viscosity of the solution, mechanical stretching induced on the polymer during spin-coating deposition is the main factor inducing self-alignment of the β-phase. These findings open up a new way to realize highly efficient devices for energy harvesting and wearable sensors.

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11

Li, Liao, and Tjong. "Electrospun Polyvinylidene Fluoride-Based Fibrous Scaffolds with Piezoelectric Characteristics for Bone and Neural Tissue Engineering." Nanomaterials 9, no. 7 (June 30, 2019): 952. http://dx.doi.org/10.3390/nano9070952.

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Polyvinylidene fluoride (PVDF) and polyvinylidene fluoride-trifluoroethylene (P(VDF-TrFE) with excellent piezoelectricity and good biocompatibility are attractive materials for making functional scaffolds for bone and neural tissue engineering applications. Electrospun PVDF and P(VDF-TrFE) scaffolds can produce electrical charges during mechanical deformation, which can provide necessary stimulation for repairing bone defects and damaged nerve cells. As such, these fibrous mats promote the adhesion, proliferation and differentiation of bone and neural cells on their surfaces. Furthermore, aligned PVDF and P(VDF-TrFE) fibrous mats can enhance neurite growth along the fiber orientation direction. These beneficial effects derive from the formation of electroactive, polar β-phase having piezoelectric properties. Polar β-phase can be induced in the PVDF fibers as a result of the polymer jet stretching and electrical poling during electrospinning. Moreover, the incorporation of TrFE monomer into PVDF can stabilize the β-phase without mechanical stretching or electrical poling. The main drawbacks of electrospinning process for making piezoelectric PVDF-based scaffolds are their small pore sizes and the use of highly toxic organic solvents. The small pore sizes prevent the infiltration of bone and neuronal cells into the scaffolds, leading to the formation of a single cell layer on the scaffold surfaces. Accordingly, modified electrospinning methods such as melt-electrospinning and near-field electrospinning have been explored by the researchers to tackle this issue. This article reviews recent development strategies, achievements and major challenges of electrospun PVDF and P(VDF-TrFE) scaffolds for tissue engineering applications.

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12

Rocher, Lison, Andrew S. Ylitalo, Tiziana Di Luccio, Riccardo Miscioscia, Giovanni De Filippo, Giuseppe Pandolfi, Fulvia Villani, et al. "Interaction of Poly L-Lactide and Tungsten Disulfide Nanotubes Studied by In Situ X-ray Scattering during Expansion of PLLA/WS2NT Nanocomposite Tubes." Polymers 13, no. 11 (May 27, 2021): 1764. http://dx.doi.org/10.3390/polym13111764.

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In situ synchrotron X-ray scattering was used to reveal the transient microstructure of poly(L-lactide) (PLLA)/tungsten disulfide inorganic nanotubes (WS2NTs) nanocomposites. This microstructure is formed during the blow molding process (“tube expansion”) of an extruded polymer tube, an important step in the manufacturing of PLLA-based bioresorbable vascular scaffolds (BVS). A fundamental understanding of how such a microstructure develops during processing is relevant to two unmet needs in PLLA-based BVS: increasing strength to enable thinner devices and improving radiopacity to enable imaging during implantation. Here, we focus on how the flow generated during tube expansion affects the orientation of the WS2NTs and the formation of polymer crystals by comparing neat PLLA and nanocomposite tubes under different expansion conditions. Surprisingly, the WS2NTs remain oriented along the extrusion direction despite significant strain in the transverse direction while the PLLA crystals (c-axis) form along the circumferential direction of the tube. Although WS2NTs promote the nucleation of PLLA crystals in nanocomposite tubes, crystallization proceeds with largely the same orientation as in neat PLLA tubes. We suggest that the reason for the unusual independence of the orientations of the nanotubes and polymer crystals stems from the favorable interaction between PLLA and WS2NTs. This favorable interaction leads WS2NTs to disperse well in PLLA and strongly orient along the axis of the PLLA tube during extrusion. As a consequence, the nanotubes are aligned orthogonally to the circumferential stretching direction, which appears to decouple the orientations of PLLA crystals and WS2NTs.

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13

Lippert, Th, F. Zimmermann, and A. Wokaun. "Surface Analysis of Excimer-Laser-Treated Polyethylene-Terephthalate by Surface-Enhanced Raman Scattering and X-Ray Photoelectron Spectroscopy." Applied Spectroscopy 47, no. 11 (November 1993): 1931–42. http://dx.doi.org/10.1366/0003702934065911.

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Silver and gold island films have been evaporated onto various polymer surfaces; the samples were characterized by surface-enhanced Raman spectroscopy (SERS), UV-visible spectroscopy, and x-ray photoelectron spectroscopy (XPS). Among the series of investigated polymers, the SERS spectra recorded on stretched polyethylene-terephthalate (PET) foils are unique with respect to resolution and intensity; the signal strengths are comparable to those observed in enhanced resonance Raman scattering. This exceptional behavior is attributed to the semicrystalline nature of the investigated material, and to the preferred interaction of the deposited silver with carbonyl groups of the polymer. The formation of a metal/polymer bond was established by the observation of corresponding bands in the XPS spectrum. Upon melting or amorphization of PET, the SERS intensities are reduced; this result is attributed to a decrease in the metal/polymer bond strength, due to changes in orientation of the phenyl rings and of the carbonyl groups on the polymer surface. The PET surfaces have been modified by excimer laser irradiation at the wavelengths of 308 and 248 nm. The characteristic laser-induced structuring of the surface, as revealed by scanning electron microscopy, is related to the biaxial stretching applied during production of the PET foils, and has been studied for various orientations of the samples and different laser fluences. As a consequence of irradiation, a loss of oxygen is detected by a decrease of the C 1 s XPS bands assigned to carbon atoms with singly or doubly bound oxygen, and by an overall decrease of the oxygen-to-carbon ratio. The surface polarity is observed to decrease, as accompanied by a red shift of the absorption maximum for silver island films deposited onto the irradiated surfaces. SERS spectra recorded on these samples are weaker in intensity, as compared to those recorded on untreated PET foils. This decrease is interpreted in terms of partial amorphization of the sample accompanied by polymer reorientation, loss of the preferred anchoring sites for nucleation of silver islands, and changes in the surface structure and morphology.

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14

Yang, Shuai, Yang He, Yanju Liu, and Jinsong Leng. "Non-contact magnetic actuated shape-programmable poly(aryl ether ketone)s and their structural variation during the deformation process." Smart Materials and Structures 31, no. 3 (February 16, 2022): 035035. http://dx.doi.org/10.1088/1361-665x/ac4ff7.

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Abstract Here, a series of thermoplastic shape memory poly(aryl ether ketone)s (PAEKs) with programmable transition temperature were synthesized via a condensation polymerization reaction. The introduction of flexible segments and side groups onto PAEK main chains promoted the formation of the alternating rigid-flexible structures and the enhanced shape memory properties. The synthesized PAEKs exhibited the great thermal stability and strength which could greatly meet the demands in engineering applications. In addition, non-contact actuation of the shape memory behaviors of PAEKs was realized through the integration of Fe3O4 nanoparticles with magnetocaloric effect. More significantly, small-angle X-ray scattering analysis was utilized to reveal the transition of molecular chains and phase states during the stretching and heating processes. The change of internal structures and orientation of molecular chains during the deformation process might contribute to the regulation of shape memory behaviors. These studies on the fabrication of shape memory PAEKs with non-contact magnetic actuation performances and the investigation of their structural variation during the stretching and heating process were expected to open doors for the fabrication and investigation of new type of shape memory polymers.

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15

Serbinovskiy, Mikhail Yu, Natal'ya A. Vasil'yeva, and Olga V. Popova. "ON COMPLEXATION IN PROCESS OF CHEMICAL COPPER PLATING FROM SOLUTIONS CONTAINING POLYVINYLPYRROLIDONE." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 60, no. 2 (April 7, 2017): 26. http://dx.doi.org/10.6060/tcct.2017602.5478.

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A formation of multifunctional composite coatings with a copper matrix by chemical vapor deposition is an effective method of modifying the surface of metals and non-metals and the increase in the deposition rate of coatings. It is important that the copper complex compounds are formed during chemical vapor deposition coatings and are included in the coatings composition. During the work by methods of thermogravimetric analysis and IR spectroscopy the composite coatings with copper matrix obtained from solutions containing copper sulphate and polyvinylpyrrolidone were studied. The results of thermogravimetry and IR spectroscopy of these components were presented. Samples of composite coatings for IR spectroscopy were obtained as a suspension of the coatings in vaseline oil. Deposited coating was scraped off from the substrate, and then was triturated in an agate mortar with vaseline oil until they formed a stable not stratified suspension. These suspensions were analyzed. The samples for thermogravimetry containing copper sulfate and polyvinylpyrrolidone were obtained by mixing these components. The following proofs of interaction in polyvinylpyrrolidone - copper sulphate system with forming a complex of polyvinylpyrrolidone - copper and includings of this complex into the coating were obtained. The differences of thermogravimetric curves of the mixture CuSO4 5H2O and polyvinylpyrrolidone were established. They are softening temperature increasing in the polymer material on 30 ... 35 °С towards to the softening temperature of polyvinylpyrrolidone, the appearance of the endothermic process, probably associated with the interaction of the polyvinylpyrrolidone with the copper, and the increase in the thermal stability of the polymer component of the system on 50-60 °С, which can be also with the result of complexation of polyvinylpyrrolidone - copper. The estimated structure of this complex, which reflects the results of the IR-spectrogram of the composite coatings analysis was presented. The IR spectra have absorption bands with wave numbers corresponding to the stretching vibrations of C-H bonds in the aromatic ring of polyvinylpyrrolidone, the stretching vibrations of the group – CH2 - and C-N bonds, which are also typical for the polyvinylpyrrolidone. This indicates the presence of polyvinylpyrrolidone in the coating or in its complex compound. In the spectra of the coatings the absorption bands in the range of 1750-1250 cm-1 are presented, which correspond to the stretching vibrations of C=O in the aromatic part of polyvinylpyrrolidone compound, in particular, in the group -CONHR, but they are shifted on about 50 cm-1 with respect to the same bands in the spectra of polyvinylpyrrolidone solution. Such shift is typical for the complex compounds of polyvinylpyrrolidone - copper which caused the C=O bond deformation, which occurs during the formation of additional bond of oxygen and copper atoms: C=O ∙∙∙ Cu, and indicates the presence of such complexes in a coating.Forcitation:Serbinovskiy M.Yu., Vasil'yeva N.A., Popova O.V. On complexation in process of chemical copper plating from solutions containing polyvinylpyrrolidone. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 2. P. 26-32.

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16

Chen, Jianhong, Konrad Schneider та Gert Heinrich. "In-Situ Synchrotron X-ray Study on the Structure Variation of Morphology-Identified Injection-Molded β-Nucleated iPP under Tensile Deformation". Polymers 13, № 21 (28 жовтня 2021): 3730. http://dx.doi.org/10.3390/polym13213730.

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The deformation behavior of semi-crystalline polymers is strongly dependent on the morphology formed during processing. In this study, in-situ synchrotron X-ray was firstly used to identify the morphological distributions of injection-molded isotactic polypropylene (iPP) with different concentrations of β-nucleating agent. It was found that under relatively high concentration of β-nucleating agent (i.e., ≥0.03 wt.%), the outer region (skin and shear region) of the iPP was dominated by mainly highly oriented α-phase as well as certain amount γ-phase, while the core region was rich in β-crystals with little if any orientation. The addition of the β-nucleating agent was beneficial for the formation of lamellae with large lamellar stacking distance in the shear layer. Then the synchrotron X-ray was applied to study the structure variation of those morphology-identified samples under tensile deformation. It was found that voids and cavities along the stretching direction existed in the deformed iPP samples and their volume increased with increasing concentration of β-nucleating agent. The increased volume of void and cavity was associated with the β to α phase transition, which mainly occurred at the core region. In addition, upon stretching crystalline fragmentation and rearrangement took place following the formation of thinner lamellae.

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Takahara, Atsushi, Yuji Higaki, Tomoyasu Hirai, and Ryohei Ishige. "Application of Synchrotron Radiation X-ray Scattering and Spectroscopy to Soft Matter." Polymers 12, no. 7 (July 21, 2020): 1624. http://dx.doi.org/10.3390/polym12071624.

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Light produced by synchrotron radiation (SR) is much brighter than that produced by conventional laboratory X-ray sources. The photon energy of SR X-ray ranges from soft and tender X-rays to hard X-rays. Moreover, X-rays become element sensitive with decreasing photon energy. By using a wide energy range and high-quality light of SR, different scattering and spectroscopic methods were applied to various soft matters. We present five of our recent studies performed using specific light properties of a synchrotron facility, which are as follows: (1) In situ USAXS study to understand the deformation behavior of colloidal crystals during uniaxial stretching; (2) structure characterization of semiconducting polymer thin films along the film thickness direction by grazing-incidence wide-angle X-ray scattering using tender X-rays; (3) X-ray absorption fine structure (XAFS) analysis of the formation mechanism of poly(3-hexylthiophene) (P3HT); (4) soft X-ray absorption and emission spectroscopic analysis of water structure in polyelectrolyte brushes; and (5) X-ray photon correlation spectroscopic analysis of the diffusion behavior of polystyrene-grafted nanoparticles dispersed in a polystyrene matrix.

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Fazullin, D. D., G. V. Mavrin, and I. G. Shaikhiev. "Influence of Ultraviolet Radiation on the Properties of Polymer Microfiltration Membranes." Elektronnaya Obrabotka Materialov 57, no. 4 (August 2021): 54–60. http://dx.doi.org/10.52577/eom.2021.57.4.54.

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To improve the parameters of the process of membrane separation of oil-in-water emulsions, the surface of thin-film membranes of nylon, cellulose acetateб and polytetrafluoroethylene (PTFE) was treated with ultraviolet (UV) radiation in the wavelength range 280–320 nm at a radiation power of 36 W, during 1–10 min. As a result of exposure to UV radiation, a change in the mass of the membranes was revealed depending on the treatment time. Thus, for membranes made of nylon and PTFE, an increase in weight is not significant, while for a membrane made of cellulose acetate, a decrease in weight up to 2.5% was found. An increase in the wettability of the surface layer of a PTFE and nylon membranes, as a result of their exposure to UV radiation, has been established. Changes in the supramolecular structure of the membranes were confirmed by the results of Fourier transform infrared spectroscopy: an increase in the intensity of absorption bands in the IR spectra in the range 600–3600 cm-1 was revealed. An increase in the intensity of the absorption bands of the IR spectra after the treatment of the nylon membrane with UV radiation is associated with the destruction of the defective regions of the surface layer of the membrane as a result of oxidative destruction. A decrease in the intensity of the absorption bands in the IR spectra of the PTFE membrane is observed over the entire spectral range. In addition, the expansion of the bases of the most intense absorption bands related to stretching vibrations of CF2 groups (1203 and 1150 cm-1) was revealed, which may be associated with the formation of the oxide group of the C–O bond. That is, the surface layer of the membrane is oxidized, which leads to an increase in the membrane wettability. UV radiation also influenced the main parameters of the membrane separation of the oil-in-water-emulsion: an increase of up to 7% in the specific productivity of membranes made of nylon and cellulose acetate, depending on the time of UV treatment with a decrease in the separation efficiency was established. When the PTFE membrane was exposed to UV radiation, a decrease in the specific productivity of the process by 14% was observed with an increase in the separation efficiency of the studied emulsion by 14%.

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Tian, Yu, Caizhen Zhu, Jinghua Gong, Shenglin Yang, Jinghong Ma, and Jian Xu. "Lamellae break induced formation of shish-kebab during hot stretching of ultra-high molecular weight polyethylene precursor fibers investigated by in situ small angle X-ray scattering." Polymer 55, no. 16 (August 2014): 4299–306. http://dx.doi.org/10.1016/j.polymer.2014.06.056.

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Zhang, Xueyu, Binjie Xin, Yuansheng Zheng, Meiwu Shi, LanTian Lin, Cong Gao, Yanan Yi, Zumin Yang, and Handian Li. "Fiber recognition with machine learning methods by fiber tensile fracture via acoustic emission method." Textile Research Journal 90, no. 21-22 (May 11, 2020): 2552–63. http://dx.doi.org/10.1177/0040517520924130.

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Energy release usually accompanies the single-fiber tensile fracture, and can be monitored using acoustic emission technology. Generated during the process of molecular structure fracture of various fibers, the acoustic emission signals can be extracted to identify different fracture types of fiber, which is especially important to the yarn formation process. In this study, a low-noise fiber-stretching device was employed to process the weak-intensity signal generated during fiber tensile fracture; in addition, the Hilbert–Huang transform (HHT), principal component analysis (PCA) and least squares support vector machine (LSSVM) algorithms were combined to identify the collected acoustic emission signals of polyester and cotton fibers. At the same time, it was verified that compared with the single-fiber breaking acoustic emission signal obtained by the electronic single-fiber strength tester, the signal acquisition device based on pneumatic components proposed in this paper can significantly improve the signal-to-noise ratio of the signal. According to the algorithm recognition results, the recognition rate of the two fibers increased from 74% to 95%.The experimental results indicate successful measurements of different fractures of two types of fiber.

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21

Dan, Olena, and Larysa Trofimova. "A Study of The Properties of Forming Mixtures Containing Polystyrene Wastes." Journal of Casting & Materials Engineering 5, no. 2 (June 9, 2021): 14–19. http://dx.doi.org/10.7494/jcme.2021.5.2.14.

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Expanded polystyrene is widely used as a material for packaging, in modern construction as a heat and sound insulation layer, in thermal insulation systems for buildings, as well as tanks and pipelines. It is additionally used in foundry engineering for the production of models which are gasified during the production of castings from ferrous and non-ferrous alloys under the contact with liquid metal. The use of expanded polystyrene products is associated with waste generation, both in production and in consumption. About 40–50 kg/person of polystyrene waste is generated per year. The peculiarity of polymeric wastes is their resistance to aggressive environments. They do not rot and the destruction processes in natural conditions proceed rather slowly, with the formation of harmful substances that poison the environment. Therefore, the problem of the processing of waste from polymeric materials is of great importance, not only from the standpoint of environmental protection, but also due to the fact that in conditions of a shortage of polymer raw materials, this waste becomes a powerful raw material resource. This article describes the prospects for recycling expanded polystyrene wastes in foundry engineering. In this work, the properties of molding and core sands containing a combined binder, consisting of a solution of expanded polystyrene wastes in turpentine and clay were investigated, and their main characteristics (weight during stretching and crumbling) were determined. Molding and core mixtures, which contain only a binder in the form of a solution of expanded polystyrene in turpentine, have a crude strength of not more than 0.01 MPa. The introduction of a mixture of clay in the amount of 2–3% allows a crude strength of the mixture of up to 0.05 MPa to be obtained. After drying, the investigated mixtures containing a solution of expanded polystyrene wastes and clay have a tensile strength of up to 2.1 MPa. Mixtures into which a solution of polystyrene wastes and clay was introduced have an insignificant gas capacity and satisfactory gas permeability.

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22

Hamza, A., R. K. Arya, A. D. Palsodkar, G. R. Bhadu та S. J. A. Rizvi. "Influence of Crystal Structure on Thermo-Mechanical Properties of Injection Molded 𝛃-Nucleated iPP". International Polymer Processing 36, № 5 (1 листопада 2021): 545–56. http://dx.doi.org/10.1515/ipp-2020-4106.

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Abstract Isotactic polypropylene (iPP) was nucleated in-situ with calcium pimelate during melt compounding. Calcium pimelate is a highly effective β-nucleator for isotactic polypropylene (iPP). The β-nucleated iPP was characterized by wide angle x-ray diffraction (WAXD) and differential scanning calorimetry (DSC) for its crystallinity and crystal structure. In addition, the injection-molded samples were tested for thermo-mechanical properties. It is found that very low quantity (< 0.1 wt. %) of β-nucleator is required to produce sufficiently high β-crystal fraction (Kβ) in isotactic polypropylene. β-nucleated iPP shows increment of 11 to 14 °C in its heat deflection temperature (HDT). It was also observed that slow cooling rate of β-nucleated iPP promotes the formation of β-crystals and that tensile stretching leads to complete transformation of β crystals into a-crystals at room temperature. It was also revealed that the presence of maleic anhydride grafted polypropylene (PP-g-MA), a well-known coupling agent (or compatibilizer), may reduce the (Kβ) value to a marginal extent. It was also observed that the thermo-mechanical properties were not much affected by the presence of PP-g-MA. Therefore, calcium pimelate may be used as β-nucleator in case of neat as well as reinforced polypropylene containing maleic anhydride as coupling agent.

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23

Samoylov, A. V. "REGULARITIES OF FORMATION OF SYNTHETIC OPTICAL ANISOTROPY OF POLYMETHYL METHACRYLATE FOR POLARIMETRIC APPLICATION." Optoelektronìka ta napìvprovìdnikova tehnìka 55 (December 31, 2020): 173–78. http://dx.doi.org/10.15407/iopt.2020.55.173.

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General principles of wav plate manufacturing are considered. The possibility of the formation of synthetic optical anisotropy of polymethyl methacrylate (PMMA) by the method of its uniaxial stretching is investigated. The most promising is a method for manufacturing waveplates, which includes the stage of controlled stretching of the polymer material to the required phase shift value, which would generally exclude the stage of machining the plates. The general orderliness of the molecules in the polymer resulting from stretching (orientation) leads to the oriented state of the polymer, and, consequently, to the general anisotropy of the physical and optical properties. In this state, a clearly pronounced uniaxial orientation of polymer chains is observed. As a result, chain macromolecules, randomly (statistically) oriented in the initial PMMA, acquire orientation under the influence of an external directed tensile force. The anisotropy of the optical properties of uniaxially stretched PMMA is manifested in the fact that it has different refractive indices for light polarized parallel to the direction of stretching (orientation) and in the perpendicular direction (birefringence). The regularities of the formation of the synthetic optical anisotropy of PMMA have been studied. The dependences of the birefringence values of uniaxially stretched PMMA on the initial sheet thickness, stretching temperature, and degree of stretching have been measured. It has been shown that the value of birefringence is directly proportional to the thickness of the initial sheet and the degree of stretching and inversely proportional to the stretching temperature. The spectral dependence of the birefringence value is measured. Achromatic and superachromatic waveplates were made from uniaxially stretched PMMA. The spectral characteristics of the phase shift of the manufactured waveplates are given. The availability of the starting material, the technological simplicity of the formation of the initial components for waveplates, as well as the possibility of manufacturing waveplates of large dimensions and high quality, make polymethyl methacrylate with artificially induced anisotropy a promising material for the manufacture of achromatic and superachromatic waveplates.

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24

Kanai, Toshitaka. "Process Analysis During the Bioxial Stretching and Polymer Design." Seikei-Kakou 28, no. 11 (October 20, 2016): 450–55. http://dx.doi.org/10.4325/seikeikakou.28.450.

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25

Miyazaki, Tsukasa, Keisuke Shimokita, Hiroki Ogawa, and Katsuhiro Yamamoto. "System forin situobservation of three-dimensional structural changes in polymer films during uniaxial deformation." Journal of Applied Crystallography 48, no. 4 (June 16, 2015): 1016–22. http://dx.doi.org/10.1107/s1600576715008031.

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A simple three-dimensional structural evaluation system for a film during uniaxial deformation has been developed. The system is realized with an automatic film stretching machine, which allows the horizontally symmetric stretching of a film, and a synchrotron radiation X-ray scattering apparatus. Using this system, two-dimensional patterns of small-angle X-ray scattering and wide-angle X-ray diffraction can be obtained simultaneously during film stretching in the so-called edge and end views, together with stress–strain data. As cylindrical symmetry of the structure can be expected for a uniaxially stretched film, the two-dimensional patterns in the through view are identical to those in the edge view, indicating that three-dimensional structural characterization can be performed with a combination of edge and end views during film stretching. For amorphous poly(ethylene terephthalate) and crystalline poly(vinyl alcohol) films, the preliminary results of three-dimensional structural characterization during film stretching are shown.

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26

Hippler, Thomas, Shichun Jiang, and Gert Strobl. "Block Formation during Polymer Crystallization." Macromolecules 38, no. 22 (November 2005): 9396–97. http://dx.doi.org/10.1021/ma051337u.

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27

Hashimoto, Yoshinori, Shotaro Nishitsuji, Takashi Kurose, and Hiroshi Ito. "Structural Formation of UHMWPE Film Tracked by Real-Time Retardation Measurements during Uniaxial/Biaxial Stretching." Materials 11, no. 11 (November 15, 2018): 2292. http://dx.doi.org/10.3390/ma11112292.

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This work reports on an experimental study of the stretching of ultra-high molecular weight polyethylene (UHMWPE) film in various uniaxial/biaxial stretching modes at various temperatures and stretching speeds. We examined the stress-birefringence relationship as a stress-optical rule (SOR) under uniaxial stretching and evaluated the stress-optical coefficient (SOC). Wide-angle X-ray diffraction (WAXD) measurements were applied to evaluate the contribution to birefringence of the crystalline and amorphous phases and to characterize stretching modes. In simultaneous biaxial stretching, the melting temperature (Tm) proved critical to structural formation. We applied thermal analysis techniques and tensile testing to evaluate higher order structures after each stretching mode.

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28

Egoshi, Kentaro, Toshitaka Kanai, and Kazuhiro Tamura. "Development of a biaxial stretching test machine and its applications." Journal of Polymer Engineering 38, no. 6 (July 26, 2018): 605–16. http://dx.doi.org/10.1515/polyeng-2017-0210.

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Abstract The evaluation method for a biaxially oriented film was developed using in-situ measurement during the stretching process. It can obtain basic data such as stress-strain curves, birefringence, light scattering, three dimensional refractive indexes and birefringence distribution. Stress and strain as functions of stretching speed and stretching temperature, as well as the deformation of spherulite of semi-crystalline polymer can be obtained by measuring the birefringence and light scattering during the biaxial stretching process with a small piece of polymer sample. The experimental results show the stress, retardation and three dimensional molecular orientations behavior during the simultaneous biaxial stretching and the sequential biaxial stretching process. Stretchability, thickness uniformity and spherulite size can be obtained simultaneously. In this paper, advantages and details of the newly developed system will be discussed with some experimental data.

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29

Li, Kaiwei, Nan Zhang, Ting Zhang, Zhe Wang, Ming Chen, Tingting Wu, Shaoyang Ma, et al. "Formation of ultra-flexible, conformal, and nano-patterned photonic surfaces via polymer cold-drawing." Journal of Materials Chemistry C 6, no. 17 (2018): 4649–57. http://dx.doi.org/10.1039/c8tc00884a.

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30

Zhou, Y., and K. W. Neale. "Texture Evolution During the Biaxial Stretching of FCC Sheet Metals." Textures and Microstructures 22, no. 2 (January 1, 1993): 87–111. http://dx.doi.org/10.1155/tsm.22.87.

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Using a rate-sensitive crystal plasticity model together with the full constraint Taylor theory, the formation of textures during biaxial stretching of FCC sheet metals is investigated in detail. Three-dimensional lattice rotation fields, orientation evolution and polycrystalline texture development are simulated for the entire range of biaxial strain ratio. The investigation discloses the paths of orientation development and respective stable end orientations, as well as the relation between the evolution paths and the biaxial strain ratio. Our results show that the formation of textures depends mainly on the behaviour of the α- and βρ fibres in biaxial stretching. The strain ratio affects the composition of the βρ-fibre, as well as the flow direction and velocity of orientations towards and along α and βρ, and thus results in different biaxial-stretching textures. The predictions of FCC biaxial-stretching textures are compared with experimental observations reported in literature. Finally, we discuss the influence of complex strain paths on texture formation.

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31

Ren, Meng, Xin Hu, Yongsheng Li, Hong Shao, Peng Jiang, Wenwen Zeng, Cong Wang, and Changyu Tang. "Crack growth-driven wettability transition on carbon black/polybutadiene nanocomposite coatings via stretching." Soft Matter 15, no. 38 (2019): 7678–85. http://dx.doi.org/10.1039/c9sm01234f.

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32

Sakellarides, S. L., and A. J. McHugh. "Structure formation during polymer blend flows." Polymer Engineering and Science 27, no. 22 (December 1987): 1662–74. http://dx.doi.org/10.1002/pen.760272204.

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33

Baker, John P., Harvey W. Blanch, and John M. Prausnitz. "Popcorn-polymer formation during hydrogel synthesis." Polymer Gels and Networks 3, no. 1 (January 1995): 47–58. http://dx.doi.org/10.1016/0966-7822(94)00007-t.

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34

Xu, R. J., C. Lei, Q. Cai, B. Hu, W. Shi, H. Mo, and C. Chen. "Micropore formation process during stretching of polypropylene casting precursor film." Plastics, Rubber and Composites 43, no. 8 (July 31, 2014): 257–63. http://dx.doi.org/10.1179/1743289814y.0000000100.

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35

Wang, Xiaohui, Feifei Yan, Xue Bai, Hanchuan Li, Ming Yuan, Yanping Liu, Benjamin S. Hsiao, Chuntai Liu, and Zhen Wang. "Lamellar crystal-dominated surfaces of polymer films achieved via melt stretching-induced free surface crystallization." Soft Matter 17, no. 48 (2021): 10829–38. http://dx.doi.org/10.1039/d1sm01492g.

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36

López-Barrón, Carlos R., Wesley R. Burghardt, and Mu Sung Kweon. "Local and Global Stretching of Polymer Chains during Startup of Extensional Flow." ACS Macro Letters 9, no. 1 (December 11, 2019): 26–31. http://dx.doi.org/10.1021/acsmacrolett.9b00772.

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37

Vasilyev, Gleb, Michael Burman, Arkadii Arinstein, and Eyal Zussman. "Estimating the Degree of Polymer Stretching during Electrospinning: An Experimental Imitation Method." Macromolecular Materials and Engineering 302, no. 8 (April 5, 2017): 1600554. http://dx.doi.org/10.1002/mame.201600554.

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38

Sakellarides, S. L., and A. J. McHugh. "Oriented structure formation during polymer film extrusion." Polymer Engineering and Science 25, no. 18 (December 1985): 1179–87. http://dx.doi.org/10.1002/pen.760251811.

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39

Wu, Tong, Ming Xiang, Ya Cao, Jian Kang та Feng Yang. "Pore formation mechanism of β nucleated polypropylene stretched membranes". RSC Adv. 4, № 69 (2014): 36689–701. http://dx.doi.org/10.1039/c4ra03589e.

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40

Nadareishvili, Levan, Roland Bakuradze, Jimsher Aneli, Manana Areshidze, Ineza Pavlenishvili, Liana Sharashidze, and Giorgi Basilaia. "Method and Mathematical Modeling of Formation of Gradually and Homogeneously Oriented Linear Polymers." International Journal of Polymer Science 2019 (November 25, 2019): 1–11. http://dx.doi.org/10.1155/2019/8132518.

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Previously, we developed several technical solutions for the conversion of isotropic polymers into materials of a new type—gradually oriented polymers with a gradient of physical and mechanical properties, thereby materializing for the first time the unused possibilities inherent in the polymeric nature of the substance. The scientific basis of these developments is the concept of a new structural state of linear polymers—a gradually oriented (stretched) state (GOS), the essence of which is set out briefly. An algorithm and a mathematical model for controlling the process of uniaxial, zonal stretching of linear polymers are proposed, which allow the formation of gradually or homogeneously oriented polymers (polymer composites). At the same time, specified values of quantitative parameters are ensured, in particular, the selected profile of distribution of the relative elongation (linear, sinusoidal, etc.) along the length of the gradually oriented polymer sample and the specified constant relative elongation along the length of the homogeneously oriented polymer. Mathematical expressions for calculating the conditions to obtain gradually oriented polymers with given geometric dimensions (length, width) and with a given distribution of relative elongation along the length of the resulting sample were also derived. The description of method and principles of operation of the appropriate device is given. Experimental data illustrating the possibilities of the proposed method and the efficiency of mathematical modeling are presented. The issues of creating functionally graded materials with a gradient of microstructure (gradient of degree of orientation/relative elongation) or chemical composition (volume fraction of functional fillers), respectively, based on thermoplastic polymer/copolymer or polymer composite (containing functional fillers) by method of uniaxial, zonal graded stretching are discussed.

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41

Golla, Manohar, Baku Nagendra, Christophe Daniel, Paola Rizzo, and Gaetano Guerra. "Axial Orientation of Co-Crystalline Phases of Poly(2,6-Dimethyl-1,4-Phenylene)Oxide Films." Polymers 12, no. 10 (October 17, 2020): 2394. http://dx.doi.org/10.3390/polym12102394.

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Films exhibiting co-crystalline (CC) phases between a polymer host and low-molecular-mass guest molecules are relevant for many applications. As is usual for semi-crystalline polymers, axially oriented films can give relevant information on the crystalline structure, both by Wide Angle X-ray diffraction fiber patterns and by polarized Fourier-transform infrared spectroscopy. Axially oriented CC phases of poly(2,6-dimethyl-1,4-phenylene)oxide (PPO) with 1,3,5-trimethylbenzene (mesitylene) can be simply obtained by the stretching of CC PPO films. In fact, due to the plasticization effect of this highly boiling guest, PPO orientation can occur in a stretching temperature range (170–175 °C) nearly 50 °C lower than that generally needed for PPO films (220–230 °C). This low stretching temperature range allows avoidance of polymer oxidation, as well as formation of the mesomorphic dense γ PPO phase. Axially oriented CC phases of PPO with toluene, i.e., with a more volatile guest, can be instead obtained by the stretching (in the same low temperature range: 170–175 °C) of CC PPO blend films with polystyrene.

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42

Skyba, M. Ye, O. M. Synyuk, and B. M. Zlotenko. "Model of changing the stressed-deformed state of a polymer sheet during stretching." Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, no. 1 (February 2019): 83–89. http://dx.doi.org/10.29202/nvngu/2019-1/4.

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43

YONEZAWA, Y., T. SATO, T. MIYAMA, A. TAKAMI, J. UMEMURA, and T. TAKENAKA. "PHOTOINDUCED FORMATION OF AGGREGATED SILVER PARTICLES FROM SILVER SALT OF POLYSACCHARIDE." Surface Review and Letters 03, no. 01 (February 1996): 1109–12. http://dx.doi.org/10.1142/s0218625x96001984.

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The thin film of silver salt of alginic acid is available for synthesis of small silver particles and aggregates embedded in the polymer matrix. Variations in the Raman spectrum of the silver alginate film with UV irradiation have been examined. A Raman signal at 1398–1405 cm−1 corresponding to symmetric COO− stretching vibration of silver alginate has been increased, manifesting the contribution of surface-enhanced Raman scattering (SERS).

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44

Oliveira, Mónica S. N., Roger Yeh, and Gareth H. McKinley. "Iterated stretching, extensional rheology and formation of beads-on-a-string structures in polymer solutions." Journal of Non-Newtonian Fluid Mechanics 137, no. 1-3 (August 2006): 137–48. http://dx.doi.org/10.1016/j.jnnfm.2006.01.014.

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45

Takaki, Tomohiro, M. Asanishi, A. Yamanaka, and Yoshihiro Tomita. "Phase-Field Simulation during Spherulite Formation of Polymer." Key Engineering Materials 345-346 (August 2007): 939–42. http://dx.doi.org/10.4028/www.scientific.net/kem.345-346.939.

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The establishment of the coupled numerical model which enable to simulate the spherulite formation and its mechanical behavior continuously is our final goal. In this paper, we have developed Phase-field model for spherulte growth of polymer by generalizing the model proposed by Granasy et. al.. The numerical simulations for single spherulite and multi-sperulites have been performed with isotropic interface energy.

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46

Boczar, Elisa M., B. Camille Dionne, Zhenwen Fu, Andrea B. Kirk, Patricia M. Lesko, and Anne D. Koller. "Spectroscopic studies of polymer interdiffusion during film formation." Macromolecules 26, no. 21 (October 1993): 5772–81. http://dx.doi.org/10.1021/ma00073a035.

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47

Mouhamad, Y., P. Mokarian-Tabari, N. Clarke, R. A. L. Jones, and M. Geoghegan. "Dynamics of polymer film formation during spin coating." Journal of Applied Physics 116, no. 12 (September 28, 2014): 123513. http://dx.doi.org/10.1063/1.4896674.

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48

Petersen, Christian, Carsten Heldmann, and Diethelm Johannsmann. "Internal Stresses during Film Formation of Polymer Latices." Langmuir 15, no. 22 (October 1999): 7745–51. http://dx.doi.org/10.1021/la990256m.

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49

Tobita, Hidetaka. "Comb-Branched Polymer Formation During Copolymerization with Macromonomer." Polymer Reaction Engineering 7, no. 4 (April 1999): 577–605. http://dx.doi.org/10.1080/10543414.1999.10744531.

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50

Zheng, Bingqian, and Surita R. Bhatia. "Cluster formation during aging of colloid-polymer dispersions." Colloids and Surfaces A: Physicochemical and Engineering Aspects 520 (May 2017): 729–35. http://dx.doi.org/10.1016/j.colsurfa.2017.02.027.

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