Polymer International最新文献

{"title":"Thermo-mechanical properties of epoxy composites filled with inorganic particulate fillers for robust solder mask application","authors":"William Yung Ling Lim,&nbsp;Mariatti Jaafar,&nbsp;Ku Marsilla Ku Ishak,&nbsp;Karuna Chinniah,&nbsp;Wooi Keong Chan","doi":"10.1002/pi.6648","DOIUrl":"10.1002/pi.6648","url":null,"abstract":"<p>Filler components play a crucial role as thermo-mechanical reinforcement to the epoxy-based solder mask, ensuring effective insulation and passivation. This study investigates the impact of different inorganic filler types (talc, silica (SiO₂), boron nitride (BN) and barium sulfate (BaSO₄)) and loadings (5 and 15 wt%) on the tensile and thermal properties of the epoxy composites. The composites were blended, cast and thermally cured. Of these composites, only 15 wt% SiO₂/epoxy composite exhibits notable increments in both tensile strength and modulus, surpassing unfilled epoxy by 11.65% and 31.9%, respectively. It also displays the highest elongation at break, supported by small particle size, high specific surface area and minimal void volume fraction. For thermal tests, the addition of all fillers increases the storage modulus in both glassy and rubbery regions, especially 15 wt% talc/epoxy composite with 30.09% increment at 25 °C. Additionally, all fillers raise the glass transition temperature (<i>T</i>_g), notably improving it by 9 °C in the 15 wt% BN/epoxy composite. Moreover, their inclusion generally enhances the onset decomposition temperature (<i>T</i>_onset) and reduces weight loss during decomposition. © 2024 Society of Chemical Industry.</p>","PeriodicalId":20404,"journal":{"name":"Polymer International","volume":"73 9","pages":"779-788"},"PeriodicalIF":2.9,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141119974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of sodium 2-acrylamido-2-methylpropanesulfonate on the structure and properties of thermoplastic polyvinyl alcohol copolymers","authors":"Liang Wang,&nbsp;Jiawei Zhao,&nbsp;Bing Song,&nbsp;Liuchun Zheng,&nbsp;Yong Liu","doi":"10.1002/pi.6663","DOIUrl":"10.1002/pi.6663","url":null,"abstract":"<p>Thermoplastic poly(vinyl alcohol) (PVA) with water-soluble behavior has received great attention. In this work, a thermoplastic PVA was prepared via solution radical polymerization of vinyl acetate, vinyl pivalate and sodium 2-acrylamido-2-methyl propane sulfonate (SAMPS). The effects of SAMPS content on the structure and properties of modified poly(vinyl alcohol) (MPVA) were investigated. On increasing the proportion of SAMPS, the characteristic band of –OH moved to a larger wavenumber. Compared to PVA, the melting temperature (<i>T</i>_m) of MPVA decreased from 223.1 to 161.5 °C at 0.03 mol of SAMPS, and the initial thermal decomposition temperature (<i>T</i>_d) of MPVA increased from 244.3 to 262.2 °C at 0.05 mol of SAMPS. The crystallinity of the resin reduced from 51.46% to 10.21%. The enlarged difference between <i>T</i>_d and <i>T</i>_m ensured the preparation of MPVA by thermal processing. The maximum tensile strength and elastic modulus of the obtained sheets were 137.56 and 2639.32 MPa, respectively. The introduction of SAMPS reduced the alcoholysis degree from 99.03% to 95.80%. The high alcoholysis degree of MPVA meant that it could be dissolved in water at 60 °C. This type of thermoplastic PVA shows a promising application on film and textiles that require water solubility. © 2024 Society of Chemical Industry.</p>","PeriodicalId":20404,"journal":{"name":"Polymer International","volume":"73 10","pages":"815-823"},"PeriodicalIF":2.9,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141120916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and comparison of cationic polymers for structural effects of backbones and grafted side chains on their DNA transfection for efficient gene delivery","authors":"Ting-Yi Hou,&nbsp;Kuang-Hung Pan,&nbsp;Mei-Fen Shih,&nbsp;Jong-Yuh Cherng","doi":"10.1002/pi.6662","DOIUrl":"10.1002/pi.6662","url":null,"abstract":"<p>Many cationic polymers with varied architectures either in backbones or in side chains have been used for gene delivery. However, these polymers yielding different DNA transfection efficiency cannot answer whether backbones or side chains have more influence on DNA delivery. In this research, polyurethanes (PUs) made from the reaction of <span>l</span>-lysine diisocyanate and 1,4-piperazinediethanol were synthesized. Together with poly(<span>l-</span>lysine) (PLL), these polymers were further modified to carry side chains by connecting to low-molecular-weight polyethylenimine (PEI) via imine linkages. The PEI was either linear (423 Da) or branched (600 Da) and grafted to the backbone representing two distinct shapes (i.e. a twig with needle-leaves or round-leaves). In addition, one PU derivative was synthesized to have shorter side chains (as PU-PEI S₄₂₃) than PU-PEI₄₂₃ by aminolysis reaction. These synthesized polymers were compared for their transfection potential as gene vectors into cells. Electrophoretic mobility, dynamic light scattering and zeta potential analyses of polymer/DNA complexes confirmed that, after grafting of PEI (PEI₄₂₃ or PEI₆₀₀), PLL-PEIs and PU-PEIs were able to self-assemble with plasmid DNA to form nano-scaled (<i>ca</i> 200 nm) and positively charged (<i>ca</i> +25 mV) complexes. These cationic polymers hardly showed any cytotoxicity on COS-7 cells. The outcome of fluorescence imaging and flow cytometry verified that the order of greater transfection efficiency is PLL-PEI₆₀₀ = PU-PEI₆₀₀ &gt; PLL-PEI₄₂₃ = PU-PEI₄₂₃ &gt; PEI_25K (commercial standard) = PU-PEI S₄₂₃ &gt;&gt; PLL &gt; PEI₄₂₃ = PEI₆₀₀ (starting materials). These results reveal that the polymers with longer side chains or higher charge density have positive influence on transfection efficiency. Nevertheless, different polymer backbones may reflect their biodegradability and cytotoxicity, but their effect on transfection efficiency is less significant. © 2024 Society of Chemical Industry.</p>","PeriodicalId":20404,"journal":{"name":"Polymer International","volume":"73 10","pages":"803-814"},"PeriodicalIF":2.9,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141062704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of synthesis conditions and raw materials on the properties of N-chlorosulfonamides immobilized on granular styrene–divinylbenzene polymer carriers","authors":"Bohdan Murashevych,&nbsp;Dmitry Girenko,&nbsp;Dmytro Stepanskyi,&nbsp;Iryna Koshova,&nbsp;Nikolay Toropin,&nbsp;Konstantin Burmistrov","doi":"10.1002/pi.6649","DOIUrl":"10.1002/pi.6649","url":null,"abstract":"<p>Polymer materials with immobilized functional groups–donors of active chlorine are widely used to create products with a microbiocidal effect and increased resistance to microbial contamination. In this work, various methods for the synthesis of granular styrene–divinylbenzene polymers with <i>N</i>-chlorosulfonamide groups were investigated. It has been shown that the synthesis of polymers with chlorine-active <span></span>SO₂NNaCl groups from a non-functionalized styrene–divinylbenzene polymer matrix through the stage of its sulfochlorination with chlorosulfonic acid in dichloromethane for 6–7 h is optimal. These products contain approximately 11% of active chlorine and maintain a stable particle size distribution. When cation exchangers such as Purolite C100 are used as the initial polymer carrier, the content of chlorine-active groups in the target product is approximately 9%, and an increase in the content of the dust fraction is observed. The obtained samples, regardless of the synthesis method, are capable of releasing active chlorine into solutions containing amino compounds. The microbial impurities in water also cause the emission of active chlorine in an amount that does not depend on the loading of the polymer, but is determined by the concentration of microbes, due to which a pronounced antimicrobial effect is observed. In this case, the resulting products do not cause further decomposition of the functional groups of the polymer, which indicates the high service life of the latter. The availability of raw materials, relative ease of synthesis, stability, possibility of regeneration and microbiocidal properties of the studied polymers make them promising for use as components of water and air purification systems and other products for medical and industrial purposes. © 2024 Society of Chemical Industry.</p>","PeriodicalId":20404,"journal":{"name":"Polymer International","volume":"74 1","pages":"28-36"},"PeriodicalIF":2.9,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140972401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting the glass transition temperature and solubility parameter between rubber/silica and rubber/resins via all-atom molecular dynamics simulation","authors":"Qionghai Chen,&nbsp;Ziyi Zhang,&nbsp;Wanhui Huang,&nbsp;JiaJun Qu,&nbsp;Qi Zhang,&nbsp;Xiaohui Wu,&nbsp;Liqun Zhang,&nbsp;Jun Liu","doi":"10.1002/pi.6647","DOIUrl":"10.1002/pi.6647","url":null,"abstract":"<p>Resin is a widely used additive in rubber composites, which not only improves the processing properties of the composites but also enhances their mechanical properties, rolling resistance and wear resistance. However, there are specific differences in compatibility among resin, rubber and silica, which directly affect the performance of the composite materials. In this work, we first computed the glass transition temperature (<span></span><math>\u0000 <mrow>\u0000 <msub>\u0000 <mi>T</mi>\u0000 <mi>g</mi>\u0000 </msub>\u0000 </mrow></math>) of five resins in styrene−butadiene rubber (SBR) composites to prove the reliability of the computational method. Then, we explored the effects of different components and resin types on <span></span><math>\u0000 <mrow>\u0000 <msub>\u0000 <mi>T</mi>\u0000 <mi>g</mi>\u0000 </msub>\u0000 </mrow></math> of SBR and found that the addition of silica can increase <span></span><math>\u0000 <mrow>\u0000 <msub>\u0000 <mi>T</mi>\u0000 <mi>g</mi>\u0000 </msub>\u0000 </mrow></math> due to weak attractive interactions between silica and rubber molecular chains, which restrict the movement of the molecular chains. Furthermore, using solubility parameters, we analyzed the compatibility of rubber and five different resins and found that all five resins had good compatibility with rubber, especially C5/C9 copolymerized petroleum resin and hydrogenated resin. Finally, we revealed that there is a mutually attractive force between resin and silica. In summary, understanding the interactions among resins, silica and rubber is crucial for optimizing the performance of composite materials. © 2024 Society of Chemical Industry.</p>","PeriodicalId":20404,"journal":{"name":"Polymer International","volume":"73 9","pages":"770-778"},"PeriodicalIF":2.9,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-performance, semi-bio-based degradable epoxy resins and their application to recyclable carbon fiber composites","authors":"Shuanghong Yu,&nbsp;Kaixuan Xiao,&nbsp;Zhaodi Wang,&nbsp;Yahong Xu,&nbsp;Nannan Ni,&nbsp;Dongyuan Hu,&nbsp;Zhiyi Lyu,&nbsp;Soochan Kim,&nbsp;Xin Yang","doi":"10.1002/pi.6646","DOIUrl":"10.1002/pi.6646","url":null,"abstract":"<p>Epoxy resins containing dynamic covalent networks enable recycling of carbon fiber composites. However, the simultaneous realization of high performance and mild condition recycling of composites is still a challenge. In the present work, we mixed citric acid epoxy resin with bisphenol A epoxy resin to form a hybrid resin (DER) that meets the requirements of medium temperature curing epoxy resin, and prepared a carbon fiber reinforced resin composite material (DER@CF) that can rapidly degrade and recycle carbon fibers under mild conditions. The <i>T</i>_g of the DER was 125.67 °C, and the tensile strength (79.63 MPa) was comparable to that of the bisphenol A epoxy resin (79.90 MPa). It degraded rapidly after 2 h in ethylene glycol solution at 120 °C. The tensile strength of DER@CF was 825 MPa, and clean fibers could be obtained after 8 h of treatment in ethylene glycol solution at 120 °C. The results of SEM, Raman and tensile tests showed that the recycled fibers were similar to the original fibers in terms of morphology, chemical structure and mechanical properties. © 2024 Society of Chemical Industry.</p>","PeriodicalId":20404,"journal":{"name":"Polymer International","volume":"74 6","pages":"520-527"},"PeriodicalIF":2.9,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140810117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cellulose nanocomposite tough hydrogels: synergistic self-healing, adhesive and strain-sensitive properties","authors":"Mohammed Nujud Badawi,&nbsp;Namrata Agrawal,&nbsp;Yogesh Kumar,&nbsp;Mujeeb Khan,&nbsp;Mohammad Rafe Hatshan,&nbsp;Abdulmajeed Abdullah Alayyaf,&nbsp;Syed Farooq Adil","doi":"10.1002/pi.6644","DOIUrl":"10.1002/pi.6644","url":null,"abstract":"<p>Recent advancements are notable in electrically conductive hydrogels emulating human skin functions. However, a significant challenge remains: crafting a single conductive gel that integrates self-healing, robust mechanical strength, and excellent electrical traits. Our innovation lies in a strong, lightweight, curable gel achieved through multiple coordination bonds between cellulose crystals and acid-treated multi-walled carbon nanotubes (MWCNTs) in a polymer network. Embedded MWCNTs act as dynamic bridges within a porous structure, giving exceptional mechanical performance. Reversible coordination interactions confer remarkable recovery and reliable mechanical and electrical self-healing. Additionally, these ionic gels function as adaptable stress sensors, detecting significant movements like finger and joint motions. This work introduces MWCNT-incorporated nanomaterials with good stretchability, high ion conductivity, remarkable self-healing nature, and good stress sensitivity. Such proteins hold promise for electronic sensors, wearable devices, and healthcare monitoring, unveiling a path to diverse applications. Our study addresses challenges and unlocks possibilities for materials that can adapt, withstand, and sense in innovative ways. © 2024 Society of Chemical Industry.</p>","PeriodicalId":20404,"journal":{"name":"Polymer International","volume":"73 9","pages":"748-760"},"PeriodicalIF":2.9,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140658472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation and properties of poly[(butylene adipate)-co-terephthalate]/thermoplastic hydroxypropyl starch films","authors":"Muxi Wang,&nbsp;Zehao Li,&nbsp;Wenbo Zhao,&nbsp;Zhenyu Huang,&nbsp;Hong Liu,&nbsp;Li-Jun Ma,&nbsp;Liting Yang","doi":"10.1002/pi.6645","DOIUrl":"10.1002/pi.6645","url":null,"abstract":"<p>Poly[(butylene adipate)-<i>co</i>-terephthalate] (PBAT) is currently the most widely used and versatile petroleum-based fully biodegradable polyester, drawing extensive attention from researchers. However, the high production cost of PBAT restricts its widespread application. Currently, incorporating fillers into PBAT materials is considered the most effective approach to reduce production costs, with thermoplastic starch recognized as the optimal filler for PBAT base materials. Nevertheless, the low mechanical strength of thermoplastic starch significantly compromises the performance of PBAT base materials. In this study, thermoplastic starch with higher mechanical strength was prepared by partially substituting commonly used glycerol with a higher molecular weight sorbitol as the plasticizer. The enhanced thermoplastic starch was then used as a filler for PBAT materials, leading to the fabrication of PBAT-based blend films with high starch content. Mechanical property tests revealed a 52.2% and 65.3% increase of tensile strength in the transverse and longitudinal directions, respectively, when sorbitol partially replaced glycerol as the plasticizer for thermoplastic starch. Scanning electron microscopy results demonstrated improved dispersion of thermoplastic starch particles in PBAT when sorbitol and glycerol were used together. Meanwhile, the thermal performance and stability of PBAT were not significantly affected by the thermoplastic starch filling. © 2024 Society of Chemical Industry.</p>","PeriodicalId":20404,"journal":{"name":"Polymer International","volume":"73 9","pages":"761-769"},"PeriodicalIF":2.9,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140657468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication and characterization of PZT/PVDF composite films for force sensor applications","authors":"Suprapto,&nbsp;Yung Ting,&nbsp;Hariyanto Gunawan,&nbsp;Edwar Yazid,&nbsp;Aditya Sukma Nugraha,&nbsp;Budi Azhari,&nbsp;M Luthfi Ramadiansyah,&nbsp;M Fathul Hikmawan,&nbsp; Jubaidah","doi":"10.1002/pi.6643","DOIUrl":"10.1002/pi.6643","url":null,"abstract":"<p>This study explored the impact of hot press parameters on lead zirconate titanate (PZT)/poly(vinylidene fluoride) (PVDF) composite films designed for force-sensing applications. The systematic fraction (PZT/PVDF), pressure, temperature, and time during hot pressing processes are subject to variation. The focus is on the resulting composite film thickness and its subsequent influence on the piezoelectric properties, which are essential for the performance of force sensors. The present study investigated the characteristics and performance of PZT/PVDF composite films with fraction ratios 2/5, 5/5, and 7/3 and hot pressure of 10, 40, and 60 MPa and temperature at 150 °C for 2 h. The characterization of these films was conducted using X-ray diffraction, Fourier transform infrared spectroscopy, atomic force microscopy, and scanning electron microscopy. The piezoelectric properties (<i>d</i>₃₃ and <i>d</i>₃₁) were measured using impact and extraction tests to evaluate the performance of films with applied forces. The results show that the highest piezoelectric coefficients (<i>d</i>₃₃ and <i>d</i>₃₁) were determined to be 35.8 and 12.60 pC N⁻¹, with fraction ratios of 7/3 and 2/5. The study revealed a positive correlation between the PZT/PVDF ratio and sensitivity, indicating that an increase in the ratio leads to an increase in sensitivity. Conversely, a negative relationship was observed between the impact load and the sensor sensitivity, suggesting that an increase in the impact load results in a sensitivity decrease. The results of this work demonstrate the great potential of piezoelectric PZT/PVDF composite films in force sensors for small load applications. © 2024 Society of Chemical Industry.</p>","PeriodicalId":20404,"journal":{"name":"Polymer International","volume":"73 9","pages":"727-747"},"PeriodicalIF":2.9,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140660592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of nanoclay filler addition on the foaming and mechanical properties of polypropylene","authors":"Salih Hakan Yetgin,&nbsp;Huseyin Unal,&nbsp;Kemal Ermis","doi":"10.1002/pi.6642","DOIUrl":"10.1002/pi.6642","url":null,"abstract":"<p>In this study, onium-ion-added nanoclay (NC)/microcellular polypropylene (PP) composites were created using a conventional injection molding machine. A chemical foaming agent was utilized to facilitate mixing. The primary focus was to analyze how altering the NC content affects the mechanical characteristics and the properties of the endothermic chemical foaming agent added PP/NC composites. The composites were created using a chemical foaming agent at a weight ratio of 1 wt% and NC at weight ratios of 0 wt%, 2.5 wt% and 5 wt%. The findings indicated that an increase in the NC ratio led to higher cell count and cell density, along with a reduction in cell diameter. Additionally, the outcomes demonstrated that the foaming of PP/NC composites resulted in decreased modulus of elasticity and tensile strength while enhancing impact strength. © 2024 The Authors. <i>Polymer International</i> published by John Wiley &amp; Sons Ltd on behalf of Society of Industrial Chemistry.</p>","PeriodicalId":20404,"journal":{"name":"Polymer International","volume":"73 9","pages":"719-726"},"PeriodicalIF":2.9,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/pi.6642","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140568399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}