{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,7]],"date-time":"2025-11-07T19:18:16Z","timestamp":1762543096538,"version":"build-2065373602"},"reference-count":56,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2019,9,9]],"date-time":"2019-09-09T00:00:00Z","timestamp":1567987200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Phase diagrams of n-type low bandgap poly{(N,N\u2032-bis(2-octyldodecyl)naphthalene -1,4,5,8-bis(dicarboximide)-2,6-diyl)-alt-5,5\u2032,-(2,2\u2032-bithiophene)} (P(NDI2OD-T2)) solutions and blends were constructed. To this end, we employed the Flory\u2013Huggins (FH) lattice theory for qualitatively understanding the phase behavior of P(NDI2OD-T2) solutions as a function of solvent, chlorobenzene, chloroform, and p-xylene. Herein, the polymer\u2013solvent interaction parameter (\u03c7) was obtained from a water contact angle measurement, leading to the solubility parameter. The phase behavior of these P(NDI2OD-T2) solutions showed both liquid\u2013liquid (L\u2013L) and liquid\u2013solid (L\u2013S) phase transitions. However, depending on the solvent, the relative position of the liquid\u2013liquid phase equilibria (LLE) and solid\u2013liquid phase equilibria (SLE) (i.e., two-phase co-existence curves) could be changed drastically, i.e., LLE &gt; SLE, LLE \u2248 SLE, and SLE &gt; LLE. Finally, we studied the phase behavior of the polymer\u2013polymer mixture composed of P(NDI2OD-T2) and regioregular poly(3-hexylthiophene-2,5-dyil) (r-reg P3HT), in which the melting transition curve was compared with the theory of melting point depression combined with the FH model. The FH theory describes excellently the melting temperature of the r-reg P3HT\/P(NDI2OD-T2) mixture when the entropic contribution to the polymer\u2013polymer interaction parameter (\u03c7 = 116.8 K\/T \u2212 0.185, dimensionless) was properly accounted for, indicating an increase of entropy by forming a new contact between two different polymer segments. Understanding the phase behavior of the polymer solutions and blends affecting morphologies plays an integral role towards developing polymer optoelectronic devices.<\/jats:p>","DOI":"10.3390\/polym11091474","type":"journal-article","created":{"date-parts":[[2019,9,9]],"date-time":"2019-09-09T11:26:17Z","timestamp":1568028377000},"page":"1474","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Phase Diagrams of n-Type Low Bandgap Naphthalenediimide-Bithiophene Copolymer Solutions and Blends"],"prefix":"10.3390","volume":"11","author":[{"given":"Gada Muleta","family":"Fanta","sequence":"first","affiliation":[{"name":"Institute of Engineering Materials and Biomaterials, Faculty of Mechanical Engineering, Silesian University of Technology, 44-100 Gliwice, Poland"},{"name":"School of Materials Science and Engineering, Jimma Institute of Technology, Jimma University, Post Office Box 378 Jimma, Ethiopia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pawel","family":"Jarka","sequence":"additional","affiliation":[{"name":"Institute of Engineering Materials and Biomaterials, Faculty of Mechanical Engineering, Silesian University of Technology, 44-100 Gliwice, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Urszula","family":"Szeluga","sequence":"additional","affiliation":[{"name":"Center of Polymer and Carbon Materials to the Polish Academy of Sciences, M. Curie-Sk\u0142odowska 34 Street, 41-819 Zabrze, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4024-1231","authenticated-orcid":false,"given":"Tomasz","family":"Ta\u0144ski","sequence":"additional","affiliation":[{"name":"Institute of Engineering Materials and Biomaterials, Faculty of Mechanical Engineering, Silesian University of Technology, 44-100 Gliwice, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7736-6858","authenticated-orcid":false,"given":"Jung Yong","family":"Kim","sequence":"additional","affiliation":[{"name":"School of Materials Science and Engineering, Jimma Institute of Technology, Jimma University, Post Office Box 378 Jimma, Ethiopia"},{"name":"School of Chemical Engineering, Jimma Institute of Technology, Jimma University, Post Office Box 378 Jimma, Ethiopia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,9,9]]},"reference":[{"key":"ref_1","unstructured":"Flory, P.J. (1953). Principles of Polymer Chemistry, Cornell University Press."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"9026","DOI":"10.1021\/acs.macromol.8b01498","article-title":"Order-Disorder Phase Equilibria of Regioregular Poly(3-hexylthiophene-2,5,diyl) Solution","volume":"51","author":"Kim","year":"2018","journal-title":"Macromolecules"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"4317","DOI":"10.1021\/acs.macromol.9b00477","article-title":"Phase Diagrams of Binary Low Bandgap Conjugated Polymer Solutions and Blends","volume":"52","author":"Kim","year":"2019","journal-title":"Macromolecules"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1063\/1.1695731","article-title":"Phase Separation by Spinodal Decomposition in Isotropic Systems","volume":"42","author":"Cahn","year":"1965","journal-title":"J. Chem. Phys."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"898","DOI":"10.1126\/science.251.4996.898","article-title":"Polymer-Polymer Phase Behavior","volume":"251","author":"Bates","year":"1991","journal-title":"Science"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3840","DOI":"10.1002\/adma.200900783","article-title":"Conjugated-Polymer Blends for Optoelectronics","volume":"21","author":"McNeill","year":"2009","journal-title":"Adv. Mater."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"6387","DOI":"10.1063\/1.445747","article-title":"Collective Diffusion, Nucleation, and Spinodal Decomposition in Polymer Mixtures","volume":"79","author":"Binder","year":"1983","journal-title":"J. Chem. Phys."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"25","DOI":"10.25103\/jestr.011.05","article-title":"What is spinodal decomposition?","volume":"1","author":"Favvas","year":"2008","journal-title":"J. Eng. Sci. Technol. Rev."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"329","DOI":"10.1021\/nn102899g","article-title":"Surface-Directed Spinodal Decomposition in Poly[3 -hexylthiophene] and C61-Butyric Acid Methyl Ester Blends","volume":"5","author":"Vaynzof","year":"2011","journal-title":"ACS Nano"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2418","DOI":"10.1126\/science.1070821","article-title":"Self-Assembly at All Scales","volume":"295","author":"Whitesides","year":"2002","journal-title":"Science"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"4769","DOI":"10.1073\/pnas.082065899","article-title":"Beyond Molecules: Self-Assembly of Mesoscopic and Macroscopic Compounds","volume":"99","author":"Whitesides","year":"2002","journal-title":"PNAS"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"4129","DOI":"10.1002\/anie.201808976","article-title":"All-Polymer Solar Cells: Recent Progress, Challenges, and Prospects","volume":"58","author":"Wang","year":"2019","journal-title":"Angew. Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1703906","DOI":"10.1002\/adma.201703906","article-title":"All-Polymer Solar Cells Based on a Conjugated Polymer Containing Siloxane-Functionalized Side Chains with Efficiency over 10%","volume":"29","author":"Fan","year":"2017","journal-title":"Adv. Mater."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2212","DOI":"10.1039\/C7EE01858D","article-title":"9.0% power conversion efficiency from ternary all-polymer solar cells","volume":"10","author":"Li","year":"2017","journal-title":"Energy Environ. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"434","DOI":"10.1016\/j.nanoen.2018.06.081","article-title":"Designing ternary blend all-polymer solar cells with an efficiency of over 10% and a fill factor of 78%","volume":"51","author":"Li","year":"2018","journal-title":"Nano Energy"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"6540","DOI":"10.1021\/acs.chemmater.8b03229","article-title":"All-Polymer Solar Cells with 9.4% Efficiency from Naphthalene Diimide-Biselenophene Copolymer Acceptor","volume":"30","author":"Kolhe","year":"2018","journal-title":"Chem. Mater."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1141","DOI":"10.3762\/bjnano.7.106","article-title":"Manufacturing and investigation of physical properties of polyacrylonitrile nanofibre composites with SiO2, TiO2 and Bi2O3 nanoparticles","volume":"7","author":"Matysiak","year":"2016","journal-title":"Beilstein J. Nanotechnol."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"\u00d6chsner, A., and Altenbach, H. (2017). Analysis of the Optical Properties of PVP\/ZnO Composite Nanofibers. Properties and Characterization of Modern Materials, Springer.","DOI":"10.1007\/978-981-10-1602-8"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"807","DOI":"10.1016\/j.apsusc.2019.04.274","article-title":"Study of dye sensitized solar cells photoelectrodes consisting of nanostructures","volume":"491","author":"Jarka","year":"2019","journal-title":"Appl. Surf. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/j.solmat.2018.09.024","article-title":"Non-fullerene polymer acceptors based on perylene diimides in all-polymer solar cells","volume":"189","author":"Liu","year":"2019","journal-title":"Solar Energ. Mat. Sol. C."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"17604","DOI":"10.1039\/C6TA06978A","article-title":"Non-fullerene small molecule acceptors based on perylene diimides","volume":"4","author":"Liu","year":"2016","journal-title":"J. Mater. Chem. A"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"6955","DOI":"10.1021\/acs.jpclett.8b03247","article-title":"Chlorinated Wide-Bandgap Donor Polymer Enabling Annealing Free Nonfullerene Solar Cells with the Efficiency of 11.5%","volume":"9","author":"Liu","year":"2018","journal-title":"J. Phys. Chem. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"360","DOI":"10.1002\/cssc.201701917","article-title":"Pyran-Bridged Indacenodithiophene as a Building Block for Constructing Efficient A\u2013D\u2013A-Type Nonfullerene Acceptors for Polymer Solar Cells","volume":"11","author":"Wen","year":"2018","journal-title":"ChemSusChem"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"762","DOI":"10.1021\/acsami.7b16406","article-title":"Fine-Tuning the Quasi-3D Geometry: Enabling Efficient Nonfullerene Organic Solar Cells Based on Perylene Diimides","volume":"10","author":"Liu","year":"2018","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"417","DOI":"10.1021\/acsenergylett.8b02114","article-title":"Efficient All-Polymer Solar Cells based on a New Polymer Acceptor Achieving 10.3% Power Conversion Efficiency","volume":"4","author":"Yao","year":"2019","journal-title":"ACS Energy Lett."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1007\/s11426-019-9457-5","article-title":"Achieving over 16% efficiency for single-junction organic solar cells","volume":"62","author":"Fan","year":"2019","journal-title":"Sci. China Chem."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"679","DOI":"10.1038\/nature07727","article-title":"A high-mobility electron-transporting polymer for printed transistors","volume":"457","author":"Yan","year":"2009","journal-title":"Nature"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1002\/aenm.201000035","article-title":"Polymer Blend Solar Cells Based on a High-Mobility Naphthalenediimide-Based Polymer Acceptor: Device Physics, Photophysics and Morphology","volume":"1","author":"Moore","year":"2011","journal-title":"Adv. Energy Mater."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"5891","DOI":"10.1039\/c0jm03405c","article-title":"Role of photoactive layer morphology in high fill factor all-polymer bulk heterojunction solar cells","volume":"21","author":"Fabiano","year":"2011","journal-title":"J. Mater. Chem."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1530","DOI":"10.1021\/ma102451b","article-title":"Surface and Bulk Structural Characterization of a High-Mobility Electron-Transporting Polymer","volume":"44","author":"Schuettfort","year":"2011","journal-title":"Macromolecules"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"18303","DOI":"10.1021\/ja306844f","article-title":"Aggregation in a High-Mobility n-Type Low-Bandgap Copolymer with Implications on Semicrystalline Morphology","volume":"134","author":"Steyrleuthner","year":"2012","journal-title":"J. Am. Chem. Soc."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"369","DOI":"10.1002\/aenm.201100601","article-title":"Influence of Aggregation on the Performance of All-Polymer Solar Cells Containing Low-Bandgap Naphthalenediimide Copolymers","volume":"2","author":"Schubert","year":"2012","journal-title":"Adv. Energy Mater."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"677","DOI":"10.1021\/nn204150f","article-title":"Correlating the Efficiency and Nanomorphology of Polymer Blend Solar Cells Utilizing Resonant Soft X-ray Scattering","volume":"6","author":"Yan","year":"2012","journal-title":"ACS Nano"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2939","DOI":"10.1039\/C4EE01326C","article-title":"Highly efficient charge-carrier generation and collection in polymer\/polymer blend solar cells with a power conversion efficiency of 5.7%","volume":"7","author":"Mori","year":"2014","journal-title":"Energy Environ. Sci."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"25352","DOI":"10.1021\/acsami.5b07605","article-title":"Donor\/Acceptor Molecular Orientation-Dependent Photovoltaic Performance in All-Polymer Solar Cells","volume":"7","author":"Zhou","year":"2015","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"6549","DOI":"10.1021\/acs.macromol.6b00988","article-title":"Surface Structure of Semicrystalline Naphthalene Diimide\u2013Bithiophene Copolymer Films Studied with Atomic Force Microscopy","volume":"49","author":"Zerson","year":"2016","journal-title":"Macromolecules"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"6987","DOI":"10.1021\/acs.macromol.6b01526","article-title":"Molecular Orientation and Phase Separation by Controlling Chain Segment and Molecule Movement in P3HT\/N2200 Blends","volume":"49","author":"Zhang","year":"2016","journal-title":"Macromolecules"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Pope, M., and Swenberg, C.E. (1999). Electronic Processes in Organic Crystals and Polymers, Oxford Science Publications. [2nd ed.].","DOI":"10.1093\/oso\/9780195129632.001.0001"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"3605","DOI":"10.1063\/1.1544413","article-title":"Comparing organic to inorganic photovoltaic cells: Theory, experiment, and simulation","volume":"93","author":"Gregg","year":"2003","journal-title":"J. Appl. Phys."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1063\/1.1723621","article-title":"Thermodynamics of High Polymer Solutions","volume":"10","author":"Flory","year":"1942","journal-title":"J. Chem. Phys."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1021\/j150415a018","article-title":"Some Properties of Solutions of Long-chain Compounds","volume":"46","author":"Huggins","year":"1942","journal-title":"J. Phys. Chem."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"304","DOI":"10.1016\/0021-9797(90)90067-X","article-title":"A Reformulation of the Equation of State for Interfacial Tensions","volume":"137","author":"Li","year":"1990","journal-title":"J. Colloid Interface Sci."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"190","DOI":"10.1016\/0021-9797(92)90127-8","article-title":"Contact Angles on Hydrophobic Solid Surfaces and Their Interpretation","volume":"148","author":"Li","year":"1992","journal-title":"J. Colloid Interface Sci."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1814","DOI":"10.1002\/jcc.20098","article-title":"Hildebrand and Hansen solubility parameters from Molecular Dynamics with applications to electronic nose polymer sensors","volume":"25","author":"Belmares","year":"2004","journal-title":"J. Comput. Chem."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"672","DOI":"10.1021\/ma60012a021","article-title":"Free Volume and Polymer Solubility. A Qualitative View","volume":"2","author":"Patterson","year":"1969","journal-title":"Macromolecules"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1002\/pol.1968.160060202","article-title":"Liquid\u2013liquid phase separation in multicomponent polymer solutions. II. The critical state","volume":"6","author":"Koningsveld","year":"1968","journal-title":"J. Polym. Sci. Part A-2: Polym. Phys."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1769","DOI":"10.1002\/polb.1988.090260816","article-title":"Thermodynamics of miscible polymer blends using a concentration-dependent \u03c7 parameter","volume":"26","author":"Riedl","year":"1988","journal-title":"J. Polym. Sci. B Polym. Phys."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1655","DOI":"10.1021\/ma00007a031","article-title":"Phase Diagrams of Binary Polymer Solutions and Blends","volume":"24","author":"Qian","year":"1991","journal-title":"Macromolecules"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"2522","DOI":"10.1021\/nl4005805","article-title":"Remarkable Order of a High-Performance Polymer","volume":"13","author":"Takacs","year":"2013","journal-title":"Nano Lett."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"163306","DOI":"10.1063\/1.3110904","article-title":"Determining exciton bandwidth and film microstructure in polythiophene films using linear absorption spectroscopy","volume":"94","author":"Clark","year":"2009","journal-title":"Appl. Phys. Lett."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1039\/tf9464200010","article-title":"The phase equilibria between a crystalline polymer and solvents","volume":"42","author":"Richards","year":"1946","journal-title":"Trans. Faraday Soc."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"2532","DOI":"10.1021\/ja01150a035","article-title":"Crystallization in High Polymers. VII. Heat of Fusion of Poly-(N,N\u2032-sebacoylpiperazine) and its Interaction with Diluents","volume":"73","author":"Flory","year":"1951","journal-title":"J. Am. Chem. Soc."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"270","DOI":"10.1016\/j.dyepig.2017.06.018","article-title":"Effect of pre-aggregation in conjugated polymer solution on performance of diketopyrrolopyrrole-based organic field-effect transistors","volume":"145","author":"Dereje","year":"2017","journal-title":"Dyes Pigments"},{"key":"ref_54","doi-asserted-by":"crossref","unstructured":"Hiemenz, P.C., and Lodge, T.P. (2007). Polymer Chemistry, CRC Press Taylor & Francis Group. [2nd ed.].","DOI":"10.1201\/9781420018271"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"17726","DOI":"10.1021\/jp8061493","article-title":"Correlation of Phase Behavior and Charge Transport in Conjugated Polymer\/Fullerene Blends","volume":"112","author":"Kim","year":"2008","journal-title":"J. Phys. Chem. C"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"253","DOI":"10.1038\/s41563-017-0005-1","article-title":"Quantitative Relations Between Interaction Parameter, Miscibility and Function in Organic Solar Cells","volume":"17","author":"Ye","year":"2018","journal-title":"Nat. Mater."}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/11\/9\/1474\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:18:12Z","timestamp":1760188692000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/11\/9\/1474"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,9,9]]},"references-count":56,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2019,9]]}},"alternative-id":["polym11091474"],"URL":"https:\/\/doi.org\/10.3390\/polym11091474","relation":{},"ISSN":["2073-4360"],"issn-type":[{"type":"electronic","value":"2073-4360"}],"subject":[],"published":{"date-parts":[[2019,9,9]]}}}