The equilibrium thermodynamic properties of a linear polymer chain confined to a space between two impenetrable walls (lines) at a distance D under various solvent conditions have been studied using series analysis and exact enumeration technique. We have calculated the end-to-end distance of polymer chain, which shows a nonmonotonic behavior with inter wall separation D. The density distribution profile shows a maxima at a particular value of (D=)D*. Around this D*, our results show that the collapse transition occurs at higher temperature as compared to its bulk value of 2d and 3d. The variation of theta-temperature with D shows a re-entrance behavior. We also calculate the force of compression exerted by the walls (lines) on the polymer.
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http://dx.doi.org/10.1063/1.1796233 | DOI Listing |
Sci Adv
March 2025
Department of Chemistry, Hanyang University, Seoul 04763, Republic of Korea.
Polymer blend films exhibit unique properties and have applications in various fields. However, understanding their nanoscale structures and polymer component distributions remains a challenge. To address this limitation, we have developed a super-resolution fluorescence microscopy-based technique called oxygen-excluded nanoimaging.
View Article and Find Full Text PDFJ Am Chem Soc
March 2025
CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Surface-catalyzed polymerization is crucial in both chemical science and industrial manufacturing, yet achieving regioselective radical polymerization on the surface remains challenging. Here, we demonstrate the regioselective Ullmann polymerization of nonsymmetrical 2,8-dibromoquinoline (DBQ) on an Au(111) surface. By combining scanning tunneling microscopy, density functional theory calculations, and kinetic modeling, we reveal the regioselectivity and its evolution with surface temperature at the molecular level.
View Article and Find Full Text PDFACS Appl Mater Interfaces
March 2025
Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China.
Green-solvent-processed all-polymer solar cells (AP-SCs) are regarded as an excellent candidate for renewable energy due to their better stability and eco-friendly features. Two polymers, PYF-U and PYF-BO, have been designed by introducing a Y-series derivative with difluoro-substituted dicyanindenone units and a difluorobenzotriazole derivative as the first and second electron-deficient (A) units, respectively. The introduction of two additional F atoms on dicyanindenone units leads to a more coplanar backbone because of noncovalent interactions.
View Article and Find Full Text PDFAdv Mater
March 2025
Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
Adsorbed natural gas (ANG) storage is emerging as a promising alternative to traditional compressed and liquefied storage methods. However, its onboard application is restricted by low volumetric methane storage capacity. Flexible porous adsorbents offer a potential solution, as their dense structures and unique gate-opening effects are well-suited to enhance volumetric capacity under high pressures.
View Article and Find Full Text PDFEndokrynol Pol
March 2025
Medical Genetics Department and Prenatal Diagnosis Centre, The Affiliated Hospital of Qingdao University, Qingdao, China.
Background: Congenital hypothyroidism (CH) is the most common neonatal disorder, primarily caused by thyroid dysgenesis (TD). While the genetic cause has been identified in less than 5% of TD cases, there is an urgent need to investigate additional gene mutations that may be responsible. In 2018, TUBB1 was identified as a novel candidate gene associated with TD.
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