Tuning thermal conductivity of crystalline polymer nanofibers by interchain hydrogen bonding

RSC Advances ◽  
2015 ◽  
Vol 5 (107) ◽  
pp. 87981-87986 ◽  
Author(s):  
Lin Zhang ◽  
Morgan Ruesch ◽  
Xiaoliang Zhang ◽  
Zhitong Bai ◽  
Ling Liu
Keyword(s):  
Thermal Conductivity ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Group Velocity ◽  
Thermal Conduction ◽  
Crystalline Polymer ◽  
Polymer Chains ◽  
Torsional Motion ◽  
Polymer Nanofibers

Interchain hydrogen bonds enhance thermal conduction in crystalline polymer nanofibers by confining torsional motion of polymer chains and by increasing the group velocity of phonons.

scholarly journals Crystalline polymer nanofibers with ultra-high strength and thermal conductivity

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Ramesh Shrestha ◽  
Pengfei Li ◽  
Bikramjit Chatterjee ◽  
Teng Zheng ◽  
Xufei Wu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Strength ◽  
Crystalline Polymer ◽  
Polymer Nanofibers

Self-healing and phase behavior of liquid crystalline elastomer based on a block copolymer constituted of a side-chain liquid crystalline polymer and a hydrogen bonding block

2015 ◽  
Vol 3 (33) ◽  
pp. 8526-8534 ◽  
Author(s):  
Miao Yan ◽  
Jun Tang ◽  
He-Lou Xie ◽  
Bin Ni ◽  
Hai-Liang Zhang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Block Copolymer ◽  
Hydrogen Bonds ◽  
Phase Behavior ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Side Chain ◽  
Self Healing ◽  
Healing Property

Self-healing liquid crystalline elastomers were fabricated by hydrogen-bonding and the hydrogen bonds in this system played an important role both in self-healing property and the liquid crystalline phase behavior.

Thermal Conductivity of Individual Electrospun Polymer Nanofibers

2015 ◽  
Author(s):  
Jian Ma ◽  
Qian Zhang ◽  
Anthony Mayo ◽  
Richard Mu ◽  
Leon Bellan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Polyvinylidene Fluoride ◽  
Polymer Chains ◽  
Strongly Correlated ◽  
Polymer Nanofibers ◽  
Conductivity Enhancement ◽  
Degree Of Orientation ◽  
High Degree ◽  
Enhanced Thermal Conductivity

In this work, the thermal conductivity of individual polyethylene (PE) nanofibers fabricated by electrospinning was experimental measured. Our results show that polyethylene nanofibers can have a thermal conductivity up to 2.6 Wm−1K−1, (more than 9 times higher than the bulk PE value) and that the thermal conductivity is strongly correlated with the electric field intensity used in electrospinning. This, combined with micro-Raman characterization of individual nanofibers, suggests that the enhanced thermal conductivity is due to the high degree of orientation of the polymer chains. The stronger elongational forces experienced by the jet at higher electrospinning voltage result in the formation of nanofibers with a higher degree of molecular orientation. Similar thermal conductivity enhancement is also observed with other polymer nanofibers including polyethylene oxide (PEO), Nylon-6, and polyvinylidene fluoride (PVDF). Collectively, our results indicate that electrospinning could be an effective approach to produce polymer nanofibers with enhanced thermal conductivity.

Tuning of Electronic Properties in Conducting Polymers

2001 ◽  
Vol 66 (8) ◽  
pp. 1208-1218 ◽  
Author(s):  
Guofeng Li ◽  
Mira Josowicz ◽  
Jiří Janata
Keyword(s):  
Hydrogen Bonding ◽  
Binding Site ◽  
Binding Sites ◽  
Polymer Chains ◽  
Electronic Transitions ◽  
Weakly Bound ◽  
Ordered Structures ◽  
Doped Polymer ◽  
Positively Charged ◽  
Repeated Cycling

Structural and electronic transitions in poly(thiophenyleneiminophenylene), usually referred to as poly(phenylenesulfidephenyleneamine) (PPSA) upon electrochemical doping with LiClO4 have been investigated. The unusual electrochemical behavior of PPSA indicates that the dopant anions are bound in two energetically different sites. In the so-called "binding site", the ClO4- anion is Coulombically attracted to the positively charged S or N sites on one chain and simultaneously hydrogen-bonded with the N-H group on a neighboring polymer chain. This strong interaction causes a re-organization of the polymer chains, resulting in the formation of a networked structure linked together by these ClO4- Coulombic/hydrogen bonding "bridges". However, in the "non-binding site", the ClO4- anion is very weakly bound, involves only the electrostatic interaction and can be reversibly exchanged when the doped polymer is reduced. In the repeated cycling, the continuous and alternating influx and expulsion of ClO4- ions serves as a self-organizing process for such networked structures, giving rise to a diminishing number of available "non-binding" sites. The occurrence of these ordered structures has a major impact on the electrochemical activity and the morphology of the doped polymer. Also due to stabilization of the dopant ions, the doped polymer can be kept in a stable and desirable oxidation state, thus both work function and conductivity of the polymer can be electrochemically controlled.

scholarly journals Hydrogen Bonds: Raman Spectroscopic Study

2021 ◽  
Vol 22 (10) ◽  
pp. 5380
Author(s):  
Boris A. Kolesov
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Spectroscopic Study ◽  
Raman Spectra ◽  
Temperature Region ◽  
Vibrational Frequency ◽  
Chemical Compounds ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Study ◽  
Proton Dynamics

The work outlines general ideas on how the frequency and the intensity of proton vibrations of X–H×××Y hydrogen bonding are formed as the bond evolves from weak to maximally strong bonding. For this purpose, the Raman spectra of different chemical compounds with moderate, strong, and extremely strong hydrogen bonds were obtained in the temperature region of 5 K–300 K. The dependence of the proton vibrational frequency is schematically presented as a function of the rigidity of O-H×××O bonding. The problems of proton dynamics on tautomeric O–H···O bonds are considered. A brief description of the N–H···O and C–H···Y hydrogen bonds is given.

Effect of Zeolite Addition on the Properties of Bioplastic Composites of Carboxymethyl Cellulose-Urea

2019 ◽  
Vol 948 ◽  
pp. 175-180 ◽  
Author(s):  
Indriana Kartini ◽  
Kukuh Handaru Iskandar ◽  
Chotimah ◽  
Eko Sri Kunarti ◽  
Rochmadi
Keyword(s):  
Tensile Strength ◽  
Hydrogen Bonds ◽  
Strong Interaction ◽  
Carboxymethyl Cellulose ◽  
Slow Release ◽  
Polymer Chains ◽  
Solvent Casting ◽  
Ammonium Ions ◽  
Petri Dishes ◽  
Urea Inclusion

Bioplastic composites based on carboxymethyl cellulose (CMC) and urea have been successfully synthesised at various amount of zeolites. Urea inclusion into the bioplastics was supposed to result in nitrogen slow-release composites. The bioplastic composites were prepared by solvent casting the precursor gel containing 0.5 % (w/w) urea in CMC in the petri dishes. The zeolites content was varied at 0.1, 0.5, 1.0, 2.0, and 3.0 % (w/w to CMC). It showed that the addition of zeolites to the bioplastic composites up to 0.5% increased their tensile strength. More addition of zeolites decreased the strain of the bioplastic composite. It could be due to the formation of hydrogen bonds between CMC and zeolites. The amount of urea absorbed in the bioplastics increased as the amount of zeolites increases. It is possibly to be due to the strong interaction between urea and zeolites. The ammonium ions may interact with interchangeable cations in the zeolite. This interaction will also extend the time for the bioplastics to biodegrade. The presence of zeolites in the CMC polymer chains is useful to give nitrogen slow-release composites.

Influence of the Material and Thickness of the Specimen on an Infrared Stress Image

2004 ◽  
Vol 261-263 ◽  
pp. 1641-1646
Author(s):  
Kenji Machida ◽  
Mamtimin Gheni
Keyword(s):  
Thermal Conductivity ◽  
Hybrid Method ◽  
Thermal Conduction ◽  
Crack Problem ◽  
High Stress ◽  
High Accuracy ◽  
Problem Analysis ◽  
Principal Stresses ◽  
Distribution Form ◽  
Stress Components

The thickness dependency of the temperature image obtained by an infrared thermography was investigated using specimens with three kinds of materials and four kinds of the thickness of the specimen. Only the sum of the principal stresses which is the first invariant of stress tensor is measured, and it is impossible to measure individual stress components directly. Then, the infrared hybrid method was developed to separate individual stress components. Although the form of the contour line of low stress side differs greatly, the distribution form of high stress side was considerably alike. The stress intensity factor of material with low thermal conductivity can be estimated with high accuracy by the infrared hybrid method. On the crack problem, it was elucidated that the influence of thermal conduction is large and an inverse problem analysis is required.

2-Hydroxy-3-methoxybenzaldehyde (pyridinium-4-ylcarbonyl)hydrazone chloride hemihydrate

2006 ◽  
Vol 62 (5) ◽  
pp. o2043-o2044 ◽  
Author(s):  
Shao-Wen Chen ◽  
Han-Dong Yin ◽  
Da-Qi Wang ◽  
Xia Kong ◽  
Xiao-Fang Chen
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Compound C

The crystal structure of the title compound, C14H14ClN3O3 +·Cl−·0.5H2O, exhibits O—H...O, C—H...O, C—H...Cl, N—H...Cl and O—H...Cl hydrogen bonds. The chloride anions participate in extensive hydrogen bonding with the aminium cations and link molecules through multiple N—H+...Cl− interactions.

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