POLYMERS FOR ADVANCED TECHNOLOGIES
·
2024
·Vol. 35
·期 4
·e6358
·
IF 3.1
Qinqin Luo,Yulin Sun
A novel organic salt containing DOPO and pyrimidine (AD) was successfully synthesized through a simple acid–base neutralization reaction. The salt was used as a reactive flame retardant for epoxy resin. Non-isothermal DSC tests disclosed that the epoxy resin displayed a lower temperature of onset curing and exothermic peak in the presence of AD. By using only 3 wt% AD, the epoxy resin achieved a UL-94 V-0 rating and a limited oxygen index value of 27.4%, revealing the high flame-retardant efficiency of AD. AD inhibited the release of heat and smoke. The analysis of the flame-retardant mode of action indicated that AD was able to impede combustion not only by the dilution and quenching effects in the gas phase but also by the charring effect in the condensed phase. During UL-94 testing, 3 wt% AD gave the epoxy resin good flame retardancy due to the charring and blowing-out effects formed by adding AD. The blowing-out effect was that the release of strong airflows suppressed or even blew out the flame based on the dilution and quenching effects of phosphorous-containing radicals and numerous non-combustible gases produced by the degradation of AD and epoxy resin matrix. Additionally, the incorporation of AD slightly increased the glass transition temperature and the tensile and flexural strengths of the epoxy resin. This study provided a meaningful attempt to improve the flame retardance of epoxy resin by introducing a reactive pyrimidine-organophosphonic acid salt.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
LIQUID CRYSTALS
·
2019
·
IF 3.078
Xiaodong Wang,Lu Bai,Shengwen Kong,Ying Song,Fanbao Meng
Series of novel star-shaped liquid crystals containing [1,1ʹ-biphenyl]-4,4ʹ-diyl diisonicotinate mesogens with various counterions (Br−, B-SO3−,C-SO3−,H2PO4−, BF4−) have been synthesized and characterized, which display a nematic phase. The molecular structures of the liquid crystals, thereof consisting of rod-like mesogens linked together by different long alkyl spacers to a small disc-like core of central benzene-1,3,5-triyl triisonicotinate, have been fully characterized by 1H NMR. Their thermal and supramolecular organization behaviours have been studied by combining polarized optical microscopy, differential scanning calorimetry and small-angle X-ray scattering. These investigations showed that the mesophase temperature range increased with increasing alkyl chain length and the clearing point decreased with increase of anion size. These star-shaped liquid crystals have a long and ordered molecular structure, the electron delocalization of the π-π stacking conjugation effect and the electrostatic attraction of ionic make them have good ferroelectric properties and ionic conductivity properties. The interest in preparing ionic liquid crystal with a nematic phase lies in the technological applications as it is well known that the nematic phase has the highest fluidity of all liquid crystalline phases and hence the possibility to align it by applying an external electric/magnetic field, commonly used in electro-optical devices.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2015
·
IF 6.723
Guojian Chen,Xiaochen Wang,Jing Li,Wei Hou,Yu Zhou,Jun Wang
A family of nitrogen-enriched ultramicroporous carbon materials was prepared by direct carbonization of task-specifically designed molecular carbon precursors of cyanopyridinium-based crystalline dicationic salts (CISs). Varying the molecular structure of CISs, large surface area (918 m2 g–1), high N content (20.10 wt %), and narrow distributed ultramicropores (0.59 nm) can be simultaneously achieved on the sample PCN-14 derived from methyl-linked 4-cyanopyridinium D[4-CNPyMe]Tf2N. It therefore exhibited exceptional performance in greenhouse gas CO2 capture, i.e., simultaneously possessing (1) high CO2 adsorption uptakes: 5.33 mmol g–1 at 273 K, and 3.68 mmol g–1 at 298 K (both at 1.0 bar); (2) unprecedented selectivity of CO2 versus N2: 156; and (3) a high adsorption ratio of CO2 to N2: 148 (at 1.0 bar). This is the first time such a high selectivity and adsorption ratio over carbon materials has been achieved, which is among the highest values over solid adsorbents.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 34
·17943-17953
·
IF 8.867
Guiting Chen,Fan Zhang,Meiyue Liu,Jun Song,Jiarong Lian,Pengju Zeng,Hin-Lap Yip,Wei Yang,Bin Zhang,Yong Cao
A novel alcohol-soluble conjugated bispyridinium salt (FPyBr) is developed and used as a cathode modifier to improve the cathode interface of planar heterojunction perovskite solar cells (PHJ PVSCs). The excellent electron-withdrawing ability of bispyridinium rings endows FPyBr with a favorable energy level alignment with phenyl-C60-butyric acid methyl ester (PCBM) and the cathode (e.g., Al), which leads to an ideal ohmic contact and efficient electron transport and collection. The deep-lying highest occupied molecular orbital energy level of FPyBr can also effectively block hole carriers and thus decrease leakage current and hole–electron recombination at the cathode interface. In addition, FPyBr can n-dope PCBM through an anion-induced electron transfer process, which increases the electron mobility of PCBM drastically, thereby diminishing interfacial resistance and promoting electron transport. As a result, by incorporating an FPyBr cathode interlayer with ethanol solvent, high-performance and low-hysteresis PHJ PVSCs with a maximal power conversion efficiency (PCE) of 19.61% can be realized. In contrast, reference devices without any cathode interlayer display a distinctly worse performance, with a PCE of 16.97%. Therefore, this excellent cathode modifier provides a new opportunity to fabricate high performance multilayer PVSCs using low-temperature solution processing without interfacial erosion/mixing.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 66
·38891-38896
·
IF 3.049
Qiaohong Zhang,Honghao He,Huibin Wang,Zhan Zhang,Chen Chen
A series of N-alkyl pyridinium salts were synthesized and employed as metal-free catalyst for the selective oxidation of methyl aromatic hydrocarbon with molecular oxygen. The electronic effect of the substitutes was found to be an important factor for the catalytic performance. With the introduction of electron-donating substitute –N(CH3)2, the conversion of p-xylene and selectivity of p-toluic acid could be simultaneously increased. 1-Benzyl-4-N,N-dimethylaminopyridinium salt showed the highest catalytic activity, and 95% conversion with 84% of selectivity to p-toluic acid could be obtained for the selective oxidation of p-xylene. Several methyl aromatic hydrocarbons could all be efficiently oxidized with the reported catalyst at the absence of any metal species.
研究领域:
化学催化
·
有机合成
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Kang Ma,Qian Tang,Chun-rong Zhu,Jun-fei Long,Cheng-bin Gong,Xiang-kai Fu
This work reports novel dual-colored and fast switching electrochromic materials based on pyridinium salts , 1,1′,1″,1‴-tetrakis(4,4′,4″,4‴-tetrapyridyl)cyclobutane derivatives (TPCBDs). TPCBDs show outstanding electrochromic properties including fast electrochromic switching, dual color, reasonable contrast, low driving voltage, and good stability. TPCBDs are promising candidates for visible electrochromic displays because of their remarkable electrochromic behaviors.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2020
·
IF 2.029
Xiuxiu Wang,Lijuan Guo,Shaokui Cao,Weizhen Zhao
In this work, we proposed an effective route of introducing poly(ionic liquid) (PIL) gel as electrolyte to suppress dimer formation of viologen radical cation during switching in electrochromic devices (ECDs). The ECDs were fabricated based on ion gels consisting of various viologens, PIL and ferrocene (Fc). We found that incorporation of PIL contributed to the suppression of dimer production. The suppression of dimer formation can provide ECDs with improved colouration efficiencies, faster switching times, longer cycle lives, and potentially reduced costs. The results showed that an excellent cyclic stability over 96% of initial transmittance change after 4000 cycles of switching.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2015
·
IF 2.133
Li-Te Ren,Xiao-Pei Li,Jian-Lan Liu,Xiao-Ming Ren
The proton-conducting materials have potential application in devices such as fuel cells. In this study, a mineral kaolinite-based proton conducting material, kaolinite-4-amidinopyridinium hydrochloride (K-4-APy–HCl), was synthesized by the intercalated compound kaolinite-4-amidinopyridine (K-4-APy) adsorbing volatilizing HCl. The thermogravimetric analysis (TG), powder X-ray diffraction (PXRD) and IR spectrum confirmed the HCl successfully inserting into the interlayer space of kaolinite and the 4-aminopyridine being protonated. The intercalation efficiency is estimated to be ca. 85.6%. With respect to K-4-APy, the interlayer space expends by 1.53 Å. The thermal decomposition mechanism was studied by PXRD and TG techniques. The K-4-APy–HCl shows proton conductivity with σ =3.379×10 −8 S cm −1 at 373 K and E a =1.159 eV in the anhydrous condition, which are comparable to MOFs-based proton conducting materials.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 4
·1696-1703
·
IF 3.269
Guiting Chen,Ruifeng He,Wei Yang,Bin Zhang
Two novel water-soluble π-conjugated small molecules based on dibenzothiophene-S,S-dioxide and bispyridinium salts, named FSOPyCl and FSOmiCl, were successfully synthesized. Both molecules showed deep blue light emission, with photoluminescence peaks at about 408 and 405 nm in aqueous solution, respectively. Their photoluminescence quantum yields (PLQYs) in aqueous solution were as high as 68.9% and 50.3%, respectively. Electrochemical measurements suggested that they have excellent electron affinity, with lowest unoccupied molecular orbital (LUMO) energy levels at −3.78 and −3.94 eV, respectively. Due to their unique properties including large planarity, good thermal stability, excellent electron affinity and high fluorescence efficiency, FSOPyCl and FSOmiCl may be promising construction units for preparing water/alcohol-soluble conjugated materials with good optoelectronic performance.
研究领域:
有机化学
·
材料科学
·
光电材料
✓ 已验证
DOI
高影响因子
POLYHEDRON
·
2022
·
IF 2.975
Shun-Ping Zhao,Qiang-hong Yu,Ping Yang,Yu Guo,Jie Wang,Heng Xu
Oriented design of crystal structures to obtain specific properties is one of the hot topics in the field of chemistry and materials. In this paper, three organic–inorganic hybrid crystals were synthesized by the reaction of 1-aminopyridinium salts with o -, m -, and p -cyanobenzaldehyde and PbBr 2 . The asymmetric unit of 1 ([1- aminopyridinium][Pb 2 Br 5 ], P 2 1 / m ) contains half of the 1-aminopyridinium cation and the anion forms a zig-zag shaped puckered sheet of [Pb 2 Br 5 ] ∞ ; while 2 ([ m -cyanobenzaldehyde-1-aminopyridinium][PbBr 3 ], Pna 2 1 ) includes a m -cyanobenzaldehyde-1-aminopyridinium Schiff base cation, and the anion forms a [PbBr 3 ] ∞ single chain. On the other hand, 3 ([ p -cyanobenzaldehyde-1- aminopyridinium][PbBr 3 ], P 2 1 / c ) consists of a p -cyanobenzaldehyde-1- aminopyridinium Schiff base cation, with the anion forming a [Pb 2 Br 6 ] ∞ double chain. Structural analysis and energy framework calculations show that 2 possesses stronger π-π stacking and hydrogen bonding interactions, and its lattice energy and thermal stability are higher than those of 1 and 3 . The combined use of CE and dielectric modulus analysis reveals a good correlation between multi-step dielectric relaxation and intermolecular forces. This strategy of modulating the crystal structure and dielectric properties by altering the position of the substituents provides useful assistance in the design of new relaxation dielectric materials.
研究领域:
材料化学
·
晶体工程
·
介电材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）