scholarly journals Preparation of Ultrathin and Degradable Polymeric Films by Electropolymerization of 3-Amino-L-Tyrosine

2021 ◽  
Author(s):  
Tommaso Marchesi D’Alvise ◽  
Sruthi Sunder ◽  
Roger Hasler ◽  
Julia Moser ◽  
Wolfgang Knoll ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Quartz Crystal ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Polymer Processing ◽  
Polymeric Films ◽  
Suitable Candidate ◽  
The Past ◽  
Quenching Efficiency ◽  
Wide Ph Range ◽  
Ph Range

The resource intensive and environmentally unfriendly synthesis, recycling and disposal of today’s plastics has sparked interest in greener polymer processing. Bioderived polymers are one of many current areas of research that show promise for a sustainable future. One bioderived polymer that has been in the spotlight for the past decade due to its unique properties is polydopamine (PDA). Its ability to adhere to virtually any surface showing high stability in a wide pH range from 2-10 and in several organic solvents makes it a suitable candidate for several applications ranging from medical devices, coatings to biosensing applications. However, its strong and broad light absorption limits many applications that rely on transparent material, moreover fluorescence applications are limited by the high quenching efficiency of PDA. Therefore, new bioderived polymers that share similar features as PDA without fluorescent quenching are highly desirable. In this study, the electropolymerization of a bioderived analogue of dopamine, 3-amino-L-tyrosine (ALT) is demonstrated. The properties of the resultant polymer, poly-amino-L-tyrosine (p-ALT), exhibit several characteristics complementary to or even exceeding those of PDA and of its analog, poly-norepinephrine (p-NorEp), rendering p-ALT attractive for the development of sensors and photoactive devices. Cyclic voltammetry, spectroelectrochemistry and electrochemical quartz crystal microbalance have been applied to study the electrodeposition of this material and the resulting polymeric films have been compared to PDA and p-NorEp. Impedance spectroscopy revealed increased ions permeability of p-ALT with respect PDA and p-NorEp. Moreover reduced fluorescence quenching of p-ALT film was achieved supporting its application as coating for biosensors, organic semiconductors and new nanocomposite materials.

Comparing the suitability of sodium hyposulfite, hydroxylamine hydrochloride and sodium sulfite as the quenching agents for permanganate oxidation

RSC Advances ◽  
2016 ◽  
Vol 6 (16) ◽  
pp. 13335-13342 ◽  
Author(s):  
Bo Sun ◽  
Dandan Rao ◽  
Hongyu Dong ◽  
Xiaohong Guan
Keyword(s):  
Sodium Sulfite ◽  
Hydroxylamine Hydrochloride ◽  
Phenol Oxidation ◽  
Permanganate Oxidation ◽  
Quenching Efficiency ◽  
Wide Ph Range ◽  
Ph Range

The graphic abstract showed the quenching efficiency of different quenchers for phenol oxidation by permanganate with different molar of quencher : permanganate over wide pH range.

Polarographic and spectrophotometric behaviour of some N-p-phenyl substituted benzamidines

1991 ◽  
Vol 56 (12) ◽  
pp. 2791-2799 ◽  
Author(s):  
Juan A. Squella ◽  
Luis J. Nuñez-Vergara ◽  
Hernan Rodríguez ◽  
Amelia Márquez ◽  
Jose M. Rodríguez-Mellado ◽  
...  
Keyword(s):  
Spectrophotometric Study ◽  
Absorption Bands ◽  
Electrochemical Parameters ◽  
Wide Ph Range ◽  
Group A ◽  
Substituent Constants ◽  
Ph Range ◽  
The Waves

Five N-p-phenyl substituted benzamidines were studied by DC and DP polarography in a wide pH range. Coulometric results show that the overall processes are four-electron reductions. Logarithmic analysis of the waves indicate that the process are irreversible. The influence of the pH on the polarographic parameters was also studied. A UV spectrophotometric study was performed in the pH range 2-13. In basic media some variations in the absorption bands were observed due to the dissociation of the amidine group. A determination of the pK values was made by deconvolution of the spectra. Correlations of both the electrochemical parameters and spectrophotometric pK values with the Hammett substituent constants were obtained.

High degradation efficiency of sulfamethazine with the dual-reaction-center Fe-Mn-SiO2 Fenton-like nanocatalyst in a wide pH range

2021 ◽  
Author(s):  
Manoj Kumar Panjwani ◽  
Qing Wang ◽  
Yueming Ma ◽  
Yuxuan Lin ◽  
Feng Xiao ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Reaction Center ◽  
Degradation Efficiency ◽  
Heterogeneous Fenton ◽  
Wide Ph Range ◽  
Ph Range

The development of a heterogeneous Fenton-like catalyst, possessing high degradation efficiency in a wide pH range, is crucial for wastewater treatment. The Fe-Mn-SiO2 catalyst was designed, and prepared by a...

Fused Ambipolar Aza-isoindigos with NIR absorption

2021 ◽  
Author(s):  
Liping Yao ◽  
Danlei Zhu ◽  
Hailiang Liao ◽  
Sheik Haseena ◽  
Mahesh kumar Ravva ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
High Performance ◽  
Low Cost ◽  
Light Weight ◽  
The Past ◽  
Pi Conjugated ◽  
Nir Absorption ◽  
Conjugated Organic Semiconductors

Due to their advantages of low-cost, light-weight, and mechanical flexibility, much attention has been focused on pi-conjugated organic semiconductors. In the past decade, although many materials with high performance has...

scholarly journals Defect-Rich Heterogeneous MoS2/rGO/NiS Nanocomposite for Efficient pH-Universal Hydrogen Evolution

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 662 ◽  
Author(s):  
Guangsheng Liu ◽  
Kunyapat Thummavichai ◽  
Xuefeng Lv ◽  
Wenting Chen ◽  
Tingjun Lin ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Reduced Graphene ◽  
Heterogeneous Interfaces ◽  
Wide Ph Range ◽  
Ph Range ◽  
A Current ◽  
Poor Stability

Molybdenum disulfide (MoS2) has been universally demonstrated to be an effective electrocatalytic catalyst for hydrogen evolution reaction (HER). However, the low conductivity, few active sites and poor stability of MoS2-based electrocatalysts hinder its hydrogen evolution performance in a wide pH range. The introduction of other metal phases and carbon materials can create rich interfaces and defects to enhance the activity and stability of the catalyst. Herein, a new defect-rich heterogeneous ternary nanocomposite consisted of MoS2, NiS and reduced graphene oxide (rGO) are synthesized using ultrathin αNi(OH)2 nanowires as the nickel source. The MoS2/rGO/NiS-5 of optimal formulation in 0.5 M H2SO4, 1.0 M KOH and 1.0 M PBS only requires 152, 169 and 209 mV of overpotential to achieve a current density of 10 mA cm−2 (denoted as η10), respectively. The excellent HER performance of the MoS2/rGO/NiS-5 electrocatalyst can be ascribed to the synergistic effect of abundant heterogeneous interfaces in MoS2/rGO/NiS, expanded interlayer spacings, and the addition of high conductivity graphene oxide. The method reported here can provide a new idea for catalyst with Ni-Mo heterojunction, pH-universal and inexpensive hydrogen evolution reaction electrocatalyst.

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