Smart microcapsules for precise delivery systems

2018 ◽  
Vol 11 (05) ◽  
pp. 1850041 ◽  
Author(s):  
Anna Trojanowska ◽  
Valentina Marturano ◽  
Nuno A. G. Bandeira ◽  
Marta Giamberini ◽  
Bartosz Tylkowski
Keyword(s):  
High Performance ◽  
Main Chain ◽  
Interfacial Polymerization ◽  
Uv Light ◽  
Active Material ◽  
Morphological Variations ◽  
Uv Light Irradiation ◽  
Oil In Water ◽  
Chemical Companies ◽  
Polymerization Method

Photosensitive microcapsules are important targets for medical, pharmaceutical, agriculture, consumer goods and chemical companies. In this study, we report the development of UV-sensitive capsules containing vanillin as a model encapsulated active material. Polyamide microcapsule shells containing azobenzene moieties in the main chain of the polymer were fabricated by oil-in-water interfacial polymerization method. Triggered perfume release and morphological variations of the microcapsule shell during UV light irradiation were observed by means of high-performance liquid chromatography (HPLC) and optical microscopy.

scholarly journals High Density Polyethylenes Bearing Isolated In-Chain Carbonyls

2021 ◽  
Author(s):  
Kyoko NOZAKI ◽  
Shan Tang ◽  
Falk William Seidel
Keyword(s):  
Main Chain ◽  
Uv Light ◽  
High Density ◽  
Chemical Recycling ◽  
Metal Carbonyls ◽  
Uv Light Irradiation ◽  
Selective Approach ◽  
Carbon Carbon Bonds ◽  
Palladium Catalyzed ◽  
Synthesized Materials

Abstract Polyethylene materials are highly important polymers which are produced in the largest volume among all plastics. Due to the chemical inert property of saturated carbon-carbon bonds, the degradation of polyethylene is extremely challenging, which prevents them from efficient chemical recycling. Installing functional groups in the main chain of polyethylenes may facilitate the degradation and following chemical recycling of polyethylene materials. Here we report a highly selective approach for the synthesis of high-density polyethylenes bearing isolated in-chain carbonyls. Linear high-molecular weight polyethylene chains are synthesized via the palladium catalyzed copolymerization of ethylene with metal carbonyls. Different from traditional ethylene/CO copolymerization reactions, excellent non-alternating selectivity has been achieved. While the properties of polyethylene have been retained in the copolymer, faster degradation compared with that of polyethylene was observed upon UV light irradiation. The synthesized materials may therefore serve as more environmentally friendly alternative plastics than traditional polyethylene materials.

scholarly journals Photocatalytic oxidation of nitrite ion over carbon nitride

2018 ◽  
Vol 14 (1-2) ◽  
pp. 174-178 ◽  
Author(s):  
Siti Maryam Jasman ◽  
Hendrik Oktendy Lintang ◽  
Siew Ling Lee ◽  
Leny Yuliati
Keyword(s):  
High Performance ◽  
Photocatalytic Oxidation ◽  
Carbon Nitride ◽  
Uv Light ◽  
Nitrogen Adsorption ◽  
Thermal Polymerization ◽  
Light Irradiation ◽  
Polymerization Process ◽  
Nitrite Ion ◽  
Uv Light Irradiation

Nitrite ion (NO2-) is a toxic inorganic contaminant, which is widely used in industry and agriculture as a food preservative and a fertilizing agent. One of the methods to reduce the toxicity of the NO2- is by oxidizing it into less hazardous compounds, such as nitrate ion (NO3-). In this study, we demonstrated that a simple and green photocatalytic process can be employed to oxidize the NO2- to NO3- over a metal free-carbon nitride photocatalyst under ultraviolet (UV) light irradiation. The carbon nitride was synthesized via pyrolysis of urea precursor by a thermal polymerization process at 823 K for 4 hours. The prepared carbon nitride was then characterized by using X-ray diffractometer (XRD), field emission scanning electron microscope (FESEM), diffuse reflectance UV-visible (DR UV-vis), fluorescence, and Fourier transform infrared (FTIR) spectrophotometers, as well as nitrogen  adsorption-desorption isotherm analyzer. All the characterization results supported the successful synthesis of the carbon nitride. The carbon nitride was then used as the photocatalyst for oxidation of NO2- to NO3- under UV light irradiation for 3 h. The decrease of the NO2- and the formation of the NO3- were analyzed by using a high performance liquid chromatography (HPLC) equipped with Hypersil GoldTM PFP column. The mobile phase used was a mixture of methanol (MeOH) and water (H2O) with the ratio of MeOH:H2O was 30:70. The addition of orthophosphoric acid was required to set the pH at 2.5. The flow rate was fixed at 0.8 ml min-1 and the monitored wavelength was 220 nm. It was revealed that carbon nitride could oxidize NO2- to NO3- with a moderate conversion of 15%. Fluorescence quenching showed that there were good interactions between the emission sites of carbon nitride and the NO2- molecules. The good interactions would be one driving force for the carbon nitride to act as a good photocatalyst to oxidize the NO2- to NO3-. The oxidation pathway by the photogenerated species was also proposed.

Highly efficient organic ultraviolet photodetectors based on excellent Cu (I) complexes

2013 ◽  
Vol 21 (3) ◽  
Author(s):  
C. Liu ◽  
B. Su ◽  
M. Liu ◽  
X. Zhang ◽  
L. Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Uv Light ◽  
High Response ◽  
Working Mechanism ◽  
Photoluminescence Quenching ◽  
Uv Light Irradiation ◽  
Donor And Acceptor ◽  
Electron Donor And Acceptor ◽  
Ultraviolet Photodetectors ◽  
Photoinduced Charge

AbstractWe demonstrate high response organic ultraviolet photodetectors using 4,4′,4″-tris[3-methyl-pheny(phenyl)amino]tri-phenylamine (m-MTDATA) and two novel Cu(I) complexes, [Cu(DPEphos)(PyPhen)]BF4 (CuDP)(DPEphos = Bis [2-(diphenylphosphino)phenyl]ether, PyPhen = pyrazino[2,3-f][1,10]phenanthroline) and [Cu(DPEbenz)(PyPhen)]BF4 (CuBP) (DPEbenz = 1,2-bis(diphenylphosphino)benzene) to act as the electron donor and acceptor, respectively. Strong photoluminescence quenching of m-MTDATA by Cu(I) complexes is observed manifesting the efficient photoinduced charge transfer that occurs between m-MTDATA and Cu(I) complexes. The optimized photodetector based on CuBP exhibits a maximum response of 276 mA/W at −12 V under an illumination of 365 nm UV light irradiation with an intensity of 1.75 mW/cm2. The high response is attributed to feasible energy level match, efficient electron transfer from m-MTDATA to CuBP and skillful device design. More detailed working mechanism of harvesting high performance is also discussed.

Study of Photocatalytic Activity of TiO2 Nanotube Derived from Different Anodized Parameters

2012 ◽  
Vol 488-489 ◽  
pp. 1519-1524 ◽  
Author(s):  
Kittirong Srimuangmak ◽  
Sutham Niyomwas
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
High Performance ◽  
Uv Light ◽  
Photocatalytic Reaction ◽  
Uv Light Irradiation ◽  
Anodization Process ◽  
Temperature Time ◽  
Anodization Method

In this study titanium dioxide nanotube (TNT) were prepared by anodization method. The effects of the temperature, time and voltage on the anodization process were investigated in detail. Photocatalytic activity of the TNT films was evaluated in terms of the degradation of methylene blue in aqueous solution under UV light irradiation. The results showed that the optimization of temperature, voltage and time on anodization process were 45oC, 20 V and 1 day, respectively. Consequently, these results indicate that the optimization of anodization process is critical to achieve the high performance of photocatalytic reaction.

High-solubility aromatic polyesters with fluorene and phthalein groups: Synthesis and property

2020 ◽  
Vol 32 (8) ◽  
pp. 933-944
Author(s):  
Xing-Hua Guan ◽  
He-Ran Nie ◽  
Hong-Hua Wang ◽  
Ji-Yong Zhao ◽  
Zhi-Peng Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Interfacial Polymerization ◽  
Thermal Decomposition Mechanism ◽  
Elongation At Break ◽  
Good Solubility ◽  
Flexible Films ◽  
Content Range ◽  
Polymerization Method ◽  
Aromatic Polyesters

A series of aromatic polyesters bearing fluorene and phthalein groups were synthesized from commercially available 9,9-bis(4-hydroxyphenyl)fluorene (BPF), phenolphthalein, and terephthaloyl chloride through an interfacial polymerization method. The microstructure, molecular weight, morphology, thermal properties, and thermal decomposition mechanism of these aromatic polyesters were investigated. Their mechanical properties were also evaluated. The results suggested that the copolymer compositions were approximately equal to the feed compositions. Moreover, the increase in the BPF unit content increased the glass transition and weight loss temperatures of the aromatic polyesters, owing to the strong rigidity of the bulky fluorene group. All the polymers were amorphous and exhibited good solubility in common organic solvents. Hence, the synthesized polymers could be easily cast into flexible films. The copolymer film samples exhibited better mechanical properties than those of the homopolymers. The tensile strength, Young’s modulus, and elongation at break of the polymers first increased gradually, and then decreased with increasing BPF content. Notably, the copolymers exhibited the best mechanical properties at the BPF content range 30–50%. Owing to their characteristics, these synthesized polymers show great potential for application as high performance membrane materials.

Ultra-high performance and flexible polypyrrole coated CNT paper electrodes for all-solid-state supercapacitors

2019 ◽  
Vol 7 (17) ◽  
pp. 10751-10760 ◽  
Author(s):  
Liang Tong ◽  
Mingyuan Gao ◽  
Cong Jiang ◽  
Kefeng Cai
Keyword(s):  
Solid State ◽  
High Performance ◽  
Interfacial Polymerization ◽  
Polymerization Method

Ultra-high performance and flexible polypyrrole coated CNT paper electrodes prepared by an in situ interfacial polymerization method for all-solid-state supercapacitors.

Photoelectrocatalytic degradation of Rhodamine B using graphene and titanium dioxide composite catalyst

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744098
Author(s):  
Yu Zhao ◽  
Wen-Han Du ◽  
Lei Chen ◽  
Jin Xiao ◽  
Chao Xiong ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Rhodamine B ◽  
High Performance ◽  
Separation Efficiency ◽  
Uv Light ◽  
Synthesis Method ◽  
Light Irradiation ◽  
Composite Catalyst ◽  
Uv Light Irradiation ◽  
Photoelectrocatalytic Degradation

Graphene and titanium dioxide (TiO2) composite catalyst has been synthesized by hydrothermal synthesis method, and used for the degradation of Rhodamine B (Rh.B) in water. The photoelectrocatalytic activity of this composite was evaluated by decomposing of Rh.B in water under visible or UV light irradiation. The degradation results indicated that the photoelectrocatalytic performance of this composite catalyst was greatly enhanced due to the improved adsorption performance and separation efficiency of photo-generated carriers possibly. The composite with graphene content of 10 wt.% exhibited superior activity under UV light irradiation. After 30 min of reaction, the photoelectrocatalytic degradation ratio of Rh.B was about 96% when pH [Formula: see text] 6–7. The results of this work provide a good method for the treatment of organic wastewater with high performance.

scholarly journals Benzothiazole heterogeneous photodegradation in nano α-Fe 2 O 3 /oxalate system under UV light irradiation

2018 ◽  
Vol 5 (6) ◽  
pp. 180322 ◽  
Author(s):  
Xiangyun Han ◽  
Xi Zhang ◽  
Lei Zhang ◽  
Mei Pan ◽  
Jinlong Yan
Keyword(s):  
Liquid Chromatography ◽  
Oxalic Acid ◽  
High Performance ◽  
Uv Light ◽  
Transformation Products ◽  
Light Irradiation ◽  
Order Kinetic ◽  
Uv Light Irradiation ◽  
Order Kinetic Model ◽  
Set Up

The photodegradation of benzothiazole (BTH) in wastewater with the coexistence of iron oxides and oxalic acid under UV light irradiation was investigated. Results revealed that an effective heterogeneous photo-Fenton-like system could be set up for BTH abatement in wastewater under UV irradiation without additional H 2 O 2 , and 88.1% BTH was removed with the addition of 2.0 mmol l −1 oxalic acid and 0.2 g l −1 α-Fe 2 O 3 using a 500 W high-pressure mercury lamp (365 nm). The degradation of BTH in the photo-Fenton-like system followed the first-order kinetic model. The photoproduction of hydroxyl radicals (·OH) in different systems was determined by high-performance liquid chromatography. Identification of transformation products by using liquid chromatography coupled with high resolution tandem mass spectrometry provided information about six transformation products formed during the photodegradation of BTH. Further insight was obtained by monitoring concentrations of the sulfate ion ( SO 4 2 − ) and nitrate ion ( NO 3 − ) , which demonstrated that the intermediate products of BTH could be decomposed ultimately. Based on the results, the potential photodegradation pathway of BTH was also proposed.

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