Unexpected visible-light-induced free radical photopolymerization at low light intensity and high viscosity using a titanocene photoinitiator

2012 ◽  
Vol 128 (1) ◽  
pp. 611-618 ◽  
Author(s):  
Hajime Kitano ◽  
Karthik Ramachandran ◽  
Ned B. Bowden ◽  
Alec B. Scranton
Keyword(s):  
Free Radical ◽  
Light Intensity ◽  
Visible Light ◽  
High Viscosity ◽  
Low Light ◽  
Low Light Intensity ◽  
Free Radical Photopolymerization

scholarly journals Recent Advances on Visible Light Metal-Based Photocatalysts for Polymerization under Low Light Intensity

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 736 ◽  
Author(s):  
Frédéric Dumur
Keyword(s):  
Light Intensity ◽  
Visible Light ◽  
Light Metal ◽  
Industrial Applications ◽  
Polymerization Process ◽  
High Tech ◽  
Low Light ◽  
Low Light Intensity ◽  
Wide Range ◽  
Photochemical Polymerization

In recent years, polymerization processes activated by light have attracted a great deal of interest due to the wide range of applications in which this polymerization technique is involved. Parallel to the traditional industrial applications ranging from inks, adhesives, and coatings, the development of high-tech applications such as nanotechnology and 3D-printing have given a revival of interest to this polymerization technique known for decades. To initiate a photochemical polymerization, the key element is the molecule capable to interact with light, i.e., the photoinitiator and more generally the photoinitiating system, as a combination of several components is often required to create the reactive species responsible for the polymerization process. With the aim of reducing the photoinitiator content while optimizing the polymerization yield and/or the polymerization speed, photocatalytic systems have been developed, enabling the photosensitizer to be regenerated during the polymerization process. In this review, an overview of the photocatalytic systems developed for polymerizations carried out under a low light intensity and visible light is provided. Over the years, a wide range of organometallic photocatalysts has been proposed, addressing both the polymerization efficiency and/or the toxicity, as well as environmental issues.

scholarly journals New, highly versatile bimolecular photoinitiating systems for free-radical, cationic and thiol–ene photopolymerization processes under low light intensity UV and visible LEDs for 3D printing application

RSC Advances ◽  
2020 ◽  
Vol 10 (13) ◽  
pp. 7509-7522 ◽  
Author(s):  
Emilia Hola ◽  
Monika Topa ◽  
Anna Chachaj-Brekiesz ◽  
Maciej Pilch ◽  
Paweł Fiedor ◽  
...  
Keyword(s):  
Free Radical ◽  
3D Printing ◽  
Light Intensity ◽  
Low Light ◽  
Low Light Intensity ◽  
Iodonium Salt ◽  
Methyl Naphthalene

1-Amino-4-methyl-naphthalene-2-carbonitrile derivatives are proposed for the role of photosensitizers of iodonium salt during the photopolymerization processes upon near UV-A and visible ranges.

scholarly journals Response of Photosynthesis and Chlorophyll Fluorescence Parameters of Castanopsis kawakamii Seedlings to Forest Gaps

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Zhong-sheng He ◽  
Rong Tang ◽  
Meng-jia Li ◽  
Meng-ran Jin ◽  
Cong Xin ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Light Intensity ◽  
Seedling Growth ◽  
Group Treatment ◽  
Control Group ◽  
Low Light ◽  
Chlorophyll Fluorescence Parameters ◽  
Forest Gaps ◽  
Low Light Intensity ◽  
Weak Light

Light is a major environmental factor limiting the growth and survival of plants. The heterogeneity of the light environment after gap formation in forest influences the leaf chlorophyll contents, net photosynthetic rate (Pn), and chlorophyll fluorescence, thus influencing the growth and regeneration of Castanopsis kawakamii seedlings. The aim of this study was to explore the effects of weak light on the photosynthetic physiology of C. kawakamii seedlings in forest gaps and non-gaps. The results showed that (1) the contents of chlorophyll a (Chl-a), chlorophyll b (Chl-b), and total chlorophyll (Chl-T) in forest gaps were lower than in non-gaps. Seedlings tended to increase chlorophyll content to absorb light energy to adapt to low light intensity in non-gap environments. (2) The Pn values of C. kawakamii seedlings in forest gaps were significantly higher than in non-gaps, and forest gaps could improve the seedlings’ photosynthetic capacity. (3) The C. kawakamii seedlings in forest gaps were more sensitive to weak light and control group treatment, especially the tall seedlings, indicating that seedlings require more light to satisfy their growth needs in the winter. The seedlings in non-gaps demonstrated better adaptability to low light intensity. The light intensity was not adequate in weak light conditions and limited seedling growth. We suggest that partial forest selection cutting could improve light intensity in non-gaps, thus promoting seedling growth and regeneration of C. kawakamii more effectively in this forest.

scholarly journals The Effect of Low Light Intensity on the Early Development of Radish Hypocotyl

1983 ◽  
Vol 51 (4) ◽  
pp. 421-426 ◽  
Author(s):  
Yasuyoshi HAYATA ◽  
Yutaka SHINOHARA ◽  
Yoshio SUZUKI
Keyword(s):  
Light Intensity ◽  
Early Development ◽  
Low Light ◽  
Low Light Intensity

scholarly journals Nighttime Temperatures and Sunlight Intensities Interact to Influence Anthocyanin Biosynthesis and Photooxidative Sunburn in “Fuji” Apple

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaomin Xue ◽  
Ying Duan ◽  
Jinzheng Wang ◽  
Fengwang Ma ◽  
Pengmin Li
Keyword(s):  
Light Intensity ◽  
Low Temperatures ◽  
Anthocyanin Biosynthesis ◽  
High Light ◽  
Anthocyanin Accumulation ◽  
Low Light ◽  
Low Light Intensity ◽  
Apple Peel ◽  
Fuji Apple ◽  
Nighttime Temperatures

Light and low temperatures induce anthocyanin accumulation, but intense sunlight causes photooxidative sunburn. Nonetheless, there have been few studies of anthocyanin synthesis under different sunlight intensities and low nighttime temperatures. Here, low nighttime temperatures followed by low light intensity were associated with greater anthocyanin accumulation and the expression of anthocyanin biosynthesis genes in “Fuji” apple peel. UDP-glucose flavonoid-3-O-glucosyltransferase (UFGT) activity was positively associated with anthocyanin enrichment. Ascorbic acid can be used as an electron donor of APX to scavenge H2O2 in plants, which makes it play an important role in oxidative defense. Exogenous ascorbate altered the anthocyanin accumulation and reduced the occurrence of high light–induced photooxidative sunburn by removing hydrogen peroxide from the peel. Overall, low light intensity was beneficial for the accumulation of anthocyanin and did not cause photooxidative sunburn, whereas natural light had the opposite effect on the apple peel at low nighttime temperatures. This study provides an insight into the mechanisms by which low temperatures induce apple coloration and high light intensity causes photooxidative sunburn.

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