A pendant peptide endows a sunscreen with water-resistance

Aubrey J. Ellison; Ronald T. Raines

doi:10.1039/c8ob01773e

The Puncture and Water Resistance of Polyurethane- Impregnated Fabrics after UV Weathering

Polymers ◽

10.3390/polym12010015 ◽

2019 ◽

Vol 12 (1) ◽

pp. 15

Author(s):

Antonella Patti ◽

Domenico Acierno

Keyword(s):

Experimental Data ◽

Uv Radiation ◽

Water Resistance ◽

Uv Light ◽

Crosslinking Agent ◽

Waterborne Polyurethane ◽

Impregnation Method ◽

Polyurethane Dispersion ◽

Spectroscopic Analyses ◽

Before And After

Polyurethane is a polymer adaptable to different scientific and industrial requirements; nevertheless it is also extremely susceptible to UV radiation, which compromises the physical and mechanical functionality. In this framework, our study investigated the effect of waterborne polyurethane dispersion (WPUD) applied to a polyester (PET)-based fabric, through the impregnation method, on the puncturing and water resistance of the pristine material, before and after UV weathering. Results confirmed an increment of both features in the prepared fabrics, attributed to the PUR textile treatment; but a partially loss of the gained properties in the samples due to the UV weathering. In order to improve the efficiency of the impregnating dispersions, in protecting the durability of the treated materials, the addition of different UV light stabilizers, or/and of crosslinking agent into WPUD was also tested. From the experimental data, it can be concluded that formulations based on WPUD, containing both the crosslinker and UV organic absorber, have displayed an increment of their perforation and water resistance for the treated samples with respect to the starting textile, and contemporary have preserved the features against the UV light. Finally, microscopic and spectroscopic analyses have been performed as further characterization techniques of the samples surface.

Download Full-text

Study on the Synthesis of Polyester Type Waterborne Polyurethane and Modifying by Nano-Sized Particles

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.217-219.656 ◽

2012 ◽

Vol 217-219 ◽

pp. 656-660

Author(s):

Yi Chen ◽

Wen Yong Liu ◽

Guang Sheng Zeng ◽

Xiang Gang Li ◽

Ling Gu

Keyword(s):

Small Molecule ◽

Mass Fraction ◽

Water Resistance ◽

Raw Materials ◽

Waterborne Polyurethane ◽

Chain Extender ◽

Polyester Polyol ◽

Polyurethane Film ◽

Mechanical Characters

The waterborne polyurethane was prepared by reaction between polyester polyol and isophorone diisocyanat, different nanoparticles were filled into the system for modification. The effect of different ratio of materials, the kinds and mass of nanoparticles on the characters of waterborne polyurethane latex and film were investigated. The results showed that the stable polyurethane latex and polyurethane film with perfect characters could be prepared when the ratio of NNCO/NOH was 2.5~3.0, the DMPA with a mass fraction of 5%~6% was added into reaction as a macromolecule extender after adding small molecule chain extender BPO. Filling nanoparticles into the polyurethane latex could improve the water resistance and mechanical characters of the film. Nano-sized SiO2 was a better modifier than TiO2, and the appropriate mass fraction of SiO2 was 6% of polyurethane raw materials.

Download Full-text

The Involvement of Xanthone and (E)-Cinnamoyl Chromophores for the Design and Synthesis of Novel Sunscreening Agents

International Journal of Molecular Sciences ◽

10.3390/ijms22010034 ◽

2020 ◽

Vol 22 (1) ◽

pp. 34

Author(s):

Justyna Popiół ◽

Agnieszka Gunia-Krzyżak ◽

Karolina Słoczyńska ◽

Paulina Koczurkiewicz-Adamczyk ◽

Kamil Piska ◽

...

Keyword(s):

Uv Radiation ◽

Broad Spectrum ◽

Estrogenic Activity ◽

Spectroscopic Properties ◽

Skin Aging ◽

Systemic Absorption ◽

Uv Filters ◽

Wet Milling ◽

Uv Filter ◽

Sunscreening Agents

Excessive UV exposure contributes to several pathological conditions like skin burns, erythema, premature skin aging, photodermatoses, immunosuppression, and skin carcinogenesis. Effective protection from UV radiation may be achieved with the use of sunscreens containing UV filters. Currently used UV filters are characterized by some limitations including systemic absorption, endocrine disruption, skin allergy induction, and cytotoxicity. In the research centers all over the world new molecules are developed to improve the safety, photostability, solubility, and absorption profile of new derivatives. In our study, we designed and synthesized seventeen novel molecules by combining in the structures two chromophores: xanthone and (E)-cinnamoyl moiety. The ultraviolet spectroscopic properties of the tested compounds were confirmed in chloroform solutions. They acted as UVB or UVA/UVB absorbers. The most promising compound 9 (6-methoxy-9-oxo-9H-xanthen-2-yl)methyl (E)-3-(2,4-dimethoxyphenyl)acrylate) absorbed UV radiation in the range 290–369 nm. Its photoprotective activity and functional photostability were further evaluated after wet milling and incorporation in the cream base. This tested formulation with compound 9 possessed very beneficial UV protection parameters (SPFin vitro of 19.69 ± 0.46 and UVA PF of 12.64 ± 0.32) which were similar as broad-spectrum UV filter tris-biphenyl triazine. Additionally, compound 9 was characterized by high values of critical wavelength (381 nm) and UVA/UVB ratio (0.830) thus it was a good candidate for broad-spectrum UV filter and it might protect skin against UVA-induced photoaging. Compound 9 were also shown to be photostable, non-cytotoxic at concentrations up to 50 µM when tested on five cell lines, and non-mutagenic in Ames test. It also possessed no estrogenic activity, according to the results of MCF-7 breast cancer model. Additionally, its favorable lipophilicity (miLogP = 5.62) does not predispose it to penetrate across the skin after topical application.

Download Full-text

Neutrophil Myeloperoxidase Destruction by Ultraviolet Irradiation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102778 ◽

1988 ◽

Vol 46 ◽

pp. 138-139

Author(s):

J. Hanker ◽

B. Giammara ◽

G. Strauss

Keyword(s):

Uv Radiation ◽

Myeloid Leukemia ◽

Stratospheric Ozone ◽

Psoriasis Patient ◽

Whole Body ◽

Human Neutrophils ◽

Cupric Nitrate ◽

The Earth ◽

Routine Handling ◽

Uvb Phototherapy

Only a fraction of the UV radiation emitted by the sun reaches the earth; most of the UVB (290-320nm) is eliminated by stratospheric ozone. There is increasing concern, however, that man-made chemicals are damaging this ozone layer. Although the effects of UV on DNA or as a carcinogen are widely known, preleukemia and acute myeloid leukemia (AML) have only rarely been reported in psoriasis patients treated with 8-methoxypsoralen and UV (PUVA). It was therefore of interest to study the effects of UV on the myeloperoxidase (MP) activity of human neutrophils. The peroxidase activity of enriched leukocyte preparations on coverslips was shown cytochemically with a diaminobenzidine medium and cupric nitrate intensification.Control samples (Figs. 1,4,5) of human bloods that were not specifically exposed to UV radiation or light except during routine handling were compared with samples which had been exposed in one of several different ways. One preparation (Fig. 2) was from a psoriasis patient who had received whole-body UVB phototherapy repeatedly.

Download Full-text

A privileged ternary blend enabling non-fullerene organic photovoltaics with over 14% efficiency

Journal of Materials Chemistry C ◽

10.1039/d0tc02778b ◽

2020 ◽

Vol 8 (43) ◽

pp. 15135-15141

Author(s):

Jing Yan ◽

Yuan-Qiu-Qiang Yi ◽

Jianqi Zhang ◽

Huanran Feng ◽

Yanfeng Ma ◽

...

Keyword(s):

Small Molecule ◽

Organic Photovoltaics ◽

Power Conversion ◽

Ternary Blend ◽

Conversion Efficiencies

Two non-fullerene small molecule acceptors, NT-4F and NT-4Cl, were designed and synthesized. Power conversion efficiencies of 11.44% and 14.55% were achieved for NT-4Cl-based binary and ternary devices, respectively.

Download Full-text