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Herzog B, Sengün F. Scattering particles increase absorbance of dyes--a model study with relevance for sunscreens. Photochem Photobiol Sci 2016; 14:2054-63. [PMID: 26356574 DOI: 10.1039/c5pp00109a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sunscreens used for the protection of human skin against the harmful effects of solar radiation contain UV absorbers as key ingredients, which are either dissolved in one of the phases of the preparation or, when insoluble, suspended as particles. Although the UV protective effect of particulate UV filters, inorganic and organic, is mainly due to absorption, they scatter UV and visible light. The scattering can have an additional attenuating effect on the incoming radiation by increasing the pathlength of the photons, especially when soluble filters are also present. This is investigated with model systems of dyes and absorbing and non-absorbing particles. The presence of particles causes an increase of the dye absorbance without changing dye concentration or cuvette thickness. It is possible to relate this amplification of dye absorbance to the turbidity of the system. Plots are constructed which allow for a given particle type the representation of all data on one single curve, though measured at different turbidity and cuvette thickness. With that, extrapolations to practical applications of sunscreens are possible.
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Affiliation(s)
- Bernd Herzog
- BASF Grenzach GmbH, G-9001.2.28, Köchlinstrasse 1, 79639 Grenzach-Wyhlen, Germany.
| | - Fazilet Sengün
- University of Basel, Institute of Pharmaceutical Technology, Klingelbergstrasse 50, 4056 Basel, Switzerland.
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Houben C, Nurumbetov G, Haddleton D, Lapkin AA. Feasibility of the Simultaneous Determination of Monomer Concentrations and Particle Size in Emulsion Polymerization Using in Situ Raman Spectroscopy. Ind Eng Chem Res 2015; 54:12867-12876. [PMID: 26900256 PMCID: PMC4749093 DOI: 10.1021/acs.iecr.5b02759] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 11/27/2015] [Accepted: 12/07/2015] [Indexed: 11/29/2022]
Abstract
An immersion Raman probe was used in emulsion copolymerization reactions to measure monomer concentrations and particle sizes. Quantitative determination of monomer concentrations is feasible in two-monomer copolymerizations, but only the overall conversion could be measured by Raman spectroscopy in a four-monomer copolymerization. The feasibility of measuring monomer conversion and particle size was established using partial least-squares (PLS) calibration models. A simplified theoretical framework for the measurement of particle sizes based on photon scattering is presented, based on the elastic-sphere-vibration and surface-tension models.
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Affiliation(s)
- Claudia Houben
- Department of Chemical Engineering and Biotechnology, University of Cambridge , Pembroke Street, Cambridge CB2 3RA, U.K
| | - Gabit Nurumbetov
- Department of Chemistry, University of Warwick , Gibbet Hill, Coventry CV4 7AL, U.K
| | - David Haddleton
- Department of Chemistry, University of Warwick , Gibbet Hill, Coventry CV4 7AL, U.K
| | - Alexei A Lapkin
- Department of Chemical Engineering and Biotechnology, University of Cambridge , Pembroke Street, Cambridge CB2 3RA, U.K
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Aggarwal A, Qureshy M, Johnson J, Batteas JD, Drain CM, Samaroo D. Responsive porphyrinoid nanoparticles: development and applications. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424611003422] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The economy of space and materials and the continuously increasing demand for advanced functionalities for diverse technologies requires the development of new synthetic methods. Many nanomaterials have enhanced photophysical and photochemical properties in solutions and/or on surfaces, while others have enhanced chemical properties, compared to the atomic, molecular, or bulk phases. Nanomaterials have a wide range of applications in catalysis, sensors, photonic devices, drug delivery, and as therapeutics for treatment of a variety of diseases. Inorganic nanoparticles are widely studied, but the formation of organic nanomaterials via supramolecular chemistry is more recent, and porphyrinoids are at the forefront of this research because of their optical, chemical, and structural properties. The formation of nanoscaled materials via self-assembly and/or self-organization of molecular subunits is an attractive approach because of reduced energy requirements, simpler molecular subunits, and the material can be adaptive to environmental changes. The presence of biocompatible groups such as peptides, carbohydrates, polyglycols and mixtures of these on the periphery of the porphyrin macrocycle may make nanoparticles suitable for therapeutics. This perspective focuses on responsive, non-crystalline porphyrinoid nanomaterials that are less than about 100 nm in all dimensions and used for catalytic or therapeutic applications.
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Affiliation(s)
- Amit Aggarwal
- Department of Chemistry and Biochemistry, Hunter College of the City University of New York, 695 Park Avenue, New York, NY 10065, USA
| | - Meroz Qureshy
- Department of Chemistry and Biochemistry, Hunter College of the City University of New York, 695 Park Avenue, New York, NY 10065, USA
| | - Jason Johnson
- Department of Chemistry, New York City College of Technology of the City University of New York, 300 Jay Street, Brooklyn, NY 11201, USA
| | - James D. Batteas
- Department of Chemistry, Texas A & M University, College Station, TX 77842, USA
| | - Charles Michael Drain
- Department of Chemistry and Biochemistry, Hunter College of the City University of New York, 695 Park Avenue, New York, NY 10065, USA
- The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
| | - Diana Samaroo
- Department of Chemistry, New York City College of Technology of the City University of New York, 300 Jay Street, Brooklyn, NY 11201, USA
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Hass R, Munzke D, Reich O. Inline-Partikelgrößenmesstechniken für Suspensionen und Emulsionen. CHEM-ING-TECH 2010. [DOI: 10.1002/cite.200900172] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Herzog B, Quass K, Schmidt E, Müller S, Luther H. Physical properties of organic particulate UV absorbers used in sunscreens. J Colloid Interface Sci 2004; 276:354-63. [PMID: 15271563 DOI: 10.1016/j.jcis.2004.04.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2004] [Accepted: 04/08/2004] [Indexed: 10/26/2022]
Abstract
In this study the UV-attenuating properties of microparticles consisting of a benzotriazole derivative were investigated, which are used as absorbers for UV radiation in cosmetic sunscreens. The particles were micronized in presence of a dispersing agent by means of a ball milling process. According to the energy input different particle sizes were produced in the range of 0.16 to 4 microm. In order to study even smaller particles, the sample with particle size 0.16 microm was fractionated further by centrifugation. Particle sizes were measured using fiberoptic quasi-elastic light scattering (FOQELS) and laser diffractometry. The UV-attenuating properties of the dispersions with different particle sizes were assessed using UV spectroscopy. With decreasing particle size the efficiency of the UV extinction of the dispersion increases up to a particle size of 80 nm. For particles smaller than 80 nm the UV extinction decreases again indicating an optimum at 80 nm. From reflection spectroscopic measurements it was found that scattering makes about 10%, and absorption 90%, of the UV-attenuating effect of the particles, which are obtained at the end of the milling process.
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Affiliation(s)
- Bernd Herzog
- Ciba Specialty Chemicals Inc., Grenzach-Wyhlen, Germany.
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Herzog B, Katzenstein A, Quass K, Stehlin A, Luther H. Physical properties of organic particulate UV-absorbers used in sunscreens. J Colloid Interface Sci 2004; 271:136-44. [PMID: 14757087 DOI: 10.1016/j.jcis.2003.09.055] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this study microparticles consisting of a benzotriazole derivative, which are used as absorbers for UV radiation in cosmetic sunscreens, were investigated. The particles were micronized in presence of a dispersing agent by means of a ball milling process. According to the energy input different particle sizes were produced in the range of 0.16 to 4 microm. The particle sizes obtained after different stages of the micronization process were measured using fiber-optic quasi-elastic light scattering (FOQELS), disc centrifugation, and laser diffractometry. All methods showed satisfactory agreement over the whole range of sizes. With the FOQELS technique the particle size distribution could be resolved to sizes well below 0.1 microm.
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Affiliation(s)
- Bernd Herzog
- Ciba Specialty Chemicals Inc., Grenzach-Wyhlen, Germany.
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Rega C, Lloyd CJ, Attwood D, Clarke D, Geraghty P. Temporal autocorrelation function for a diffusing-wave spectroscopy experiment with a point source and backscattering detection. APPLIED OPTICS 2001; 40:4204-4209. [PMID: 18360456 DOI: 10.1364/ao.40.004204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The autocorrelation function of the backscattered intensity in a diffusing-wave spectroscopy experiment that uses a point source is calculated by use of the diffusive-wave model. We show that in this approximation the calculated autocorrelation function decays faster than if the plane-source approximation were used. The design of a probe that implements this geometry is presented together with preliminary results that show the utility of the probe as a sizing tool in concentrated dispersions.
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Auweter H, Haberkorn H, Heckmann W, Horn D, Lüddecke E, Rieger J, Weiss H. Die supramolekulare Struktur ausgefällter, nanometergroßer β-Carotinpartikel. Angew Chem Int Ed Engl 1999. [DOI: 10.1002/(sici)1521-3757(19990802)111:15<2325::aid-ange2325>3.0.co;2-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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