By AFM we report the successful modulation of shell structure (morphology and shell thickness) of microcapsules through tailoring molecular substituents of chitosan. The shell thickness of hollow (HPCS/SA)(n) (n=5, 7, 9) capsules is more than 3 times that of the (QACS/SA)(n) (n=5, 7, 9) capsules, due to less charges carried by the neutral -NH(2) substituent group and the induced coily conformation in HPCS, while more charges carried by the positively charged -N(CH(3))(3)(+) substituent and the induced extended conformation in QACS (HPCS: hydroxyl propyl chitosan; QACS: quaternary ammonium chitosan; SA: sodium alginate). The ultrathin shells of microcapsules assembled in this work by the layer-by-layer (LbL) self-assembly technique rather than the traditional method of mixing CS, SA and CaCl(2) enable the thickness modulation characterization by AFM on the atomic scale. These microcapsules with tunable shell thickness provide important guidance for potential drug delivery and sustained release.
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http://dx.doi.org/10.1016/j.jcis.2012.01.026 | DOI Listing |
J Hazard Mater
January 2025
Department of Mechanical, Robotics and Energy Engineering, Dongguk University, Seoul 04620, Republic of Korea. Electronic address:
This paper introduces a highly absorbent and sensitive cellulose nanofiber (CNF)/gold nanorod (GNR)@Ag surface-enhanced Raman scattering (SERS) sensor, fabricated using the vacuum filtration method. By optimizing the Ag thickness in the GNR@Ag core-shell structures and integrating them with CNFs, optimal SERS hotspots were identified using the Raman probe molecule 4-aminothiophenol (4-ATP). To concentrate pesticides extracted from fruit and vegetable surfaces, we utilized the evaporation enrichment effect using hydrophilic CNF and hole-punched hydrophobic polydimethylsiloxane (PDMS).
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January 2025
Department of Biochemistry, Microbiology &Biotechnology, University of Limpopo, Private BagX1106, Sovenga, Limpopo, 0727, South Africa.
Egg quality is affected by lot of factors. Study was conducted to compare performance of data mining algorithms; Classification and regression tree (CART), Chi-square automatic interaction detection (CHAID), Exhaustive chi-square automatic interaction detection (Ex-CHAID) and Multivariate adaptive regression spline (MARS) in prediction of Potchefstroom Koekoek's eggshell thickness from egg quality traits. 350 eggs were collected at 31st to 39th week to examine the egg quality traits.
View Article and Find Full Text PDFEcology
January 2025
Bodega Marine Laboratory, University of California Davis, Bodega Bay, California, USA.
A growing body of theoretical studies and laboratory experiments has focused attention on reciprocal feedbacks between ecological and evolutionary processes. However, uncertainty remains about whether such eco-evolutionary feedbacks have an important or negligible influence on natural communities. Thus, recent discussions call for field experiments that explore whether selection on phenotypic variation within populations leads to contemporaneous effects on community dynamics.
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January 2025
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China.
An effective long-term nitrogen dioxide (NO) monitoring at trace concentration is critical for protecting the ecological environment and public health. Tellurium (Te), as a recently discovered 2D elemental material, is promising for NO detection because of its suitable band structure for gas adsorption and charge mobility. However, the high activity of Te leads to poor stability in ambient and harsh conditions, limiting its application as a gas-sensitive material.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
ConspectusReactions of gas phase molecules with surfaces play key roles in atmospheric and environmental chemistry. Reactive uptake coefficients (γ), the fraction of gas-surface collisions that yield a reaction, are used to quantify the kinetics in these heterogeneous and multiphase systems. Unlike rate coefficients for homogeneous gas- or liquid-phase reactions, uptake coefficients are system- and observation-dependent quantities that depend upon a multitude of underlying elementary steps.
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