The arrangement of liquid molecules on surfaces bristling with alkyl chains is deduced from adsorption studies, X-ray powder diffraction data, and microcalorimetric measurements of swelling-type layered materials, especially clay minerals. Small polar molecules such as water, ethanol, formamide, dimethylsulfoxide, and aromatic compounds are clustered between the alkyl chains pointing away from the surface. The energetic contribution related to the movement of the alkyl chains from direct contact with the surface atoms into upright positions is decisive. The importance of the interactions between the liquid molecules on the structure of the adsorption layer is clearly indicated by the changes of the adsorption layer thickness by salt addition. Thermodynamic data are obtained from surface excess adsorption isotherms from binary liquid mixtures combined with microcalorimetric measurements. Long-chain adsorptives such as long-chain alcohols interact with the surface alkyl chains by forming stable bimolecular films. These films undergo a series of higher-order phase transitions into kink- and gauche-block structures as the consequence of rotational isomerization of the alkyl chains. Such transitions are considered elementary processes in self-assembling films (layer-by-layer deposition, fuzzy films, Langmuir-Blodgett technique), and lipid membranes.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.cis.2004.07.015 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Gold(I)-Catalyzed 2-Deoxy-β-glycosylation via 1,2-Alkyl/Arylthio Migration: Synthesis of Velutinoside A Pentasaccharide.
J Am Chem Soc
January 2025
Molecular Synthesis Center, Key Laboratory of Marine Drugs of Ministry of Education, Shandong Key Laboratory of Glycoscience and Glycotherapeutics, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
2-Deoxy-β-glycosides are essential components of natural products and pharmaceuticals; however, the corresponding 2-deoxy-β-glycosidic bonds are challenging to chemically construct. Herein, we describe an efficient catalytic protocol for synthesizing 2-deoxy-β-glycosides via either IPrAuNTf-catalyzed activation of a unique 1,2--positioned C2--propargyl xanthate (OSPX) leaving group or (PhO)PAuNTf-catalyzed activation of a 1,2--C2--alkynylbenzoate (OABz) substituent of the corresponding thioglycosides. These activation processes trigger 1,2-alkyl/arylthio-migration glycosylation, enabling the synthesis of structurally diverse 2-deoxy-β-glycosides under mild reaction conditions.
View Article and Find Full Text PDFCircular Polymer Designed by Regulating Entropy: Spiro-Valerolactone-Based Polyesters with High Gas Barriers and Adhesion Strength.
J Am Chem Soc
January 2025
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States.
Enthalpy is often the focal point when designing monomers for polymer circularity, but much less is explored on how entropy can be exploited to create polymers with synergistic circularity and properties. Here, we design a series of spiro-lactones (SLs) with closed-chain cycloalk(en)yl substituents at the α,α-position of δ-valerolactone (δVL), which, when combined with the parent δVL and -α,α-dialkyl-substituted δVL with open-chain alkyl groups, provide a desired platform for exploring the circular polymer design by focusing on the entropy change of polymerization. These SLs exhibit finely balanced (de)polymerizability that is regulated chiefly by entropy differentiation, allowing both the facile synthesis of polyester PSLs ( up to 1000 kg mol) in a living fashion and selective depolymerization of the PSLs to completely recover monomers under mild conditions (using a recyclable catalyst at 100 °C).
View Article and Find Full Text PDFMolecular docking and molecular dynamics simulation studies of inhibitor candidates against 3-hydroxykynurenine transaminase and implications on vector control.
Heliyon
January 2025
The African Computational Genomics (TACG) Research Group, MRC/UVRI, and LSHTM, Entebbe, Uganda.
Isoxazole and oxadiazole derivatives inhibiting 3-hydroxykynurenine transaminase (3HKT) are potential larvicidal candidates. This study aims to identify more suited potential inhibitors of 3HKT (3HKT) through molecular docking and molecular dynamics simulation. A total of 958 compounds were docked against 3HKT (PDB ID: 2CH2) using Autodock vina and Autodock4.
View Article and Find Full Text PDFCellulose-based multifunctional materials with robust hydrophobic, antibacterial, and antioxidant properties through dynamic cross-linked network structures.
Int J Biol Macromol
January 2025
Key Lab of Paper Science and Technology of Ministry of Elucation, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, China; State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, China. Electronic address:
Environmental pollution and health problems caused by traditional non-degradable fossil-based plastics are significant concerns, rendering green and renewable bio-based materials, such as cellulose and C-Priamine (1074), as attractive substitutes. In particular, the low plasticity of cellulose can be optimized using soft alkyl chains. Herein, multifunctional cellulose-based materials were constructed via covalent adaptable networks using the Schiff base reaction of oxidized microcrystalline cellulose with varying aldehyde (dialdehyde cellulose (DAC)) contents and C-Priamine (1074).
View Article and Find Full Text PDFNontarget screen and identify sulfate and sulfonate surfactants in personal care products using UHPLC-Q-Orbitrap-HRMS based on fragmentation characteristics and sulfur isotopologue pattern.
J Chromatogr A
January 2025
State Key Laboratory of Advanced Environmental Technology, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address:
Sulfate and sulfonate compounds are extensively used as anionic surfactants in personal care products (PCPs), which might pose adverse potential to human health. However, available research mostly identified certain subsets of sulfated and sulfonated surfactants based on target analysis. In this study, we developed a comprehensive nontarget strategy for identification of sulfated and sulfonated surfactants in PCPs using UHPLCHRMS supplemented by an in-lab R script based on characteristic fragment ions and sulfur isotope patterns.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!