Monolayers of Cellulose Ethers at the Air−Water Interface

Abstract

Aliphatic ethers of cellulose are found to form stable monolayers when spread from dilute chloroform solution at the air−water interface. Monolayer pressure−area isotherms exhibit a liquid analogous phase followed by a transition region of relatively high compression at constant pressure. Limiting molecular areas are found to depend on side-chain length, indicating that the hydrocarbon substituents do not adopt an orientation strictly perpendicular to the water surface. Monolayers of mixed ethers containing, on average, a single long chain substituent per repeat unit, form liquid analogous phases at molecular areas equivalent to the area of the anhydroglucose ring. It is thus concluded that the cellulose backbone lies flat on the water surface. The transition region observed upon compression beyond the liquid analogous phase is attributed to the formation of bi- or multilayers, with molecules leaving the water surface. This interpretation is consistent with the observed decrease in plateau pressure with increasing temperature.

Langmuir-Blodgett films of cellulose ethers containing carbazole

“…Since the plateau region extends to molecular areas too small to accommodate the spread molecules as a single monomolecular layer, and the plateau transition can be attributed to the formation of bi-or multilayers. Similar transitions have been observed in the compression isotherms of a number of cellulose derivatives [15,16] and other rigid polymers. [17][18][19] From Fig.…”

First Cellulose Langmuir‐Blodgett Films towards Photocurrent Generation Systems

“…[9,10] LB films consisting of cellulose derivatives can overcome these problems, because of the inherent rigidity of the cellulose backbone, as well as the strictly defined molecular structure with its three reactive hydroxyl groups per anhydro glucose unit. [11][12][13][14] In addition, the LB films of highly regioselectively substituted cellulose derivatives with a controlled pattern of functionalization and with well defined supramolecular nanoscale architecture, based on the basic concept of the role-sharing functionalization of cellulose, have bright prospects in the development of molecular assemblies with highly efficient photo-energy conversion. [15,16] We report herein the fabrication of LB films consisting (Figure 1).…”

Preparation of cellulose derivatives containing carbazole chromophore

“…In the dodecylcellulose this method is thus similar to a reaction at room temperature. 10 It should be noted that the spectra presented in Figure 1 were recorded for sample films cast on KBr substrates. The IR spectra of the same samples recorded in chloroform solution exhibited less intense hydroxyl bands.…”

“…A variety of cellulose ethers have been shown to be suitable materials for the fabrication of ultrathin films by the Langmuir-Blodgett technique. 10,11 In general, stable monolayers can be spread at the air-water interface and successfully transferred to a variety of solid substrates. The potential applications of Langmuir-Blodgett films in fields such as integrated optics and solid-state electronics have long been appreciated.…”