Investigation of Solutions of Cellulose

Abstract

Three independent but complementary methods (OSL photoetching combined with etch rate profiling, spatially resolved PL and LST) were employed to Study the distribution of microdefects and electrically active centres in commercially available SI undoped. LEc-grown GaAs after different ingot-annealing treatments. A one-to-one correlation was obtained on comparing the microscale distribution of decoration precipitates (OPS), matrix precipitates (MPI) and microdefects (MMS) by the DSL and LST methods. Clustering of MPS is also revealed by PL intensity profiling and photoetch rate measurements. Two types of matrix microdefects are distinguishable by OSL photoetchlng In Samples after two-stage annealing. A high degree of homogeneity across the dislocation cells (after low-temperature and multiple annealing) was clearly revealed by a drastic decrease in the uniformity parameter (U) after DSL photoetching and by a significant decrease in the x intensity measured at the cell walls with respect to the cell interiors. Using the present results and recent data from the literature, an explanation of phase transitions during ingot annealing is proposed. This is based on the assumption that the final properties and structures after annealing are the result of two competitive processes: (i) formation of decoration and matrix microdefects; (ii) generation of electrically active point defects (clusters), presumably EL2

Rheological Properties of Cellulose/Ionic Liquid Solutions: From Dilute to Concentrated States

“…For cellulose dissolved in LiCl/DMAc, higher α values were reported in literature (see crosses in Figure ): α = 1.2 (data from Table 3 in ref 3) and 0.7 (data from Table of ref 5), which reflects a good thermodynamic solvent quality. In general, α varies from 0.65 to 0.95 for cellulose solutions depending on solvent type, temperature, sample polydispersity, and molecular weight. ,− …”

“…In general, R varies from 0.65 to 0.95 for cellulose solutions depending on solvent type, temperature, sample polydispersity, and molecular weight. 33,[35][36][37] Radius of gyration R g can be estimated in a rough approximation using Flory approach for flexible polymer chains: R g 2 ) (1/6)[([η]/Φ)M] 2/3 , where Φ ) 2.8 × 10 23 mol is Flory constant. R g varies from 7.5 to 11 nm for MC (DP 300), from 15 to 22 nm for SSP (DP 1000), and from 30 to 40 nm for BC (DP 4420) for temperatures from 0 to 100 °C, respectively.…”

Multivalent Ions as Reactive Crosslinkers for Biopolymers—A Review

“…Another example is tartaric acid which is able to form stable iron(III)-complexes in alkaline solution. Dependent on the composition of the solution two main species are formed [(C 4 H 2 O 6 )Fe]Na at a molar ratio of Fe 3+ :tartaric acid:NaOH of 1:1:1 and [(C 4 H 3 O 6 ) 3 Fe]Na 6 at a molar ratio of 1:3:6, respectively [25]. A proposed structure for the complex between iron(III) and tartaric acid at a molar ratio of 1:3 [(C 4 H 3 O 6 ) 3 Fe]Na 6 is shown in Figure 4.…”