β-mercaptoethanol (BME) has been used as an "anti-blinking" reagent with quantum dots (QDs), but its exact effects on the luminescence behavior of different QD materials have not been quantified. In this study, the luminescence lifetime decays of aqueous solutions of CdTe QDs solubilized with mercaptopropionic acid (MPA) are measured by timecorrelated single photon counting (TCSPC) in the presence of varying concentrations of BME. The decays are fit to a model of radiative recombination and trapping that yields the respective time constants as well as the coefficient of intermittency (blinking). It is found that low concentrations of BME in its thiol form (neutral pH) lead to decreases in average lifetime but increased or constant quantum yields, indicating a higher fraction of radiative QDs than without BME. Correspondingly, the blinking coefficients are greatly reduced in the presence of BME at neutral pH. Higher concentrations of BME reduce emission by creating hole traps, a process that requires several hours after BME addition to manifest. Lifetimes are also reduced by the thiolate form of BME (basic pH) but to a lesser degree than at neutral pH. Strikingly, the blinking coefficients are almost entirely unchanged with BME addition at basic pH. In deoxygenated solutions, quantum yields are decreased rather than increased with BME, confirming that the enhancement results from BME's antioxidant effects. These results provide a quantitative approach to studying blinking and trapping dynamics using time-resolved decays.

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In the reaction of cellulose-containing flax material with aqueous solutions of LiOH, NaOH, and KOH, the degree of swelling, sorption of water and alkali, parameters of the crystal lattice formed by alkali cellulose, degree of removal of lignin, and change in the degree of polymerization are a function of the type of cation. For the sorption characteristics and crystal lattice parameters of alkali cellulose, this dependence is determined by the change in the structure of the first and second hydrate shells of the cations. Despite the important differences in the degree of swelling, crystal lattice parameters of alkali cellulose, and degree of removal of lignin, the changes in the crystal structure of the cellulose related to the transition from crystalline modification I to modification II under the effect of the three different bases are similar and take place in approximately the same concentration region.In order to obtain cellulose from plant raw material (flax, jute, hemp) with industrially acceptable reactivity and a broad spectrum of applications, it is necessary to know the structural changes it undergoes both during modification and in chemical processing into cellulose ethers.The reaction of alkali metal hydroxides with purified cellulose (basically wood and cotton cellulose) is examined in sufficient detail in the literature, but the structural changes in cellulose in cellulose-containing plant material have been studied much less. For this reason, we investigated the specific features of structural rearrangement of flax cellulose treated with different basic solutions. We used intermediate-flax fibres undergoing mechanical separation from chaff alone and ground in a impact-pulse loading dry grinding mill.The method of determination of swelling and sorption of base and water were similar to the methods reported in [1,2]. The fibre samples were treated with solutions of bases (LiOH, NaOH, and KOH) at 20°C and ratio of 1:10 for 1 h. The degree of swelling of the fibres and sorption of water and base were determined by the method in [2] and excess base was forced out with a centrifuge.Sorption of water and base from solutions by the cellulose was measured with the following method. A weighed portion of air-dried cellulose with a known moisture content, taken with an accuracy of under 0.0002 g, was placed in a special vessel for swelling, a solution of the base was poured in, and it was thermostated for 1 h. The vessels were then placed in a previously tempered centrifuge, and the alkali cellulose was treated for 10 min at a centrifuge rotor rotation rate of 8000 min -1 . The results of the preliminary experiments showed that these conditions of swelling and wringing out were sufficient to attain the equilibrium state of the cellulosebasewater system. The samples were weighed and then the amount of absorbed NaOH was determined by titration with a 0.1 N solution of H 2 SO 4 (the sample was held in distilled water for 3 h before titration). Three parallel experiments were conducted for each solution of base....