In this article, cotton is modified by m- DMDHEU and choline chloride. The modified cotton can adsorb and ion exchange ion CrO4 2- , H2AsO4 - in water solution as effectively as anionit resin. The material are activated by soaking in 24 h with mixed m-DMDHEU and choline chloride, then dried and activated in 1 h at 140 oC, all residual reactants was removed by water. Adsorption and ion exchange process were studied with a model solution contained ion CrO4 2- , H2AsO4 - in different conditions. Results showed that the modified cotton is able to adsorb ion CrO4 2- , H2AsO4 - of the model, solution is nearly completely, respectively 99,95 % and 99,60 %; the values of anionit resin is respectively 97,99 % and 97,60 % at pH=7,0.

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Esterification of citric acid (CA) with the primary alcohols and the hydroxyl groups of cellulose chain (n = 1-2) in parched condition were investigated by using density functional theory (DFT) method and a two-layer ONIOM approach. Geometry and energy of reactants, products, and transition state (TS) structures were optimized at B3LYP/6-311g (d, p) level and ONIOM (B3LYP/6-311g (d, p):PM3MM) level. The computational results show that the esterification occurs in the two main steps: the first step is the dehydration reaction of CA to form anhydrides of 5-membered ring and 6-membered ring and the second step is the ring opening reaction with the hydroxyl –OH groups to form the ester products. The energy barrier of dehydration reaction step is much higher than that of ring opening reaction step. Effect of substituent R in primary alcohol R-CH2OH (R: CH=CH2, CH2NHCH3, CH2OCH3, CH2Cl) and cellulose chain (1G, 2G) on the reactivity, which has negative inductive effect –I, is significant. The combination of calculation data and experiment data were applied to make findings more rigorous. The activation energy of CA was determined by using differential scanning calorimetry (DSC) and thermal gravimetric (TG) analysis to be E a exp  = 47.8 kcal/mol; the experimental data favoured the dehydration reaction step of CA.

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Etherification mechanism of 4,5-dihydroxy-1,3-bis (hydroxymethyl) imidazolidin-2-one (DMDHEU) with primary alcohols in acidic and parched condition were investigated by using density functional theory combined with comparision and reference to results of experiment and spectral analysis. Geometry and energy of reactants, products, actived complexes and carbocation intermediate were optimized at B3LYP/6-311g(d,p) level. Energy level diagram is compatible with type of cation -molecule reaction. Reactants and products form actived complexes with H+ and water, in this state H+ is occupied by both alcohol and water or ether and water. This state has lower energy level compared to both of the following cases: H+ is only occupied by water; and H+ is only occupied by the product or reactant. Computational results indicate that the etherification reaction

The aims of this study was to evaluate the quality of coffee in Vietnam market.Two methods Soxhlet and supercritical fluid extraction (SFE) were used to investigate the content of caffeine in 15 coffee samples; in which, 8 sample of roasted coffee and 7 sample of instant coffee. –The content of caffeine in 15 samples was different, and dependent on the object of the manufactures; caffeine is in charge of contribution of bitter and alert for customers. The content of caffeine was about 0.3% - 1.79% for the roasted coffee and 0.32% - 0.88% for the instant coffee. This study was also found out the method to extract the volatile compounds by using SDE and SPME. The major volatile compounds were pyrazine, furan, pyrrole, and pyridine. The number of the volatile compounds was 45 and 49 for SDE and SPME, respectively.

Some novel Ursolic Acid (UA) derivatives were designed and synthesized with substitution at positions of C-3-OH and C-28-COOH of UA, the product (1)-(6) has the yeild higher than (7)-(9), in reaction UA with CDI (10) has medium yield. These compounds showed ability ester reaction to product was easily, form these products give pharmacological activity better than UA .Their structures were confirmed using 1H-NMR.

A new denaturation agent is the mixture of 4,5-dihydroxy-1,3-bis(methoxymethyl)imidazolidin-2-one ( m -DMDHEU)/choline chloride (CC) introduced to modify three kinds of lignocellulosic materials containing different lignin contents in the following order: cotton used in medicine < sawdust from acacia auriculiformis wood < powder from the coconut shell. The modification process is carried out through two main steps: 0.2 N NaOH solution with 70% v/v ethanol and 30% v/v water was applied to remove lignin and activate the initial raw materials, and then delignified materials were modified with m -DMDHEU/CC by using a parched heat supply method after chemical impregnation. Structural characterictics and physicochemical properties of modified materials were tested and dissected by scanning electron microscopy, Fourier transform infrared spectroscopy, solid-state 13 C nuclear magnetic resonance spectroscopy (solid-state 13 C CP-MAS NMR), specific surface area, and pH at the point of zero charge (pH PZC ). The ability to adsorb and exchange anions of modified materials was referred and examined by using aqueous solutions containing CrO 4 2– , NO 3 – , and H 2 AsO 4 – anions in different conditions. The results revealed that anionite lignocellulosic materials could separate these anions with very good efficiency and better than strong anion exchange resin (GA-13) in the same conditions; outlet water could meet the permissible drinking and living water standards; and the m -DMDHEU cross-link bridge also was a good bridge to connect CC to cellulose chain beside other common urea cross-link bridges.