Student's critical thinking and their learning result depend on learning design and student's activity. Most students use their spare time with playing game. Students are more challenged by the difficulty in playing game rather than facing the difficulty in understanding the lesson. This phenomenon is the basic reason of the researchers to develop a game that has the essence of the subject matter, namely Chemistry Board Game (CBG) or we can call it with Al Chemist Knight. This research aims to develop a suitable digital game based on android system. In this research media was used to improve the cognitive learning and critical thinking. It also has purpose to evaluate the response of learners in learning chemistry through alkane derived compound topic. The development of this game was adapted from the procedure of game development process in mobile 3D presentation. The collection of evaluation data model applied was pre test and post test in trial class. The result showed that in the pretest the learning result average was 34.35 with classical target of 5%. While the posttest learning result average was 80.51 with classical target of 85%. The n-gain factor was 0.703. Based on the result of the students questionnaire data analysis, 3.025 of students responded positively to the implementation of CBG. A CBG media makes an assessment of critical thinking, in which the indicator of critical thinking which are focusing on questions get 3,1 point, giving arguments get 2.95, asking and answering questions get 3.0, making decision get 3.05, and the average score of critical thinking indicator is 3.025 which belongs to good category. Based on the students' response questionnaire, we get the average score of 3.3 or 82.5% which is classified in good category.

Direct fully bio-based polymer synthesis by cellulose modification involving simply mixing cellulose and cinnamaldehyde “cinnamon flavor” in an ionic liquid.

The role of 1-ethyl-3-methylimidazolium carboxylate-type ionic liquid as the solvent and organocatalyst for transesterification reaction of cellulose was investigated.

To become independent of petroleum resources, societies have to develop methods to synthesize full-biobased polymers from natural products directly. In this study, full-biobased cellulose esters were synthesized by the oxidative esterification process between cellulose and natural α,β-unsaturated aldehydes in an ionic liquid working as solvent and catalyst. The role of the ionic liquid in this cellulose-modification system was systematically investigated, and a newly designed noncarboxylate-type ionic liquid, 1-ethyl-3-methylimidazolium 2-pyridinolate (EmimOPy), was developed to prevent a serious side reaction in which the carboxylate anion of the carboxylate-type ionic liquid is introduced into the hydroxyl group of cellulose as an ester group on the products. Under optimized conditions, this oxidative esterification-reaction system in EmimOPy afforded fully substituted cellulose ester (up to the degree of substitution = 3.0). Furthermore, cellulose reacted with several types of aldehyde substrates, even biobased low-reactive α- or β-substituted unsaturated aldehydes (e.g., citral and perillaldehyde). Thus, this synthesis demonstrates excellent atom economy without using any additional catalysts or activators under metal-free conditions.

The title compound when bound to Zn(II) or Co(II) displays many properties in common with carbonic anhydrase. These include a weak ability of the Zn(II) complex to catalyze the interconversion of C02 and HC03~a nd anion-dependent visible absorption spectra of the Co(II) complex. Titration data indicate both the Zn(II) and Co(II) complexes labilize an additional group associated with the complex which appears to be M+-OH2. In the presence of anions, the spectrophotometric pK" for the Co(II) complex shifts to higher values as it does in Co(II)CA. An explanation for the anion-dependent properties of CA is offered on the basis of the observations with this small-molecule complex.

Ionic liquids (ILs) are recyclable, non-volatile, and can dissolve cellulose, a natural polymer that is insoluble in versatile solvents. Therefore, ILs have been used to modify cellulose. However, 1-ethyl-3-methylimidazolium acetate (EmimOAc), a commercially available IL often used to dissolve and modify cellulose to prepare cellulose-based materials, causes the undesired introduction of an acetyl group derived from the acetate anion of EmimOAc onto the hydroxy group of cellulose during esterification. In this study, for cellulose esterification, we prepared aryloxy ILs as non-carboxylate-type and basic ILs, which can theoretically prevent the undesired introduction of an acyl group from the IL onto the hydroxy group of cellulose. The optimized 1-ethyl-3-methylimidazolium 2-pyridinolate (Emim2OPy) and mixed solvent system achieved rapid cellulose esterification (within 30 min) with an excellent degree of substitution (DS) value (up to >2.9) derived from the employed low-reactive vinyl esters and bio-based unsaturated aldehydes, without any undesired substituent introduction from side reactions.

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The purpose of this research was to determine the best of solvent for extracting tannins as a feed additive from coffee husks using the soxhlet method. The method used was quantitative with a completely randomized design experimental. The coffee husk used was a type of Robusta taken from the Kaliwates Region, Jember Regency, Indonesia. The material was the waste from the grinding of coffee cherries, namely the pericarp (parchment, pectin layer, pulp, and outer husk). This research consisted of 3 treatments (P1: Methanol, P2: Ethanol, P3: Acetone), each treatment consisted of 3 replications. The variables were the tannin extracts and residue of tannin extracts. The results showed that different types of tannin solvents had a significant effect on the tannin extracts yield and residue of tannin extracts (P<0.05). Methanol and ethanol solvents produced higher tannin than acetone solvents: 0.5392%, 0.6120%, and 0.2457% respectively. Coffee husk with ethanol solvent gave the least residue compared to methanol and acetone: 61.64%, 66.89%, and 85.26% respectively. The conclusion of this research was Ethanol is a solvent that produces the highest total tannin (0.6120%) and the lowest residue (61.64 ± 0.6688%) from coffee husks compared to methanol and acetone. The result of this research can be used as a consideration for the tannins extraction of other plantation waste.