Cyclopentasiloxane (D5) as a Non-Polar Masking Agent for Water-Sensitive Substrates During Polar Solvent Treatment

D5 (decamethylcyclopentasiloxane), a non-polar solvent that evaporates slowly, was tested for its suitability as a temporary masking agent for water-sensitive media on paper objects undergoing aqueous treatment. Three different treatment-related settings were tested on five different paper types, some prepared with water-soluble inks. In 10-min water immersion treatments, D5 proved largely ineffectual in protecting the water-soluble inks. In conjunction with melt-applications of cyclododecane, the addition of D5 enhanced its barrier function only in one case. To test the ability of D5 to prevent tideline formation, the test samples received applications of water, acetone, and a water-ethanol-mixture, creating an interface with freshly D5-impregnated areas. The papers were evaluated visually (VIS, UVA), some after artificial aging. D5 diminished the formation of visible tidelines in the two internally sized papers with low water absorbency in contact with acetone and the ethanol-water mixture, but did not prevent tidelines in contact with water. It also did not protect water-absorbent paper. The results indicate that D5, which is miscible with ethanol and acetone, may disperse tidelines caused by these solvents, but it proved largely insufficient for protecting media during water immersion.

Pemanfaatan Jerami Padi Sebagai Bioplastik Dengan Menggunakan Metode Perlakuan Pelarut Organik

Jerami padi memilki kandungan selulosa yang dapat dimanfaatkan sebagai bahan baku pembuatan bioplastik. Penelitian ini bertujuan untuk mensintesis bioplastik dari bahan baku jerami padi menggunakan perlakuan pelarut organik serta menganalisis pengaruh rasio massa pati dengan selulosa karakteristik produk bioplastik. Proses delignifikasi jerami menggunakan larutan etanol 5% dan 35% pada suhu 80oC selama dua jam. Bioplastik dibuat dengan rasio massa pati dengan selulosa sebesar 1:0,5; 1:1; dan 1:1,5. Karakterisasi menggunakan metode SEM, XRD, TG-DTA, uji tarik, uji transmisi uap, serta uji degradasi. Hasil penelitian menunjukkan bahwa proses delignifikasi menggunakan etanol menyebabkan peningkatan kadar selulosa serta kristalinitas jerami. Morfologi bioplastik menunjukkan permukaan yang tidak rata serta terdapat bagian matriks yang terpisah dengan fiber. Hasil TG-DTA menunjukkan pengurangan massa bioplastik sebesar 81,01% pada suhu 550oC. Hasil kuat tarik terbaik pada bioplastik yang dibuat dengan rasio massa pati dengan selulosa 1:0,5 pada konsentrasi delignifikasi etanol 35%. Nilai kuat tarik yang diperoleh sebesar 8,773 Mpa. Pengujian degradasi bioplastik dilakukan selama 10 hari diperoleh nilai % degradasi terbesar bioplastik adalah sebesar 99,9%. Rice straw contains cellulose which can be used as raw material for making bioplastics. This study aims to synthesize bioplastics from rice straw using organic solvent treatment and analyze the effect of the mass ratio of starch to cellulose on the characteristics of bioplastic products. The straw delignification process used 5% and 35% ethanol solution at 80oC for two hours. Bioplastics are made with a mass ratio of starch to cellulose of 1:0.5; 1:1; and 1:1.5. Characterization using SEM, XRD, TG-DTA methods, tensile test, vapour transmission test, and degradation test. The results showed that the delignification process using ethanol caused an increase in cellulose content and straw crystallinity. The morphology of the bioplastic shows an uneven surface and there are parts of the matrix that are separated from the fiber. The results of TG-DTA showed a reduction the mass of bioplastic by 81.01% at a temperature of 550oC. The best tensile strength results in bioplastics made with a mass ratio of starch to cellulose 1:0.5 at a delignification concentration of 35% ethanol. The tensile strength value obtained was 8,773 Mpa. The bioplastic degradation test was carried out for 10 days and the largest percentage of bioplastic degradation was 99.9%.

Preparation of Polystyrene Microsphere-Templated Porous Monolith for Wastewater Filtration

Porous monoliths prepared using templates are highly sought after for filtration applications due to their good mass transport properties and high permeability. Current templates, however, often lead to the formation of dead-end pores and irregular pore distributions, which reduce the efficiency of the substrate flow across the monolith column. This study focused on the preparation of a microsphere-templated porous monolith for wastewater filtration. The optimal template/monomer ratio (50:50, 60:40, 70:30) was determined, and appropriate template removal techniques were assessed for the formation of homogenous pores. The physicochemical characteristics and pore homogeneity of the monoliths were examined. The 60:40 ratio was determined to result in monoliths with homogeneous pore distributions ranging from 1.9 μm to 2.3 μm. SEM and FTIR investigations revealed that solvent treatment was effective for removing templates from the resulting solid monolith. The water quality assessments revealed reductions in the turbidity and the total number of suspended particles in the tested wastewater of up to 96–99%. The findings of this study provide insightful knowledge regarding the fabrication of monoliths with homogenous pores that are beneficial for wastewater treatment.

Application of Molecular Dynamics Simulations in the Analysis of Cyclodextrin Complexes

Cyclodextrins (CDs) are highly respected for their ability to form inclusion complexes via host–guest noncovalent interactions and, thus, ensofance other molecular properties. Various molecular modeling methods have found their applications in the analysis of those complexes. However, as showed in this review, molecular dynamics (MD) simulations could provide the information unobtainable by any other means. It is therefore not surprising that published works on MD simulations used in this field have rapidly increased since the early 2010s. This review provides an overview of the successful applications of MD simulations in the studies on CD complexes. Information that is crucial for MD simulations, such as application of force fields, the length of the simulation, or solvent treatment method, are thoroughly discussed. Therefore, this work can serve as a guide to properly set up such calculations and analyze their results.

Preparation of Poly O-Toluidine/Titanium Dioxide by In situ Chemical Oxidation Polymerization and Application for Solar Cell.

Various treatments on the PEDOT:PSS films were carried out to investigate it’s influence on the conductivity, morphology, transmittance and the corresponding impact of the performance of the organic photovoltaic devices based on the PCPDTBT:PCBM and P3HT:PCBM blends. These processing including doping PEDOT:PSS with DMF and ME solvents and exposing these films to the vapor of DMF and ME solvents, separately. A considerable enhancement of the conductivity and transmittance of PEDOT:PSS was observed after doping solvent into the PEDOT;PSS solution followed by solvent treatment through exposing these films to solvents environment. The best organic PV doped devices based on either PCPDTBT:PCBM or based on P3HT:PCBM with power conversion efficiency were 2.93% compared to 1.87% for the pristine PV devices or 2.79% compared to 1.77% for the pristine devices, respectively. The conductivity improvement was highly influenced by solvent treatment.