Analytical reagent grade sodium hydroxide, hydrogen peroxide, ethanol, AA, N,N′-methylenebisacrylamide (MBA), AMPS, potassium Persulfate (KPS) were supplied by Tianjin Fuchen Chemicals. Corn straws were purchased from Huimin County, Binzhou City, Shandong Province.
1.1 Preparation of sulfonic cellulose by pretreating corn straws
Dry corn straws were ground and sieved using a 40-mesh sieve. Then, the resulting corn straw crash was made alkaline with 15% NaOH solution at 55 °C in a water bath for 2.5 h. The resulting solution was oxidized and bleached by H2O2, dried, and ground to get cellulose.
Cellulose was immersed in 17.5% NaOH solution and stirred for 1 h, followed by immersing for 3 h. Then, it was washed and neutralized with
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In the meantime, the control sample hydrogel was synthesized by AA without the sulfonated cellulose. The formulation for the control sample is listed in Table 1. The resulting hydrogels were dried at 80 °C in an oven for 24 h and then ground.
1.3 Measurements of hydrogels
1.3.1 Measurement of swelling ratio Q
After sieving the dried hydrogels using a 40-mesh sieve, a certain amount of sample was transferred to a tea bag, which was further immersed in deionized water for 48 h at room temperature. After the swelling equilibrium was achieved, the samples were weighed. The swelling ratio (Q) was calculated by the following formula.
Q = (W1 – W0)/W0 where W0 and W1 are the mass of the dry and swollen hydrogels, respectively.
1.3.2 FTIR analysis of hydrogels
The corn straws, pretreated corn straws, and hydrogels were ground into fine powders, mixed with KBr, and pressed into pellets for FTIR analysis. FTIR spectra were scanned in the wavelength range 400–4,000 cm-1.
1.3.3 Measuring the swelling dynamics of hydrogels
A certain amount of hydrogels was transferred to a tea bag. Then, the tea bag was immersed into deionized water. The mass was measured at regular intervals until it become constant.
1.3.4 Salt resistance of hydrogels
NaCl, CaCl2, and AlCl3 solutions with different concentrations were prepared. The dry hydrogel samples with the same mass were immersed in salt solutions. Salt resistance was determined by the swelling ratio when the hydrogel
Change in mass of potatoes submerged in sucrose solution Rebekah Schmitz Introduction: Diffusion explains the passive movement of materials into and out of the cell due to the presence of a concentration gradient from a high to low concentration across a membrane (Choinski and Karafit 2015). In this experiment, we studied the effects of differing concentrations of sucrose solutions on samples of potato material over time. This experiment focused on the effects of tonic solutions such as hypertonic and hypotonic solutions.
Water was added to the glue in a separate cup and another separate ratio of water was added to the sodium borate. The mixtures were mixed with glass stirring rods. In each trial, different mass ratios were used. Grams was the metric unit that was used in this experiment. After adding up the ratio of glue/water/sodium borate/water for one trial, forty grams should be the total mass. In trials
I. Abstract The purpose of these experiments were to examine the process, and subsequent effect, of osmosis and diffusion, in relation to weight and solute concentration. Osmosis was observed through the use of potato disks soaking in varying concentrations of distilled water and sucrose. Diffusion was observed through the use of a solution-filled dialysis bag soaking in a different solution.
Once the hour was over, the potato slices were removed from the solution, dried off in a paper towel, and weighed once again. In the 0.0, 0.1, and 0.2 M of sucrose concentrations the final mass of the potato increased. Therefore H2O enters the potato cell because the solution is hypotonic. In the 0.3, 0.4, and 0.5 M of sucrose concentration the final mass of potato decreases. The solution is hypertonic which causes H2O to exit the potato cells through the semipermeable phospholipid bilayer. The results prove that the different molarities of concentration affect the mass of the potato in different ways; the mass of potato either increased or decreased depending on the molarity of sucrose concentration.
Abstract: This experiment was performed to determine the molar mass of an unknown using the ideal gas equation. The measurements needed to determine the molar mass were obtained by heating the unknown to 90 degrees Celsius while recording the required measures such as the mass, volume, and temperature as the unknown became a gas. Then the measurements were inserted into the ideal gas equation PV=nRT. Using the ideal gas formula and measurements determined the molar mass was found by rearranging the formula leaving the unknown’s molar mass of ethylene glycol.
10g of the LB broth media was weighted in 500ml of deionized water and was put in 1L flask. The solution allowed to be autoclaved at 121°C for 15 minutes. Finally the solution was allowed to be cooled 4 ml of it was poured in a sterile test tube and was stored at 4 ᵒC.
These microbes are capable of breaking down cellulose due to their ability to produce an enzyme referred to as cellulase. Microbes with active cellulase can aid in the efficiency of producing biofuels. Research methods consist of acquiring the most productive cellulose degrading microbes. Therefore, many samples of cellulosic material must be collected in order to analyze which microbes are present and which are the most efficient at breaking down organic plant material. By conducting experiments and analyzing the microbes through research methods, the results could aid in the discovery of different cellulose degrading
First, 350 mL of water in a 600-mL beaker was heated up to a boil on a hot plate, While the water was heating, a clean 125-mL Erlenmeyer flask was dried out with a paper towel. Then, a piece of aluminum foil and a rubber band were placed on top of the Erlenmeyer flask. The flask, aluminum foil and rubber band were weighed on the balance. Their mass, in grams, was recorded on a piece of paper.
Plain alginate solution was prepared by dissolving sodium alginate at different concentrations (1% w/w,1.5% w/w, 2% w/w) in distilled water stirring at 70ᵒC for 20 minutes and maintaining the pH at 2. The cross-linking solutions were produced by mixing Spirulina (20 % w/w, 25%w/w) and Calcium chloride (10% w/w, 15 %w/w) at various combinations of concentrations with distilled water. The pH of the solution was altered to 3 by adding citric acid buffer. The obtained solutions were drawn into a 20mL syringe and extruded through 22 gauge and 26 gauge needle into a sodium alginate solution while stirring using a magnetic stirrer. Later the formed hydrogen beads were washed several times using distilled water and later stored in 5% w/w Calcium chloride solution overnight.
Furthermore, discussing the structure of chitin, it is reported that chitin and chitosan are heteropolymers as compared to cellulose which is a homopolymer (Kumar R 2000). In addition to the structure of chitin the degree of N-acetylation is also an important part of its chemistry. It is important to know the chemistry related to the degree of N-acetylation that is the ratio of 2-acetamido-2-deoxy-D-glucopyranose to 2-amino-2-deoxy-D-glucopyranose (Kumar R 2000), before considering its application for specific purposes. Furthermore, chitosan is one such universally accepted derivative of chitin that is obtained by N-deacetylation to such a degree at which it is soluble in aqueous solution of acetic acid and formic acid, an optimized degree to achieve chitosan is 0.35 or less. This ratio is can be defined by several analytical methods such as gel permeation
In this part we want to improve the disadvantages without loss the advantage of hydrogels, by preparing a composite materials specially nanocomposite materials.
The effects of citric acid on the rheological properties of cornstarch pastes were studied by steady shear and dynamic oscillatory viscoelasticity, intrinsic viscosity measurements and microscopic observation. The pH of cornstarch dispersion was adjusted between 6.0 and 3.0. The viscosity of the pastes was increased by lowering the pH (between 5.5 and 3.6), while the viscosity of samples with pH below 3.5 decreased further than that of the control (pH ) 6.3). Citric
Aerogels can be inorganic (silica-based) or organic (example of resorcinol-formaldehyde). They have a very low thermal conductivity, and are often super insulation, but they are relatively fragile (silica aerogel) or toxic (organic aerogels). A new avenue of research was recently conducted in the aim of developing type aerogels materials bio-sources and super insulation. Thus aerogels made from cellulose or derivatives, or other polysaccharides were investigated (for example in the articles: Fischer
A fibril is a threadlike bundle of molecules stabilized laterally by hydrogen bonding between adjacent molecules. The molecular arrangement of these fibrillar bundles is called Microfibrils. One microfibril contains several elementary fibrils which are in turn composed of multiple cellulose chains. The arrangement of microfibrils is regular enough to exhibit a crystalline X-ray pattern [17]. The microfibrils are about 10 – 30 nm wide and can contain 2 – 30,000 cellulose molecules. As mentioned earlier, cellulose can be natural (native) or man made (regenerated). It is very difficult to find cellulose in pure state. When derived from plant source, cellulose is associated with other substances like lignin and hemicellulose. In addition to lignin and hemicellulose, a number of non structural components such as waxes, inorganic salts and nitrogenous substances are also present [18] . Figure 4 shows the schematic of hierarchical structure of wood
Dry corn straws were ground and sieved using a 40-mesh sieve. Then, the resulting corn straw crash was made alkaline with 15% NaOH solution at 55 °C in a water bath for 2.5 h. The resulting solution was oxidized and bleached by H2O2, dried, and ground to get cellulose. The obtained cellulose was immersed in 17.5% NaOH solution and stirred for 1 h, followed by immersing for 3 h. Then, it was washed and neutralized with deionized water, filtered, and dried to afford alkaline fibers. The alkaline fibers (1.6 g) and 100 mL deionized water were added to a 250 mL three-neck flask. The resulting mixture was stirred for 10 min at 40 °C under N2, followed by adding KPS. After 20 min, 4.8 g AMPS monomer was added. After another 4 h, the sulphonated cellulose was cooled, washed successively with water and ethanol, and dried.