scholarly journals Valorization of Pet-Al Composite Obtained From Packaging Waste in Basic Conditions

2020 ◽  
Author(s):  
Aymen Souilhi ◽  
Rym Abidi
Keyword(s):  
Chemical Treatment ◽  
Scientific Community ◽  
Aluminum Foil ◽  
Strong Acid ◽  
Optimal Conditions ◽  
Critical Aspect ◽  
Strong Base ◽  
Aluminum Salts ◽  
Al Composite ◽  
The Cost

Abstract The recycling of Risidu Pet-Al (a laminated foil made from polyethylene and aluminum foil in food brike packaging) continues to be a challenge. Despite the fact that previous studies proposed green solutions for the recycling of the Pet-Al composite, the handicaps linked to the increase of the cost of the reagents involved in the recycling mechanism, the complexity of the steps, resulting in products with a critical aspect, really reflect a problem. The growing concern about environmental impacts such as greenhouse gas emissions from inceneration treatment is distinctly clear to the scientific community. This article involves chemical treatment by adding a strong base NaOH or KOH as the dissolving reagent, Followed by the addition of the strong acid HCl . The birth of a neutral environment promotes the recovery of aluminum salts as well as sodium (or potassium). The released H2, polyethylene and cardboard are also products regenerated by this recycling.The study contributes to the optimal conditions of time concentration temperature as well as the mode of separation. The recovered salts are identified, however their purity remains an important factor of quality before adapting their use.

A Very Low-Cost, Labor-Efficient, and Simple Method to Block Scattered Ultraviolet Light in PDMS Microfluidic Devices by Inserting Aluminum Foil Strips

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuo Wang ◽  
Peter Shankles ◽  
Scott Retterer ◽  
Yong Tae Kang ◽  
Chang Kyoung Choi
Keyword(s):  
Soft Lithography ◽  
Uv Light ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Aluminum Foil ◽  
Material Synthesis ◽  
Simple Method ◽  
Micro Particles ◽  
Complex Shapes ◽  
The Cost

Abstract Opto-microfluidic methods have advantages for manufacturing complex shapes or structures of micro particles/hydrogels. Most of these microfluidic devices are made of polydimethylsiloxane (PDMS) by soft lithography because of its flexibility of designing and manufacturing. However, PDMS scatters ultraviolet (UV) light, which polymerizes the photocrosslinkable materials at undesirable locations and clogs the microfluidic devices. A fluorescent dye has previously been employed to absorb the scattered UV light and shift its wavelength to effectively solve this issue. However, this method is limited due to the cost of the materials (tens of dollars per microchip), the time consumed on synthesizing the fluorescent material and verifying its quality (two to three days). More importantly, significant expertise on material synthesis and characterization is required for users of the opto-microfluidic technique. The cost of preliminary testing on multiple iterations of different microfluidic chip designs would also be excessive. Alternatively, with a delicate microchannel design, we simply inserted aluminum foil strips (AFS) inside the PDMS device to block the scattered UV light. By using this method, the UV light was limited to the exposure region so that the opto-microfluidic device could consistently generate microgels longer than 6 h. This is a nearly cost- and labor-free method to solve this issue.

scholarly journals Utilization of Extract of Sambang Getih Leaves (Hemigraphis colorata. Hall. F) as a Acid-Base Indicator

2020 ◽  
Vol 9 (1) ◽  
pp. 7-15
Author(s):  
Eksari Ekasari ◽  
Purnama Ningsih
Keyword(s):  
Leaf Extract ◽  
Strong Acid ◽  
Weak Base ◽  
Acid Base ◽  
Strong Base ◽  
Unique Color ◽  
Acid Base Titration ◽  
Naoh Solution ◽  
Ph Range ◽  
Color Pigment

Getih sambang leaves (Hemigraphis Colorata. Hall. F) are plants that have a distinctive and unique color, namely the upper surface of the leaf is green and the bottom of the leaf is burgundy where sambang leaves contain anthocyanin compounds. Anthocyanin is the color pigment in plants that forms the basis of the use of natural indicators. This study aims to prove whether getih cucumber leaves can be used as an acid-base indicator, to determine the type of acid-base titration that is suitable for indicators of getih cucumber leaves, and to find out what the pH-changing color route of getih cucumber leaves is. The method used is extraction, namely maceration. Wee leaves are macerated by using methanol as a solvent for 24 hours. The extract was previously tested using HCl solution and NaOH solution as a test to prove the presence of anthocyanin. The results obtained in this study, getih sambang leaf extract can be used as an indicator of acid base, and also the type of acid-base titration that is suitable for use in the indicator of getih leaf extract extract precisely on the titration of strong-base strong acid, and strong weak base-acid It is best used as a substitute for the phenolphthalein indicator. In titration of strong and weak acids and bases, it is good to be used as a substitute for the indicator of methyl orange. The pH range obtained from the getih sambang leaf extract is pH 4-7 (red-purple).

Principle of conservation of energy and modern theories

2020 ◽  
Vol 33 (4) ◽  
pp. 444-452
Author(s):  
H. Hamam
Keyword(s):  
Energy Conservation ◽  
Scientific Community ◽  
18Th Century ◽  
Scientific Progress ◽  
Modern History ◽  
Conservation Of Energy ◽  
The Cost ◽  
The Universe ◽  
Principle Of Energy Conservation

The famous quote of Antoine Laurent de Lavoisier (18th century) “Nothing is lost, nothing is created: everything is transformed” illustrates a principle that has marked minds throughout modern history. It deals with the principle of energy conservation. In our minds, energy is conserved in our world (in our dimensions). If part of the energy drifts out of our dimensions, this will contradict the statement “Nothing is lost.” If some energy penetrates our dimensions, this will contradict the statement “Nothing is created.” Everything is transformed within our dimensions. This article discusses the latest attempts through cosmic theories, still unverified, that have tried to explain the start and development of the universe even at the cost of concepts and principles unanimously agreed to date by the scientific community through the history, such as the principle of conservation of energy. This article raises some questions that we scientists must answer before we move forward. We must from time to time take a step back and have a critical look at our scientific progress before we branch off into a web of various theories.

Synthesis of Dendritic Silver Nanostructures on Al Foil by Galvanic Displacement for Catalytic Degradation of Methylene Blue

2014 ◽  
Vol 1004-1005 ◽  
pp. 10-13
Author(s):  
Li Fu ◽  
Mika Matsunaka Sokiransky ◽  
Ai Min Yu
Keyword(s):  
Methylene Blue ◽  
Room Temperature ◽  
Reaction Rate ◽  
Aluminum Foil ◽  
Silver Nanostructures ◽  
Optimal Conditions ◽  
Galvanic Displacement ◽  
Reduced Graphene ◽  
Vis Spectroscopy ◽  
Silver Dendrites

Silver dendrites were synthesized via a simple and straightforward strategy based on the galvanic displacement between Ag ions and aluminum foil in the room temperature. Because the presence of Al2O3thin layer on the surface of aluminum foil, the NaCl was added to accelerates the reaction rate. The formed Ag dendrites was characterized by UV-vis spectroscopy, SEM and XRD. The as-prepared Ag dendrites were developed as a catalyst by mixed with reduced graphene oxide and used for degradation of methylene blue when the presence of NaBH4. Moreover, the optimal conditions of degradation were also investigated.

scholarly journals An Active Absorbent for Cleanup of High-Concentration Strong Acid and Base Solutions

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3389
Author(s):  
Nara Han ◽  
Sol Park ◽  
Byung Kwon Kaang ◽  
Wooree Jang ◽  
Hye Young Koo ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Strong Acid ◽  
Absorption Capacity ◽  
Dust Particles ◽  
High Concentration ◽  
Strong Base ◽  
Base Solution ◽  
Acid And Base ◽  
Drop Tests ◽  
High Absorption

There is significant interest in developing novel absorbents for hazardous material cleanup. Iron oxide-coated melamine formaldehyde sponge (MFS/IO) absorbents with various IO layer thicknesses were synthesized. Various other absorbents were also synthesized and compared to evaluate the absorption capability of the MFS/IO absorbents for strong acid (15%, v/v) and base (50%, m/m) solutions. Specifically, absorbent and solution drop tests, dust tests, and droplet fragment tests were performed. Among the various absorbents, MFS/IO absorbents possessing a needlelike surface morphology showed several unique characteristics not observed in other absorbents. The MFS/IO absorbents naturally absorbed a strong base solution (absorption time: 0.71–0.5 s, absorption capacity: 10,000–34,000%) without an additional external force and immediately absorbed a strong acid solution (0.31–0.43 s, 9830–10,810%) without absorption delay/overflow during absorbent and solution drop tests, respectively. The MFS/IO absorbents were also demonstrated to be ideal absorbents that generated fewer dust particles (semiclass 1 (ISO 3) level of 280 piece/L) than the level of a clean room (class 100). Furthermore, the MFS/IO absorbents were able to prevent the formation of droplet fragments and solution overflow during the solution drop test due to their unique surface morphology and extremely high absorption speed/capacity, respectively.

Calibration of pH glass electrodes by direct strong acid/strong base titrations under dilute conditions

2000 ◽  
Vol 405 (1-2) ◽  
pp. 167-172 ◽  
Author(s):  
Paula Gameiro ◽  
Salette Reis ◽  
J.L.F.C Lima ◽  
Baltazar de Castro
Keyword(s):  
Strong Acid ◽  
Strong Base ◽  
Glass Electrodes

Equivalence Points and Inflexion Points in Acid-Base Titration Curves

1963 ◽  
Vol 16 (5) ◽  
pp. 759 ◽  
Author(s):  
RH Stokes
Keyword(s):  
Strong Acid ◽  
Ionization Constants ◽  
Weak Acids ◽  
Acid Base ◽  
Strong Base ◽  
Titration Curves ◽  
Acid Base Titration

General equations are derived for the relation between pH and stoichiometric degree of neutralization in the titration of monoprotic and diprotic weak acids (or bases) with strong acid or strong base. From these equations the number and position of inflexion points in the curves is derived, and their relation to the equivalence points is shown. Methods for determining ionization constants from inflexion points are discussed.

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