Coagulation performance of Al/Fe based covalently bonded composite coagulants for algae removal

Block copolymers are composed of sequences of dissimilar chemical moieties covalently bonded together. If the block lengths of each component are sufficiently long and the blocks are thermodynamically incompatible, these materials are capable of undergoing microphase separation, a weak first-order phase transition which results in the formation of an ordered microstructural network. Most efforts designed to elucidate the phase and configurational behavior in these copolymers have focused on the simple AB and ABA designs. Few studies have thus far targeted the perfectly-alternating multiblock (AB)n architecture. In this work, two series of neat (AB)n copolymers have been synthesized from styrene and isoprene monomers at a composition of 50 wt% polystyrene (PS). In Set I, the total molecular weight is held constant while the number of AB block pairs (n) is increased from one to four (which results in shorter blocks). Set II consists of materials in which the block lengths are held constant and n is varied again from one to four (which results in longer chains). Transmission electron microscopy (TEM) has been employed here to investigate the morphologies and phase behavior of these materials and their blends.

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Morphological behavior of compatibilized ternary blends prepared by mechanical mixing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151830 ◽

1993 ◽

Vol 51 ◽

pp. 1200-1201

Author(s):

S.D. Smith ◽

R.J. Spontak ◽

D.H. Melik ◽

S.M. Buehler ◽

K.M. Kerr ◽

...

Keyword(s):

Interfacial Adhesion ◽

Diblock Copolymers ◽

Ternary Blends ◽

Mechanical Mixing ◽

Design Considerations ◽

Covalently Bonded ◽

Homopolymer Blends ◽

Emulsifying Agent ◽

Surface Active ◽

Low Entropy

When blended together, homopolymers A and B will normally macrophase-separate into relatively large (≫1 μm) A-rich and B-rich phases, between which exists poor interfacial adhesion, due to a low entropy of mixing. The size scale of phase separation in such a blend can be reduced, and the extent of interfacial A-B contact and entanglement enhanced, via addition of an emulsifying agent such as an AB diblock copolymer. Diblock copolymers consist of a long sequence of A monomers covalently bonded to a long sequence of B monomers. These materials are surface-active and decrease interfacial tension between immiscible phases much in the same way as do small-molecule surfactants. Previous studies have clearly demonstrated the utility of block copolymers in compatibilizing homopolymer blends and enhancing blend properties such as fracture toughness. It is now recognized that optimization of emulsified ternary blends relies upon design considerations such as sufficient block penetration into a macrophase (to avoid block slip) and prevention of a copolymer multilayer at the A-B interface (to avoid intralayer failure).

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BOND EQUILIBRIUM THEORY IN COVALENTLY BONDED ALLOYS

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1981441 ◽

1981 ◽

Vol 42 (C4) ◽

pp. C4-201-C4-204

Author(s):

M. Cutler

Keyword(s):

Equilibrium Theory ◽

Covalently Bonded

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Removal of nutrients from Organic Liquid Agricultural Waste using filamentous algae.

Brazilian Journal of Biology ◽

10.1590/1519-6984.224708 ◽

2020 ◽

Author(s):

Gonzalo Flores-Morales ◽

Mónica Díaz ◽

Patricia Arancibia-Avila ◽

Michelle Muñoz-Carrasco ◽

Pamela Jara-Zapata ◽

...

Keyword(s):

Organic Waste ◽

Low Cost ◽

Organic Liquid ◽

Agricultural Waste ◽

Filamentous Algae ◽

Tertiary Treatment ◽

Nutrient Reduction ◽

Algae Removal ◽

Algae Growth ◽

Waste Effluents

Abstract A feasibility analysis of tertiary treatment for Organic Liquid Agricultural Waste is presented using filamentous algae belonging to the genus Cladophora sp. as an alternative to chemical tertiary treatment. The main advantages of tertiary treatments that use biological systems are the low cost investment and the minimal dependence on environmental variables. In this work we demonstrate that filamentous algae reduces the nutrient load of nitrate (circa 75%) and phosphate (circa 86%) from the organic waste effluents coming from dairy farms after nine days of culture, with the added advantage being that after the treatment period, algae removal can be achieved by simple procedures. Currently, the organic wastewater is discarded into fields and local streams. However, the algae can acquire value as a by-product since it has various uses as compost, cellulose, and biogas. A disadvantage of this system is that clean water must be used to achieve enough water transparency to allow algae growth. Even so, the nutrient reduction system of the organic effluents proposed is friendly to the ecosystem, compared to tertiary treatments that use chemicals to precipitate and collect nutrients such as nitrates and phosphates.

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Thermally-Induced Dehydrogenative Coupling of Organosilanes and H-Terminated Silicon Quantum Dots onto Germanane Surfaces

10.26434/chemrxiv.11794404 ◽

2020 ◽

Author(s):

Haoyang Yu ◽

Alyxandra Thiessen ◽

Md Asjad Hossain ◽

Marc Julian Kloberg ◽

Bernhard Rieger ◽

...

Keyword(s):

2D Materials ◽

Future Generation ◽

Optical Devices ◽

Surface Reactivity ◽

Organic Monolayers ◽

Present Contribution ◽

Thermally Induced ◽

Dehydrogenative Coupling ◽

Silicon Quantum Dot ◽

Covalently Bonded

<div><div><div><p>Covalently bonded organic monolayers play important roles in defining the solution processability, ambient stability, and electronic properties of two-dimensional (2D) materials such as Ge nanosheets (GeNSs); they also hold promise of providing avenues for the fabrication of future generation electronic and optical devices. Functionalization of GeNS normally involves surface moieties linked through covalent Ge−C bonds. In the present contribution we extend the scope of surface linkages to include Si−Ge bonding and present the first demonstration of heteronuclear dehydrocoupling of organosilanes to hydride-terminated GeNSs obtained from the deintercalation and exfoliation of CaGe2. We further exploit this new surface reactivity and demonstrated the preparation of directly bonded silicon quantum dot-Ge nanosheet hybrids.</p></div></div></div>

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