Polypiperazinamides: new polymers useful for membrane processes

Parrini, Paolo

doi:10.1016/0011-9164(83)80006-x

Cited by 20 publications

(11 citation statements)

References 2 publications

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“…The reduced presence of amidic hydrogen also improves the resistance to chlorine attack [63]. However, this membrane was not commercialised due to its relatively low salt rejection (≤ 95 %) [64]. The presence of the sulphonic and phenyl groups in sulfonated polysulfone was expected to enhance permeability, mechanical, chemical and biological stability however the salt rejection was below the acceptable level required to be commercialised [65].…”

Section: Challenges and Trends In Ro Desalination Technology Developmentmentioning

confidence: 99%

A review of reverse osmosis membrane materials for desalination—Development to date and future potential

Lee

Arnot

Mattia

2011

Journal of Membrane Science

1,890

961

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Reverse osmosis (RO) is currently the most important desalination technology and it is experiencing significant growth. The objective of this paper is to review the historical and current development of RO membrane materials which are the key determinant of separation performance and water productivity, and to define the targets for those who are developing new RO membrane materials. The chemistry, synthesis mechanism(s) and desalination performance of various RO membranes are discussed from the point of view of membrane materials science. The review starts with the first generation of asymmetric polymeric membranes and finishes with current proposals for nano-structured membrane materials. The review provides an overview of RO performance in relation to membrane materials and methods of synthesis. To date polymeric membranes have dominated the RO desalination industry. From the late 1950s to the 1980s the research effort focussed on the search for optimum polymeric membrane materials. In subsequent decades the performance of RO membranes has been optimised via control of membrane formation reactions, and the use of poly-condensation catalysts and additives. The performance of the state-of-the-art RO membrane has been highlighted. Nevertheless, the advances in membrane permselectivity in the past decade has been relatively slow, and membrane fouling remains a severe problem. The emergence of nano-technology in membrane materials science could offer an attractive alternative to polymeric materials. Hence nano-structured membranes are discussed in this review including zeolite membranes, thin film nano-composite membranes, carbon nano-tube membranes, and biomimetic membranes. It is proposed that these novel materials represent the most likely opportunities for enhanced RO desalination performance in the future, but that a number of challenges remain with regard to their practical implementation.

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Section: Challenges and Trends In Ro Desalination Technology Developmentmentioning

confidence: 99%

A review of reverse osmosis membrane materials for desalination—Development to date and future potential

Lee

Arnot

Mattia

2011

Journal of Membrane Science

1,890

961

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“…However, the performance of the membranes was significantly affected by chlorine at pH of 7 and below. In order to improve chlorine resistance, integrally-skinned asymmetric membranes based on polypiperazinamides (PPA) were developed [217][218][219][220]. Despite their high chlorine resistance, PPA membranes were not commercialized due to unfavorable salt rejections [186].…”

Section: Integrally-skinned Asymmetric Membranesmentioning

confidence: 99%

Reverse osmosis desalination: A state-of-the-art review

et al. 2019

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Water scarcity is a grand challenge that has always stimulated research interests in finding effective means for pure water production. In this context, reverse osmosis (RO) is considered the leading and the most optimized membrane-based desalination process that is currently dominating the desalination market. In this review, various aspects of RO desalination are reviewed. Theories and models related to concentration polarization and membrane transport, as well as merits and drawbacks of these models in predicting polarization effects, are discussed. An updated review of studies related to membrane modules (plate and frame, tubular, spiral wound, and hollow fiber) and membrane characterization are provided. The review also discusses membrane cleaning and different pre-treatment technologies in place for RO desalination, such as feed-water pre-treatment and biocides. RO pre-treatment technologies, which include conventional (e.g., coagulationflocculation, media filtration, disinfection, scale inhibition) and non-conventional (e.g., MF, UF, and NF) are reviewed and their relative attributes are compared. As per the available literature, UF, MF and coagulation-flocculation are considered the most widely used pre-treatment technologies. In addition, this review discusses membrane fouling, which represents a serious challenge in RO processes due to its significant contribution to energy requirements and process economy (e.g., flux decline, permeate quality, membrane lifespan, increased feed pressure, increased pre-treatment and membrane maintenance cost). Different membrane fouling types, such as colloidal, organic, inorganic, and biological fouling, are addressed in this review. Principles of RO process design and the embedded economic and energy considerations are discussed. In general, cost of water desalination has dropped to values that made it a viable option, comparable even to conventional water treatment methods. Finally, an overview of hybrid RO desalination processes and the current challenges faced by RO desalination processes are presented and discussed.

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“…The lack of solubility of poly(piperazinamides) has been attributed to the presence of a relatively rigid backbone and intermolecular dipole-dipole interactions in the polymers, similar to those of aramids. 3 Although hydrogen-bonded interactions are removed with incorporation of the piperazine ring, the rigidity of the polymer backbone in aromatic poly(piperazinamides) possibly remains relatively unchanged in comparison to aramids and, therefore, solubility is not improved because there is no accompanying increase in the flexibility of the polymer backbone. The piperazine ring is also expected to be in its chair conformation and, consequently, is not expected to interfere sterically with the resonance delocalization of the amide group (-NsCdO).…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Poly(piperazinenaminonitriles)

Moore

Kaur

1997

Macromolecules

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Poly(piperazinenaminonitriles), analogs of poly(piperazinamides), were synthesized by interfacial polycondensation of piperazine or 2,5-dimethylpiperazine (cis or trans) with bis-electrophilic monomers (1,3-or 1,4-bis(1-chloro-2,2-dicyanovinyl)benzene). Because of the absence of hydrogen bonding, poly(piperazinenaminonitriles) showed limited solubility in dipolar aprotic solvents and, compared to poly(piperazinamides), gave lower molecular weight materials of lower thermal stability. The barrier to internal rotation of enaminonitrile groups, measured using dynamic NMR spectroscopy of model compounds, was comparable to the barrier to internal rotation measured for amide groups.

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Polypiperazinamides: new polymers useful for membrane processes

Cited by 20 publications

References 2 publications

A review of reverse osmosis membrane materials for desalination—Development to date and future potential

A review of reverse osmosis membrane materials for desalination—Development to date and future potential

Reverse osmosis desalination: A state-of-the-art review

Synthesis and Characterization of Poly(piperazinenaminonitriles)

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