China 
Africa 
Explore chapters and articles related to this topic
Functionalization of Carbon-Based Additives
Published in Andreas Sapalidis, Membrane Desalination, 2020
Myrsini Kyriaki Antoniou, Andreas Sapalidis, Zili Sideratou
Zambare et al. (2017) developed mixed matrix membranes by blending amine functionalized graphene oxide (fGO) in polysulfone. Three polyamines, ethylenediamine (EDA), diethylenetriamine (DETA), and triethylenetetramine (TETA), with different chain lengths were used in order to functionalize GO, and it was shown that by increasing the interlayer space of GO nanosheets with polyamines, the dispersion in polysulfone–NMP solution is improved. The presence of polyamines in the membranes resulted in the increase of hydrophilicity and the formation of finely porous structures, which enhanced the membrane’s permeability. The antifouling properties of the membranes were tested by using BSA as a foulant. BSA rejection was greater than 90% for all fGO based polysulfone mixed matrix membranes, while a remarkably high pure water flux of 170.5 LMH/bar was displayed (Figure 3.14).
Selective Catalytic Synthesis of Mixed Alkylamines and Polyfunctional Amines
Published in Dale W. Blackburn, Catalysis of Organic Reactions, 2020
Michael E. Ford, Thomas A. Johnson
In the phosphate-catalyzed route to polyethylene amines, ethanolamine alkylates ammonia or a lower amine to form the next higher homolog (Scheme 4). Owing to the relatively low nucleophilicity of ammonia, formation of ethylenediamine by reaction of ammonia with ethanolamine is significant only at high pressure (>1000 psig). Reaction of ethanolamine with ethylenediamine forms diethylenetriamine. Chain extension of diethylenetriamine occurs at both the primary and secondary amines to form linear and branched tetramines. Further reaction leads to linear and branched pentamines and higher polyethylene amines. In agreement with our results on the synthesis of functionalized amines with strontium hydrogen phosphate, deaminative cyclization, e.g., of diethylenetriamine to piperazine, is not observed at temperatures below 275°C.
Dendrimers and Gene Delivery
Published in Zahoor Ahmad Parry, Rajesh Pandey, Dendrimers in Medical Science, 2017
Zahoor Ahmad Parry, Rajesh Pandey
Flexible PAMAM dendrimers having TEA (triethanolamine) as the core, and the branching units commencing at a distance of 10 consecutive bonds from the central amine was evaluated for siRNA delivery/gene silencing [79–82]. With a TEA core, there is a provision of flexibility compared to commercially PAMAM having ammonia/ethylenediamine core (in this case the branching begins at the central amine). Higher generation dendrimers within this family could efficiently deliver the siRNA and induce gene silencing. Further, the dendrimers with amine end groups almost fully retarded the siRNA during agarose gel electrophoresis at N/P ratios >2.5. However, no gel retardation was observed with dendrimers having terminal ester groups, suggesting a lack of condensation with siRNA. This model of TEA core PAMAM dendrimers successfully delivered the siRNA and inhibited the catalysis of ribozymes in Candida[82]. In another study, a TEA core PAMAM dendrimer was used to deliver HSP27-targeted siRNA inside the prostate cancer cells [80]. The dendrimer protected the siRNA from enzymatic degradation and promoted the cellular uptake of siRNA. Moreover, the siRNA also demonstrated potent as well as specific gene silencing of hsp 27 (heat shock protein 27), which is an attractive target in cases of castration-resistant prostate cancer.
Mechanochemically induced synthesis of N-ion doped ZnO: solar photocatalytic degradation of methylene blue
Published in Green Chemistry Letters and Reviews, 2022
Saša Zeljković, Milica Balaban, Dragana Gajić, Savka Vračević, Toni Ivas, Dragoljub Vranković, Dijana Jelić
In mechanochemical synthesis, chemical products are produced by avoiding or greatly reducing solvents as reaction media. However, the use of solvents in the purification and isolation of the products remains to be discussed (18). In previous research, the standard synthesis approach was zinc acetate and ethylenediamine, which are dissolved in ethanol, and subsequently dried and calcined. Ethylenediamine is highly toxic when it reacts with moisture in the air and can cause serious health damage (19). The method described in our study does not include any highly toxic compounds and products thus, it is ideal for large-scale production of an N-ion doped ZnO that can be used to treat wastewaters polluted by thiazine dyes. Other synthesis methods like chemical precipitation (13), hydrothermal method (14), and pulsed laser deposition (15) are less cost-effective and used for the production of surfaces which are photocatalytic active.