Dendrimer-Based Demulsifiers for Polymer Flooding Oil-in-Water Emulsions

Two polyamidoamine-based dendritic molecules, named here as benzyl-G3 and octyl-G3, were synthesized using H₂NCH₂CH₂NRCH₂CH₂NH₂ (where R is either rigid benzyl or flexible octyl hydrophobic tails that are linked to the central nitrogen atom). With consideration of factors, such as the settling time, demulsifier dosage, temperature, oil content, and kinds of surfactants, the synthesized molecules were systematically investigated as demulsifiers for breaking up polymer flooding oil-in-water emulsions. In comparison to traditional G3 polyamidoamine, both benzyl-G3 and octyl-G3 exhibited better demulsification efficiencies with a dosage of 200 mg/L at a relatively low temperature (30 °C) in short periods of time (40 min) and reached 99.3 and 99.8% oil removal rates as they were added to the low oil-containing emulsion (1500 mg/L), respectively. A series of measurement methods were then adopted to explore the demulsification mechanism of the two demulsifiers. The interfacial tension and ζ potential measurements indicated that the high demulsification efficiency of the two dendrimers could be due to electrostatic charge neutralization. Moreover, the dendrimers and surfactants showed strong interactions according to the turbidity measurements, the results of which demonstrated that the hydrophobic tails located at the center of the dendrimers also influenced the demulsification efficiency

Nitrogen-Rich Salts Based on the Energetic [Monoaquabis(<i>N</i>,<i>N</i>‑bis(1<i>H</i>‑tetrazol-5-yl)amine)-zinc(II)] Anion: A Promising Design in the Development of New Energetic Materials

Nitrogen-rich energetic salts involving various cations (lithium, <b>1</b>; ammonium, <b>2</b>; hydrazinium, <b>3</b>; hydroxylammonium, <b>4</b>; guanidinium, <b>5</b>; aminoguanidinium, <b>6</b>; diaminoguanidinium, <b>7</b>; and triaminoguanidinium, <b>8</b>) based on nitrogen-rich anion [Zn­(BTA)₂(H₂O)]^2– (N% = 65.37, BTA = <i>N</i>,<i>N</i>-bis­[1<i>H</i>-tetrazol-5-yl]­amine anion) were synthesized with a simple method. The crystal structures of all compounds except <b>1</b>, <b>2</b>, and <b>6</b> were determined by single-crystal X-ray diffraction and fully characterized by elemental analysis and FT-IR spectroscopy. The thermal stabilities were investigated by differential scanning calorimetry (DSC). The DSC results show that all compounds exhibit high thermal stabilities (decomposition temperature >200 °C). Additionally, the heats of formation were calculated on the basis of the experimental constant-volume energies of combustion measured by using bomb calorimetry. Lastly, the sensitivities toward impact and friction were assessed according to Bundesamt für Materialforschung (BAM) standard methods

Nitrogen-Rich Salts Based on the Energetic [Monoaquabis(<i>N</i>,<i>N</i>‑bis(1<i>H</i>‑tetrazol-5-yl)amine)-zinc(II)] Anion: A Promising Design in the Development of New Energetic Materials

Nitrogen-rich energetic salts involving various cations (lithium, <b>1</b>; ammonium, <b>2</b>; hydrazinium, <b>3</b>; hydroxylammonium, <b>4</b>; guanidinium, <b>5</b>; aminoguanidinium, <b>6</b>; diaminoguanidinium, <b>7</b>; and triaminoguanidinium, <b>8</b>) based on nitrogen-rich anion [Zn­(BTA)₂(H₂O)]^2– (N% = 65.37, BTA = <i>N</i>,<i>N</i>-bis­[1<i>H</i>-tetrazol-5-yl]­amine anion) were synthesized with a simple method. The crystal structures of all compounds except <b>1</b>, <b>2</b>, and <b>6</b> were determined by single-crystal X-ray diffraction and fully characterized by elemental analysis and FT-IR spectroscopy. The thermal stabilities were investigated by differential scanning calorimetry (DSC). The DSC results show that all compounds exhibit high thermal stabilities (decomposition temperature >200 °C). Additionally, the heats of formation were calculated on the basis of the experimental constant-volume energies of combustion measured by using bomb calorimetry. Lastly, the sensitivities toward impact and friction were assessed according to Bundesamt für Materialforschung (BAM) standard methods