Nitrogen-Doped Hollow Copolymer Tube via Template-Free Asynchronous Polymerization with Highly Selective Separation of Hydrophilic Dipeptide for Enhancing Inhibitory Activity of Angiotensin Converting Enzyme

Abstract

A N-doped hollow copolymer tube (NHCT) was fabricated via template-free one-pot asynchronous polymerization strategy. Discrepancies of monomer polymerization speed and their hydrophilic–hydrophobic interaction resulted in the assembly of a hollow tube having inner diameter and double wall thickness of ∼230 and 40 nm, respectively. The formation and growth mechanism of NHCT analyzed via advanced characterization revealed that the unique growth processes tuned a demarcating surface layer between inner (hydrophilic) and outer (hydrophobic) layers. The screening and recognition ability of NHCT were determined for two specific dipeptides (WW and RR) possessing great discrepancies in hydrophilicity and angiotensin converting enzyme inhibitory (ACE-I) activity. NHCT realized high adsorption capacity (1.57 mmol/g) and selectivity (∼1274) for hydrophilic dipeptide RR (low ACE-I activity) from the mixture of RR/WW. As a result, ACE-I activity for residual solution were enhanced about 4.1 times as compared to original solution from natural silkworm pupae protein hydrolysate. Awarding to these results and its facile and discerning ability, NHCT can be envisioned to be of great value for the separation of small functional peptides from a natural edible source.

Construction of PPSU-MoS2/PA-MIL-101(Cr) Membrane with Highly Enhanced Permeance and Stability for Organic Solvent Nanofiltration

“…The N 2 adsorption and desorption curves of MIL-101(Cr) in Figure 4 a demonstrate an obvious type-I N 2 isotherm. The adsorption amount of N 2 increases rapidly under low pressure of P/P 0 = 0~0.1, indicating the nanoporous structure of MIL-101(Cr) [ 33 ]. Curve variation at P/P 0 = 0.1 and P/P 0 = 0.2 corresponds to the bigger and smaller porous cage structures in MIL-101(Cr) [ 34 ], respectively; the pore size distribution of MIL-101(Cr) in Figure 4 b confirms these two windows’ sizes of 1.1~1.3 and 1.6~1.8 nm, respectively.…”

Swellable Array Strategy Based on Designed Flexible Double Hypercross-linked Polymers for Synergistic Adsorption of Toluene and Formaldehyde

“…HCP was prepared via the Friedel–Crafts reaction as reported earlier. , First, a series of monomers with different dimensions and chemical properties (Ben/BA/BDM, 1.0 mmol, Table S1), a cross-linking agent (FDA, 3.0 mmol), and a catalyst (anhydrous FeCl 3 , 1.0 mmol) were successively added to DCE (100 mL) solution and stirred in a 250 mL three-necked round-bottom flask. Afterward, the mixed solution was heated at 45 °C for 5 h and then heated at 80 °C for 19 h. The whole reaction was performed under a N 2 atmosphere.…”

“…At P/P 0 < 0. three HCPs remained relatively hydrophobic with slowly increased water adsorption (<4 mmol/g) due to the hydrophobic benzene ring skeleton. 25 Above P/P 0 = 0.5, the water adsorption of HCPs raised sharply due to water condensation in their mesopores until reaching the saturated adsorption amount at P/P 0 = 0.94. 52 Compared with Ben-SHCP, BA−DHCP and BDM-DHCP had increased hydroxyl blocks, exhibiting higher H 2 O adsorbed uptake.…”

“…Notably, different from the structure of BDM-DHCP, hollow sphered N 0.1 /BDM-FDHCP was cross- linked through a distinct tubular network structure constructed by the interconnection with Py molecules. 25 Figure 1g demonstrates the formation of a unique network structure connected to the hollow sphere in N 0.1 /BDM-FDHCP. Furthermore, the elemental mappings of Figure S4a−d revealed the apparent presence of C (86.23%), N (1.36%), and O (12.41%) elements on N 0.1 /BDM-FDHCP.…”

“…The SSA and V total of N 0.15 /BDM-FDHCP and N 0.2 /BDM-FDHCP decreased significantly, indicating that the excessive substitution of Py blocks declined the structural stability of the polymer. 25 Figure S8a and Table S4 show the elemental composition and valence state distribution of Ben-SHCP, BA−DHCP, BDM-DHCP, and N 0.1 /BDM-FDHCP as determined by X-ray photoelectron spectroscopy (XPS). All samples contained C and O elements.…”