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Polyampholyte nanogels based on N-isopropylacrylamide (NIPAM), (3-acrylamidopropyl) trimethylammonium chloride (APTAC) and 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt (AMPS) were synthesized via conventional redox-initiated free radical copolymerization. The resultant nanogels of various compositions, specifically [NIPAM]:[APTAC]:[AMPS] = 90:5:5; 90:7.5:2.5; 90:2.5:7.5 mol.%, herein abbreviated as NIPAM90-APTAC5-AMPS5, NIPAM90-APTAC7.5-AMPS2.5 and NIPAM90-APTAC2.5-AMPS7.5, were characterized by a combination of 1H NMR and FTIR spectroscopy, TGA, UV–Vis, DLS and zeta potential measurements. The temperature and salt-responsive properties of amphoteric nanogels were studied in aqueous and saline solutions in a temperature range from 25 to 60 °C and at ionic strengths (μ) of 10−3 to 1M NaCl. Volume phase transition temperatures (VPTT) of the charge-balanced nanogel were found to reach a maximum upon the addition of salt, whereas the same parameter for the charge-imbalanced nanogels exhibited a sharp decrease at higher saline concentrations. A wide bimodal distribution of average hydrodynamic sizes of nanogel particles had a tendency to transform to a narrow monomodal peak at elevated temperatures and higher ionic strengths. According to the DLS results, increasing ionic strength results in the clumping of nanogel particles.

The article presents a comparison of the traditional methods to investigate the fractional composition of nanosized powders, namely atomic force microscopy (AFM), scanning electron microscopy (SEM), dynamic light scatterin, (DLS) and a new one – analysis of the aerosol products of submillimeter pulse laser ablation (SLA). As has previously been proven, biological macromolecules retain activity after ablation under submillimeter wavelengths, molecules become separated in the aerosol phase and each sort of molecules forms its own fraction of the aerosol particles. We suggest that this process is made possible as the result of influence on the hydrogen and van der Waals’ bonds, with the energies within the submillimeter range. Results of investigations on SiO2 and artificial diamond clusters using the above methods in both powder and colloid states are discussed. SLA with subsequent detection of aerosol products with the help of convenient aerosol equipment is found to be simple, fast and informative, and can act as a competitor to mass spectrometry, X-ray scattering and other methods.