Double-stimulus sensitive (temperature and pH) self-assemblable polymers

The rheological properties of block co-polymers in water solution at different pH have been investigated. The block copolymers are based on different architectures containing poly(ethylene glycol), poly(propylene glycol) and different blocks of polymer that change their hydrophobic/hydrophilic behavior as a function of pH. The polymer chains of the starting material were extended at their functional ends with the pH-sensitive units using ATRP; this mechanism of controlled radical polymerization was chosen because of the need to minimize polydispersity and avoid transfer reactions possibly leading to homopolymeric inpurities. The starting material were modified in order to use them as macroinitiator for ATRP. The kinetic of each ATRP reaction has been investigated, in order to be able to synthesize polymers with different degree of polymerization, stopping the reaction when the desired polymers chain length has been reached. We will use polymer chains with different basicity and degree of polymerization to link any possible effect of their presence to the conditions under which they become hydrophobic. It has been shown that the rate of polymerization changes changing the type of macroinitiator and the type of monomer synthesized. The slowest rate of polymerization is the one with the most hindered monomer synthesized using the macroinitiator with the highest molecular weight. The water solubility of the synthesized polymers changes depending on the pH of the solution and on the structure of the polymers. It has been shown using 1H-NMR that some of the synthesized polymers are capable to self-aggregation in water solution. The self-aggregation and the type of aggregation is influenced from the structure of the polymer and from the pH of the solution. Changing the structure of the polymers and the pH it is possible to obtain different type of aggregates in solution. This aggregates differ for the volume occupied from them, and for their hardness. Rheological measurements have been demonstrated that the synthesized polymers are capable to form gel phases. The gelation temperature changes changing the structure of the aggregates in solution and it is possible to correlate the changing in the gelation temperature with the changing in the structure of the polymer.

Context sensitive design of provincial road Galliera SP4.

In the past centuries and before the invention of automobile, roads consisted mainly of unpaved paths connecting only few cities. Later, in the beginning of the twentieth century, the automobile was introduced and a new type of the transportation system was born. Therefore, it was necessary to change the condition of roads to fit with the automobiles. With the spread and the development of the automobiles, roads also have developed and increased all over the world. That caused negative effects on the environment and humans’ life quality. Thus, highways associations and communities had to take some steps to reduce these effects and care about environmental and cultural issues with the traditional commitment to safety and mobility, and that is known as context sensitive design. The aim of this thesis is to use the concepts of context sensitive design to reduce the negative environmental impacts of provincial road Galliera, which connects via Colombo in city of Bologna to provincial road 3 in Argelato city. Some solutions were proposed in this thesis to reduce traffic noise, fragmentation, fauna mortality and to improve the aesthetics of the road.

Bioconcentration of selected personal care products in Ruditapes philippinarum (Manila clam)

The Bioconcentration Factor (BCF) is the principal source of information used to assess and regulate the potential hazard and risk for a chemical that has the potential to bioaccumulate in the marine environment, according to the Marine Strategy Framework Directive (MSFD). The main objective of this thesis was to estimate the BCFs of two different emerging contaminants in Ruditapes philippinarum (Manila clam) under controlled laboratory conditions: the UV filter 4-methylbenzylidene camphor (4-MBC) commonly used in skincare products, and the artificial sweetener Acesulfame potassium (ACE-K) used as a food additive. Ruditapes philippinarum organisms were exposed directly to 4-MBC and ACE-K nominal concentration of 1, 10 and 100 μg L-1 during 10 days. Bioconcentration factors (BCFs) were estimated according to 3 different models for both compounds. The 4-MBC estimated BCFs fall in range of 61553 - 539143 L Kg-1, showing that this compound is very bioaccumulative and could also undergo biomagnification in the marine food chain. On the contrary, estimated ACE-K BCF is consistently lower, in order of 7 L Kg-1 for the nominal exposure concentration of 100 μg L-1. The low ACE-K BCF could be explained by its high solubility in water and thus a rapid metabolization by clams during the experiments. In summary, future research focusing on the marine environment is needed on these two emerging compounds.