For every mass product, there are problems associated with the resulting waste. Residues of hormones in urine cannot be removed sufficiently from wastewater, and this has undesired consequences. An ideal adsorbent would take up the impurity, enable a simple separation and recyclability. Polymer colloids with high affinity towards the drug, accessible porosity, high surface area, and stimuli-responsive properties would be candidates, but such a complex system does not exist. Here, porous vinyl-functionalized organosilica nanoparticles prepared from a styrene bridged sol-gel precursor act as monomers. Initiation of the polymerization at the pore walls and addition of functional monomers result in a special copolymer, which is covalently linked to the surface and covers it. An orthogonal modification of external surface was done by click attachment of a thermoresponsive polymer. The final core-shell system is able to remove quantitatively hydrophobic molecules such as the hormone progesterone from water. A change of temperature closes the pores and induces the aggregation of the particles. After separation one can reopen the particles and recycle them.

Gaining external control over self‐organization is of vital importance for future smart materials. Surfactants are extremely valuable for the synthesis of diverse nanomaterials. Their self‐assembly is dictated by microphase separation, the hydrophobic effect, and head‐group repulsion. It is desirable to supplement surfactants with an added mode of long‐range and directional interaction. Magnetic forces are ideal, as they are not shielded in water. We report on surfactants with heads containing tightly bound transition‐metal centers. The magnetic moment of the head was varied systematically while keeping shape and charge constant. Changes in the magnetic moment of the head led to notable differences in surface tension, aggregate size, and contact angle, which could also be altered by an external magnetic field. The most astonishing result was that the use of magnetic surfactants as structure‐directing agents enabled the formation of porous solids with 12‐fold rotational symmetry.

Gaining external control over self-organization is of vital importance for future smart materials.S urfactants are extremely valuable for the synthesis of diverse nanomaterials. Their self-assembly is dictated by microphase separation, the hydrophobic effect, and head-group repulsion. It is desirable to supplement surfactants with an added mode of long-range and directional interaction. Magnetic forces are ideal, as they are not shielded in water.W er eport on surfactants with heads containing tightly bound transition-metal centers.T he magnetic moment of the head was varied systematically while keeping shape and charge constant. Changes in the magnetic moment of the head led to notable differences in surface tension, aggregate size, and contact angle,which could also be altered by an external magnetic field. The most astonishing result was that the use of magnetic surfactants as structuredirecting agents enabled the formation of porous solids with 12-fold rotational symmetry.The spontaneous formation of organized patterns as an intrinsic property of asystem containing discrete constituents, ap rocess termed self-assembly,h as fascinated scientists for decades.N ature shows the enormous potential of such behavior, since many of the unexcelled properties of biological matter originate from its capacity for adaptive selfassembly.[1] Full exploration of this potential in materials science is still remote,a smost reported examples of selfassembly so far are dictated by internal factors,s uch as thermodynamic equilibrium.[2] Systems reaching as tate of higher order only under constant consumption of energy (dissipative,n on-equilibrium state) have seldom been reported.[3] Apremise for advancing research in this direction is that compounds capable of adaptive self-assembly can be equipped with the ability to be actuated externally.Examples from particle research, such as dispersions of superparamagnetic colloids, [4] demonstrate the promise of manipulation by the use of magnetism, because it can be applied in astatic or dynamic way,a nd unlike electric fields,m agnetism is not damped in aqueous electrolytes.T hus,i ti sw orth exploring the use of external magnetic fields to trigger the selforganization of molecular systems.As model systems for the self-assembly of soft matter, surfactants are the focus of much current interest. Surfactants are molecular species that contain two moieties of opposite solvent compatibility arranged in adipolar geometry.Inpolar solvents,u sually water, concentration-dependents elf-organization takes place.T he amphiphilic properties of surfactants make them suitable for the stabilization of interfaces of many kinds,f or example,f or the generation of nanoparticles or nanoporous materials.[5] Thetypical head group of surfactants is organic in nature and, thus,d iamagnetic.T om ake as urfactant magnetic, one of its constituents should contain ap aramagnetic metal species.T his emerging field was reviewed very recently by Eastoe and co-workers.[6] Most known examples involve surfac...

The development of drugs for birth-control has changed society, and they are used by billions of woman on an every day basis. As for every mass product, there are problems associated with the waste it causes. One has found that residues of hormones in the urine of woman cannot be removed sufficiently from waste-water and this, in-turn, has already observable and undesired consequences in the biosphere. Apart from the removal of drugs, one is in general seeking new methods for the removal of hydrophobic impurities from waste-water. An ideal system would quantitatively take up the impurity, entrap it followed by preferably simple separation. Finally, one wants to reuse the absorbent, which implies the possibility for regeneration and recycling. Such as complex set of tasks requires a relatively complex materials architecture. Functional organic polymers with high affinity towards the drug, with stable open porosity and high surface area, stimuli-responsive properties and in the form of colloidal dispersions could do the job. Unfortunately, such a system does not exist. We solved this problem by generating mesoporous organosilica nanoparticles, which are monomers at the same time. Initiation of the polymerization reaction by surface-bound pore-walls leads to the formation of a special type of block-copolymer. The pore-walls are covered by the polymer, which cannot leach. An orthogonal modification was achieved by modification of the external surfaces of the particles with a thermoresponsive polymer by click-chemistry. The final core-shell system was able to remove hydrophobic molecules such as the hormone progesterone from water. A change of temperature induces the collapse of the thermoresponsive polymer, which closes the pores and induces aggregation of the particles. After separation of the particles, and thus also the entrapped impurity, from the solvent, one can re-open the pores, which leads to a release of the adsorbed compound(s).

The development of drugs for birth-control has changed society, and they are used by billions of woman on an every day basis. As for every mass product, there are problems associated with the waste it causes. One has found that residues of hormones in the urine of woman cannot be removed sufficiently from waste-water and this, in-turn, has already observable and undesired consequences in the biosphere. Apart from the removal of drugs, one is in general seeking new methods for the removal of hydrophobic impurities from waste-water. An ideal system would quantitatively take up the impurity, entrap it followed by preferably simple separation. Finally, one wants to reuse the absorbent, which implies the possibility for regeneration and recycling. Such as complex set of tasks requires a relatively complex materials architecture. Functional organic polymers with high affinity towards the drug, with stable open porosity and high surface area, stimuli-responsive properties and in the form of colloidal dispersions could do the job. Unfortunately, such a system does not exist. We solved this problem by generating mesoporous organosilica nanoparticles, which are monomers at the same time. Initiation of the polymerization reaction by surface-bound pore-walls leads to the formation of a special type of block-copolymer. The pore-walls are covered by the polymer, which cannot leach. An orthogonal modification was achieved by modification of the external surfaces of the particles with a thermoresponsive polymer by click-chemistry. The final core-shell system was able to remove hydrophobic molecules such as the hormone progesterone from water. A change of temperature induces the collapse of the thermoresponsive polymer, which closes the pores and induces aggregation of the particles. After separation of the particles, and thus also the entrapped impurity, from the solvent, one can re-open the pores, which leads to a release of the adsorbed compound(s).